STANDARD SPECIFICATIONS FOR
BUILDING WORKS
AND
OTHER INSTALLATIONS
(2012 EDITION)
Published by Housing and Development Board, Republic of Singapore. No part of this document may be reproduced or copied in any form or by any means without the prior permission of the publisher.
STANDARD SPECIFICATIONS FOR BUILDING WORKS AND OTHER INSTALLATIONS
CONTENTS Page
SECTION 1
GENERAL SPECIFICATIONS
1-1
TECHNICAL SPECIFICATIONS SECTION 2
PILING
2-1
SECTION 3
EXCAVATION
3-1
SECTION 4
STRUCTURAL CONCRETE
4-1
SECTION 5
METAL FORMWORK
5-1
SECTION 6
SEMI-PRECAST CONSTRUCTION
6-1
SECTION 7
PRESTRESSED CONCRETE
7-1
SECTION 8
HOUSEHOLD SHELTER
8-1
SECTION 9
REINFORCED CONCRETE WATER TANK
9-1
SECTION 10
PRECAST LIGHTWEIGHT CONCRETE PARTITION
10-1
SECTION 11
NON-STRUCTURAL CONCRETE
11-1
SECTION 12
BRICKWORK AND BLOCKWORK
12-1
SECTION 13
ROOFING
13-1
SECTION 14
CONCRETE FLAT ROOF
14-1
SECTION 15
CARPENTRY AND JOINERY
15-1
SECTION 16
IRONMONGERY
16-1
SECTION 17
STRUCTURAL STEELWORK
17-1
SECTION 18
METALWORK
18-1
SECTION 19
FLOOR FINISHES
19-1
SECTION 20
WALL FINISHES
20-1
SECTION 21
ELECTRICAL, TELEPHONE AND BROADBAND COAXIAL CABLING INSTALLATIONS
21-1
SECTION 22
GLAZING
22-1
SECTION 23
PAINTING AND DECORATING
23-1
The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract. HDB, being a ISO 14001 certified organisation, is committed to be the leader in environment management. The details of HDB's environmental policy can be found in the Corporate Philosophy at HDB Website http://www.hdb.gov.sg
STANDARD SPECIFICATIONS FOR BUILDING WORKS AND OTHER INSTALLATIONS
CONTENTS Page
SECTION 24
UNDERGROUND PIPE SYSTEM FOR LOW TENSION RETICULATION CABLE, TELECOMMUNICATION AND BROADBAND COAXIAL CABLE
24-1
SECTION 25
CHILDREN'S PLAYGROUND, FITNESS STATION AND HARDCOURT
25-1
SECTION 26
TREE PLANTING AND TURFING
26-1
SECTION 27
MULTI-STOREY CARPARK
27-1
SECTION 28
ELECTRICAL SUB-STATION / UTILITIES CENTRE / DUSTBIN COMPOUND
28-1
SECTION 29
EATING HOUSE
29-1
SECTION 30
MISCELLANEOUS (BUILDING)
30-1
SECTION 31
FABRICATION AND PROVISION OF REFUSE BINS, LITTER BINS, BULK CONTAINERS AND TROLLEYS
31-1
SECTION 32
RESERVED
32-1
SECTION 33
RESERVED
32-1
SECTION 34
RESERVED
32-1
SECTION 35
RESERVED
32-1
SECTION 36
GENERAL REQUIREMENTS FOR SANITARY, WATER, GAS AND OTHER PLUMBING INSTALLATIONS
36-1
SECTION 37
SANITARY INSTALLATION
37-1
SECTION 38
WATER INSTALLATION
38-1
SECTION 39
GAS PIPE INSTALLATION
39-1
SECTION 40
EATING ESTABLISHMENT, MARKET FACILITIES, RETAIL AND SERVICES FACILITIES
40-1
SECTION 41
MISCELLANEOUS (SANITARY & WATER INSTALLATION)
41-1
SECTION 42
TRANSFER PUMPING SYSTEM AND TELEMONITORING SYSTEM INSTALLATION
42-1
SECTION 43
BOOSTER PUMPING SYSTEM INSTALLATION
43-1
SECTION 44
DRY/WET RISING MAIN INSTALLATION
44-1
SECTION 45
FIRE PROTECTION INSTALLATION
45-1
SECTION 46
RESERVED
46-1
The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.
STANDARD SPECIFICATIONS FOR BUILDING WORKS AND OTHER INSTALLATIONS
CONTENTS Page
SECTION 47
RESERVED
46-1
SECTION 48
RESERVED
46-1
SECTION 49
GENERAL REQUIREMENTS FOR ELECTRICAL WORKS
49-1
SECTION 50
SWITCHBOARDS, DISTRIBUTION BOARDS AND SWITCHGEARS
50-1
SECTION 51
MAINS AND SUB-MAINS CABLES
51-1
SECTION 52
CABLES SUPPORTING SYSTEMS
52-1
SECTION 53
ELECTRICAL ACCESSORIES AND FIXTURES
53-1
SECTION 54
LUMINARIES
54-1
SECTION 55
EARTHING SYSTEM
55-1
SECTION 56
LIGHTNING PROTECTION
56-1
SECTION 57
PUBLIC LIGHTING
57-1
SECTION 58
ELECTRICAL INSTALLATION OF DWELLING UNITS AND PREMISES
58-1
SECTION 59
ELECTRICAL INSTALLATION TO MULTI-STOREY CARPARKS (MSCP), GARAGES AND PLANT ROOMS
59-1
SECTION 60
OUTDOOR AMENITIES LIGHTING
60-1
SECTION 61
TELEVISION (TV) SYSTEM INSTALLATION
61-1
SECTION 62
TELEPHONE CABLING
62-1
SECTION 63
FIRE ALARM SYSTEM
63-1
SECTION 64
VENTILATION SYSTEM
64-1
SECTION 65
FANS FOR GENERAL VENTILATION
65-1
SECTION 66
REFUSE HANDLING PLANT INSTALLATION
66-1
SECTION 67
RESERVED
67-1
SECTION 68
RESERVED
68-1
SECTION 69
RESERVED
69-1
SECTION 70
LISTS OF APPENDICES
70-1
The contents on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.
SECTION 1 : GENERAL SPECIFICATIONS CONTENTS Page 1.1 1.1.1 1.1.2 1.1.3 1.1.4 1.1.5 1.1.6 1.1.7 1.1.8 1.1.9 1.1.10 1.1.11 1.1.12 1.1.13 1.1.14 1.1.15 1.1.16 1.1.17 1.1.18 1.1.19 1.1.20 1.1.21 1.1.22 1.1.23 1.1.24 1.1.25 1.1.26 1.1.27 1.1.28 1.1.29 1.1.30 1.1.31 1.1.32 1.1.33 1.1.34 1.1.35 1.1.36 1.1.37 1.1.38 1.1.39 1.1.40 1.1.41 1.1.42 1.1.43 1.1.44 1.1.45 1.1.46 1.1.47 1.1.48 1.1.49 1.1.50 1.1.51
GENERAL Definitions, Abbreviations And Interpretations Reserved Payment Of Employer's Bills Expenses, Etc Contract Payment By GIRO/EPS Diversion of Services Stamp Duties TOL Fee For Land Outside Contract Boundary Liquidated Damages For Delay In Completion Provisional Sum Items Prime Cost Sums Overclaim Leading To Overpayment Carriage By Sea Existing Ground / Road Levels Raising Or Lowering Of Existing Sewer Manholes And Other Services Manholes Work Method And Trade Demonstration Reserved Site Layout Plan Site Offices And Canteens Provision Of Equipment, Apparatus Devices, Etc Reserved Provision Of Transport Provision Of Temporary Site Facilities/Utilities Protective Roof For Temporary Site Structures Construction Site Main Signboard and Hoarding Signage Site Management Employment of Contractor's Site Personnel Contractor's Work In Connection With Subsidiary Contracts Cables/Services Detection Reserved Damage To Public/Private Property General Housekeeping Reserved Time Required For Contractor For Preparation Of Handing Over Inspection Restriction On Use Of Project Information For Publicity, Etc Provision Of Respiratory Masks Reserved Reserved Research Work Earlier Completion Of MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms Handing Over Of Completed Works And Certification Of Substantial Completion Reserved Management Of Defects Rectification Precautionary Measures To Be Taken During A Disease Pandemic Works Within Railway Protection Zone And Railway Safety Zone Recovery Of Legal Costs For Court Proceedings Novation, Assignment And Direct Submission Of Warranties And Agreements Completion Of Site Works Erection Of Temporary Buildings Goods And Services Tax Works And Materials Warranty Cost Of Water And Electricity
1-1 1-3 1-3 1-3 1-4 1-4 1-4 1-4 1-5 1-5 1-5 1-6 1-6 1-6 1-6 1-7 1-7 1-7 1-10 1-13 1-13 1-13 1-15 1-16 1-17 1-17 1-24 1-24 1-24 1-24 1-25 1-25 1-25 1-25 1-26 1-26 1-26 1-26 1-26 1-28 1-29 1-29 1-31 1-31 1-31 1-32 1-32 1-32 1-33 1-33 1-33
The contents on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.
SECTION 1 : GENERAL SPECIFICATIONS CONTENTS Page 1.1 1.1.52 1.1.53 1.1.54 1.1.55 1.1.56 1.1.57 1.1.58 1.1.59 1.1.60 1.1.61 1.1.62 1.1.63 1.1.64 1.1.65 1.1.66 1.1.67 1.1.68 1.1.69 1.1.70
GENERAL (CONT'D) Site Control And Security Assessment Of Extension Of Time Due To Exceptionally Inclement Weather Shortfall In Floor Area Registered Trade Subcontractors And M&E Subcontractors Insurance Policies Contract Documents And Reference Material On Site Provision Of Building Service Centre Reserved Lightning Protection To Temporary Structures And Metal Structures Computer Hardware And Software Electronic Submission For Progress Payments Claims And Request For Variation Works Assignment Of Copyright Of Photographs, Etc Provision Of Keys Envelopes During Handover Scheduling Of PE Submission Earth Control Measures Environmental Public Health Measures At Construction Sites Material Samples Display Room Audit of M & E Systems Environmental Management
1-34 1-35 1-36 1-36 1-37 1-39 1-40 1-40 1-41 1-41 1-45 1-47 1-47 1-48 1-49 1-51 1-58 1-58 1-59
1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.2.7 1.2.8 1.2.9 1.2.10 1.2.11 1.2.12 1.2.13
MATERIALS Metric Components Materials And Workmanship Credit Terms And Conditions For Employer's Materials Reserved Approval Of Samples And Trade Names Sample Unit And Quality Standards PSB Quality Certificate Storage Facility For Cement Precautions Against Materials Being Taken Out Of Site Ready-Mixed Concrete From Approved Suppliers Water Supply Of Concreting Materials Aggregates For Non-Concreting Works
1-60 1-60 1-60 1-60 1-61 1-62 1-65 1-65 1-65 1-65 1-65 1-66 1-67
1.3 1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6
LABOUR Labour Laws Keeping Records Of Workmen Employment Of Illegal Immigrants (Prohibition) Reserved Allocation Of Man-Year Entitlements Employment Of Skilled Tilers
1-68 1-68 1-68 1-68 1-68 1-69
1.4 1.4.1 1.4.2 1.4.3 1.4.4 1.4.5
CONSTRUCTION EQUIPMENT Provision Of Construction Equipment Technical Specification Recovery For Non-Provision Maintenance Approved Construction Equipment
1-69 1-69 1-71 1-72 1-74
1.5 1.5.1 1.5.2 1.5.3
SAFETY Site Safety Measures Safety Infringement Reporting Of Accidents And Dangerous Occurrence
1-75 1-85 1-85
1.6
NUISANCE AND IRREGULARITIES
1-86
1.7
SPECIAL CONDITIONS ON SURVEY WORKS
1-86
1.8
CONTRACTOR TO VISIT SITE OF WORK
1-88
The contents on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.
GENERAL SPECIFICATIONS
Bldg Spec Page 1-1 SECTION 1 GENERAL SPECIFICATIONS 1.1
GENERAL
1.1.1
Definitions, Abbreviations And Interpretations In the Specifications, the following words and expressions shall have the meanings hereby assigned to them except where the context otherwise requires : "SO Rep"
shall mean the Superintending Officer's Representative.
"as approved"
shall mean as approved by the Superintending Officer's Representative.
"as directed"
shall mean as directed by the Superintending Officer's Representative.
"or other approved"
shall mean as approved by the Superintending Officer's Representative and as further defined in subclause 1.2.5 "Approval Of Samples And Trade Names" of the General Specifications.
"as required" or "as shown" or "as indicated" or "as specified"
shall mean as required or as shown or as indicated or as specified in the Drawings and/or Specifications.
The following abbreviations are used in the Specifications : ABGSM AC or ac AISI Amp or amp AMCA ANSI AS ASTM BCA BS cm cm² or cm2 cm³ or cm3 CPF CP dB DC or dc DIN DU or du EIA EMA MEWR EPR FSSD GS or gs g HDB HRC HVAC Hz IDA IEC IECEE IP ISO ITE JIS KA or kA
BLDG12/S01.DOC(1) Sal(151211) (DPD)
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Association of British Generating Set Manufacturers alternating current American Iron & Steel Institute Ampere Air Movement and Control Association American National Standard Institute Australian Standard American Society for Testing and Material Building And Construction Authority British Standard centimetre square centimetre cubic centimetre Central Provident Fund Board Code of Practice decibel direct current Deutche Industrie - Normen dwelling units Electronic Industry Association Energy Market Authority Ministry of the Environment and Water Resources Ethylene Propylene Rubber Fire Safety and Shelter Department Galvanised Steel gram Housing & Development Board High Rupturing Capacity Heating Ventilation Air-Conditioning Hertz Info-Communications Development Authority of Singapore International Electrotechnical Commission IEC System for Conformity Testing and Certification of Electrical Equipment Index of Protection International Organization for Standardization Institute of Technical Education Japanese Industrial Standard Kilo Ampere
Bldg Spec Page 1-2 1.1.1
Definitions, Abbreviations And Interpretations (Cont'd) kg KN or kN kPa or KPa KV or kV kW or KW Kwh or kWh LEW MCB MCCB MSSL MW m Max or max Min or min ml mm mV m² or m2 mm² or mm2 m³ or m3 mm³ or mm3 MHz MOM MRT MS or ms N NEA No. or no. Pa ONORM PBTS PE
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
PLS PowerGrid or Grid PSB PTL PUB PVC or pvc RC or rc RCCB rms SAC SCV SINGLAS SMRT SPSL SS SWA SWG SingTel TIA UHF UL m uPVC or UPVC V V VHF v/v W w/w
= = = = = = = = = = == = = = = = = = = = = = = = = = = =
BLDG12/S01.DOC(2) Sal(151211) (DPD)
kilogram kilonewton kilopascal kilovolt kilowatt Kilowatt hour Licensed Electrical Worker Miniature Circuit Breaker Moulded Case Circuit Breaker Market Support Services Licensee Megawatt metre maximum minimum millilitre millimetre millivolt square metre square millimetre cubic metre cubic millimetre Megahertz Ministry of Manpower Mass Rapid Transit mild steel newton National Environment Agency number pascal Osterreichisches Normangsinstitut (Austrian Standard) Public Basic Telecommunications Service Operators Professional Engineer registered under the Professional Engineers Board, Singapore Product Listing Scheme PowerGrid Ltd TUV SUD PSB Pte Ltd Public Telecommunication Licensees Public Utilities Board Polyvinylchloride Reinforced Concrete Residual Current Circuit Breaker root mean square Singapore Accreditation Council StarHub Cable Vision Pte Ltd Singapore Laboratory Accreditation Scheme Singapore MRT Ltd SP Services Ltd Singapore Standard Steel wire armoured Standard Wire Gauge (British) Singapore Telecommunications Ltd Telecommunications Industry Association Ultra High Frequency Underwriters Laboratories Inc micrometre Unplasticised Polyvinylchloride microvolt Volt Very High Frequency measured by volume watt measured by weight
Bldg Spec Page 1-3 1.1.1
Definitions, Abbreviations And Interpretations (Cont'd) XLPE ºC % ± ≤ or < ≥ or > < >
= = = = = = = =
Cross linked polyethylene degree Celsius percent plus or minus less than or equal to greater than or equal to is less than is greater than
Words importing the singular shall also include the plural and vice versa where the context requires. The clause or subclause headings in the Specifications shall not be deemed to be part thereof or be taken into consideration in the interpretation or construction thereof or of the Contract. All clauses including all subclauses under them in the Specifications shall be deemed to be directed at the Contractor unless expressly specified otherwise to the contrary and the Contractor shall perform and/or comply with such instructions, directions, requirements and obligations specified in the Specifications and required under the Contract. All Acts of Parliament, statutes, regulations, bye-laws, orders, local and foreign standards and codes of practice specified shall be deemed to refer to the latest and shall be deemed to include any amendments, and/or modifications and/or additions and/or re-enactments thereto. 1.1.2
Reserved
1.1.3
Payment Of Employer's Bills, Expenses, Etc The Contractor shall duly and punctually pay to the Employer the billed and any other expenses incurred by the Employer in respect of the supply of materials, services, etc. The Contractor shall also pay to the Employer interest at the rate of seven percent per annum (7% p.a.) or such other rate as may be determined from time to time by the Employer in respect of any arrears of payment or other outstanding sums due and payable to the Employer, from the due dates until payment in full is received by the Employer. The Employer reserves the right to set off such bills and expenses against monies due or becoming due to the Contractor before payment of the balance, if any, to the Contractor. In this respect, all Employer's bills and other expenses due from the Contractor shall have priority over debts due to third parties.
1.1.4
Contract Payment By GIRO/EPS All payments under the Contract by the Employer to the Contractor shall be effected through the Interbank GIRO System and/or other Electronic Payment Systems. The Contractor shall submit all the necessary forms, such as Inter-bank GIRO (IBG) form, etc., duly completed and signed, to the Finance Department, HDB, HDB Hub, 480 Lorong 6 Toa Payoh, Singapore 310480; within fourteen days from the date of the Letter of Acceptance to effect payments through such Systems. In the event the payment arrangement through such Systems terminates for whatever reasons, the Contractor shall re-submit all the necessary forms to the Finance Department within 14 days from the date of the termination. The preceding requirements shall not be applicable to payments by the Employer to the Contractor in approved foreign currencies, where required under the Contract. Under such a case, the provisions under the clause "Tenders In Approved Foreign Currencies" including all subclauses under it shall apply.
BLDG12/S01.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 1-4 1.1.5
Diversion of Services Where in the case the SO Rep is of the opinion that it becomes essential to divert permanently any sewer, drain, pipe, cable, or other services, the cost for the diversion shall be borne by the Employer. Provided always that such diversion does not form part of the Works.
1.1.6
Stamp Duties The Contractor shall have all documents required by or arising out of or in connection with this Contract properly stamped to comply with the Stamp Duties Act. The cost and expense arising out of this obligation, including all stamp duties required, shall be borne by the Contractor and shall be deemed to have been allowed for in the Contract Sum.
1.1.7
TOL Fee For Land Outside Contract Boundary Where the Contractor requires land outside the contract boundary for the setting up of Construction Equipment and other temporary facilities for the Works, the Contractor shall check on the availability of such land and apply to the relevant Authority or Lands Management Section of HDB for the use of such land. In the event the relevant Authority or HDB's Lands Administration Section allows the Contractor the use of such land, the Contractor shall at his own cost and expense comply with all the terms and conditions, pay all TOL (Temporary Occupation Licence) fees, bear all costs and expenses for the use and maintenance of and access to the said land imposed by the relevant Authority or HDB's Lands Management Section. Such land allocated shall solely be used for the purpose of executing Works under the Contract only. Any payment for unused materials or goods stored at such land shall be subject to the provisions in Option Module B "Unused Materials or Goods not Delivered to Site" of the Conditions.
1.1.8
Liquidated Damages For Delay In Completion In the event of re-arrangement of the completion of the Works into separate phases or sub-phases, the rate of liquidated damages in respect of each phase or sub-phase of the Works shall be recomputed according to the following rates and pro-rated against the original amount specified in the Appendix To Public Sector Standard Conditions Of Contract For Construction Works. $ per unit per day per unit per day per unit per day per unit per day per unit per day per unit per day per unit per day per unit per day per no. per day per 1,000 m² of total area within the contract boundary per day 5.00 per lot per day 1.50 per lot per day
Rental Flat (30m²) Rental Flat (40m²) Studio Apartments (35m²) Studio Apartments (45m²) 2-Room Flat 3-Room Flat 4-Room Flat 5-Room Flat Electrical Substation Link Building/Linkway/ Siteworks/Landscaping works Carpark Lot Motorcycle Lot Shop Market Foodcourt/Fastfood/ Coffee House/Restaurant/ Eating House/Kiosk/ Offices/Chidcare Centre/ Various Centres
15.00 20.00 15.00 20.00 20.00 25.00 35.00 40.00 1,800.00 40.00
) ) ) ) ) ) )
Civil Engineering Works
) )
BLDG12/S01.DOC(4) Sal(151211) (DPD)
1.00 per m² of internal floor area per day
500.00 per phase per day (for Contract Sum less than or equal to $2 million) 35.00 per phase per day (for every subsequent $100,000.00 exceeding $2 million)
Bldg Spec Page 1-5 1.1.8
Liquidated Damages For Delay In Completion (Cont'd) For the purpose of this clause, the internal floor area shall be defined as the total floor area in the commercial unit/centre including the floor area occupied by toilet, store, kitchen, staircase, etc within the commercial unit/centre. The internal floor area shall be measured as follows : (a)
Partition Wall/Column For partition wall/column, to measure up to the centre line of partition wall (party wall) which separates 2 adjoining units.
(b)
External Wall And Party Wall Along Corridor For external wall and party wall along the corridor, to measure up to the external face of the wall surrounding the floor slab.
1.1.9
Provisional Sum Items Where Provisional Sum Items are included in the Contract, they shall be inclusive of all costs necessary in carrying out or supplying the work, materials or goods. These Provisional Sum Items shall be inclusive of the Contractor's profit and overheads but shall be net of trade and cash discounts.
1.1.10
Prime Cost Sums Where Prime Cost Sums (hereinafter referred to as P.C. Sum for the purposes of this subclause) are provided for any work, materials or goods, these sums shall be inclusive of carriage but exclusive of Contractor's profit and attendance. These P.C. Sum shall also be net of trade and cash discounts. The Contractor shall allow and separately price for profit and attendance in respect of such P.C. Sum in the Form of Tender. P.C. Sum shall be deducted from the Contract Sum and in lieu thereof shall be added the sums due to the Contractor for the said work, materials or goods. The sum allowed by the Contractor in the Contract for attendance in respect of any P.C. Sum shall be fixed regardless of whether the actual sum expended is greater or lesser than the P.C. Sum. In respect of profit, the amount to be paid shall be the percentage quoted by the Contractor against the actual sum expended in relation to the P.C. Sum. Should the work, materials or goods for which a P.C. Sum is provided in the Contract be not required, or if the Employer chooses to carry out or supply the aforesaid work, materials or goods by his own workmen or by other contractors, which the Employer is contractually entitled so to choose, then such P.C. Sum together with the profit and attendance allowed by the Contractor in the Contract shall be deducted in full from the Contract Sum. Should the Contractor himself be engaged or instructed to carry out or supply any work, materials or goods under a P.C. Sum, the profit and attendance allowed by the Contractor in the Contract in respect of the P.C. Sum shall be deducted in full from the Contract Sum. In such event, the amount to be paid to the Contractor for the work, materials or goods shall be inclusive of the Contractor's overheads and profit for the work, materials and goods.
1.1.11
Overclaim Leading To Overpayment If at any time during the Time for Completion and any time period where liquidated damages are imposed under the Contract, the Contractor is found to have over-claimed and was paid for more than the value of the Permanent Works carried out and/or approved unfixed materials at the Site, the SO Rep shall be empowered to deduct from the Contractor's subsequent payments the sum overpaid together with the Employer's charge, and interest calculated at seven percent per annum (7% p.a.).
BLDG12/S01.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 1-6 1.1.12
Carriage By Sea The Contractor shall ensure that the carriage by sea of all goods, materials, Plant and equipment imported for the purposes of this Contract shall be on vessels owned and operated by shipping lines which are approved lines at the time the contract of carriage is entered into. Other ships may be used only if no approved line : (a)
can deliver the goods, materials, Plant and equipment in time to meet the delivery dates specified in the Contract; or
(b)
can provide the same measure of service at the same cost.
The Bills of Lading for the goods, materials or Plant and equipment used by an approved line(s) shall be sufficient evidence of their carriage by an approved line(s) in compliance with this subclause. Where the carrier is not an approved line, the Contractor shall satisfy the SO Rep that the conditions herein stated have been satisfied. The SO Rep may require and the Contractor shall forthwith furnish to the SO Rep a letter from at least one approved line at the time the contract of carriage with the carrier is entered into stating that in respect of the shipment in issue they are either unable to quote or to provide the service required. Notwithstanding anything contained in this subclause, the Employer shall not be responsible for any act or default of the carrier or for any loss or damage sustained by the Contractor on account of him having to comply with this subclause. The list of current approved lines can be obtained from the Procurement Office, Development And Procurement Department, HDB, Basement 1, HDB Hub, 480 Lorong 6 Toa Payoh, Singapore 310480. 1.1.13
Existing Ground / Road Levels The existing ground/ road levels/ drain invert levels as shown in the drawings are approximate. The Contractor shall note that existing ground/road levels and drain invert levels may not necessarily be the same as shown in the drawings. He is to ascertain this and visits the Site prior to the tender and is deemed to include whatever extra cost of cut and fill in the Contract Sum. In the event of the Contractor failing to visit the Site, the tender shall be deemed to have been submitted with his satisfaction of the actual levels on Site and other related ground conditions. The Contractor is deemed to have made necessary provision in the Contract Sum to cater for additional earthwork arising from the difference in levels found on Site and that shown in the drawings and no claims or compensation shall be entertained.
1.1.14
Raising Or Lowering Of Existing Sewer Manholes And Other Services Manholes The Contractor shall include in his Contract Sum the cost of raising or lowering of existing sewer manholes and other services manholes / chambers, and their related works within the contract boundary to suit and match the proposed driveways and platform levels.
1.1.15
Work Method And Trade Demonstration The Contractor shall submit to the SO Rep for his approval the work methods of various trades as required by the SO Rep to ensure good in-process quality control and reasonably acceptable final workmanship. A marking system, where applicable, showing inter alia, the control, grid and level reference lines shall be included in the work methods. The Contractor shall also ensure that sub-contractors engaged for each trade shall also comply with the work methods approved by the SO Rep. As instructed by the SO Rep, the Contractor shall conduct trade demonstration for all critical work methods as approved prior to full scale production in the contract.
BLDG12/S01.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 1-7 1.1.15
Work Method And Trade Demonstration
(Cont’d)
Should it appear to the SO Rep at any time that the work methods proposed by the Contractor will not ensure good workmanship in the Works, the SO Rep may require the Contractor to make at his own cost and expense such modifications to the original work methods as the SO Rep may consider necessary or appropriate. The Contractor shall employ only skilled workers who are capable of executing the Works in accordance with the work methods approved by the SO Rep. When there is a change in subcontractors, the SO Rep may instruct the Contractor to re-conduct the relevant trade demonstration if deem necessary. Approval by the SO Rep of the Contractor’s work methods, revised work methods or any details and information provided under this subclause shall not in any way relieve the Contractor’s liabilities or obligations under the Contract. 1.1.16
Reserved
1.1.17
Site Layout Plan After the Contract is awarded, submit a site layout plan to the SO Rep indicating proposed locations of all temporary structures (for example site offices, workers' quarters, canteens, stores, hoistways, Construction Equipment and labour lines) for approval before their erection. Notwithstanding such approval, the Contractor shall relocate any such structures at his own cost and expense when required to do so by the SO Rep. All such materials and structures shall be kept away from proposed roads, driveways, car parks and services lines. Should any hoistway or structure be erected without the approval of the SO Rep, the Contractor shall pull down and re-erect the hoistway or structure in an approved position within seven days from the date of instruction by the SO Rep. The Contractor shall provide for the maintenance of all such structures in a clean, hygienic and safe condition for the duration of the Works. All such structures and hoistways shall be removed on Substantial Completion of the Works.
1.1.18
Site Offices And Canteen
1.1.18.1
Within 21 days from the date of taking possession of the Site, the Contractor shall erect site offices and a site canteen complying with the requirements of the MEWR and shall remove them on Substantial Completion of the Works or at a time approved by the SO Rep. The Employer's Standard Drawings may be used as a guide in designing the site offices and canteen. Submit proposals for the design (inclusive of PE calculations), configuration and layout for the approval of the SO Rep taking full consideration the site constraints and conditions. Locating the site offices and canteen at the first storey void areas shall only be considered under special circumstances and subject to the approval of the SO Rep. Should approval be given to set up the site offices and canteen at the first storey void areas, ensure and make all provisions necessary to protect the structures and finishes. When such void areas are required by the Employer for other purposes, remove and re-erect the site offices and canteen at alternative locations all at the Contractor's own cost and expense. No claim whatsoever shall be entertained in such event.
BLDG12/S01.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 1-8 1.1.18
Site Offices And Canteen
1.1.18.2
Site Offices
(Cont’d)
The following rooms shall have at least the minimum stipulated areas and complete with basic facilities, fittings and furniture and made available at all times for use by the SO Rep and the Employer's officers : Facilities, Furnitures and Fittings
S/N
1.
Room (Minimum size & able to accommodate all facilities specified)
2.
Tables and Chairs :
24 m
2
Computer Room
24 m2
34 m2
8 m2
a) 1.5m x 0.8m office table complete with at least 3 drawers
4
4
-
-
b) 1.5m x 0.8m working table complete with storage space for drawings
-
Maximum 2
-
-
c)
0.8m wide side tables for computer and its peripherals
-
-
-
1
d)
1.2m x 0.8m table
-
-
6
-
e)
Chairs with hand rests
4
4
-
-
f)
Chairs without hand rests
4
2
15
2
g)
High Chairs without hand rests (for working table)
-
Maximum 2
5
-
3
Steel Cabinet complete with Shelves and Double-Leaf Doors with lock
1
Maximum 3
-
-
4
Soft Board complete with Accessories
1
1
2
1
5
White Board complete with Accessories
1
1
1
-
6
Key cabinet
-
1
-
-
7
Air-Conditioner of Minimum 10,000 BTU Output
2
2
2
1
8
Telephone Installation a) Separate telephone line
1
1
-
1
b) Telephone set
1
1
-
1
Drawing Rack complete with Drawing Holders
-
2
-
-
9
BLDG12/S01.DOC(8) Sal(151211) (DPD)
SO Rep Room
No. of Items Resident Meeting Technical Officer Room Room
Bldg Spec Page 1-9 1.1.18
Site Offices And Canteen
1.1.18.2
Site Offices
(Cont’d) Facilities, Furnitures and Fittings
S/N 10
(Cont’d)
SO Rep Room
No. of Items Resident Meeting Technical Officer Room Room
Computer Room
Electrical Installation, Connections and Accessories (The illumination level in the meeting room and the SO Rep room shall be set at 300 to 400 lux) a) 40W Fluorescent lighting
4
4
4
2
b) 13 Ampere socket outlet
2
2
2
3
c) 15 Ampere socket outlet
2
2
2
1
The doors leading to the SO Rep room, the Resident Technical Officer room and the meeting room shall be provided with locksets and all the keys to the locksets shall be given to the SO Rep. 1.1.18.3
Site Canteen The structure of the site canteen shall be a steel column-roof truss design, anchored to a reinforced concrete base and footings. All structural steelwork shall comply with the requirements specified in Section 17 “Structural Steelwork” including all clause and subclause under it. The Contractor shall further submit detailed structural plans and design calculations, certified by his PE to the SO Rep not later than three months from the commencement date of the Time for Completion or two weeks before the actual commencement of the Works, whichever is earlier. The Contractor shall bear all consequences for late submission. The Contractor shall erect the site canteen in strict compliance with his Professional Engineer's plans and calculations. The Works shall be supervised by the Contractor's PE. His PE is also to ensure that the site canteen is designed in compliance with the Technical Guidelines for the Fire Safety in Temporary Buildings in Construction Sites, including any amendment thereto, issued by FSSD; and the Building Control (Temporary Buildings) Regulations (2000 edition) including any latest requirements by BCD, BCA. Not later than two weeks after the completion of the Works, the Contractor's PE shall submit a Certificate of Supervision, stating that he has carried out such supervision work and is fully satisfied that the Works have been constructed in accordance with his structural plans and design calculations as approved by the SO Rep. The site canteen is to be enclosed with half-height panels. The panels are to be made of fire-rated colour-bond galvanized steel sheet complete with 42mm thick rockwool panel (sandwich concept). Solid block wall are to be installed only at the preparation and dapur areas where wall tiles are provided. All solid block wall facing the external/exposed shall be plastered and painted with at least 3 coats of algae-resistant emulsion paint. No timber or other combustible material shall be used for the site canteen. Notwithstanding the Employer’s Standard Drawings being adopted as a guide, the site canteen shall be provided with the following facilities and amenities: S/No. 1. 2. 3. 4.
BLDG12/S01.DOC(9) Sal(151211) (DPD)
Facilities, Furniture and Fittings Wash basins Wash area Wall / Ceiling mounted fans Ceiling mounted lightings
Refreshment Area 1 4 4
No. of Items Preparation Area 1 1 2
Dapur Area 2
Bldg Spec Page 1-10
1.1.18
Site Offices And Canteen
1.1.18.3
Site Canteen
(Cont’d)
(Cont’d)
All canteen counter tops, dining tables and benches are to be wrapped with linoleum or other approved waterproof material. The concrete base shall also be 100mm above the surrounding level to keep the floor area dry. Adequate scupper drains graded to discharge into public sewer / septic tank are to be provided for washing purposes. Discharge into the site’s perimeter cut-off drains shall not be allowed. All roof purlins and runners are to be concealed with false ceiling made of softboard or other approved materials for aesthetic purposes. The site canteen is to be sited at a well-ventilated location, away from vehicular accesses and refuse collection areas for hygiene purposes. The location and layout of the site canteen shall be subjected to approval of the SO Rep. 1.1.18.4
The Contractor shall allow for the maintenance of the site offices and canteen and all the facilities, furniture and fittings therein in a clean, habitable and good working condition to the satisfaction of the SO Rep. The Contractor shall pay all charges for the provision and use of the telephone and electricity at the site offices and canteen.
1.1.18.5
Should the Contractor fails to provide any of the aforementioned facilities, furniture and fittings after the commencement date of the Time for Completion, the SO Rep shall forthwith purchase and provide the same on the Contractor's behalf and all costs and expenses for such purchase and provision plus charges shall be recovered by the Employer from any monies due or becoming due to the Contractor or be recovered as a debt due by the Contractor to the Employer.
1.1.19
Provision Of Equipment, Apparatus, Devices, Etc (A)
Facsimile Machine The Contractor shall provide 1 number of plain paper (A4 size) facsimile machine at the site office. Facsimile machine of the thermal paper type shall not be acceptable. Such machine shall be kept in the Resident Technical Officer room throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The facsimile machine shall be for the exclusive use by the SO Rep and/or Employer's officers only. The Contractor should provide another facsimile machine for their own use. The Contractor shall pay all charges, bear all costs and expenses and be responsible for the continuous proper, good and efficient working conditions and maintenance of such facsimile machine. Produce the maintenance agreement with the vendor to the SO Rep for checking when requested. The maintenance agreement shall cover the whole duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract.
(B)
Digital Camera On Site The Contractor shall provide a digital still camera on the Site throughout the Time for Completion and any time periods where liquidated damages are imposed under the Contract, for the purpose of photographing site occurrences (within the Site) by the SO Rep. The digital still camera shall have zooming functions and be capable of taking pictures at a digitized resolution of at least 2.1 million pixels. The digital still camera shall have an expandable and removable memory storage media with a minimum capacity of 128 Mbytes, and be provided with all the necessary softwares and accessories for editing and transferred digital images from the camera to the computer hardware. The Contractor shall bear all the costs and expenses incurred arising from usage of the digital camera and shall be responsible for its continuous and proper functioning.
(C)
Torch Lights The Contractor shall provide sufficient number of torch lights on the Site at all times for use by the SO Rep, Resident Technical Officer and/or representatives from other Authorities. These torch lights shall be in good working condition and sufficiently bright enough for use.
(D)
Metal Detector The Contractor shall provide a battery-operated portable metal detector for the purpose of detecting metal reinforcement embedded in cement mortar joints of brickwalls. The detector must have either a light or buzzer indicator to indicate the presence of metal.
BLDG12/S01.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 1-11 1.1.19
Provision Of Equipment, Apparatus, Devices, Etc (Cont'd) (E)
Moisture Meter The Contractor shall provide a portable, battery operated, digital LCD display moisture meter with integral electrode pins for measuring moisture content of timber doors and frames delivered to the Site. The moisture meter shall be capable of measuring actual moisture content of wood in the range from 8% to 44% (minimum) with a 1% indicating tolerance at 0 to 40 degrees Celsius ambient temperature. The meter shall also possess a built-in device for performing simple calibration checks.
(F)
Safety Helmets And Safety Boots The Contractor shall provide sufficient safety helmets and safety boots for use by the Employer's officers and visitors visiting the Site throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The ownership of the safety helmets and safety boots shall be reverted back to the Contractor upon the satisfactory Substantial Completion of the Works. The requirements are as follows : (a)
Safety Helmets (i) (ii) (iii)
(b)
white colour with HDB logo in front of helmet. (Colour code for HDB logo : Pantone 485) complete with canvas chin straps and sweat resisting lining. comply with SS98:1987.
Safety Boots (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix)
at least 24 cm in height black/brown colour with steel toe cap long-wearing of great flexibility and resilience slip proof, resistant to oil, acid and heat nail proof of excellent insulation comfortable and light comply with SS105:1987
The Contractor shall immediately replace those safety helmets and safety boots which the SO Rep considers to be not in good working condition. (G)
Stationery For Resident Technical Officer The Contractor shall provide stationery and other devices for site use by the Employer's officers upon commencement of the Works. The list of stationery to be provided is as follows : Item No.
BLDG12/S01.DOC(11) Sal(151211) (DPD)
Description
Quantity (Maximum)
1.
Ball Point Pen (Black/Blue/Red)
2.
Correction Fluid
2 no. each per Resident Technical Officer 1 no. per Resident Technical Officer
3.
Eraser (Pencil)
1 no. per Resident Technical Officer
4.
Glue Tube
1 no. per Resident Technical Officer
5.
Hard Cover Book : a) A4 size b) A5 size
a) b)
6.
Manila File
25 no.
5 each. 5 each.
Bldg Spec Page 1-12 1.1.19
Provision Of Equipment, Apparatus, Devices, Etc (Cont'd) (G)
Stationery For Resident Technical Officer (Cont’d) Item No. 7.
Description
Quantity (Maximum)
Paper Clip : a) Medium Size b) Large Size
a) b)
8.
Pen Knife
2 no.
9.
Pencil (2B)
2 no. per Resident Technical Officer
10.
Perforator
2 no.
11.
Pocket Notebook
1 no. per Resident Technical Officer
12.
Ruler (300 mm)
1 no. per Resident Technical Officer
13.
Scissor
2 no.
14.
Stamp Pad (Violet)
1 no. per Resident Technical Officer
15.
Staple Machine (B3)
1 no. per Resident Technical Officer
16.
Staples (B3)
1 no. per Resident Technical Officer
17.
Calculator (without scientific functions)
1 no.
18.
Colour Pencils
1 set
19.
Highlighter of Assorted Colours
1 set
20.
Scale Ruler
1 no.
21.
Writing Pad (A4)
1 no. per Resident Technical Officer
22.
Hard Cover Ring File
40 no. plus 3 no. per building block
23.
Ear Plugs
1 no. per Resident Technical Officer
24.
Rubber Stamp
Max. 5 nos per contract
25.
Retractable tapping rod
1 no. per Resident Technical Officer
26.
3.5 inch diskettes (1.44MB)
2 boxes of 10 formatted diskettes per contract
27.
Measuring Tape of 7.5 metre Length
1 no. per Resident Technical Officer
28.
Laser Pointer
1 no. per Resident Technical Officer
29.
CD Re-write able discs
1 box of 10 CDRW discs
2 boxes. 2 boxes.
Should the Contractor fails to provide any of the aforementioned stationery after the commencement date of the Time for Completion, the SO Rep shall forthwith purchase and provide the same on the Contractor's behalf and all costs and expenses for such purchase and provision plus charges shall be recovered by the Employer from any monies due or becoming due to the Contractor or be recovered as a debt due by the Contractor to the Employer.
BLDG12/S01.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 1-13 1.1.19
Provision Of Equipment, Apparatus, Devices, Etc (Cont'd) (H)
Photo Copying Machine Provide 1 number of plain paper photocopying machine at the site office with the following specifications : (i) (ii) (iii) (iv)
minimum 50 ppm in black and white; Support paper up to 160gsm and A3+; Auto paper selections; Auto response sensor
The photocopying machine shall be kept in the Resident Technical Officer room throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The photo copying machine shall be for the exclusive use by the SO Rep and/or Employer’s officers only. The Contractor should provide another photo copying machine for their own use. The Contractor shall pay all charges, bear all costs and expenses and be responsible for the maintenance of such photocopying machine. Produce the maintenance agreement with the vendor to the SO Rep for checking when requested. The maintenance agreement shall cover the whole duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract. 1.1.20
Reserved
1.1.21
Provision Of Transport The Contractor shall at his own cost and expense provide suitable transport throughout the Time for Completion and any time periods where liquidated damages are imposed under the Contract, for the SO Rep and other Employer's officers, from the nearest bus stop or MRT station or site or public carpark near to the Site, to the Site, including the return journey, for the discharge of their official duties. Such pick up point shall be decided by the SO Rep. The vehicle shall be driven by the Contractor's own personnel.
1.1.22
Provision Of Temporary Site Facilities/Utilities
1.1.22.1
Access Roads And Protective Crossings The Contractor shall repair and maintain all access roads serving the Site and provide temporary protective crossings over existing drains, channels, footways, etc throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall be responsible for making good all damage and/or clearing away on Substantial Completion to the requirements of the relevant Authorities and to the satisfaction of the SO Rep.
1.1.22.2
Reserved
1.1.22.3
Temporary Electricity Supply And Installation The Contractor shall engage a Licensed Electrical Worker (LEW) of at least an ‘Electrical Technician’ Grade to design all temporary electrical installations necessary for building operations and works of engineering construction. The installations shall comply fully to the requirements as stated in the latest edition of Singapore Standard CP 88 applicable at the date of closing of the Tender. Throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract, the Contractor’s LEW shall ensure good safety standards and practices and including the following : (a)
BLDG12/S01.DOC(13) Sal(151211) (DPD)
For re-development sites, the Contractor is strongly encouraged to use M/s PowerGrid Ltd’s power supply to provide temporary electricity supply during the construction stage. For new town development sites, all electrical generator sets shall be licensed with valid EMA licence. A minimum capacity of 75kVA generator shall be used at each block. However when the generator is used for the passenger cum material hoist and other general purposes, the minimum capacity of the generator for each block shall be upgraded to 100 kVA.
Bldg Spec Page 1-14 1.1.22
Provision Of Temporary Site Facilities/Utilities (Cont’d)
1.1.22.3
Temporary Electricity Supply And Installation (Cont’d) (b)
The electrical switch board which holds the ELCB shall be housed in a switch box located at least 1.5 m from the floor level.
(c)
Socket-outlet assembly complete with miniature circuit breakers (MCBs) and residual current operated circuit breakers (RCCBs) is to be provided at each storey of the building block. The precast refuse chute shall serve as a temporary service riser. The installation shall last the entire Time for Completion unless authorized to be removed earlier by the SO Rep or when permanent electricity supply is secured (whichever is earlier). The temporary incoming supply cable located within the precast refuse chute shall be supported with insulated lock bands. Upon termination of the temporary electricity supply, all cables and lock bands installed in the precast refuse chute shall be removed and the surface of the precast refuse chute shall be made good to a smooth finish.
(d)
All sheaths of cables, sockets outlets and plugs are in good working condition.
(e)
All cables are properly bound and do not cause obstruction to passageways, walkways and stairs.
(f)
All cables are properly supported with L-shaped galvanised steel brackets or insulated lock bands and placed at a suitable height, away from any source which cause mechanical damage.
(g)
All plugs, socket-outlets, socket-outlet assembly (SOA), cable couplers and plug adaptors are to be of the standard industrial type and of minimum classification of latest edition CP 88.
(h)
The supply to provide artificial lighting shall be taken from the socket-outlet assembly located at each storey. 4 feet fluorescent lighting enclosed in suitable mechanical enclosure to a minimum classification of IP 44 shall be used to provide lighting or to achieve a minimum lighting level of 400 lux.
(i)
The Contractor shall provide sufficient temporary lighting, according to the instruction of the SO Rep, for their workers/sub-contractors to carry out in-process construction works such as internal plastering/skimming, wall and floor tiling, application of water-proofing membrane etc., within the units or common areas of the building under construction.
1.1.22.4
Reserved
1.1.22.5
Temporary Store Room For Lift Parts The Contractor shall provide a temporary storage space with a floor area of at least 50 m2 and another temporary store room properly secured and complete with door and latch and with a floor 2 area of at least 15 m at the ground floor of each building block where lifts are to be installed. The temporary storage space/temporary store room shall be used solely by the lift contractor for keeping lift parts during the lift installation period which shall commence from the date of handing over of the lift hoistway and lift motor room to the lift contractor. If the abovementioned temporary storage space/temporary store room need to be removed to allow the Contractor and/or other contractors to proceed with their work, the Contractor shall at its own cost and expense first provide an alternative storage space/store room and arrange with the lift contractor to vacate the original temporary storage space/temporary store room and transfer such lift parts to the alternative storage space/store room. The location and type of temporary storage space/temporary store room shall be approved by the SO Rep.
1.1.22.6
Temporary Use Of Lift For each building block in the Works designed with lift facilities, the Contractor shall secure for the temporary use of one lift upon completion of lift testing and commissioning by the lift contractor engaged by the Employer. The Contractor shall execute an agreement with the lift contractor for the temporary usage of the lift for a period of 1 month or longer prior to the Substantial Completion of each respective building block. A copy of the executed agreement shall be given to the SO rep for record. All costs and expenses incurred in complying with the provisions of this clause shall be deemed to be included in the Contract Sum.
BLDG12/S01.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 1-15 1.1.22
Provision Of Temporary Site Facilities/Utilities (Cont'd)
1.1.22.6
Temporary Use Of Lift (Cont'd) The temporary use of the lift shall be subjected to the terms and conditions stipulated hereunder. Such terms and conditions shall be incorporated into the agreement to be executed between the Contractor and the lift contractor. The terms and conditions shall be as follows :
1.1.23
(a)
The Contractor shall seek the approval of the SO Rep for the use of the lifts.
(b)
The Contractor shall arrange for a designated person to certify that the lifts are for temporary use and seek approval from MOM before it can be used. Alternatively the lift contractor can arrange for the inspection on behalf of the Contractor at a cost of $680.00 per lift.
(c)
The Contractor shall provide proper protection such as plywood, adhesive tapes, etc. to the lift cages, floors, car doors, architraves, transoms and landing doors, etc. The Contractor shall ensure that the protection for the lifts is always in a proper condition. Any physical damage to the lifts shall be the responsibility of the Contractor.
(d)
The Contractor shall engage a full-time lift attendant to operate each lift. Under no circumstance shall a lift be left unattended when it is in operation.
(e)
The Contractor shall ensure that the lifts are not over loaded.
(f)
The Contractor shall take up additional insurance for the use of the lifts as temporary use lifts and Public Liability coverage, naming the Employer and the lift contractor as the co-insured, for the period of usage. Copies of the insurance policies shall be given to both the SO Rep and the lift contractor before the lifts are allowed to be used. Alternately, the Contractor may pay the lift contractor for taking up the insurance and public liability coverage on its behalf.
(g)
The Contractor shall be responsible for the daily maintenance of the lifts, such as cleaning up the cages and sills in order to prevent unnecessary breakdown and damage to the lifts.
(h)
The lift contractor shall service the lifts once a month during normal working hours. In case of a need for emergency service, the Contractor shall contact the lift contractor direct. The Contractor shall pay the lift contractor a monthly maintenance fee of $630.00 per lift or prorated accordingly. The lift contractor may stop the use of the lifts if the maintenance fee is not paid up.
(i)
Smoking is strictly prohibited in the lifts.
(j)
At least three days prior to handing over each building block to the Employer, a joint inspection shall be conducted between the Contractor and the lift contractor for the purpose of handing the lift back to the lift contractor. Any damage that occur during or as a result of or arising from the temporary usage of the lift which affect the handing over of the lift to the Employer shall be the responsibility of the Contractor. All costs and expense for rectification and repair shall be borne by the Contractor, subject to verification by the SO Rep.
Protective Roof For Temporary Site Structures In addition to the requirements specified in subclause 1.1.18 (or as amended) "Site Offices and Canteens" and other clauses and subclauses on temporary structures as specified, additional protective materials for the roof shall be incorporated into the roof design of these temporary structures. The protective material shall be made of 18mm thick timber ply. For site office and workers' quarters, the timber ply shall be laid in dual double layers; with one double layer laid just beneath the metal roofing sheet and another double layer at the bottom of the steel truss system supporting the metal roofing sheet. For all other temporary structures, such as canteens, toilets, carpenter yards, etc, the protective timber roof shall be laid in single double layer beneath the roofing sheet. However, at the sole discretion of the SO Rep, such protective materials may not be necessary if the temporary structures are deemed far beyond the nearest building block under construction. Under such cases, there shall be no adjustment to the Contract Sum. The Contractor's PE shall consult with the SO Rep on these protective roofs before proceeding with the design of the temporary structures.
BLDG12/S01.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 1-16 1.1.24
Construction Site Main Signboard and Hoarding Signage
1.1.24.1
The main signboard shall consist of an overall perspective of the project and is to be prominently located for maximum exposure to vehicular and pedestrian traffic. It is a separate signboard from BCA construction project data signboard. The design for the main signboard is :
1.1.24.2
(a)
Signboard Size : 4m (Width) x 5m (Height)
(b)
Perspective Size : 50% of signboard size (min) -
Perspective to be chosen by Consultant Supervising Architect and agreed by HDB Project Director.
-
Image printed on adhesive laminate film and mounted on 0.6mm thick aluminium sheet with 12mm thick waterproofed plywood backing. All exposed edges shall be weather protected.
-
The precinct name as approved by the Street and Building Names Board(SBNB) shall be prominently displayed and integrated with the perspective.
(c)
The background colour is HDB's corporate colour Pantone 485 (100M 91Y - process colour). The red symbolises new trends and directions in Singapore's public housing.
(d)
The fixing and securing of the main signboard shall be designed and endorsed by Professional Engineer. The main signboard shall be fixed with stainless steel screws of AISI Grade 304, screw driven and countersunked to form a sound fixing connection.
A pair of hoarding signage with photographs depicting HDB's Vision, shall to be located on each side of the main signboard. The design for the hoarding signage is: (a)
Hoarding Signage Size: 10m (Length) x 2.4m (Height)
(b)
HDB Corporate image printed on adhesive laminate film and mounted on 0.6mm thick aluminium sheet with 12mm thick waterproofed plywood backing. All exposed edges shall be weather protected.
(c)
The background colour is HDB's corporate colour Pantone 485 (100M 91Y - process colour). The red symbolises new trends and directions in Singapore's public housing.
(d)
The fixing and securing of hoarding signage shall be designed and endorsed by Professional Engineer. The hoarding signage shall be fixed with stainless steel screws of AISI Grade 304, screw driven and countersunked to form a sound fixing connection.
1.1.24.3
The Contractor shall submit a complete set of workshop drawings to be endorsed by his Professional Engineer and approved by the SO Rep. As and when instructed by the SO Rep, the Contractor shall remove all or part of the signboard/signage or relocate and reconstruct all or part of the signboard/signage and reinstate all the affected grounds to the satisfaction of the SO Rep all at the cost and expense of the Contractor. On satisfactory Substantial Completion of the Works, the main signboard and the hoarding signage shall be cleared away upon the approval of the SO Rep.
1.1.24.4
Where erection of signboards with more than one language is required, all translations shall be carried out by competent translators approved by the SO Rep. All completed signboards shall be approved by the SO Rep before they are erected. The Contractor shall bear all cost and expense arising.
BLDG12/S01.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 1-17 1.1.25
Site Management Within 14 days from the date of the Letter of Acceptance, the Contractor shall submit to the SO Rep for his approval the following details on site planning : (a) (b) (c) (d) (e) (f)
Site organizational structure; Names, roles and responsibilities of Contractor's site management, technical and supervisory staff; Manpower schedule for each trade; Schedule of heavy equipment and machineries; Measurement Plan and Survey method; Safety Management system;
Within 30 days from the date of the Letter of Acceptance, the Contractor shall submit to the SO Rep for his approval the Master Construction Programme for each building blocks and entire project. Furnish the SO Rep with such further details and information as the SO Rep may require in regard to the above items. Should it appear to the SO Rep at any time that the site planning proposed by the Contractor is not able to ensure a smooth progress and of good workmanship in the Works, the SO Rep is empowered to require the Contractor to make, at the Contractor’s own cost and expense, all necessary modifications to the plans. Approval by the SO Rep of the Contractor's site planning details, revised site planning details and further information provided under this subclause shall not in anyway affect, vary or relieve the Contractor's liabilities or obligations under the Contract. At least 14 days before the commencement of the Works by the sub-contractors or the supply of the materials by the manufacturers / suppliers, the Contractor shall submit the names of his subcontractors for the Works and the manufacturers / suppliers of the materials to the SO Rep. Where the Contractor changes his sub-contractors / suppliers, he shall also submit such information to the SO Rep 14 days prior to the commencement of the Works or supply of materials. 1.1.26
Employment Of Contractor’s Site Personnel
1.1.26.1
Requirements For Employment Of Site Personnel Unless otherwise stated in other clauses and sub-clauses, the Contractor shall employ all the site personnel and station them full-time on the Site throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract all as specified below : Number of Each Type of Personnel to be Employed Based On Contract Sum Value
S/N
1
Type of Personnel
Project Manager
BLDG12/S01.DOC(17) Sal(151211) (DPD)
Not Exceeding $10 Million
Exceeding $10 Million But Not Exceeding $25 Million
Exceeding $25 Million But Not Exceeding $50 Million
Exceeding $50 Million But Not Exceeding $75 Million
Exceeding $75 Million But Not Exceeding $100 Million
Exceeding $100 Million
One
One
One
One
One
One
Fully Agreed & Accepted Rate by the Contractor & the Employer For the Cost & Expense Deemed to be Allowed by the Contractor for the Employment of Each Personnel $8,600 per Project Manager per month
Bldg Spec Page 1-18 1.1.26
Employment Of Contractor’s Site Personnel (Cont'd)
1.1.26.1
Requirements For Employment Of Site Personnel
(Cont'd)
Number of Each Type of Personnel to be Employed Based On Contract Sum Value
S/N
Type of Personnel
2
Workplace Safety & Health Officer
3
Not Exceeding $10 Million
Exceeding $10 Million But Not Exceeding $25 Million
Exceeding $25 Million But Not Exceeding $50 Million
Exceeding $50 Million But Not Exceeding $75 Million
Exceeding $75 Million But Not Exceeding $100 Million
Exceeding $100 Million
Fully Agreed & Accepted Rate by the Contractor & the Employer For the Cost & Expense Deemed to be Allowed by the Contractor for the Employment of Each Personnel $5,000 per Workplace Safety & Health Officer per month $4,500 per Workplace Safety & Health Coordinator per month
Nil
One
One
One
One
One
Workplace Safety & Health Coordinator
One
Nil
Nil
Nil
Nil
Nil
4a
Site Supervisor for Architectural & Structural Works
One
Two
Three
Three
Four
Four
$4,000 per Site Supervisor per month
4b
Site Supervisor for Mechanical & Electrical Works
One
One
One
One
One
One
$4,000 per Site Supervisor per month
5
Horticultural* Supervisor
One
One
One
One
One
One
$2,000 per Horticultural Supervisor per Month
6
Environmental Control Officer
7
Security Guard
Nil
One
One
One
One
One
$2,000 per Environmental Control Officer per Month
One
One
One
One
One
One
$2,000 per Security Guard per month
* Note: The period and duration of employment of the Horticultural Supervisor shall be in accordance with sub-clause 26.1.5 and sub-clause 1.1.26.2(d) “Horticultural Supervisor”.
BLDG12/S01.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 1-19 1.1.26
Employment Of Contractor’s Site Personnel (Cont'd)
1.1.26.2
Qualifications/Experience/Responsibilities Of Site Personnel (a)
Project Manager The Contractor's Project Manager shall be qualified, competent and possess the skill, knowledge and ability to manage and co-ordinate the project effectively. The Project Manager shall be the Contractor's Representative as required under the Contract. The Project Manager shall possess the following minimum academic qualifications and experiences:
BLDG12/S01.DOC(19) Sal(151211) (DPD)
(i)
For Contract Sum of $50 million and above, the candidate shall have a Degree in Architecture, Civil / Structural / Electrical / Mechanical Engineering, Building Science or Quantity Surveying with 4 years of relevant post-graduate working experience in the building construction industry or 3 years of relevant post-graduate project management experience. The degree shall be recognized either by the respective Professional Bodies, professional institutions or Building and Construction Authority.
(ii)
For Contract Sum less than $50 million, the candidate shall have: (a)
A degree in Architecture, Civil / Structural / Electrical / Mechanical Engineering, Building Science or Quantity Surveying with 4 years of relevant post-graduate working experience in the building construction industry or 3 years of relevant post-graduate project management experience. The degree shall be recognized by the respective Professional Bodies professional institutions or Building and Construction Authority; or
(b)
A diploma in Civil / Structural / Mechanical / Electrical Engineering, Building Science, Building Management, Building Services Engineering and at least 10 years of relevant working experience in the building construction industry. The working experience should preferable be working on past HDB projects and shall be recognized by HDB as relevant working experience.
Bldg Spec Page 1-20 1.1.26
Employment Of Contractor’s Site Personnel (Cont'd)
1.1.26.2
Qualifications/Experience/Responsibilities Of Site Personnel (Cont’d) (b)
Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer (WSHO) The Contractor's Workplace Safety & Health Co-ordinator shall possess recognised and approved certification in construction safety to take charge of all matters related to safety. The said Workplace Safety & Health Co-ordinator shall spend their time fully performing the following : (i) (ii) (iii) (iv)
To supervise safety and promote safety conduct; To inspect and rectify any unsafe place of work; To correct any unsafe practice; and To ensure that the provisions of the Workplace Safety & Health Act and its Subsidiary Legislation made thereunder are complied with.
The Contractor shall employ a full-time Workplace Safety & Health Officer to comply with the requirements under the Workplace Safety & Health Act, Workplace Safety & Health (Workplace Safety and Health Officers) Regulations. The Workplace Safety & Health Officer shall implement appropriate safety measures and ensure a safe work environment and safe work procedures in accordance with the Workplace Safety & Health Act and Subsidiary Legislation including the provisions of the Workplace Safety & Health (Construction) Regulations 2007 and the requirements specified under the Contract. (c)
Site Supervisors The Contractor's Site Supervisors shall be qualified and competent and possess the relevant skills, knowledge and the ability to supervise and co-ordinate the Works; and with the following academic qualifications and experience : (i)
Possess a National Certificate in Construction Supervision (NCCS) and at least 5 years of similar capacity relevant working experience in the building construction industry; or
(ii)
Possess a recognised Diploma in Civil/Structural/ Mechanical/Electrical Engineering, Building Science, Building Management, Building Services Engineering and at least 3 years of relevant working experience in the building construction industry; or
(iii)
Possess a Degree (foreign university) in Civil/Structural/ Mechanical/Electrical Engineering and at least 2 years of relevant working experience in the local building construction industry; or
(iv)
Possess a Building Construction Safety Supervisor (BCSS) Certificate.
Notwithstanding the requirements as specified in (i) to (iv) (inclusive) above, where the Contractor is required to employ the Site Supervisor for mechanical/electrical Works, the Site Supervisor must be suitably qualified under the mechanical/electrical engineering academic qualifications and with the relevant work experiences and also received adequate safety and health training to ensure that the work which he oversees or supervises can be carried out safely. (d)
Horticultural Supervisor The Horticultural Supervisor shall be competent and possesses the skill, knowledge and ability to coordinate and supervise all tree planting and landscaping works. The qualified Horticultural Supervisor shall possess the minimum Certificate of Ornamental Horticulture with a minimum of 2 years relevant experience. The appointment of Horticultural Supervisor has to be submitted to SO Rep for approval prior to the commencement of any tree planting or landscaping works. The date of appointment shall take effect from the date of SO Rep approval and shall be in full-time site-based employment by the building contractor when the physical trees planting or/and landscaping work is progressing on site till Substantial Completion of the Works.
BLDG12/S01.DOC(20) Sal(151211) (DPD)
Bldg Spec Page 1-21
1.1.26
Employment Of Contractor’s Site Personnel (Cont'd)
1.1.26.2
Qualifications/Experience/Responsibilities Of Site Personnel (Cont’d) (e)
Environmental Control Officer (ECO) The Contractor shall employ Environmental Control Officer (hereinafter referred to as "ECO" for the purposes of this subclause) to comply with the Environmental Public Health Act – Environmental Public Health (Employment of Environmental Control Officers) Order 1999. The ECO shall be employed on a full-time basis where the Contract Sum is above $50 million or on a part-time basis where the Contract Sum is between $10 million and $50 million. The ECO shall be responsible for monitoring and advising the Contractor on the following main areas: (i) (ii) (iii) (iv) (v) (vi)
Control of disease-bearing vectors and rodents. Proper management and disposal of solid waste. Control of noise and dust pollution. Drainage and silt control. Air and water pollution control. General housekeeping management of the project/Site.
The ECO shall conduct regular site checks and take prompt corrective actions to ensure that the workers' quarters, canteens, toilets, site offices and other facilities and general surroundings of the Site are kept clean, tidy and hygienic at all times. In addition, the ECO shall also ensure that the Site is kept mosquito-free at all times. The ECO shall compile and submit environmental related data to the SO rep upon request. This data can include: (i) (ii) (iii)
Water, electricity and diesel consumption on site. Concrete wastage on site. Amount of construction debris generated on site.
The ECO shall also compile a record of on any checks by the authorities (eg. NEA for noise & vectors, PUB for ECM) and the result of such checks. This record shall also be submitted to SO rep upon request. If the Works have been certified more than 95% completed, the contractor may write to NEA’s Regional Office to seek approval to allow the ECO to perform on a part-time basis and copied to SO rep. There shall be no cost recovery from the contractor if NEA is agreeable to allow the ECO to perform on a part-time basis. (f)
BLDG12/S01.DOC(21) Sal(151211) (DPD)
Security Guards (i)
The Contractor shall employ Security Guards from agencies that are certified/accredited to the Association of Certified Security Agencies (ACSA) or the Security Association Singapore (SAS). A listing of these certified/accredited security agencies may be obtained from the Licensing Division of the Singapore Police Force. The Contractor shall inform the SO Rep in writing on the security agency who supplied the Security Guards, within two weeks from the commencement date of the Time for Completion.
(ii)
All Security Guards shall at all times be in proper uniform of their security agency with their names and identification tags on. Essential security enforcement equipment such as whistle, torchlight, walkie talkie etc shall be provided to them. They shall respond within five to ten minutes whenever they are called either through telephone or walkie talkie. They shall also have the necessary access to the telephone at the Contractor's site office during and after normal working hours for emergency reporting purpose. The Security Guards must not be armed with weapons that are disallowed by the Singapore Police Force.
(iii)
A proper guard post with adequate security lighting and communication facilities shall be erected at every major entrance to the Site. All temporary gates/openings along the fencing/hoarding shall be guarded by a Security Guard during normal working hours and locked up after normal working hours.
(iv)
The Security Guards shall be responsible for the general security of the Site and shall ensure that unauthorized personnel and vehicles do not entered the Site. They shall also responsible for the security of the contractor and HDB's site offices during and after normal working hours.
Bldg Spec Page 1-22 1.1.26
Employment Of Contractor’s Site Personnel (Cont'd)
1.1.26.2
Qualifications/Experience/Responsibilities Of Site Personnel (Cont’d) (f)
1.1.26.3
Security Guards (Cont’d) (v)
The Security Guards shall be employed to perform site security duties on a 24 hour basis. A minimum of one (1) Security Guard shall be on duty at any one shift including Sundays and public holidays throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. No Security Guard shall leave the Site until he is properly relieved by a replacement, even if his shift has ended.
(vi)
A proper record of the Security Guards' attendance must be kept and made available to the SO Rep upon request.
Replacement Of Site Personnel The SO Rep shall be empowered to instruct the Contractor for a replacement at the Contractor's own costs and expenses if any of the site personnel is found not carrying his duties to the satisfaction of the SO Rep.
1.1.26.4
Compliance With Requirements And Submission Of Information Of Site Personnel (a)
The Contractor shall submit to the SO Rep within 21 days from the date of the Letter of Acceptance, the name, identity card numbers and documentary evidence of the educational qualifications and experience of all the site personnel employed by the Contractor. The employment of the site personnel shall be subject to the approval of the SO Rep.
(b)
In addition, the Contractor shall comply with the requirements and keep records and submit these information to the SO Rep where required by him as specified below :
BLDG12/S01.DOC(22) Sal(151211) (DPD)
(i)
Except for the security guards and safety supervisors, all the site personnel employed shall be on the Contractor's monthly payroll. The Contractor shall keep records indicating the number of days the site personnel are employed for each month and the monthly contributions to CPF. Such information may be proof of employment of the site personnel.
(ii)
A letter from every site personnel employed by the Contractor to testify that he is employed full-time for this Site only;
(iii)
Further to (ii) above, if any site personnel is found to be working in more than one running site, the particular site personnel will be barred from working in all the Employer's sites for a period of two years from the date of the breach. It shall be the Contractor's duty to bring to the attention of the site personnel the contents of this clause.
Bldg Spec Page 1-23 1.1.26
Employment Of Contractor’s Site Personnel
1.1.26.5
Inclusion Of Cost And Failure To Employ The Site Personnel
1.1.26.6
(Cont'd)
(a)
The Contractor shall be deemed to have included in the Contract Sum for all costs and expenses to be incurred by him for compliance with the requirements stipulated in this clause.
(b)
In the event of the Contractor not employing the number of site personnel, required by the Contract or not employing such site personnel for the period or periods required by the Contract, without prejudice to the Employer's rights under the Contract, the Contractor shall be indebted to the Employer at the rate or rates as specified for each of the respective site personnel per month and such indebtedness shall be deducted by the Employer from any monies due or becoming due to the Contractor or be recovered by the Employer as a debt due from the Contractor. These rate or rates shall be deemed to have been fully agreed and accepted by the Contractor and the Employer as the costs and expenses allowed by the Contractor for the employment of each of the respective site personnel for each month. For the purpose of this clause, each of the site personnel shall be employed by the Contractor for at least 20 days within a calendar month before he can be considered as being employed for that particular month under the Contract, except where expressly specified otherwise. In the event that the first and/or the last calendar month of the Time for Completion or any time period where liquidated damages are imposed under the Contract, have less than 20 days, each of the site personnel shall be employed for the full number of days in the said first and last calendar month of the Time for Completion or any time period where liquidated damages are imposed under the Contract.
(c)
Notwithstanding other provisions in this clause, if the Contractor incurs additional costs and expenses over and above the agreed rates specified herein in complying with the requirements stipulated in this clause, the Contractor alone shall bear such additional costs and expenses in full.
Application For Release Of Site Personnel The SO Rep may consider a request by the Contractor in writing to release any of his site personnel from the obligations of this clause if the Works has been certified more than 95% complete. It shall be up to the absolute discretion of the SO Rep to decide whether the Contractor's site personnel can be released and the number of site personnel to be released as provided for under this clause. A written approval from the SO Rep shall be obtained in this respect.
1.1.26.7
Superintending Officer's Decision All differences and/or disputes arising under this clause including all subclauses under it (including questions relating to interpretation) shall be determined by the Superintending Officer whose decision shall be final and binding on and conclusive against the Contractor.
BLDG12/S01.DOC(23) Sal(151211) (DPD)
Bldg Spec Page 1-24 1.1.27
Contractor's Work in Connection with Subsidiary Contracts For completed service roads, driveways and drains within the Site contract boundary, the Contractor is obliged to maintain washing and cleaning; and making good any damage arising from their own actions to the satisfaction of the SO Rep all at the Contractor's cost and expense. If the Contractor fails to carry out his obligations as aforesaid, the SO Rep may exercise his right under Clause 1.6 "Nuisance and Irregularities' to impose a charge against the Contractor. Alternatively, the SO Rep may engage other parties to execute the outstanding works and all costs and expenses incurred shall be borne by the Contractor. For lift installation works, after taking over of the lift door jambs from the lift contractor, the Contractor has to schedule and complete all the brickworks (beside the lift door jambs) at all lift walls in a building block within the stipulated time period as specified below : Number of storeys
Maximum Period for Building Works (ie. Brickwork) per building block
Less than or equal to 30 storeys
2.0 weeks
Equal to or higher than 31 storeys
2.6 weeks
The Contractor may use the lifts temporarily for their material hoisting and other works associated with the preparation for handing over subject to the terms and conditions in his agreement with the relevant lift contractor. The Contractor shall be liable for any delay of the building completion arising from the late completion of the brickwall at the lift lobbies to enable the lift contractor in carrying out the lift assembly works within the lift shaft at each building block. 1.1.28
Cables/Services Detection The Contractor shall be deemed to have visited and examined the Site carefully and have ascertained its nature and made provision in the Contract Sum or prices for the type of ground conditions, constraints and underground services. The Contractor shall provide cables/services detecting devices to locate all existing cables/services prior to the commencement of excavation or any other work such as driving of piles, piling of earth electrode and lightning conductors or poles and columns which are liable to damage existing buried services. The Contractor shall engage EMA licensed cables/services detection workers to carry out all cables/services detection work. The proposed line of excavation or area of other work shall be checked for existing services in a systematic manner by making sufficient passes in a grid formation to cover the entire area of work. The extent of checking carried out shall be properly documented and countersigned by the SO Rep. The Contractor shall be liable for all costs and charges incurred if he damages any services. The Contractor shall seek assistance from the relevant Government Department or Statutory Board if he has any query on the location of existing cables/services belonging to the Government Department or Statutory Board. In the case of PowerGrid or SPSL cables/services, the Contractor may seek assistance from the Cable Damage Prevention Unit, PowerGrid or SPSL. In addition, the Contractor shall engage the services of EMA Registered Excavator Operator only for all excavation Works. In the event the Contractor fails to employ EMA Registered Excavator Operator, no excavation Works shall be allowed.
1.1.29
Reserved
1.1.30
Damage To Public/Private Property In the event damage is caused to public/private services or property such as cables, pipes, fittings and fixtures etc. by the Contractor whether by accident or otherwise leading to black-outs or other nuisance or inconvenience to the public or is likely to bring the Employer into disrepute, all costs and expenses incurred for necessary reinstatement or repairs including charges shall be recoverable by the Employer from the Contractor by deduction from monies due or becoming due to the Contractor or as a debt due by the Contractor to the Employer.
BLDG12/S01.DOC(24) Sal(151211) (DPD)
Bldg Spec Page 1-25 1.1.31
General Housekeeping (a)
Periodic Cleaning Up All rubbish and debris shall be cleared from the Site and buildings under construction at least weekly or from time to time as they accumulate or when so directed by the SO Rep. Particular attention shall be directed to those areas where other tradesmen or contractors will be working in. Housekeeping shall be carried out in such manner and at such times so as not to cause any inconvenience to either the adjoining owners, occupiers and the public. Debris shall be wet to minimize the risk of dust pollution
(b)
Provision Of Bins & Skip Containers For Waste And Debris During the course of construction, the Contractor shall provide proper bulk bins of adequate size for the proper storage of construction wastes, chemical wastes and debris in compliance with the relevant legislative requirements or regulations imposed by MEWR. Upon handing over of 1st building block, the Contractor shall provide one no. of skip container per building block for disposal of construction wastes and debris. This skip container shall be placed at the temporary lorry lot as provided for in the Contract. All skip containers shall be removed at the completion of the site works or upon the instruction of the SO Rep.
(c)
Dumping Of Debris And Rubbish The Contractor shall dispose of all unwanted debris, rubble or excess earth at MEWR approved dumping grounds/sites. All charges levied for the use of the dumping grounds/sites shall be borne by the Contractor. If the Contractor indiscriminately dumps construction debris, rubble or excess earth on land owned by the Employer or the Government without written permission, he shall remove all such debris, rubble, or excess earth from such land at his own cost and expense. Further to this, SO Rep may exercise his contractual right and impose an administrative charge for the irregularities committed in accordance with Clause 1.6 “Nuisance And Irregularities”.
1.1.32
Reserved
1.1.33
Time Required For Contractor For Preparation Of Handing Over Inspection The Contractor shall complete the Works or any phase or sub-phase thereof as set out in the Letter of Acceptance in accordance to the Time for Completion or any subsequent extensions of time approved by the Superintending Officer. All completed Works or any phase or sub-phase thereof shall be handed over to the Employer within or by the Time for Completion or any subsequent extensions of time approved by the Superintending Officer, prior to the issue of any Certificate of Substantial Completion. The Contractor shall note that the Time for Completion has been computed to include the time allowed for preparation of handing over inspections. Therefore, the duration required for the preparation of and the handing over inspections shall be incorporated into the Programme for the Works or revised Programme, if any, to be submitted to the SO Rep for approval, as required under the Contract.
1.1.34
Restriction On Use Of Project Information For Publicity, Etc The Contractor shall ensure that he or his subcontractors/suppliers do not quote or make reference to the project design, products, technologies or methods of construction used in the Works for trade promotion, advertisement, publicity, etc or for any other purposes without the written approval of the SO Rep. This requirement shall not be applicable to proprietary products, technologies or methods of construction introduced by the Contractor or his subcontractors/suppliers.
BLDG12/S01.DOC(25) Sal(151211) (DPD)
Bldg Spec Page 1-26 1.1.35
Provision Of Respiratory Masks Building contractors are required to provide suitable respirators for their outdoor workers, as well as the supervising consultants' site staff and HDB officers at the sites, when the haze level at the site reaches a very unhealthy level with a 24-hr Pollutant Standards Index (PSI) value measured by NEA exceeding 200 or upon appropriate public advisories by NEA The air-purifying respirators must have an efficiency to filter 95% of 0.3 micron diameter fine particle size, commonly referred to as N95. The contractor shall start to purchase and stock up the N95 respiratory masks when the haze condition is getting into the unhealthy range with the PSI Index value exceeding 100.
1.1.36
Reserved
1.1.37
Reserved
1.1.38
Research Work The Contractor shall provide and render all necessary assistance to the SO Rep or other authorised persons conducting research work or procuring publicity materials on any aspects of the construction Works in progress. When directed by the SO Rep, the Contractor shall also provide all brochures, quotations, sub-contract agreements, invoices, etc from his subcontractors, suppliers and specialists for goods and services provided for the Works, all at the Contractor's cost and expense.
1.1.39
Earlier Completion Of MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms (A)
Programme Requirement For Completion Of MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms The Contractor is required in the programme for the Works to be submitted under the Contract and any revised programme to show completion of the following items of works to the satisfaction of the SO Rep within the time periods specified below : Item of Works a)
BLDG12/S01.DOC(26) Sal(151211) (DPD)
Pump Rooms
Specified Time Period a)
3 calendar months
b)
Consumer Switch Rooms
b)
5 calendar months
c)
Lift Wells including Machine Rooms
c)
As specified in the table marked ## hereunder
d)
MDF Room
d)
6 calendar months
) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) )
In each case prior to the expiry of the Time for Completion, or where there are sections, phases or sub-phases, prior to the expiry of the Time for Completion as specified in the Letter of Acceptance for the respective sections, phases or sub-phases containing the item(s) of works; or by any subsequent extension of time certified by the Superintending Officer for the completion of the Works or such sections, phases or sub-phases.
Prior to the expiry of the Time for Completion, or where there are sections, phases or sub-phases, prior to the earliest expiry of the Time for Completion as specified in the Letter of Acceptance for the respective section, phase or sub-phase containing a residential building block or by any subsequent extension of time certified by the Superintending Officer for the completion of the Works or such section, phase or sub-phase containing the residential building block.
Bldg Spec Page 1-27 1.1.39
Earlier Completion Of MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms (Cont'd) (A)
Programme Requirement For Completion Of MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms ## Storey Height of Building Block
(Cont'd)
Specified Time Period for Lift Wells Including Machine Rooms (In each case prior to the expiry of the Time for Completion, or where there are sections, phases or sub-phases, prior to the expiry of the Time for Completion as specified in the Letter of Acceptance for the respective sections, phases or sub-phases containing the item(s) of works; or by any subsequent extension of time certified by the Superintending Officer for the completion of the Works or such sections, phases or sub-phases) For Lift stopping at every storey
7 and below
4.50 months (i.e. 3.50 months + 1 month*)
8 to 12
4.75 months (i.e. 3.75 months + 1 month*)
13 to 16
5.00 months (i.e. 4.00 months + 1 month*)
17 to 20
5.25 months (i.e. 4.25 months + 1 month*)
21 to 25
5.50 months (i.e. 4.50 months + 1 month*)
26 to 30
6.00 months (i.e. 5.00 months + 1 month*)
31 to 40
6.65 months (i.e. 5.65 months + 1 month*)
* where the Contractor is required to undertake the temporary usage of tested and commissioned lifts (installed by others engaged by the Employer) for testing, commissioning of the Works and other building related Works prior to the certification of Substantial Completion.
This arrangement shall not be construed as giving rise to separate sections, phases or subphases of the Works. If the Contractor fails to complete any of such items of works within the respective specified time period or if the Superintending Officer shall certify in writing that in his opinion the Contractor despite previous warning by the SO Rep in writing fails to proceed with any of such items of works with due expedition and without delay, the Employer may himself complete such item or items of works or may employ any other contractors to complete such item(s) of works. All costs and expenses for such completion including the Employer's charges shall be recovered by the Employer from monies due or becoming due to the Contractor under the Contract or may be recovered by the Employer as a debt due from the Contractor without prejudice to any other remedies available to the Employer. In the event of the Employer completing any such item(s) of works, the Contractor shall not be entitled to any extension of the Time for Completion or to any loss or expense in connection with or in consequence of the Employer carrying out such item(s) of works. The Defects Liability Period in respect of any such item(s) of works (whether completed by the Contractor or the Employer) shall not commence until the Substantial Completion of the respective sections, phases, or sub-phases in which such item(s) of works is (are) included. (B)
Payment In Connection With Work On MDF Rooms, Consumer Switch Rooms, Pump Rooms And Lift Wells Including Machine Rooms The Employer and Contractor agree that five per cent of the value of the building part of the Works as indicated by the Contractor in the Form of Tender or as amended by the Employer (if applicable) is deemed to be the value of the items of works representing the MDF Rooms, Consumer/Switch Rooms, Pump Rooms and Lift Wells including Machine Rooms irrespective of whether the Works include all or only one or more of such items of works. At any time during the carrying out of the Works, if in the opinion of the Superintending Officer, the progress of the Works is such that the Contractor is unable or unlikely to complete such Rooms and Lift Wells within the Specified Time Period for any of such Rooms and Lift Wells, the Superintending Officer shall be empowered to exclude from any certificate issued under Clause 32.2 of the Conditions up to five per cent of the said value of the building part of the Works. The Contractor shall be deemed to have allowed in the Contract Sum for all costs and expenses to comply with the requirements of this subclause or clause. For the avoidance of doubt no such sum shall be excluded from the Final Account Certificate.
BLDG12/S01.DOC(27) Sal(151211) (DPD)
Bldg Spec Page 1-28 1.1.40
Handing Over Of Completed Works And Certification Of Substantial Completion (a)
The Works can be considered as substantially completed only upon: (i)
Obtaining a Temporary Occupation Permit and a Temporary Fire Permit; and
(ii)
Successful hand over of the Works to the Employer after inspection by the SO Rep and the Employer’s Inspection Team.
(b)
The Contractor shall conduct thorough inspections of the Works to ensure that all Defects are rectified and the Works have been completed to fully meet the requirements of the Contract and the workmanship standards as displayed in the approved Sample Units or Sample Panels before the handing over inspection by the SO Rep and the Employer’s Inspection Team.
(c)
The Contractor shall notify the SO Rep in advance to request for a handing over inspection and the following functional tests: S/N 1 2 3 4 5 6 7 8 9
Type Of Test Chokage Test For Main And Secondary Stack Pipe Leakage Test For Refuse Chute Flushing System Water Pipe Pressure For Concealed Pipes Gradient Test For house Drains Gradient Test For House Sewer Lines Water Test For Main Roof Water Test For Scupper Drains Watertightness Test For Window/Wall Joints Water Test For Toilet And Kitchen
% of Units To Be Tested Per Block 100 % 100% 10% of Total DU 100% 100% 100% 100% 5 Windows 25% of Total DU
Upon receipt of the Contractor’s request, the SO Rep shall arrange for a joint inspection date with the Employer’s Inspection Team. The Employer’s Inspection Team shall be present to witness the functional tests. In the event the tests fail to meet the requirements of the Contract, the Contractor shall proceed to rectify the Defect with due diligence and expedition and without delay and arrange for re-tests in accordance with the requirements under the Contract. (d)
If the Works are considered to have met the requirements of the Contract including the approved workmanship standards and there is no major Defect detected during the handing over inspection, the Works shall then be taken over by the Employer’s Inspection Team. Otherwise, the SO Rep shall give the Contractor a list of outstanding Defect for rectification. The Contractor shall proceed to rectify the Defect with due diligence and expedition and without delay. The Contractor’s liability to rectify the Defect under this subclause shall not be limited to the list of Defect given by the SO Rep, but shall include all other Defect surfaced in between the handing over inspections. Upon completion of the Defect rectification, the Contractor shall notify the SO Rep in writing that all outstanding Defect found in the inspection, as well as all apparent Defect surfaced in between the handing over inspections have been rectified and to request for another handing over inspection. The provision of the preceding sub clause (c) above shall apply, mutatis mutandis.
(e)
If the Contractor is unable to hand over the Works to the Employer after two handing over inspections, the SO Rep shall exercise his rights under Clause 1.6 Nuisance and Irregularities.
(f)
The Contractor shall on Substantial Completion of the Works, remove all rubbish, Construction Equipment and surplus materials, wash and scrub clean all floors, staircases, pavings, drains and all parts of the buildings and leave the Works in a clean and hygienic condition fit for habitation. The Site and periphery shall be cleared of all rubbish left from the Contractor's work.
BLDG12/S01.DOC(28) Sal(151211) (DPD)
Bldg Spec Page 1-29 1.1.41
Reserved
1.1.42
Management Of Defects Rectification
1.1.42.1
Employment And Deployment of Site Supervisor The Contractor shall employ and deploy the number of site supervisors full time on the Site for every day where Defect rectification Works is carried out during the Defects Liability Period (DLP) as specified hereunder : Total No of Dwelling Units
No. Of Site Supervisors For Architectural And Structural Defect Rectification Works
Less than 800
One
Equal or more than 800
Two
The Contractor's site supervisor shall be qualified and competent and possess the relevant skills, knowledge and the ability to co-ordinate and supervise the Defect investigation and rectification Works; and possess either one of the following academic qualifications and experience: (a)
National Certificate in Construction Supervision (NCCS) and at least 5 years of similar capacity relevant working experience in the building construction industry;
(b)
Recognized Diploma in Civil/Structural/Mechanical/Electrical Engineering, Building Science, Building Management, Building Services Engineering and at least 3 years of relevant working experience in the building construction industry;
The SO Rep shall be empowered to instruct the Contractor for a replacement at the Contractor's own cost and expense if any of the site supervisor is found not carrying out their duties to the satisfaction of the SO Rep. In the event of the Contractor not employing the number of site supervisors required by the Contract or not employing such site supervisors for the period or periods required by the Contract, without prejudice to the Employer's rights under the Contract, the Contractor shall be indebted to the Employer at the rate of $133/- per day per site supervisor not employed and such indebtedness shall be deducted by the Employer from any monies due or becoming due to the Contractor or be recovered by the Employer as a debt from the Contractor. This rate shall be deemed to have been fully agreed and accepted by the Contractor and the Employer as the cost and expense allowed by the Contractor for the employment of a site supervisor for each day. Notwithstanding other provisions in this subclause, if the Contractor incurs additional cost and expense over and above the agreed rate specified herein in complying with the requirements stipulated in this subclause, the Contractor alone shall bear such additional cost and expense in full. On expiry of the Defects Liability Period, the Contractor may put forth a written request to the SO Rep for the release of the site supervisor. A written approval from the SO Rep shall be obtained with this request.
BLDG12/S01.DOC(29) Sal(151211) (DPD)
Bldg Spec Page 1-30
(Cont’d)
1.1.42
Management Of Defects Rectification
1.1.42.2
Standby Plumber And Electrician For Restoring Essential Services
1.1.42.3
(a)
The Contractor shall also provide a stand-by plumber and a stand-by electrician for 24 hour stand-by duties for every day, including Sundays and Public Holidays, throughout the Defects Liability Period. The plumber and electrician need not be stationed on the Site but would be called upon to rectify Defect causing disruption to essential supply such as water and electricity
(b)
The Contractor or his representatives shall be contactable 24 hours a day, for every day, including Sundays and Public Holidays throughout the Defects Liability Period by means of telephone, handphone, radio pager, facsimile or any other suitable modes of communications
(c)
The stand-by plumber and/or stand-by electrician shall attend to such Defect within 30 minutes from the time a request for their services is made. They shall carry out the rectification expeditiously and in a workmanlike manner to restore the essential services quickly to minimise any inconveniences to the residents. In the event the stand-by plumber and/or stand-by electrician fail to attend or fail to attend within the time frame stipulated, the SO Rep shall exercise his right to impose charges under clause 1.6 'Nuisance and Irregularities".
Information of Key Personnel st Within fourteen days from the Date of Substantial Completion of the 1 building block, the Contractor shall submit to the SO Rep for his approval the following:
1.1.42.4
(a)
Name and contact numbers of the Contractor's key management staff and the appointed site supervisors for Defect investigation and rectification Works within the Defects Liability Period;
(b)
Name and contact numbers of the relevant manufacturers, suppliers and specialist contractors etc.,
(c)
Name and contact numbers of the stand-by plumber and stand-by electrician.
Defects Investigation And Rectification During Defects Liability Period The Contractor shall within fourteen working days from the date of written notification by the SO Rep, at the Contractor's own cost and expense, investigate, repair, rectify and make good to the satisfaction of the SO Rep all Defect, imperfections, shrinkages and other faults arising from or out of the use of materials or workmanship not in accordance with the Contract or from neglect or failure of the Contractor to comply with any obligation on his part under the Contract which may become manifest. Prior to the commencement of any Defect rectification Works, the Contractor shall submit the schedule of repair and method statement for the approval of the SO Rep. The Contractor shall mobilise only skilled and certified workers who are capable of executing the Works in accordance with the method statement as approved by the SO Rep. All Works must be attended to and supervised in person by the appointed site supervisor. Dust and noise must be minimised, whenever possible and cleaning up must be carried out daily if the unit is occupied and/or after the repairs. Inconvenience caused to others should be minimised by completing the Defect rectification Works in the shortest possible time. If the Contractor fails to carry out his obligations as aforesaid, the SO Rep may exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a charge against the Contractor. Without prejudice to the foregoing provisions, the SO Rep shall have the right to engage other persons or contractors to repair, rectify and make good all such Defect, imperfections, shrinkages and other faults if the same are not repaired, rectified and made good after fourteen working days from the date of written notification by the SO Rep, and the cost and expense incurred shall be recovered from the Contractor. In addition, the SO Rep shall exercise his rights under clause 1.6 "Nuisance And Irregularities" to impose a charge against the Contractor.
BLDG12/S01.DOC(30) Sal(151211) (DPD)
Bldg Spec Page 1-31 1.1.42
Management Of Defects Rectification
(Cont’d)
1.1.42.5
Rectification of Defects Prior To Issuance Of Final Completion Certificate For the purpose of certifying completion of Defect rectification prior to the issuance of the Final Completion Certificate, one month before the expiry date of the Defects Liability Period, the Contractor shall arrange with the HDB Branch Office and the SO Rep for a final joint inspection. All Defect listed after this joint inspection shall be rectified by the end of the succeeding one month commencing from the expiry date of the Defects Liability Period. A second final joint inspection shall be arranged to verify the completion of Defect rectification. If the Contractor fails to rectify and make good the Defect on the second final joint inspection, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. Notwithstanding the above, the SO Rep shall in addition have the right to engage his own workmen or other contractors to rectify and make good all Defect and the cost of rectification and charges imposed shall be recovered from the Contractor.
1.1.43
Precautionary Measures To Be Taken During A Disease Pandemic The contractor shall be required to implement necessary precautionary measures as advised by Ministry of Health or other relevant Authorities during a disease pandemic. Based on the recommendations from government's advisory, the contractor shall follow up expeditiously to plan for such contingency and stock up necessary supplies or equipment (e.g. thermometers) so as to be able to implement the required measures in a short notice.
1.1.44
Works Within Railway Protection Zone And Railway Safety Zone The Contractor shall comply with the Land Transport Authority (LTA) Code of Practice for Railway Protection and the Mass Rapid Transit (Rail Protection, Restricted Activities) Regulations for construction of the Works and other activities within the railway protection zone and railway safety zone. The Contractor shall submit proposals on the effective measures for the protection of MRT above ground structure together with the detail of activities of mobile cranes, tower cranes and other mechanical equipment adjacent to the MRT line structures to the SO Rep for approval at least one month prior to the use of such Construction Equipment. No jib or lifting appliance or any other moving or stationary part of the mechanical Construction Equipment shall encroach within 6.0 m on plan from the edge of the nearest MRT above-ground or at-grade structure unless the Construction Equipment is restricted to work beneath the structure. The foundation of the mechanical Construction Equipment shall be certified structurally sound and adequate by the Contractor's PE prior to its installation. Auto cut-off system shall be installed for tower cranes to prevent the top of the boom to swing closer than 6.0 m from edge of the viaduct structure. The jibs of the cranes must always be pointed away from the MRT line structure. The temporary access shall be stable and level for the Construction Equipment to move on. Regular checks shall be carried out to ensure that all mechanised Construction Equipment are in good working condition at all times. Only experienced, trained and competent operators shall be employed for mobile cranes, tower cranes and other mechanical equipment. Temporary height restriction gantry with signboard shall be installed 6.0 m away from the edge of both sides of the viaduct structure for any access passing underneath the MRT line structures.
1.1.45
Recovery Of Legal Costs For Court Proceedings All legal costs, charges and expenses (including but not limited to solicitors' fees as between solicitor and client) incurred by the Employer for the purpose of or incidental to the enforcement by the Employer of any rights and remedies under the Contract or any other contracts between the Employer and the Contractor or in respect of any garnishee proceedings which may be brought or commenced against the Employer by the Contractor's creditors may be deducted by the Employer from monies due or becoming due to the Contractor including any retention monies, financial bonds or security deposits or other bonds.
BLDG12/S01.DOC(31) Sal(151211) (DPD)
Bldg Spec Page 1-32 1.1.46
Novation, Assignment And Direct Submission Of Warranties And Agreements In the event the management and maintenance of the Employer's properties or the Works or any part thereof shall be taken over by a duly constituted Town Council, the Employer shall have the right to arrange for and the Contractor and his Specialist (if applicable) shall agree and accept to the whole or part of the Contract to be novated and/or assigned to the aforesaid Town Council upon the same terms and conditions. The Employer shall also have the right to require and the Contractor and his Specialist (if applicable) shall agree and accept that any Deeds of Warranty and/or Maintenance Agreements and/or Bonds and/or Deposits required under the Contract shall be executed and submitted direct to and for the benefit of the aforesaid Town Council. The Contractor is deemed to have allowed in the Contract Sum for all costs, expenses, stamp duties and losses arising from compliance with these provisions.
1.1.47
Completion Of Site Works The Contractor shall take note that Site Works are phased together with one of the building blocks as one phase of the Works. Site Works refer to all site structures/facilities, such as, but not limited to, children play ground/hard courts/footpaths etc., and landscaping works, such as earth mound formation, turfing, trees and shrubs planting etc., where included in the Works It is essential to the Employer for the Site Works and the building block which are phased together as one phase of the Works to be completed and handed over to the Employer as one phase. In the event the Contractor fails to substantially complete the Site Works and the building block as one phase within or by the Time for Completion or any subsequent extension of time approved by the Superintending Officer, the rate of liquidated damages for the whole phase as stipulated in the Appendix shall be imposed for every day the Works for the phase so remains incomplete.
1.1.48
Erection Of Temporary Buildings In addition to the submission of the site layout plan, the Contractor shall further submit detailed structural plans and design calculations, certified by his PE, for temporary buildings of two storeys or higher, to the SO Rep not later than three months from the commencement date of the Time for Completion or 2 weeks before the actual commencement of the Works for such proposals whichever is earlier. The Contractor shall bear all consequences for late submission. His PE may make use of the Drawings in the Standard Construction Detail Manual as a guide to the design and submission of the temporary buildings in compliance with the Technical Guidelines for the Fire Safety in Temporary Buildings in Construction Sites, including any amendment thereto, issued by FSSD; and the Building Control (Temporary Buildings) Regulations (2000 edition) including any latest requirements by BCD, BCA. The Contractor shall erect all such temporary buildings in strict compliance with his Professional Engineer's plans and calculations. The Works shall be supervised by the Contractor's PE. Not later than two weeks after the completion of the Works, the Contractor's PE shall submit a Certificate of Supervision, stating that he has carried out such supervision work and is fully satisfied that the Works have been constructed in accordance with his structural plans and design calculations as approved by the SO Rep.
BLDG12/S01.DOC(32) Sal(151211) (DPD)
Bldg Spec Page 1-33 1.1.49
Goods and Services Tax The Contractor shall not include in the rates and prices quoted in the Contract Sum, the GST chargeable for the supply of goods, services or Works required in the Contract. All rates and prices quoted shall be exclusive of the GST. The Employer shall reimburse the Contractor any GST charged on the goods, services or Works supplied. The Contractor shall declare his GST status in his Tender. The Contractor shall clearly indicate whether he is, or whether he will be a taxable person under the GST Act. The Contractor shall, if available, furnish the GST registration number to the Employer. The Contractor will be deemed to be a taxable person if no declaration to the contrary is made in the Form of Tender. The Contractor who declares himself to be a non-taxable person under the GST Act but who becomes a taxable person after he has been awarded the contract shall forthwith inform the Employer of his change in GST status. The Contractor shall be entitled to reimbursement by the Employer of any GST charged on the goods, services or Works he supplies after his change in GST status.
1.1.50
1.1.51
Works And Materials Warranty (a)
In every case where the Specifications require the Contractor's Specialist to co-warrant the Works and/or materials to be executed or supplied under the Contract, such Specialist, subject to such other requirements as may be prescribed in the Specifications, may only be employed by the Contractor with the Employer's prior written approval, and the Employer will approve such employment if the Specialist gives his written undertaking to execute the Deed of Warranty prescribed in the Specifications. If such written undertaking is not given, then the Contractor shall appoint an alternative Specialist willing to give the written undertaking. The employment of any Specialist who refuses to give his written undertaking will not be recognised by the Employer, and no Specialist may commence any work or supply any materials before his written undertaking is given.
(b)
The Employer's prior written approval of such Specialist's employment shall not in any way affect or diminish the Contractor's contractual obligations to the Employer in respect of any Works or materials executed or supplied by such Specialist on behalf of the Contractor, and the provisions of this subclause shall not in any way affect or diminish the Employer's entitlement to withhold the payment of any sums due to the Contractor by reason of the Contractor's and/or Specialist's failure to execute and submit the Deed of Warranty within the time specified.
Cost Of Water And Electricity The Contractor shall provide suitable and adequate supply of water and electricity for the Site including for the purposes of conducting tests on the Works. Where directed by the SO Rep, the Contractor shall provide and allow other contractors on the Site employed by the Employer, free and unrestricted use of the water and electricity for carrying out testing and commissioning of such other contractors' works. The Contractor shall bear all costs and expenses for the water and electricity consumed at the Site including the cost of water and electricity consumed for carrying out testing and commissioning by such other contractors employed by the Employer on the Site. Where applicable, the SO Rep may at his sole discretion, direct the Contractor to transfer the account for the water and electricity supply to the Employer or such Town Council(s) or such other party. The Contractor shall be deemed to have included in the Contract Sum for all costs and expenses to be incurred by him for compliance with the requirements stipulated in this subclause.
BLDG12/S01.DOC(33) Sal(151211) (DPD)
Bldg Spec Page 1-34 1.1.52
Site Control And Security
1.1.52.1
Identification Pass The Contractor shall provide serially-numbered security identification pass to each of his workers and subcontractors' workers. The identification pass shall consist of the worker's photograph, name, identification card number or passport number and name of the Contractor. The Contractor shall issue temporary entry pass, on a day to day basis, to workers from other contractors employed by the Employer or other Government/Statutory Board authorities or other companies carrying out works on the Site. The Contractor shall be responsible for controlling and issuing these security identification passes and temporary entry passes. The Contractor shall maintain an updated list of the passes issued for accountability and to facilitate enforcement checks. The Contractor shall ensure that all workers on the Site wear and display their passes prominently and securely at all times while working on the Site.
1.1.52.2
Erection And Removal Of Temporary Metal Hoarding Unless otherwise specified, the Contractor shall provide, erect and maintain a continuous metal hoarding around the entire contract boundary before the commencement of the Works. The hoarding shall be erected at not less than 300mm away from any permanent structure such as footway, drain, pipeline etc. The Contractor shall provide metal gates/doors for the main and side entrances. Location of these entrances shall be approved by the SO Rep. There shall be a maximum of two entry points for the entire Site, unless otherwise approved by the SO Rep. The metal gate at the main entrance (for vehicular traffic) shall be closed and locked up after working hours when construction activities have stopped. A side entrance beside the main gate shall be provided for passage of workers and visitors that can be monitored by the Security Officers. These entrances/gates and the perimeter shall be well lit during the hours of darkness (7.00 pm to 7.00 am). The hoarding shall be constructed in accordance with the standard Drawings and detailing. Should the Contractor fail to comply with this requirement, the SO Rep reserves the right to impose any action deemed necessary and any cost and expense incurred thereof including charges shall be recoverable from the Contractor. The materials used for the metal hoarding shall comply with the following minimum requirements : (a)
0.42mm thick zincalume steel or galvanised steel for the metal hoarding laid horizontally. All exposed metal sheet surfaces of the metal hoarding shall be finished with 25 microns colourbond silicone modified polyester coating. The finishing coat, graphic pattern and safety slogan shall be in accordance to the theme and colour of each estate. The Contractor shall obtain the theme and colour of each estate from the SO Rep.
(b)
Timber posts and horizontal bracings of common grade timber under strength Group A of Singapore Standard CP 7. If steel members are used instead of timber, the steel members shall be of Grade 43 of BS 4360.
(c)
Grade 20 concrete foundation.
(d)
Undamaged recycled metal hoarding are allowed subject to the approval of the SO Rep. All exposed surface of the recycled metal hoarding shall be painted with at least 3 coats of approved paint. The finishing coat, graphic pattern and safety slogan shall be in accordance to the theme and colour of each estate. The Contractor shall obtain the theme and colour of each estate from the SO Rep. Notwithstanding the approval, the SO Rep reserve the right to instruct replacement of installed metal hoarding that are found dented or bent.
The hoarding and gates shall be maintained at all times to ensure no deterioration of the structures and fading of the paint works throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. 'DANGER - KEEP OUT' and 'NO TRESPASSING' signs in the four official languages are to be displayed on the exterior side of the hoarding. Such signs shall be painted in red on white background with reflective material and approved by the SO Rep.
BLDG12/S01.DOC(34) Sal(151211) (DPD)
Bldg Spec Page 1-35 1.1.52
Site Control And Security
(Cont’d)
1.1.52.2
Erection And Removal Of Temporary Metal Hoarding
(Cont’d)
As and when instructed by the SO Rep, the Contractor shall remove all or part of the hoarding or relocate and reconstruct all or part of the hoarding and reinstate all the affected grounds to the satisfaction of the SO Rep all at the cost and expense of the Contractor. On satisfactory Substantial Completion of the Works, the hoarding shall be cleared away upon the approval of the SO Rep. 1.1.53
Assessment Of Extension Of Time Due To Exceptionally Inclement Weather The assessment of exceptionally inclement weather shall not take place until the expiry of the Time for Completion or previously extended Time for Completion. Such assessment shall be made on the following basis : (a)
There shall first be assessed the number of wet days and equivalent wet days (as specified in paragraph (f) below on which the Contractor has been substantially delayed in the carrying out of the Works by rain (hereinafter called "delay days").
(b)
A wet day shall be one where the rainfall figure as calculated as described in this paragraph exceeds 10.2 mm during the 24 hour period used by the Meteorological Service. The rainfall figure shall be the average island-wide rainfall calculated by the Employer using rainfall records received by the Employer monthly from the 5 Standard Stations of the Meteorological Service.
(c)
The expected number of wet days during the Time for Completion or extended Time for Completion as the case may be shall be derived from the following table which is deemed to record the average number of wet days for the respective months based on the Meteorological Service's records between 2001 and 2010 (hereinafter referred to as "expected wet days") : Jan
Feb
Mar
Apr
May
Jun
8
3
9
9
6
5
Jul
Aug
Sep
Oct
Nov
Dec
7
6
7
7
9
9
(d)
For each month of the Time for Completion or extended Time for Completion as the case may be there shall be assessed whether the number of delay days in that month is more than (positive) or equal to (zero) or less than (negative) the expected wet days in that month.
(e)
The positive, zero and negative monthly assessments made in accordance with paragraph (d) above shall then be added together and a net total reached. If such total is a positive number then such total shall constitute the extension of time due to exceptionally inclement weather.
(f)
The period commencing from excavation works to the completion of ground beams where the ground floor slab is not a critical activity or the completion of ground floor slab where the ground floor slab is a critical activity is hereinafter called "sub-structure construction period" and the works carried out during such period is hereinafter called "sub-structure works". For the assessment of extension of time due to exceptionally inclement weather during the sub-structure construction period, the respective monthly average number of wet days as specified in paragraph (b) above shall be multiplied by a factor of 2.0 if the wet days are less than or equal to 5 or by a factor of 1.6 if the wet days exceed 5. The product so derived shall be referred to as "equivalent wet days" and are subject to a maximum of 30 days per month.
BLDG12/S01.DOC(35) Sal(151211) (DPD)
Bldg Spec Page 1-36 1.1.53
Assessment Of Extension Of Time Due To Exceptionally Inclement Weather (Cont’d) (g)
1.1.54
If the sub-structure works do not commence on the first day of the month, then the number of equivalent wet days for that month in which the sub-structure works commence shall be prorated in accordance with the proportion of the number of calendar days for the construction of sub-structure works in that month to the total number of calendar days in the said month. Similarly, if the sub-structure works are not completed on the last calendar day of the month, then the number of equivalent wet days for that month in which the sub-structure works are completed shall be pro-rated in accordance with the proportion of the number of calendar days for the construction of sub-structure works in that month to the total number of calendar days in the said month. The assessment of extension of time due to exceptionally inclement weather during the sub-structure construction period shall be based on the actual sub-structure construction period of each building block, including multi-storey carpark / garage.
Shortfall In Floor Area The Contractor shall at his own cost and expense ensure that the flats constructed comply in all respects with all Drawings and Specifications. In the event of any departure from such Drawings and Specifications resulting in a shortfall in the floor area of any of the flats constructed as compared to the same floor area as measured in accordance with the Drawings and Specifications, the Contractor shall indemnify, reimburse and hold the Employer harmless in respect of any demands, claims, damages, loss and/or expense (including any legal fees and expense that the Employer may incur) arising therefrom. The Contractor shall remain so liable notwithstanding the issuance by the Superintending Officer of any Certificate of Substantial Completion, Final Completion Certificate and/or any Final Account Certificate under the Contract.
1.1.55
Registered Trade Subcontractors And M&E Subcontractors
1.1.55.1
Registered Trade Subcontractors The Contractor, with the exception of his own direct employed workers, shall engage only BCA registered contractors or corporations/firms listed in the HDB Materials List for executing the Works for the following trades : (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23)
BLDG12/S01.DOC(36) Sal(151211) (DPD)
Timber formwork; Metal formwork; Steel reinforcement work; Structural steel fitting; Concreting; Bricklaying; Joinery; Painting; Plastering; Roofing; Tiling; Electrical engineering; Air-conditioning, refrigeration & ventilation works; Plumbing & sanitary and gas piping; Fire protection; Waterproofing; Piling; Concrete repairs; Metal work; Cable installation & road reinstatement; Drain laying/Pavement & kerb construction; Curtain Wall/Cladding; Metal scaffolding (Erectors);
Bldg Spec Page 1-37 1.1.55
Registered Trade Subcontractors And M&E Subcontractors
1.1.55.1
Registered Trade Subcontractors
(Cont’d)
(Cont’d)
At least 14 days before the commencement of the Works by the subcontractors for the respective trades, the Contractor shall submit the name of his subcontractors for the Works to the SO Rep. Where the Contractor changes his subcontractor, he shall also submit such information to the SO Rep. For the purposes of this clause, the relevant BCA register and HDB Materials List shall be those applicable at the commencement of work for the respective trades. The Contractor shall be responsible for any eventual delay in the progress of the Works owing to his failure to ensure the required on-time registration of his subcontractors and no extension to the Time for Completion shall be granted on account of such delays. 1.1.55.2
M&E Subcontractors Subcontractors engaged by the Contractor to carry out the mechanical or electrical engineering works shall be BCA registered contractors of at least L2 grade. In addition, the contractor or his electrical subcontractor shall also be registered with Qualified Electrical Contractors Registry by IES/ACES.
1.1.56
Insurance Policies The Contractor shall warrant that the insurance policies issued in accordance with Clauses 27 and 28 of the Conditions shall include the following requirements : (A)
(B)
Insurance For Work Injury Compensation (i)
The Policy shall be issued in the prescribed form as produced in Appendix A11.
(ii)
The Insured shall be "(Name of Contractor to insert) as Contractor and all his subcontractors, and the Housing & Development Board as Principal FTRR & I".
(iii)
The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.
Insurance For Personal Injury And Property Damage (i)
The Policy shall be issued in the joint names of the Employer, the Contractor and all his sub-contractors.
(ii)
The limits of liability shall be read as follows : (a) (b)
BLDG12/S01.DOC(37) Sal(151211) (DPD)
In respect of any one accident : $2,000,000.00 Unlimited for the period of insurance
(iii)
The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.
(iv)
The period of notice for cancellation of the Policy, if such period is stipulated, shall read 30 days.
Bldg Spec Page 1-38 1.1.56
Insurance Policies (B)
Insurance For Personal Injury And Property Damage (v)
(vi)
BLDG12/S01.DOC(38) Sal(151211) (DPD)
(Cont’d) (Cont’d)
The Policy shall expressly include coverage of the following risks : (a)
Death, bodily injury or damage to property caused or occasioned by the Insured's sub-contractors or by such sub-contractors' employees.
(b)
Death, bodily injury or damage to property caused or occasioned by or connected with or arising from the ownership, possession or use by or on behalf of the Insured of any equipment or machinery not expressly specified in the Schedule of such equipment or machinery.
(c)
Liability assumed by the Insured by agreement, unless such liability would have attached to the Insured notwithstanding such agreement.
(d)
Liability in respect of loss or damage to property belonging to or in the charge or control of the Insured or of any servant or agent of the Insured.
(e)
Liability in respect of injury to or illness of any person or loss or damage to any property or land or building caused by vibration or removal or weakening of support.
(f)
Liability in respect of injury, illness, loss or damage caused by or connected with or arising from any commodity, article or thing supplied, repaired, altered or treated by or to the order of the Insured, happening at any of the Insured's premises.
The Policy shall expressly contain the following endorsements : (a)
"This Policy shall cover all the Contractor's insurance obligations with regard to personal injuries or death and injury or damage to property real or personal (including property of the Housing & Development Board but not the Works themselves) arising out of or in the course of or by reasons of the carrying out of the Works stated in the Contract between the Housing & Development Board and the Contractor (name of Contractor to insert)"
(b)
"Each of the parties comprising the Insured shall for the purpose of this Policy be considered as a separate and distinct unit and the words "the Insured" shall be considered as applying to such party in the same manner as if a separate policy had been issued to each of the parties and the insurers hereby agree to waive all rights of subrogation action which they may have or acquire against any of the aforesaid parties arising out of any accident in respect of which any claim is made hereunder provided nevertheless that nothing in this clause shall be deemed to increase the limitation on extent of Insurer's liability in respect of any one accident or series of accidents as stated in the Schedule".
(c)
"This Policy is extended to cover the employees and/or representatives of the Housing & Development Board, consultants, other professional parties and Resident Technical Officer whilst on the contract site as third parties".
(d)
"Notwithstanding anything stated in the Policy to the contrary, cover under the Policy shall not be suspended in the event of stoppage of work by the Contractor on the contract site from any cause for a period not exceeding 90 days. In the event of partial or total cessation of work, the Insured shall use diligence and do all things reasonably practicable to protect the insured property. Subject otherwise to the Terms Exceptions and Conditions of this Policy".
(e)
"All deductibles shall be borne by the Contractor".
Bldg Spec Page 1-39 1.1.56
Insurance Policies (C)
1.1.57
(Cont’d)
Insurance For Works (i)
The Policy shall be issued in the joint names of the Employer and the Contractor.
(ii)
The Works insured shall read the project title given in the Employer's Letter of Acceptance.
(iii)
The sum insured shall be the same as the Contract Sum.
(iv)
The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.
(v)
The period of notice for cancellation of the Policy, if such period is stipulated, shall read 30 days.
(vi)
The policy shall expressly contain the following endorsements : (a)
"This Policy shall cover all the Contractor's Works insurance obligations stated in the Contract between the Housing & Development Board and the Contractor (name of Contractor to insert)".
(b)
"Notwithstanding anything stated in the Policy to the contrary, cover under the Policy shall not be suspended in the event of stoppage of work by the Contractor on the contract site from any cause for a period not exceeding 90 days. In the event of partial or total cessation of work, the Insured shall use diligence and do all things reasonably practicable to protect the insured property. Subject otherwise to the Terms Exceptions and Conditions of this Policy".
(c)
"All deductibles shall be borne by the Contractor".
Contract Documents And Reference Material On Site The Contractor shall keep at the Site a complete set of the signed contract documents described in the Agreement, a complete set of the further or revised Drawings and instructions referred to in the Conditions, and the relevant Codes Of Practice or Standards referred to in the Specifications. These documents shall be made available for inspection and use by the Superintending Officer, SO Rep and any other person authorised by the Superintending Officer in writing.
BLDG12/S01.DOC(39) Sal(151211) (DPD)
Bldg Spec Page 1-40 1.1.58
Provision Of Building Service Centre The Contractor shall provide an operationally ready Building Service Centre (BSC) upon the hand over of the first residential building block of the Works. The Building Service Centre shall remain open during the Defects Liability Period for a period of 1 year from the date of the hand over of the first residential building block in the Works. The Contractor shall liaise with the Employer's representative from the Building & Infrastructure Department (BID) for a suitable location within the Site at the void deck to host the Building Service Centre at least 2 months before the estimated handover date of the first residential building block. The minimum room size of BSC is 20m2. The Contractor shall use materials that are non-combustible and water-resistant properties to enclose the BSC. Provision of metal gate in front of the aluminium framed glass door is required. The plan layout of the items such as furniture, equipments within the BSC shall be submitted to Employer’s BID for comments before setting up. The Contractor shall employ a full-time staff to manage the Building Service Centre and attend to resident's feedback and complaints. The staff hired must have the relevant working experience in building trade and with educational qualifications with a minimum pass in at least 2 subjects at GCE 'A' levels or a Diploma in Civil Engineering/Building/Architecture. The staff shall be bi-lingual and have a pleasant personality and friendly disposition. The Curriculum Vitae of the staff shall be submitted to the Employer's BID for approval prior to the confirmation of employment of the staff by the Contractor. The working hours of the staff shall be decided by the Employer's BID and is to be taken into consideration in the employment contract of the staff. The Employer’s BID shall reserve the right to increase the number of staff managing the Building Service Centre. The cost of employing the additional staff will be paid according to the schedule of rate. The Building Service Centre shall be equipped with air conditioner of minimum 10,000 BTU output, a minimum of 2 office desks with lockable drawers, 1.7m x 0.8m x 0.4m steel cabinet complete with shelves and double-leave doors, 2 Personal Computers (PCs), 1 printer, 1 colour scanner, 1 photostating machine, 1 fax machine, telephone with call waiting service & auto-message recording machine with ½ hour recording time, 40W fluorescent lighting, a 1 digital camera, torch lights, chairs , 0.3m x 0.3m aluminum suggestion box, 2.4m x 1.2m soft board and white board with accessories, hot & cold drinking water dispenser, drawing rack complete with drawing holders, timber shelves to display HDB’s renovation guide booklets and catalogue, 2 potted plants and office stationary. The 2 PCs shall have a minimum of Pentium 2.0 GHz clock speed with 256 MB of memory RAM with 17 inch CRT monitors and supported with minimum 512 kbps broadband internet access. Licensed software such as Microsoft Windows 98 (Second edition) or Windows XP and Microsoft Office 2000 Professional edition and Anti-virus software shall be installed in the PCs. The Contractor shall subscribe to e-PTC e-mail account and pay prevailing subscription charges for the duration that the Building Service Centre remains open. The Contractor shall provide and install a signboard at least 1.4m x 1.0m before starting the operation of the Building Service Centre. The design of the signboard shall be submitted to Employer's BID representative for approval. The Contractor is also to provide and install two notice boards at the Building Service Centre. Each notice board shall be of size: 1.8 m x 1.2 m with aluminium casing and aluminium frame door in-filled with 5mm thick clear polycarbonate sheet. Associated hinges, locksets including softboard with velvet finish and plywood to be provided and installed. The notice boards are to be lighted with necessary lightings and wirings. The Contractor is to maintain (e.g remove stain, markings, etc) and rectify, repair or replace the notice board if there are wear and tear and/or damages. The rectified, repaired or replaced notice boards are subject to the approval of HDB. The location of the notice boards shall be subjected to the approval of HDB. The Contractor shall pay for all rental and associated ancillary charges incurred by the Building Service Centre during the period of operation including all utility bills for water, electricity and registration and subscription charges for telephone, fax, internet broadband access, directional signboards guiding residents to locate the BSC at various blocks, resident’s defects feedback forms, service survey forms and BSC’s leaflets. After closing the Service Centre, the Contractor shall reinstate and make good any Defect to the Works.
BLDG12/S01.DOC(40) Sal(151211) (DPD)
Bldg Spec Page 1-41 1.1.59
Reserved
1.1.60
Lightning Protection To Temporary Structures And Metal Structures The Contractor shall ensure that all temporary buildings such as site office, site electrical substation, workers' quarters, site canteen, carpenter and bar bending sheds and temporary structures with continuous metal such as steel framework, scaffolding, tower cranes, batching plants and mobile machinery such as crawler cranes and concrete pumps are adequately and effectively protected from lightning strike at all times. The lightning protection system shall be in accordance with and complying with latest edition of SS 555 and/or any latest requirements by the BCA. Notwithstanding the provisions of SS 555, reinforced concrete structure and foundation shall not be used as lightning conductors or earth electrodes. Lightning conductors shall not be embedded in any structural component and steel reinforcement shall not be used as part of the protection system. The Contractor shall submit detailed drawings showing the design of the lightning protection system duly signed by the Contractor's professional electrical engineer (PE) stating that the design complies with latest edition of SS 555. The Contractor's professional electrical engineer shall provide a Certificate of Supervision together with the earthing reports after the lightning protection installation is completed. The Contractor's PE shall also conduct routine inspections including submitting earthing reports once every 6 months to ensure that the Contractor has provided adequate and effective lightning protection system for the Site. The inspection and earthing reports are to be submitted to the SO Rep and a copy submitted to the Employer's Safety Unit, Building & Infrastructure Department.
1.1.61
Computer Hardware And Software
1.1.61.1
Computerised Project Management Software Within one month from the commencement date of the Time for Completion, the Contractor shall provide and implement a Computerised Project Management Software (hereinafter called the "CPMS" for the purpose of this clause including all subclauses under it) during the Time for Completion and any time period where liquidated damages are imposed under the Contract. The SO Rep and the Employer's officers shall be allowed to have full and free access and usage of the CPMS at all times. The Contractor shall use the CPMS which shall be installed on the Site to prepare the programme for the Works based on the Critical Path Method. The programme for the Works shall include the duration, early start/finish dates, late start/finish dates and floats for all activities involved in the Works. It shall also include constraints and parameters such as fixed start/finish and target start/finish dates for the activities and milestones for the different phases or stages of the Works. The programme for the Works shall comprise of summary and detailed reports in textual and graphical forms. It shall be updated monthly or as and when required by the SO Rep to indicate, inter-alia, the critical path, actual start and finish dates of completed activities, actual start dates and percentage completion of the activities in progress and target start and finish dates of the delayed activities, their slippages and floats. The Contractor shall submit to the SO Rep the actual programme for the Works within three weeks after the Date of Substantial Completion.
BLDG12/S01.DOC(41) Sal(151211) (DPD)
Bldg Spec Page 1-42 1.1.61
Computer Hardware And Software (Cont’d)
1.1.61.2
Computer Hardware Within one month from the commencement date of the Time for Completion, the Contractor shall provide the Computer Hardware during the Time for Completion and any time period where liquidated damages are imposed under the Contract. Personal Computer The Contractor shall provide ONE Personal Computer (hereinafter referred to as "PC") for the exclusive use of the SO Rep. The PC shall comply with the following minimum specifications : (i)
An Intel Core 2 Duo running at a speed of 1.86GHz or higher;
(ii)
2 GB of Memory RAM or more;
(iii)
One 3½-inch form factor Serial ATA hard disk of total capacity of 80 GB or more [The hard disk must have 2 partitions eg. C and D drive];
(iv)
Minimum 256 MB Integrated Intel graphic Media Accelerator 3100 or equivalent, able to display at least 32-bit true colour at minimum resolution of 1024 x 768 pixels.
(v)
One 17” LCD monitor;
(vi)
Integrated sound card audio feature with integrated/external speakers;
(vii)
System BIOS updateable via software should be licensed flash BIOS of the latest version;
(viii)
One bi-directional 25-pin parallel port, one 16550 UART compatible asynchronous serial ports, one mouse port, one keyboard port and at least four universal serial bus(USB) port;
(ix)
Bus architecture should consist of 64-bit process-cache memory data bus and at least three PCI/PCI-express expansion slots;
(x)
One power supply of at least 250 Watts at 220/230 Volts 50Hz;
(xi)
One enhanced AT type keyboard with 104 typematic repeating keys;
(xii)
One optical USB mouse or compatible;
(xiii)
One internal IDE DVD/CD-RW Combo drive; (48X Write / 32X Rewrite / 40X for CD Read and 16X for DVD Read) or higher. Must be able to read CD-ROM, Multi Read, CD Text, Audio CD, CD-I, CD-RW, CD-R, CD-DA, Video CD, CD EXTRA, CD-ROM XA, Photo CD/Multi-session, DVD, DVD+R, DVD+R Multi-session, DVD+RW and DVD-RW Multi-Border and also able to write CD-R and CD-RW, Track at once, Disc at once, Fixed Packet, Variable Packet and Multisession;
(xiv)
Integrated 10/100 network interface or higher;
(xv)
Casing must be secure and comes with one good quality chassis lock of unique combination. All keys to the lock shall be given to the SO Rep.
(xvi)
Must include all the necessary features and accessories required to support the type of broadband connection services specified in this clause including all sub-clauses under it.
(xvii) Loaded with the software as specified in this clause including all subclauses under it.
BLDG12/S01.DOC(42) Sal(151211) (DPD)
Bldg Spec Page 1-43 1.1.61
Computer Hardware And Software (Cont’d)
1.1.61.2
Computer Hardware (Cont’d) Personal Computer (Cont’d) The PC must be fully compatible with Windows XP Professional, with provision for upgrade to Windows Vista or later, and shall be Microsoft certified. The Contractor shall at his own cost and expense provide and maintain Broadband Connection Services (with minimum connection speed of 512 kbps) via a major Broadband Service Provider (such as StarHub MaxOnline, Pacific Internet Ltd, SingNet or equivalent to be approved by the SO Rep) for the PC during the Time for Completion and any time period where liquidated damages are imposed under the Contract. The broadband cable or telephone line shall be used solely for the PC Laser Printer The Contractor shall provide ONE LaserJet printer complying with the following specifications : (i)
At least 16 MB of RAM and upgradeable to at least 160 MB;
(ii)
Able to print at least 20 pages of A4 per minute and 11 pages of A3 per minute;
(iii)
Automatic Duplex Printing Unit;
(iv)
Print at 600 x 600 dpi resolution or more;
(v)
Support high speed bi-directional IEEE 1284-compliant parallel port (C-type connector);
(vi)
Support PCL 5e, PCL 6 and Postscript Level 3 emulation;
(vii)
Must be able to support printing in the software specified in this clause including all sub-clauses under it;
(viii)
Bundled with drivers for the software specified in this clause including all sub-clauses under it.
Uninterruptible Power Supply (UPS) The Contractor shall provide ONE Uninterruptible Power Supply (UPS) complying with the following specifications : (i)
Conform to industry standards as follows : IEEE 446, NEMA PE1, ANSI C62.41, IEEE587B, IEC 801-146;
(ii)
Conform to the safety standards as follows : UL 1778, CSA C22.2 and VDE;
(iii)
10 minutes or more runtime at full load;
(iv)
Shall provide alert on AC power failure, power restore and diagnostic tests through management software;
(v)
Shall provide at least 3 output ports;
(vi)
Must include all connecting cables joining the UPS output ports and equipment.
BLDG12/S01.DOC(43) Sal(151211) (DPD)
Bldg Spec Page 1-44 1.1.61
Computer Hardware And Software (Cont’d)
1.1.61.2
Computer Hardware (Cont’d) Colour Scanner The Contractor shall provide ONE colour scanner complying with the following specifications :
1.1.61.3
(i)
Flatbed, one-pass colour and monochrome
(ii)
At least 600dpi x 600dpi resolution
(iii)
Able to scan A4 size documents
(iv)
Support Universal Serial Bus(USB) port
(v)
Shall include scanning software that can display the image file size to users at the preview screen
(vi)
Able to support all image formats including but not limited to, TIFF BMP JPEG FPX GIF WMF PDF
(vii)
Bundled with drivers for the software specified in this clause including all sub-clauses under it.
Computer Software Within one month from the commencement date of the Time for Completion, the Contractor shall provide the Computer Software during the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall provide the following licensed software packages (full packs with original licences, documentation and media provided) for each PC provided under this clause including all subclauses under it : (i)
Microsoft Windows XP Professional, with provision for upgrade to Windows Vista or later;
(ii)
Microsoft Project 2003 Standard Edition or later;
(iii)
Microsoft Office 2003 Professional Edition or later;
(iv)
Norton Internet Security Software 2008 (with firewall & anti-virus package) or later.
The Contractor shall purchase maintenance license for the VirusScan softwares to cover the Time for Completion and any time period where liquidated damages are imposed under the Contract. The PC must be set to automatically scan for virus at least once a day when the PC is switched on. 1.1.61.4
Computer Software Licensing All the Computer Software as specified in this clause including all subclauses under it shall be licensed copies obtained from Authorised distributors or dealers. The Contractor shall at his own cost and expense provide any software upgrade, to the latest version or release upon request by SO Rep during the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall ensure that only authorised software are used with the Hardware and obtain written approval from the SO Rep before installing any software other than the ones specified in this clause including all subclauses under it, into the Computer Hardware System.
1.1.61.5
Approval and Testing of Computer Hardware and Software The Contractor shall submit specifications and details of the Computer Hardware and Software as specified in this clause including all subclauses under it to the SO Rep for approval BEFORE the purchase of the Hardware and Software. The Contractor shall at his own cost and expense make such necessary arrangement for the hardware and software to be tested at the relevant Consultant's office and the subsequent delivery to the work site upon request by the SO Rep.
BLDG12/S01.DOC(44) Sal(151211) (DPD)
Bldg Spec Page 1-45 1.1.61
Computer Hardware And Software (Cont’d)
1.1.61.6
Installation/Upgrade/Removal of HDB Applications The Contractor shall at his own cost and expense make such necessary arrangement for the installation/upgrade/removal of HDB software at HDB office and the subsequent delivery to the work site upon request by the SO Rep.
1.1.61.7
Computer Furniture and Accessories The Contractor shall provide the necessary furniture and accessories at the site office to accommodate and facilitate the usage of the Computer Hardware and Software. The PC designated for the exclusive use of the SO Rep shall be located in a fully enclosed room within the site office. The room shall be of minimum size 8 m² as specified. The room shall be provided with a lock and be partitioned in half-height glass panels.
1.1.61.8
Computer System Maintenance The Contractor shall ensure that the Computer Hardware and Software are in good working condition and pay for all maintenance, license fees, subscription fees and etc for the Hardware and Software during the Time for Completion and any time period where liquidated damages are imposed under the Contract. If the Contractor fails to make available the Hardware and Software within one calendar month from the commencement date of the Time for Completion or fails to rectify any Hardware or Software faults, within one day, the SO Rep will make the necessary arrangement to acquire or to rectify the faults and all costs and expenses thus incurred shall be deducted from payments due to or becoming due to the Contractor or recovered as a debt due from the Contractor.
1.1.61.9
Security The Contractor shall make all necessary arrangement and provision to prevent theft/burglary of the Computer Hardware and Software. The Contractor shall replace any stolen or missing Hardware and Software within 3 days of such occurrence, failing which the SO Rep will make the necessary arrangement to acquire the systems and all costs and expenses thus incurred shall be deducted from payment due to or becoming due to the Contractor or recovered as a debt due from the Contractor.
1.1.61.10 Unauthorised Usage The Contractor shall ensure that the Hardware and Software are not used for any other purpose except for those approved by the SO Rep. 1.1.61.11 E-mail Account The Contractor shall apply for and maintain an E-mail account to facilitate transmission of information and correspondence. Provide the E-mail address to the SO Rep within one month from the date of the Letter of Acceptance. 1.1.62
Electronic Submission For Progress Payments Claim And Request For Variation Works The Contractor may be required to use an online web-based electronic submission system provided by the Employer for the submission of the Monthly Claims for Progress Payment and Claim for Authorisation / Variation Order (collectively and hereinafter known as e-submission system). There will be no additional charges to be imposed by Employer for the use of the e-submission system. If the Employer decided that the e-submission system is to be used, the Contractor shall at his own expenses arrange to use e-submission system complying with the requirement hereinafter mentioned.
BLDG12/S01.DOC(45) Sal(151211) (DPD)
Bldg Spec Page 1-46 1.1.62
Electronic Submission For Progress Payments Claim And Request For Variation Works (Cont’d) The e-submission system shall be Secured Socket Layer encrypted, password-protected with rolebased workflow security features at the document/form level and have an audit trail. The e-submission system shall be accessible by all relevant users from the Employer, Superintending Officer, SO Rep and Contractor concurrently and all data accessed shall be confined to the Project and the relevant role and scope of works. All relevant parties in the workflow shall be timely notified by email to complete their respective area of work. The e-submission system shall comprise the following modules: (A)
Monthly Claims For Progress Payment This module allows the Contractor to submit online, the values of the monthly progressive valuation of work completed for the assessment and certification of the SO Rep as hereinafter described but not limited to the following: a.
This module shall capture the monthly detailed breakdown of the scope of works and cost information as specified in the Contract showing both the Contractor’s claims and the SO Rep’s corresponding assessment in terms of individual percentage of work done for each work item.
b.
The validation rules shall apply to each item of claim and shall be based on the following rules or such rules to be given by the SO Rep: i.
The SO Rep's certification should not be more than Contractor’s claim.
ii.
The values submitted/certified for current month should not be less than previous the month’s submission.
c.
The Contractor shall not be allowed to amend the SO Rep’s valuation and vice-versa.
d.
The following data shall be automatically uploaded each month into the e-submission system and shall include but not limited to the following: i. ii. iii. iv. v. vi. vii.
(B)
Nett Contract Sum (Less Provisional Quantities / Sums) Probable Actual Contract Value (Adjusted For Variation Orders) Contractor's Cumulative Total Claim (excludes Loss & Expense) Contractor's Nett Claim for Month (excludes Loss & Expense) Total SO Rep's Estimated Value Computed (excludes Loss & Expense) Cumulative Certified Value of Work Value for each work category for apportionment under respective activity account codes.
Authorisation / Variation Order This module shall include but not limited to the following: a.
Allow the SO Rep to submit an Authorisation / Variation Order for the approval of the SO for subsequent issue to the Contractor.
b.
Allow the SO Rep to issue to the Contractor an Authorisation Order.
c.
Allow the SO Rep to issue a Variation Order.
All the differences and/or disputes arising under this Clause (including questions relating to interpretation) shall be determined by the Superintending Officer whose decision shall be final and binding on and conclusive against the Contractor.
BLDG12/S01.DOC(46) Sal(151211) (DPD)
Bldg Spec Page 1-47 1.1.63
Assignment Of Copyright Of Photographs, Etc The Contractor shall assign the copyright of the photographs (including the prints/slides/transparencies/negative) taken and all documents prepared under this Contract to the Employer. The Employer shall have unfettered rights to use or reproduce all the photographs (including the prints/slides/transparencies/negatives) taken and all documents prepared by the Contractor under this Contract for any purpose other than for the purpose for which the Contract was entered into. In the event that the Contractor engages third parties to take the photographs (including the prints/slides/transparencies/negatives) or prepare the documents, the Contractor shall procure the assignment of the copyright from such third parties to himself and thereafter, assign the copyright to the Employer. The Contractor and/or any third parties are strictly prohibited from using or reproducing any of the photographs (including the prints/slides/transparencies/negatives) taken and all documents prepared under this Contract in any other publication or for any other purpose whatsoever.
1.1.64
Provision Of Keys Envelopes During Hand Over Upon successful hand over of the Works to the Employer after inspection by the SO Rep and the Employer's Inspection Team, the Contractor shall provide the necessary number of envelopes to contain the household keys of each dwelling unit in the Contract. The envelope to be provided shall fulfil the following requirements : (a) (b) (c) (d)
C6 size (114mm by 162mm) Key envelope with string and white eyelet 120 gsm paper Colour - white
The Contractor shall propose the type of envelope to the SO Rep for approval. The 2 external sides of the envelope may either be printed or stamped with the following information : On the Front of the envelope –To print/stamp in Arial Black Font Type of Font Size 18, the following statement:
KEY TO PREMISES NO. ___________ and; On the Back of the envelope:–To print/stamp in Arial Black Font Type of Font Size 12, the following statements:
S/N 1 2 3 4 5 6 7 8 9
BLDG12/S01.DOC(47) Sal(151211) (DPD)
Location Main Gate Main Door Master Bedroom Bedroom 1 Bedroom 2 Balcony Service Duct Letter Box Others Total
No. of keys
Bldg Spec Page 1-48 1.1.65
Schedule Of PE Submission The Contractor shall provide the required PE submission as specified for the Works as shown in the table below : Category
General
Maintenance
Clause No.
Description Of Works
Date Of Submission
1.1.18 or as amended
Site offices & canteen
At least 2 weeks prior to erection
1.1.48 or as amended
Temporary buildings
At least 2 weeks prior to erection
1.1.67.8 or as amended
Temporary chute
At least 1 week prior to installation
1.4.2(c) or as amended
Passenger cum material hoist foundation, masts & tie-back
At least 2 weeks prior to construction
The Contractor shall provide the required PE submission as specified for the Works as shown in the table below : Category
Clause No.
Description Of Works
Date Of Submission
1.5.1(b) or as amended
Access scaffold and working platforms. Temporary structures.
At least 2 weeks prior to erection
1.5.1(d) or as amended
Alternative system to safety net system
At least 1 week prior to installation
1.5.1(e) or as amended
Working platforms for lift shafts, central refuse chute and voids
At least 2 weeks prior to construction
1.5.1(f) or as amended
Overhead shelters
At least 1 week prior to construction
1.5.1(m) or as amended
Tower cranes & other tall construction equipment foundation & tie-back
At least 1 month prior to construction
1.5.1(n) or as amended
Mobile crane & piling machine access
At least 2 weeks prior to construction
1.5.1(t) or as amended
Temporary staircases
At least 2 weeks prior to erection
3.15 or as amended
Planking & strutting
At least 2 weeks prior to the excavation work
4.18 or as amended
Rectification of defective work
At least 1 week prior to the rectification work
4.19.2 or as amended
Design of formwork
At least 2 weeks prior to erection
Formwork
9.5 or as amended
Formwork system for reinforced concrete water tank
At least 2 weeks prior to erection
Metal Roofing and Insulation Sheet
13.3.1 or as amended
Metal roof structural plans & fastening details
At least 2 weeks prior to installation
Site Safety Measures
Excavation Structural Concrete
For the avoidance of doubts, requirements for PE submission for other Works which are not shown in the table above shall be as specified in the respective clauses and/or subclauses in the Specifications.
BLDG12/S01.DOC(48) Sal(151211) (DPD)
Bldg Spec Page 1-49 1.1.66
Earth Control Measures The Contractor shall be responsible for preventing silt from being washed into public drains by implementing effective Earth Control Measures (ECM) for the construction site to meet the requirements under the latest Sewerage and Drainage Act Cap 294. (Information on ECM requirements can be found in the Code of Practice on Surface Water Drainage and the website www.pub.gov.sg/ECM). The contractor shall note that the ECM are for the containment and treatment of silty discharges due to the impact of rainwater. ECM are not meant for the treatment of wastewater due to construction activities (such as slurry from tunnelling, pipe-jacking and bore-piling works) which shall be treated to comply with the requirements under Environmental Protection and Management Act (EPMA) (Chapter 94A).
. In his tender submission, the Contractor shall submit his schematic ECM plans of the construction site for the whole of the Time for Completion including any time period where liquidated damages are imposed under the Contract, taking into account the different phases of construction activities. He shall also provide the name of the Qualified Erosion Control Professional (QECP) who will be endorsing the ECM plan after the tender is awarded. These schematic ECM plans shall make the Contractor aware of the ECM requirements and the cost to implement an effective ECM. Notwithstanding the submission of these schematic ECM plans, the Contractor shall be deemed to have included all costs and expenses for complying with all the ECM requirements in the Contract Sum. Before construction works commence on site, the Contractor shall engage a QECP to plan and design the ECM, and he shall install the ECM according to the QECP's design. The ECM plan and design shall be submitted 1 week after the award of the contract. During the course of the construction works, the Contractor together with his QECP shall review the ECM proposal regularly to meet the changing needs of the construction activities. The Contractor shall improve the ECM as advised by his QECP. The planning and design of the ECM shall meet the minimum requirements stipulated and in accordance to the Code of Practice on Surface Water Drainage. The Contractor shall maintain the ECM for the whole duration of the Time for Completion including any time period where liquidated damages are imposed under the Contract, to ensure that it is effective at all times. Proper records detailing the maintenance works, supported by dated photographs, shall be kept by the Contractor for verification. The Contractor shall not remove the ECM until all works are completed and upon the advice of his QECP. The Contractor shall submit the ECM proposal duly endorsed by his QECP to PUB for records. The proposed ECM shall consist of the following four parts: (i)
Project Particulars The following information shall be provided under the Project Particulars: (a) (b) (c) (d)
Project description Name and address of site occupier; Site area and contract period; Location map and site plan.
(ii)
Erosion Control Plan (described in 1.1.66.1)
(iii)
Sediment Control Plan (described in 1.1.66.2)
(iv)
Site ECM Management System (described in 1.1.66.3)
BLDG12/S01.DOC(49) Sal(151211) (DPD)
Bldg Spec Page 1-50 1.1.66
Earth Control Measures (Cont’d)
1.1.66.1
Erosion Control Plan During construction, the Contractor shall minimize the formation of bare surfaces under the ECM's Erosion Control Plan. The Plan shall depict graphically the activities, including sequence of work, type and duration for each phase of construction activities to include the following measures to:
1.1.66.2
(a)
sequence and schedule of the earthworks I demolition works in stages and progressively with the subsequent construction activities and building works.
(b)
minimise site disturbance by keeping site clearance works to a minimum by retaining as much of the existing vegetation as possible.
(c)
pave up the bare surfaces and all construction access by concrete or milled waste or other suitable materials.
(d)
protect the bare slopes with close-turfing, concrete grouting, or erosion control blanket.
(e)
protect the earth stockpiles with erosion control blanket.
(f)
restore ground cover over disturbed areas, which are or have become bare, as soon as possible.
(g)
cover up the active work surfaces with canvas sheet during rain or at the end of the workday.
Sediment Control Plan The Contractor shall put in place the ECM's Sediment Control Plan, which aims to capture the sediments washed down from the construction sites. Some of these sediment control measures and facilities, which must be in place before the works start, shall include but not limited to the following:
1.1.66.3
(a)
concrete-lined cut-off drains (minimum C7 precast channel) along the perimeter of the construction sites.
(b)
silt fence properly installed and embedded onto the ground along the perimeter cut-off drains (between the construction site and the cut-off drain).
(c)
sedimentation basins or any other sediment filtering or settling system of adequate size and sufficient numbers along the perimeter cut-off drain and before the discharge points into public drain.
(d)
a storage basin / tank may be required to temporarily store the large amount of rainwater falling on to the whole site before treatment.
(e)
a treatment system to treat silty discharge shall be provided before the discharge points into public drain.
(f)
turbidity curtains shall be installed along all the exposed slopes / riverbanks for works in or adjacent to water bodies, such as canals, rivers, sea or in a reclamation work. The silty discharge trapped within the turbidity curtain shall be allowed to be settled / treated and removed.
Site ECM Management System The contractor, shall at the advice of his QECP, put in place a site monitoring and reporting system including but not limited to the following: (a)
Daily ECM inspection report by the QECP appointed site personnel
(b)
Regular site inspection by the QECP
(c)
Continuous monitoring and recording system shall be installed at the discharge point (after ECM) before public drain
BLDG12/S01.DOC(50) Sal(151211) (DPD)
Bldg Spec Page 1-51 1.1.66
Earth Control Measures (Cont’d)
1.1.66.4
Submission Of Design Basis And Calculations The QECP shall submit full basis of design back up with design calculations to show clearly how the perimeter cut-off drains, silt fence, sedimentation basins, storage basin / tank and treatment system are designed and sized as well as how such design will effectively filter off silt and allow only clean water to discharge into public drains. The QECP shall also submit the design specifications on the treatment system which can effectively treat the silty discharge from the construction site. The intensity of a one-in-two year storm should be adopted for the proposed design.
1.1.67
Environmental Public Health Measures At Construction Sites
1.1.67.1
General Requirements The Contractor shall comply with the Environmental Public Health Act (hereafter referred to as "the Act" for the purposes of this subclause) and its Subsidiary Legislations including the Environmental Public Health (Employment of Environmental Control Officers) Order 1999, (hereafter referred to as "the Order" for the purposes of this subclause) and any amendment or re-enactment thereto throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract.
1.1.67.2
Reserved
1.1.67.3
Noise Nuisance Judicious management and control over the activities within the Site shall be exercised by the Contractor for the abatement of noise nuisance. In this respect, the Contractor shall implement all necessary noise control measures at his own cost and expense, to comply with the Environmental Protection and Management Act (hereafter referred to as "the Act" for the purposes of this subclause) and its Subsidiary Legislations including the Environmental Protection and Management (Control of Noise at Construction Sites) Regulations, (hereafter referred to as "the Regulations" for the purposes of this sub-clause) and any amendment or re-enactment thereto throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall be deemed to have inspected and examined the Site and its surroundings and to have satisfied himself as to the surrounding developments and construction activities. Prior to the commencement of Works, the Contractor shall propose a noise management plan and execute the appropriate noise control measures at his own cost and expense.
1.1.67.4
Noise Control At Construction Site (i)
Noise Management Plan Within 14 days from the date of the Letter of Acceptance, the Contractor shall submit a noise management plan complying with SS CP 49: Code of Practice for Noise Control on Construction and Demolition Sites (hereafter referred to as "the Code" for the purposes of this sub-clause) to the SO Rep for approval. The noise management plan shall include, but not limited to the following :
BLDG12/S01.DOC(51) Sal(151211) (DPD)
(a)
comparison charts between baseline noise monitoring results prior to the commencement of works and the anticipated noise emission levels during construction ;
(b)
identification of sensitive buildings, for example hospitals, schools, institutions of higher learning, homes for the aged sick, etc., and residential buildings within 150m from the construction site boundary ;
(c)
site utilisation plan, indicating the locations of site facilities and noise generating equipments including, but not limited to generators, compressors and concrete pumps ;
Bldg Spec Page 1-52 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.4
Noise Control At Construction Site (Cont’d) (i)
Noise Management Plan (d)
specification of the machinery, equipment and plant proposed to be utilised on site as well as their indicative noise emission levels. Construction equipment and methods of work that generates excessive noise will not be allowed to be used on Site ;
(e)
identification of noise generating activities and delineate the sequence of work and construction methods for such activities, as well as indicate the anticipated noise levels accompanying each type of activity ;
(f)
propose noise control measures for noise generating activities along with the estimated reduced noise levels in the form of administrative and engineering controls or other measures deemed effective in noise abatement. Noise control measures shall take into consideration site planning and layout (administrative controls), adoption of engineering controls and behavioral considerations of site personnel ;
(g)
propose scheduling of works with due consideration to noise generating activities;
(h)
contingency noise abatement measures for unavoidable works that have to be carried out after 7pm with the approval of the SO Rep ;
(i)
noise monitoring system to be implemented, which includes the details of instrumentation, locations of installation, measured values of Leq and correction factor to be applied in the presence of ambient noise ; and
(j)
Public relations strategies to foster close community relationships throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract, such as signboards, newsletters, circulars, complaint handling procedures and investigation, standard response time to public feedback and complaints and rapportbuilding events or activities with residents.
In formulating the noise management plan, the Contractor shall take into account the working days and hours, as well as consider the effects of construction noise on personnel working in or around the site as well as the neighbourhood within proximity of the Site. The Contractor shall take into account the nature of land use in the area, duration of works and the effect of lengthening works period or other nuisances that may affect the neighbourhood. (ii)
Noise Control Measures The Contractor shall implement all noise control measures included in the approved noise management plan, including any other noise control measures as instructed by the SO Rep or NEA from time to time. Noise control measures shall include the following, where necessary to comply with the Regulations :
BLDG12/S01.DOC(52) Sal(151211) (DPD)
(a)
all machinery and plant shall be identified to be sound-reduced prior to entering the site ;
(b)
all plant, machinery and equipment shall be pasted with a weather-proof sticker clearly indicating its noise emission level (at source) under normal operating condition ;
(c)
all machinery in operation shall have their covers properly shut at all times ;
(d)
noisy plant and equipment shall be housed in acoustic sheds or enclosures ;
(e)
noisy activities shall be barricaded with portable noise barriers and panels ; and
(f)
noise barriers shall be erected prior to commencement of works.
Bldg Spec Page 1-53 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.4
Noise Control At Construction Site (Cont’d) (ii)
Noise Control Measures (Cont’d) Noisy construction equipment (for example compressors) and installation (for example temporary refuse chute) shall be sited away from occupied blocks. All construction equipment shall be properly insulated and maintained to minimise its operating noise level. The SO Rep has the discretion to require the Contractor to take necessary precautions, whether specified herein or not, to maintain or to repair such construction equipment or to instruct their removal from site when it is determined that the noise level generated from the construction works fails to comply with the Regulations or the Code.
(iii)
Noise Monitoring System The Contractor shall be required to set up the wireless, web-based real-time noise monitoring system prior to the commencement of work on Site. The cost of setting up, operating and maintaining the noise monitoring system shall be borne by the Contractor. The system shall include an integrated solar-powered sound level meter complying with IEC 61672 (Type 1) or other comparable standards approved by the SO Rep. In addition, the system shall provide wireless, real-time transmission of the sound level data to a secured (password-protected) website, where data is presented for Leq 5 mins, Leq 1 hour and Leq 12 hours periods. The system shall enable all current and historical sound level data recorded from the Site to be retrieved from the website. The system shall also incorporate a short message service (SMS) alert system to notify the designated recipients when the construction noise levels exceed the permissible noise limits stated under the Regulations. The sound level meter must comply with the following requirements: (a)
an integrating-averaging sound level meter set to frequency weighting ‘A’ ;
(b)
Equipped with a data logger for sampling the running value of ‘A’-weighted sound level pressure levels with adequate memory to store 5-minute equivalent continuous readings on a 24-hour basis for up to one month ;
(c)
Dynamic range shall be of at least 40 dB ;
(d)
The sound level meter shall have a laboratory calibration certificate dated not more than three (3) months before the commencement date of the contract. The integrating sound level meter shall be sent to an approved accredited laboratory for calibration at every six (6) months interval or as and when required by the SO Rep.
The Contractor shall install the sound level meter at a suitable location at the nearest occupied building. The location is to be approved by SO Rep or NEA. The Contractor shall liaise with the relevant authorities, for example Town Council, for permission to install the sound level meter. Where there is no suitable location outside the Site, the Contractor may install the sound level meter within the Site, subject to approval the SO Rep or NEA. The installed sound level meter can be sheltered, but the microphone of the sound level meter must face the construction site and in the line of sight of the construction activities without any physical barrier or obstruction. (iv)
Sites In Close Proximity to Sensitive Buildings For construction sites close to premises that are sensitive to noise disturbances, for example schools, hospitals, institutions of higher learning, homes for the aged sick, etc., the SO Rep reserves the right to direct the Contractor to implement any noise control measures deemed necessary to reduce the noise disturbances regardless of the noise level generated and compliance with the permissible noise levels in the Regulations. For the avoidance of doubt, the measures could include, but not limited to erection of temporary noise barriers to shield the affected buildings from excessive noise, switching to use of quieter machinery or adoption of quieter construction methods, installation of airconditioning systems within the noise sensitive premises, etc. The Contractor shall also be responsible for dismantling all temporary noise control measures and make good any affected premises when requested by the occupier of the affected buildings. The Contractor shall obtain written permission from the SO Rep prior to the dismantling of such measures. The cost of implementation of such measures, including dismantling, shall be borne by the Contractor.
BLDG12/S01.DOC(53) Sal(151211) (DPD)
Bldg Spec Page 1-54 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.5
Preservation Of Trees Where any existing tree(s) on the Site is stipulated to be preserved (hereinafter referred to as "Preserved Trees" for the purpose of this subclause), the Contractor shall take all necessary precaution to avoid damage or injury to such trees and its roots and comply with the following requirements : (A)
Treatment of Preserved Trees In Area Of Fill (a)
Tolerable Depth of Fill The area around Preserved Trees shall not be filled more than 300mm in depth.
(b)
Construction of Well Around Trees Well not exceeding 1 m in depth shall be constructed around Preserved Trees. The minimum diameter of the well shall be 6 times the diameter of Preserved Trees measured at the trunk 0.5 m above ground level. Details of the well shall be as shown in the Drawings.
(B)
Treatment Of Preserved Trees in Area of Cut (a)
Tolerable Depth of Cut The area around Preserved Trees shall not be cut to a depth exceeding 300 mm.
(b)
Retention of Raised Planter Around Tree An area around Preserved Trees shall be retained as raised planter to conserve the root system. The minimum diameter of raised planter shall be 6 times the diameter of Preserved Trees measured at the trunk 0.5 m above ground level. Details of retention of raised planter are as shown in the Drawings.
(C)
Protection Of Existing Trees From Physical Damage By Equipment Etc During Construction (a)
All Preserved Trees shall be protected against damage during construction operation by suitable fencing or armouring. The protection of Preserved Trees shall be placed before commencing any excavation or grading operation/work and shall be maintained in repair for the duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract unless otherwise directed. The extent of fencing shall be determined by the SO Rep. Fencing shall be erected all round not less than 1.2 m from the trunk of Preserved Trees. Individual Preserved Trees near heavy construction traffic shall be wrapped with gunny sacks and 50 mm x 100 mm planks worn vertically as armour around the trunk and spaced at no more than 50 mm apart to a height of 1.5 m above ground.
(b)
Any damage to Preserved Trees root system shall be repaired immediately by the Contractor under the supervision of a qualified horticulturist. Roots that are exposed and/or damaged during grading operations shall be cut off immediately and the inside of the exposed and/or damaged area cleaned; cut surfaces shall be treated with approved sealing compound and topsoil spread over the exposed root area.
(c)
Any damage to Preserved Trees branches shall be treated in accordance with the Drawings. (i)
Branch Trimming Of Damaged Branches (1) (2) (3) (4) (5)
BLDG12/S01.DOC(54) Sal(151211) (DPD)
A first cutting is to be made at point A, 300 mm from the main trunk of Preserved Trees; depending on the diameter of the branch being cut. The depth of the cut shall not be more than ½ of the diameter of the branch. A second cutting is to be made at point B, parallel to cutting at point A. The distance between these two cuttings shall be 75 mm to 150 mm. Make a shallow cut at C. Final cut is to be sharp and clear. 2 coats of anti-fungus wound sealant are to be applied on cut area.
Bldg Spec Page 1-55 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.5
Preservation Of Trees (Cont’d) (ii)
Wound Treatment (1) (2) (3)
(d)
(D)
If any Preserved Trees are severely injured by mechanical equipment, etc., the SO Rep shall impose charges against the Contractor in accordance with Clause 1.6 "Nuisance And Irregularities".
Health & Condition Of Preserved Trees (a)
The Contractor shall ensure that : (1) (2) (3) (4) (5) (6) (7)
1.1.67.6
Clean away ragged or loose edges of bark with a sharp pruning knife. Shape the wound into an oval, pointed at both ends. Coat the entire exposed surface with tree-wound paint.
Compaction of soil around Preserved Trees shall be avoided. No materials shall be stored within the root system. There shall be no spillage of any nature within the spread of the Preserved Trees. There shall be no parking of vehicles underneath the Preserved Trees. There shall be no dumping of excavated materials, concrete, equipment etc. within the spread of the Preserved Trees crown. Soil around Preserved Trees is properly cultivated to ensure that adequate supply of air and water get to the roots. The site is drained in periods of heavy rainfall and irrigated during periods of drought.
(b)
The Contractor shall also carry out any other routine maintenance of the Preserved Trees eg. branch trimming, pesticide spraying etc. as instructed by the SO Rep.
(c)
If the growth of the Preserved Trees is stifled, the Contractor shall inter-alia bear the cost of making good and charges in accordance with Clause 1.6 "Nuisance and Irregularities" shall be imposed against the Contractor.
Temporary Site Access Within Site Boundary The Contractor shall propose and construct a temporary site access within the Site boundary linking the main construction entrance/exit to all building blocks, inclusive of multi-storey carpark building. The Contractor shall engage a PE to design the access. The drawings and calculations endorsed by the PE shall be submitted to the SO Rep for approval before the construction of the access. The access shall be of concrete or bituminous pavement or precast concrete plank. It shall be laid over well compacted hardcore base or other suitable material to the Contractor’s PE design. The access shall be inspected by the Contractor’s PE and certificate of supervision issued prior to use. The precast concrete plank shall be 175mm thick with modular size of 1.20m by 2.20m. Contractor can opt for any other size subject to SO reps approval. It shall be reinforced with welded mesh and the edges shall be protected with angle iron. It can be cast with grade 40 eco-green concrete. To ensure proper site drainage, properly-graded Type C7 composite channel cut-off drains shall be laid along the perimeter of the construction site. Similar cut-off drains shall be laid along the access and other areas where required. The drainage system shall comply with the requirements specified in Clause 1.1.66 “Earth Control Measures” and sub-clauses under it. The area between the temporary site access and the building blocks/multi-storey carpark shall be laid with well compacted sub-grade with lean concrete surface. The access shall be provided immediately after the completion of the first storey. The provision of access prior to the completion of first storey shall comply with the requirements specified in Clause 1.9.1.1 (o) “Access For The Use Of Mobile Crane And Piling Machines Next To Build Area”. The access shall be maintained in good working condition and free from water stagnation at all times throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract, or unless otherwise approved by the SO Rep.
BLDG12/S01.DOC(55) Sal(151211) (DPD)
Bldg Spec Page 1-56 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.6
Temporary Site Access Within Site Boundary (Cont’d) As part of the housekeeping effort, the Contractor shall deploy workers to clear the mud deposits/droppings regularly and maintain the access as clean and dry as practically possible. A heavy duty vehicular washing bay shall also be provided at the main entrance/exit point abutting completed public road. All tyres of vehicles shall be thoroughly clean if necessary before leaving the Site. The area at main construction entrance/exit shall laid with concrete surface to improve the maintainability of the site access. Where the access had been excavated for underground services work (e.g. sewer construction, underground piping system draw pit), the Contractor shall use steel plate to temporarily cover these excavated areas and the access shall be immediately reinstated to good working condition upon the completion of the underground services work in accordance to PE design.
1.1.67.7
Temporary Sanitary Facilities Within 21 days from the date of the Letter of Acceptance, the Contractor shall provide temporary sanitary facilities in suitable structures with adequate lighting, on the Site. Such temporary sanitary facilities shall be subject to approval by the SO Rep. The Contractor may use the Employer's Standard Drawings as a guide in designing the temporary sanitary facilities. The temporary sanitary facilities shall comprise water closets and shower compartments in the proportion of 1 closet and 1 shower to every 25 workmen, throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. In addition, the Contractor shall provide separate sanitary facilities with water closet and shower compartment for the exclusive use of the Employer's officers. Prior written approval by the SO Rep shall be obtained before commencing the erection of these facilities. The water closets shall be of the type, make and pattern approved by the MEWR and PUB (Water). Provide and lay glazed wall tiles or other approved material to the internal walls of the temporary sanitary facilities up to a height of 1.8 m from the floor. The doors to the cubicles of the temporary sanitary facilities shall be of approved material. All waste discharge from the water closets and all waste water from the temporary sanitary facilities and from the Site shall be discharged into a public sewer. Arrange with the MEWR to carry out connection work from the temporary sanitary facilities to the public sewer and pay all charges and maintenance in connection therewith. The Contractor shall be responsible for all damages to and shall indemnify the Employer against all liabilities in respect of such sewer connections. Where a public sewer is not available or where it is not possible to connect to a public sewer, the Contractor shall provide and install temporary septic tanks of the type, pattern and capacity approved by the MEWR, to serve the water closets, showers and baths. Prior to commencing the installation of the temporary septic tanks on the Site, the Contractor shall engage a Licensed Plumber who shall submit his proposal to the MEWR and SO Rep for approval. The proposal shall include the manner and frequency of post installation management and maintenance of the septic tanks on the Site. The Contractor and his Licensed Plumber shall be fully responsible for any mis-management or mis-use of the temporary sanitary facilities, which may result in the pollution of the controlled water course.
1.1.67.8
Removal Of Construction Debris From Building Blocks Before the commencement of Works on site, the Contractor shall submit proposal for the daily removal of the construction debris from the building blocks to the SO Rep. for approval.
1.1.67.9
Pest Control And Surveillance The Contractor shall engage an approved Pest Control Operator who is registered with the (i) (ii)
BCA under the Work Head for Pest Control NEA under the Control of Vector and Pesticide Act
to provide comprehensive pest control and surveillance work on the Site. In this respect, the Contractor shall submit the name of the Pest Control Operator and proof of BCA/NEA registration to the SO Rep for approval prior to carrying out the Works. The SO Rep may disapprove the Pest Control Operator selected by the Contractor and the Contractor shall not be entitled to any claims for compensation and extension of time arising from such decisions. BLDG12/S01.DOC(56) Sal(151211) (DPD)
Bldg Spec Page 1-57 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.9
Pest Control And Surveillance
(Cont’d)
Pest Control measures and surveillance programmes shall fully comply with the requirements of NEA as well as the following : (a)
The Contractor is required to submit a detailed pest control and surveillance programme inclusive of “Source reduction regime/strategy”, “Water bearing receptacle removal team” at the Site to the respective NEA’s regional office and the SO Rep prior to commencement of the Works. The frequency of fogging shall be in accordance to NEA’s requirement. Fogging is to be carried out only by licensed Pest Operator using approved chemical.
(b)
The Contractor shall maintain a site register containing an up-to-date record of the pest control and surveillance work that has been carried out. The site register shall be made available and ready for inspection by the SO Rep when required.
(c)
The Contractor shall submit monthly summarised returns of the site records required by NEA to the respective NEA’s regional office.
(d)
On the instruction of the SO Rep, the Contractor shall seal up all sanitary openings in the dwelling units prior to the handing over of the completed Works all at the Contractor's cost and expense.
The Works required under this subclause shall include all necessary measures to prevent the Site from becoming conducive to the breeding or harbouring of vectors. The Contractor shall carry out site checks at least once a week to detect and remove all breeding and harbouring grounds. If breeding or harbouring of vectors is found at the Site, enforcement action may be taken against the Contractor by NEA. The SO Rep may also exercise his right under Clause 1.6 "Nuisance & Irregularities" by imposing charges on the Contractor. 1.1.67.10 Air Pollution By Construction Equipment The Contractor shall take all necessary measures to abate the discharge of smoke, fumes or obnoxious gases from Construction Equipment and other equipment on the Site. When notified by the SO Rep that a particular Construction Equipment or equipment is discharging excessive smoke, fumes or obnoxious gases, the Contractor shall stop the use of that Construction Equipment or equipment, and replace the same with acceptable Construction Equipment or equipment. No claims from the Contractor for extension of Time for Completion or costs and expenses shall be allowed. 1.1.67.11 Reserved 1.1.67.12 Cleaning Of Public And HDB Maintained Roads And Drains The Contractor shall ensure that all vehicles used by him, his servants or agents, or by his subcontractors or suppliers, their servants or agents (hereinafter referred to as the "Contractor's Vehicles" for the purposes of this subclause) shall not dirty any public or HDB maintained roads and drains. In this respect, it is the Contractor's responsibility to ensure that all such Contractor's Vehicles are properly cleaned before they move onto these roads. The Contractor shall check with the SO Rep if he is in doubt whether any road is a public or HDB maintained road and the decision of the Superintending Officer in this respect shall be final and binding on and conclusive against the Contractor. In the event the Site abuts a public or HDB maintained road and the Contractor's Vehicles use the road for site access, the Contractor shall provide a washing bay to wash and clean the Contractor's Vehicles before they move onto the public or HDB maintained road. If vehicles of other contractors also use such public or HDB maintained road for site access, the Contractor shall provide at his own cost and expense, similar washing, cleaning facilities and services for these other contractors' vehicles before they move onto the public or HDB maintained road. The Contractor shall also provide at his own cost and expense, the same facilities and services for similar purposes in the event a road abutting the Site becomes a public or HDB maintained road and is used for site access by the Contractor's Vehicles or other contractors' vehicles.
BLDG12/S01.DOC(57) Sal(151211) (DPD)
Bldg Spec Page 1-58 1.1.67
Environmental Public Health Measures At Construction Sites (Cont’d)
1.1.67.13 Restriction On The Use of Styrofoam in Construction processes Where specified in Section 4 "Structural Concrete", the use of styrofoam in the course of formwork erection or concreting Works shall be disallowed. The Contractor shall ensure that he or his sub-contractors do not use styrofoam in openings and recesses. 1.1.68
Material Samples Display Room Within 21 days from taking possession of the site, a Material Samples Display Room of 3m X 5 m 2 (ie.15 m ) shall be provided at the Site office and situated beside the meeting room. A new airconditioner set and adequate lightings shall be provided to the Material Samples Display Room. Appropriate and proper display racks/shelves shall be provided. The display room shall be maintained neat and tidy at all times. The following material samples, among others, shall be displayed upon HDB’s Technical Professional/SO Reps’ approval if they are to be provided under the contract : (a)
Architectural materials: (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) (xii) (xiii)
sanitary wares, pipes and fittings, solvent cement; integral cultured basins and vanity tops; water taps, pipes, valves and fittings; shower sets and accessories; gratings; rainwater downpipe system; clothes drying racks; doors, door holders, viewers and hinges, door locks, ironmongery; windows, stainless steel screws, friction stays, window stoppers, gaskets; paint and primer; foot-operated steel hoppers; tiles, tile grout; parquet flooring and related products etc.
(b)
Structural materials : Splice sleeves, sealants for precast joints, form ties etc.
(c)
Civil Engineering Materials : Road marking paint, interlocking concrete blocks etc.
(d)
Rendering/screeding/waterproofing/repair materials : Waterproofing membranes, prepacked waterproof screed and prepacked skim-coat, polymer modified cement mortar etc.
(e)
Electrical materials : Electrical conduits and fittings/CATV materials eg. sockets, switches, door bells, splash proof guards, light fittings etc.
The SO Rep reserves the right to instruct the Contractor to provide and display the sample for other building materials and components, especially newly introduced items, big ticket items and special items, under the Contract where deemed necessary and fit all at the Contractor's cost and expense. The approved material samples shall be provided and displayed before construction, erection or installation. All approved materials shall be labelled with the Supplier's name and materials' type/grade/model. 1.1.69
Audit Of M & E Systems The Contractor shall test the M&E systems and rectify all Defect before submitting all M&E systems test reports endorsed by the Consultant to HDB Building Quality Department. HDB Building Quality Department reserves the right to audit any of the M & E systems installed by the Contractor. The Contractor shall provide the necessary manpower, equipment and means of access for the audit by HDB. The Contractor shall rectify all Defect detected during the audit and report to the Consultant for verification. For buildings under construction, the Contractor shall ensure compliance with the requirements of the FSSD (such as dry/wet rising mains etc). The Contractor shall make the necessary arrangements to enable the officers from FSSD, SO Rep, and/or officers from HDB Building Quality Department to carry out any inspection and testing during the construction stage.
BLDG12/S01.DOC(58) Sal(151211) (DPD)
Bldg Spec Page 1-59 1.1.70
ENVIRONMENTAL MANAGEMENT
1.1.70.1
Environmental Management Programme (a)
The contractor shall implement an effective Environmental Management Programme.
(b)
The Programme shall including monitoring and tracking to minimise: (i) (ii) (iii) (iv)
1.1.70.2
Electricity consumption; Diesel consumption; Water consumption; Concrete wastage
(c)
The contractor shall submit data to the SO rep on a monthly basis and present it as a standing item in the monthly meeting.
(d)
The programme shall also include measures to be taken to raise awareness and promote environment friendly habits amongst site personnel.
Environment Friendly Practices (a)
The contractor shall implement a system to facilitate the use recycled water obtained through Earth Control Measure for: (i) (ii) (iii) (iv)
wash bay; dust control; tremie piles; washing of site access.
(b)
The contractor shall segregate metal and concrete waste from general construction waste for recycling purpose.
(c)
The contractor shall provide recycling bins near the site office to facilitate recycling.
(d)
The contractor can use eco-green concrete, subject to Contractor’s PE approval where necessary, for the base slab of: (i) (ii) (iii) (iv) (v)
(e)
site office; worker’s quarter; canteen; worker’s toilet; cube room
To reduce energy consumption for the site office, the contractor is encouraged to : (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi)
Use aircon with green rating; Use white colour for the roof of the site office; Use the east and west end for meeting room or toilet as it has lower occupancy; Reduce the office ceiling height at about 2.4 m reduce air con and lighting energy consumption; Provide UV film or blinds at site office windows; Maintain office temperature at more than 24 deg C; Provide door closer at doors where space is air conditioned Design the site office toilet such that they do not need mechanical ventilation; Use pedestal pan integrate with wash basin; Use motion sensor for lights and ventilation fan for toilet; Orientate the site office in the north–south facing if feasible
(f)
The contractor is encouraged to be familiar and closely follow the BCA’s Green and Gracious Builder’s Guide. (e.g use energy efficient air conditioning system complying with Singapore Energy Labelling Scheme, use T5 lights combined with motion sensors to reduce energy consumption etc).
(g)
The contractor is also encouraged to : (i) (ii)
BLDG12/S01.DOC(59) Sal(151211) (DPD)
Provide more greening on site to lower ambient temperature during construction period; Elimination of environmentally unfriendly products and packaging
Bldg Spec Page 1-60 1.2
MATERIALS
1.2.1
Metric Components All components for incorporation into the Works shall be in metric units. However, when metric components are not available, their equivalent in imperial units may, subject to the approval of the SO Rep, be used and such a substitution shall not constitute a variation to the Contract.
1.2.2
Materials And Workmanship As directed, furnish the SO Rep with approved documents to prove that materials are as specified. The documents shall include but not be limited to any or all of the following, such that the authenticity of the materials can be easily ascertained : (i) (ii) (iii)
shipping documents serial numbers warranty certificates
In the event that any documents submitted are not original copies, they shall be duly certified by the originating parties. No information within the documents shall be tampered with, unless it is clearly discernible that the items are not related to the materials specified in the Contract. Where specific brand and model number are specified, or where alternative brands and model numbers are offered by the Contractor and accepted by the SO Rep, it shall be deemed that the finished products are entirely of original make by the registered manufacturer and fully supported by the Manufacturer's warranty. In the event that any alteration is made to the goods by a local agent or any other intermediary, the approval of the SO Rep shall be sought and the result of the alteration shall be fully supported by the Manufacturer such that the Manufacturer's warranty is maintained. All references to local or foreign standards and/or Codes of Practice shall be deemed to be inclusive of the prevailing amendments to these standards and/or Codes of Practice. Samples of materials shall be submitted to the SO Rep for approval before order is placed with the supplier. Such approval by the SO Rep shall not relieve the Contractor of its obligations under the Contract. The Contractor shall ensure that the materials are free from any defects, damages or any other flaws. 1.2.3
Credit Terms And Conditions For Employer's Materials For materials directly supplied by the Employer, a 2-month credit facility from the date of delivery may be allowed. The Employer reserves the right to deliver the materials to the Contractor's site or other designated locations even if he fails to re-confirm his earlier purchase order to the Employer. The cost of the materials so delivered shall be deducted by the Employer from the Contractor by deduction from monies due or becoming due to the Contractor or as a debt due by the Contractor to the Employer. The Employer reserves its sole and unfettered discretion to withdraw such credit facilities without any prior notice to the Contractor under any circumstance as it deems fit, including but not limited to where a garnishee order is served on the Employer in respect of any contracts the Contractor has with the Employer or where a petition in bankruptcy or winding up order is presented by or made against the Contractor. Under no circumstances shall the Employer be liable to the Contractor's claim for any cost, expense, profit and loss arising out of or in consequence of the withdrawal of such credit facility. Where such credit facility is withdrawn, the Contractor has to pay the Employer in cash for all materials he has ordered for the Works before the Employer will deliver the materials to the Site or allow the Contractor to collect the materials. Where the garnishee order is discharged or withdrawn or made absolute or where the petition in bankruptcy or winding up order is withdrawn, the Contractor may apply to the Employer in writing, with documentary proof, to have the credit facility reinstated. The Employer shall have the absolute right to decide whether or not to reinstate credit facility to the Contractor and the Employer is under no obligation to provide any explanation if it decides not to reinstate the credit facility.
1.2.4
Reserved
BLDG12/S01.DOC(60) Sal(151211) (DPD)
Bldg Spec Page 1-61 1.2.5
Approval Of Samples And Trade Names Where trade names or catalogue numbers are specified in the Specifications and/or shown in the Drawings, they are intended only to serve as a guide to the respective type and quality of material required. Other material proposed by the Contractor may be used subject to the prior approval of the SO Rep. In this respect, the Contractor shall submit samples of the proposed material to the SO Rep for approval. When a sample is approved by the SO Rep and subsequently work is carried out in accordance with this approved sample, any cost difference resulting from the higher price of the approved sample as compared with the price of the material as required and/or as shown shall not be payable to the Contractor, unless the change of material is ordered by the SO Rep. With the exception of lighting luminares, where the requirements for cost recovery are provided for differently, in the event that the price of the approved sample is lower than that of the material as required and/or as shown, the cost difference shall be recovered by the Employer by way of contract variation in accordance with the following table : Recovery (or Non-Recovery) by the Employer from the Contractor in the event that the price of the approved material is lower than that of the material as required and/or as shown S/N
Material as required and/or as shown
Material proposed by Contractor and approved by the SO Rep
Cost Adjustment
1.
On the HDB Materials List
On the HDB Materials List
No cost recovery
2.
On the HDB Materials List
Not on the HDB Materials List
3.
Not on the HDB Materials List
On the HDB Materials List
4.
Not on the HDB Materials List
Not on the HDB Materials List
) ) ) ) ) ) ) )
Cost Recovery by the Employer from the Contractor
For lighting luminaires, in the event that the price of the approved sample is lower than that of the material as required and/or as shown, the cost difference shall be recovered by the Employer by way of contract variation regardless of whether or not the approved sample and/or the material as required and/or as shown are shown in the HDB Materials List. For the purposes of this subclause only, the applicable HDB Materials List shall be the prevailing HDB Materials List applicable at the time the Contractor submits the material for approval by the SO Rep. Where cost recovery is required, the basis of such adjustment shall be the difference between the price of the proposed material and that of the material as required and/or as shown (where one type of material is specified) or that of the cheapest of the materials as required and/or as shown (where more than one type of material is specified). The Contractor shall point out to the SO Rep all items in the approved sample which do not comply with the Specifications and/or Drawings. Notwithstanding approval of the sample by the SO Rep, the Contractor shall be liable for any items in the sample which do not comply with the Specifications and/or Drawings and which the Contractor has failed to point out to the SO Rep. Where the Contract requires the Contractor to obtain materials from the HDB Materials List or where it is specified that materials provided are subject to the approval of the SO Rep, such requirements shall not in any way affect, vary or relieve the Contractor's obligations under the Contract. The Contractor shall ensure that the materials used or selected by them: (a) are free from defects, damages or faults; (b) are of merchantable quality and fit for their intended purpose; and (c) comply with the Specifications and/or Drawings.
BLDG12/S01.DOC(61) Sal(151211) (DPD)
Bldg Spec Page 1-62 1.2.6
Sample Unit And Quality Standards
1.2.6.1
Sample Unit The Contractor shall provide at his own costs and expenses, for the inspection, testing and approval of sample units for each of the different dwelling unit types as instructed by the SO Rep. These sample units shall be truly representative of the actual units to be constructed in every respect inclusive of all architectural details, architectural and structural features, finishes, services, fittings, etc. The Contractor shall comply with the Quality Standards specified under this clause for setting up of sample units and sample panels. The specifications, drawings or details shall be read in conjunction with the quality standards specified under this clause. In case of discrepancies between the specifications, drawings or details and the quality standards specified under this clause, the Contractor shall obtain approval from the SO Rep before proceeding with the works. The approved sample units shall be used as reference for the standard and quality of workmanship and materials that are acceptable to the SO Rep. The Contractor shall ensure that the completed Works (including works that are not listed in the quality standards specified under this clause) are at least of the same standard and quality as that in the sample units. The Contractor shall commence to construct the sample units when the structural works of the first building block reaches the fifth (5th) storey floor slab. The contractor shall complete the sample units within three (3) months from the aforesaid commencement date for inspection and approval by the SO Rep. The Contractor shall maintain the sample units to a clean, neat and tidy condition at all times. Adequate artificial lightings shall be provided where possible and as directed by SO Rep all at the Contractor’s cost and expense. Notwithstanding the approval of the SO Rep in respect of these sample units, the Contractor shall not be released from any of his duties and obligations as required of him under the Contract.
1.2.6.2
Quality Standards For Architectural Works S/N 1.
2.
ITEMS Column/ Wall (Plaster or skim finish)
Ceiling /Beam (Skim finish)
• • • • • • • • • • •
3.
BLDG12/S01.DOC(62) Sal(151211) (DPD)
Metal Gate and Frame
• • • • • •
QUALITY STANDARDS Walls meet at right angles (deviation not to exceed 4mm over 300mm) Surface unevenness not more than 3mm over 1.2 m No stain marks, paints drips and any visible damage No crack No hollow sound when tapped with a hard object Straightness of corners and joints Beams meet at right angles (deviation not to exceed 4mm over 300mm) Surface unevenness not more than 3mm over 1.2 m No crack Straightness of corners and joints Surface should be visually even with no waviness or patches due to patching works Verticality (tolerance of max 3mm) Evenly painted, no stain or scratches No dent, rust or mortar dropping Inner frame align with outer frame with consistent gap Welding at joints ground even or flushed Consistent gap between gate and unit slab (between 45mm to 55mm)
Bldg Spec Page 1-63 1.2.6
Sample Unit And Quality Standards
1.2.6.2
Quality Standards For Architectural Works S/N 4.
ITEMS Door
• • • • • • • • • • • • • • •
5.
6
Wall Tiles
Floor: a) Unfinished floor b) Screed Finish
BLDG12/S01.DOC(63) Sal(151211) (DPD)
• • • • • • • • • • • • • • • • • • •
(Cont’d) (Cont’d)
QUALITY STANDARDS Alignment/level with walls No visible gaps between door frame and wall Door surface and joints properly sanded down and with consistent varnish finish (including on top and bottom of door leaf ) Both leaves aligned when close (offset not more than 2mm) Consistent gap between door & frame (not more than 5mm) Warp not more than 2mm Ease in opening and closing No stain marks and any visible damage Door and frame corners maintained at right angles No sign of corrosion and any visible damage in ironmongery or metal frame Consistent gap between door & finished floor (between 3mm to 10mm) Door gap between door frame & finished floor to comply to FSSD’s requirements for fire-rated door Consistent gap between door and unfinished floor level (between 45mm to 55mm) Verticality (tolerance of max 3mm) Gap between HS door and unfinished floor level (not less than 60mm) No mortar stains or paint drips No hollow sound when tapped with a hard object Consistent colour tone Consistent and neat pointing Consistent joint size Lippage between 2 adjacent tiles not more than 1mm. For homogenous tiles, the lippage between 2 adjacent tiles not more than 0.8mm Surface unevenness not more than 3mm over 2m Alignment of joints with floor tiles where applicable Surface unevenness not more than 10mm within the unit No foot print or indentation No mortar dropping No faeces stains Ponding not deeper than 3 mm No crack No hollow sound when tapped with a hard object Surface unevenness not more than 3mm per 1.2m No stain marks and any visible damage Surfaces should not be unduly rough or patchy Consistent skirting thickness and no gap between wall & skirting
Bldg Spec Page 1-64 1.2.6
Sample Unit And Quality Standards
1.2.6.2
Quality Standards For Architectural Works S/N 6
ITEMS c) Floor Tile
• • • • • • • • • •
d) Timber floor
• • • • • • • • • •
7.
Windows
• • • • • • • • • • • • •
8
BLDG12/S01.DOC(64) Sal(151211) (DPD)
Painting
• • • • •
(Cont’d) (Cont'd)
QUALITY STANDARDS Surface unevenness for dry areas (without fall) not more than 3mm over 2m Falls in wet areas should be in the correct direction towards floor traps or discharge points Consistent colour tone Consistent skirting thickness Consistent joint size No mortar stains or paint drips No hollow sound when tapped with a hard object Lippage between 2 adjacent tiles not more than 1mm. For homogenous tiles, the lippage between 2 adjacent tiles not more than 0.8mm Consistent drop between kitchen and unfinished living room floor (between 45mm and to 50mm) Alignment of joints with wall tiles where applicable No cracks and warpage Timber strips to rest firmly on screed with no hollow sound when tapped No gaps in between timber strips (joint width not more than 0.5mm at localized areas) Edges of the floor to be properly sealed No unevenness between timber strips Surface unevenness (not more than 3mm per 1.2m) Consistent skirting thickness and no gap between wall & skirting Uniformity in timber strip tone Surfaces are evenly varnished with no patchiness resulted from touch up works No stain marks and any visible damage Alignment /level with wall openings (offset not more than 5mm) No visible gap between window frame and wall No sign of rainwater leakage Ease of opening and closing When closed, tight fit with no gap No mortar droppings and paint drips on frames and glazing Window leaf and frame corners maintained at right angles Neat joint between window and wall internally and externally Consistent gap between window leaf and frame (not more than 5mm) No dents, scratches or visible damage Accessories firmly secured and functioning Glazing clean, evenly sealed with gasket for aluminium windows Glazing no chips, cracks, scratches, mortar droppings, paint drips No obvious brush line Surfaces are evenly painted Good opacity, no patchiness resulted from touch up works Free from peeling, blistering and chalkiness No tonal variation, discoloration and fading
Bldg Spec Page 1-65 1.2.7
PSB Quality Certificate Where two or more alternative materials are proposed by the Contractor under subclause 1.2.5 "Approval Of Samples And Trade Names", the SO Rep may at his sole discretion give preference to the use of a material that is approved under any of the PSB quality certification schemes.
1.2.8
Storage Facility For Cement Where storage of cement is required, the Contractor shall provide adequate storage facilities at the Site to accommodate cement up to two weeks' requirements for the Works. The store to accommodate the cement shall be constructed so that each consignment of cement can be separately stacked. Each consignment of cement shall also be used in the same sequence as they are delivered, that is, on a "first-in first-out" basis. The Contractor shall ensure that the cement stored at the Site is kept dry and properly protected against loss or damage at all times.
1.2.9
Precautions Against Materials Being Taken Out Of Site The Contractor shall be responsible for the safe custody of cement and all other materials delivered to the Site and shall therefore ensure adequate protection and prevention of such materials from being taken out of the Site. The SO Rep will not accept any excuse for materials taken out of the Site by the Contractor, his foreman or other individual even without the knowledge of the Contractor who is deemed to have provided for proper control against such malpractice. If it is established that cement or any other material is taken out of the construction Site without specific written approval from the SO Rep, this shall be deemed to be an irregularity and inter-alia, the right of the Contractor to compensation for price fluctuations for all materials shall lapse.
1.2.10
Ready-Mixed Concrete from Approved Suppliers The Contractor shall obtain ready-mixed concrete from any of the pre-approved suppliers. Provide the name and address of the ready-mixed concrete suppliers to the SO Rep. The use of ready-mixed concrete shall be subject to the terms and conditions set by the SO Rep. All Delivery Orders for ready-mixed concrete delivered to the Site shall be endorsed by the Employer's Resident Technical Officer and submitted to the SO Rep. Failure to inform the SO Rep or non-compliance with the terms and conditions set by the SO Rep for the use of ready-mixed concrete shall, inter-alia, result in the Contractor forfeiting his right under the Contract to claim compensation for price fluctuations for all materials.
1.2.11
Water Water approved by the SO Rep shall be used for building purposes except where specified in Clause 4.3 "Water". The Contractor shall pay for all charges and temporary plumbing required.
BLDG12/S01.DOC(65) Sal(151211) (DPD)
Bldg Spec Page 1-66 1.2.12
SUPPLY OF CONCRETING MATERIALS
1.2.12.1
Supply Of Concreting Materials From The Employer Notwithstanding other provisions in the Specifications, the Contractor shall have the option to purchase the following concreting materials from the Employer: (a) (b) (c)
Ordinary Portland Cement 20mm Granite Aggregate Concreting Sand
For the purpose of this clause, these materials to be supplied by Employer shall hereinafter be referred to as the “Protected Materials” and their respective quantities indicated by the Contractor shall hereinafter be referred as the “Protected Quantity” for the purpose of this clause only. . 1.2.12.2
Quantity To Be Supplied The Contractor shall indicate the respective quantities of the above materials to be purchased from the Employer in Annex D – Part A of the Form of Tender, subject to the Maximum Protected Quantity specified therein. The Maximum Protected Quantity indicated in Annex D – Part A of the Form of Tender does not include the quantity of concreting materials required for precast concrete components that are supplied by the Employer. The Contractor shall place his orders directly with the Employer and comply strictly with the "Conditions For The Supply Of Materials From The Employer" as stipulated in Appendix A13. The Contractor shall be deemed to have included all costs and expenses to be incurred by him in compliance with the requirements stipulated in this clause in the Contract Sum. The SO Rep reserves the right to allocate the monthly quantity to the Contractor as well as to nominate the Employer’s supplier. The Contractor shall absorb the total quantity allocated to him. If the Contractor's requirement is more than the Employer's capacity to supply, the SO Rep may direct the Contractor to supplement his requirement from other sources. In this event, the Contractor shall bear any additional cost and expense so incurred.
1.2.12.3
Quantity To be Protected The quantity to be covered under the provision of this clause shall be as stipulated in the Maximum Protected Quantity (MPQ) or Protected Quantity (PQ) whichever applicable (hereinafter referred to as the "Protected Quantity"). The Contractor shall be invoiced for the Protected Quantity at the Basic Price. In the event that the source of any precast concrete components listed in Annex F of the Form of Tender is obtained from the Employer or where the Contractor’s production of precast components are carried out in overseas precast plants, the Protected Quantity shall be reduced according to the quantities indicated in the same Annex F and the Contractor shall be notified within one (1) month from the date of the Letter of Acceptance. The HDB posted prices of the Protected Materials at any time shall be deemed to be those in the HDB's Monthly Price Lists which are also available for viewing at the Procurement Office, Basement 1 HDB Hub. The Contractor is deemed to have based his Tender on the posted price for the Protected Materials and Protected Quantity, at the date Fourteen (14) days before the closing date of the Tender (hereinafter referred to as the "Basic Price"), for the Protected Materials. To illustrate: if a Tender closes on the 14th day of a particular month, the Contractor is deemed to have based his Tender on the posted price prevailing on the last day of the preceding month.
BLDG12/S01.DOC(66) Sal(151210) (DPD)
Bldg Spec Page 1-67 1.2.12
SUPPLY OF CONCRETING MATERIALS
1.2.12.3
Quantity To be Protected
(CONT’D)
(Cont’d)
In the event of the Contractor failing to obtain the Protected Quantity in full throughout the Time for Completion and any time during which liquidated damages are imposed under the Contract, a shortfall recovery shall be effected using the following formula: Amount of Shortfall Recovery where:
=
PB x (QP - QA)
PB QP
= =
QA
=
Basic Price; Protected Quantity (MPQ or PQ where applicable); Actual quantity purchased under this clause;
In a situation where the Employer is not able to supply in full the Protected Quantity and the SO Rep has directed the Contractor to supplement his requirement from other sources, such purchases shall not be covered by the provisions under this clause. However, for the purpose of ascertaining for shortfall quantity, the quantity purchased from the Contractor's own source shall be included in QA when determining whether the Contractor has obtained in full the Protected Quantity. For this purpose, the Contractor shall be required to maintain proper documentary evidence of the delivery of each of the materials and such evidence shall be duly endorsed by the SO Rep. 1.2.12.4
Supply Of Concreting Materials From The Contractor’s Sources The Contractor shall be allowed to use his own supply only after the Protected Quantity or Approved Protected Quantity, whichever is applicable, has been used up. The Contractor shall be required to seek the SO Rep’s approval in writing prior to using his own supply. The Contractor shall also ensure that the quality of the concreting materials obtained from his own supply shall fully comply with the Specifications.
1.2.13
AGGREGATES FOR NON-CONCRETING WORKS Where the contractor intends to buy imported aggregates that fail the S2 or S3 Tests under the BCA testing regime and use these aggregates for non-concreting works must seek prior written permission from the SO Rep. The contractor is required to inform BCA (Strategic Materials Department, Attn: Officer-in-Charge, email to
[email protected] and
[email protected]) of such purchases by providing the following details and cc a copy of the e-mail to the relevant officer of the Employer within 7 days of approval from the SO Rep to use the aggregates for the said project: i. ii. iii. iv. v. vi. vii. viii. ix. x.
BLDG12/S01.DOC(67) Sal(151210) (DPD)
Project Name; Project Location; Contact details of relevant officer of the Employer overseeing the project; Name of Importer of the Aggregates; Quantity of Aggregates (Tonnes) Delivered; Date of Delivery; Intended Non-concreting Use of Aggregates; The Contractor shall declare that he has obtained the SO Rep's permission for the intended nonconcreting use; Location and Quantity of Aggregates Used; Remarks.
Bldg Spec Page 1-68 1.3
LABOUR
1.3.1
Labour Laws The Contractor shall pay his workmen promptly, and observe workmen's working hours and holidays in accordance with current laws and regulations. He shall keep records and produce them for inspection by the SO Rep.
1.3.2
Keeping Records Of Workmen The Contractor shall comply with all labour laws regarding the engagement of non-citizen workmen. Work Permits from MOM shall be obtained for these workmen. The Contractor shall be held solely liable for and shall indemnify the Employer in respect of all actions against the Employer for employing foreign workmen without permits. The Contractor shall keep proper records of all workmen engaged on Site. These records shall include the following information : (a) (b) (c) (d) (e)
Name of Workmen (and alias if any) Identity Card No./Passport No. Address Work Permit No., if any Expiry date of work permit
This information shall be recorded before any workman is allowed to commence duty. Appropriate action will be taken by the SO Rep if the Contractor fails to record any of the abovementioned information of any worker found at the Site. 1.3.3
Employment Of Illegal Immigrants (Prohibition) For the purpose of this subclause "Illegal Immigrants" shall refer to any person who enters the Republic of Singapore in contravention of the provisions of the Immigration Act or any statutory modification or re-enactment thereof. The Contractor shall ascertain the legitimacy of all Foreign Workers employed by him and/or any subcontractor prior to employment and throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. Clarification as to the legitimacy of Foreign Workers may be made with the Immigration Authority, the Ministry of Manpower and/or the Police. The Contractor shall ensure that no illegal immigrants are employed by him and/or any sub-contractor in the execution of the Works. The Employer shall not be responsible for any such act or acts by the Contractor and/or any of his sub-contractors and the Contractor shall indemnify the Employer for all consequences arising thereof.
1.3.4
Reserved
1.3.5
Allocation Of Man-Year Entitlements Where materials, goods or products for the Works are to be purchased and/or obtained by the Contractor from HDB and/or the Employer, the Contractor shall allocate Man-Year Entitlements to such suppliers and/or contractors engaged by HDB and/or the Employer for the supply of such materials, goods or products. This requirement shall be applicable for, but not limited to, the supply of precast components and cut and bend steel reinforcement bars which are supplied by HDB and/or the Employer. The Contractor shall be deemed to have included in the Contract Sum for all costs and expenses arising from his compliance with the requirements stipulated in this subclause.
BLDG12/S01.DOC(68) Sal(151210) (DPD)
Bldg Spec Page 1-69 1.3
LABOUR
(CONT’D)
1.3.6
Employment Of Skilled Tilers The Contractor shall employ workers that are capable of producing good workmanship for all tiling Works. They shall possess Skill Evaluation Certificate on tiling works from local institutions. A list of these workers shall be submitted to the SO Rep for pre-screening and approval before they are allowed to commence work. These workers are also required to wear identification pass upon approval by the SO Rep. The pass shall be easily distinguishable from other pass used at the Site, by their colour, size or pattern.
1.4
CONSTRUCTION EQUIPMENT
1.4.1
Provision Of Construction Equipment Where the Contract comprises 200 or more dwelling and/or commercial units, the Contractor shall provide for a minimum of one number concrete pump, one number crane and one number rough terrain forklift to the Site. Notwithstanding the foregoing requirements, the Contractor shall provide one tower or luffing crane and one passenger cum material hoist per building block of six storeys and above regardless of the number of units in the Contract. The Contractor shall provide formwork system in accordance with the Drawings and Specifications for the construction of all building blocks.
1.4.2
Technical Specification (a)
Concrete Pump The concrete pump shall be either trailer mounted or truck mounted type. The pump shall have an output of at least 40 m³ per hour of compacted concrete. The pump shall be used for casting of slabs from the second storey to the roof of all building Blocks / MSCP. The requirement for provision of concrete pump may be waived at the discretion of the SO Rep if an extra crane over and above the specified requirements is used to transport fresh concrete.
(b)
Crane The crane shall be either crawler truck mounted, rough terrain or tower crane. The age of the crane used on the Site shall not exceed 15 years. The lifting capacity of the crawler truck mounted or rough terrain crane shall be at least 20 metric tonnes. The moment capacity of the tower crane shall be at least 50 metre-tonnes. The crane shall be based on the Site during the concreting stage. The concreting stage shall be defined as the duration of concreting work from the second storey slab to the roof of all building blocks.
BLDG12/S01.DOC(69) Sal(151210) (DPD)
Bldg Spec Page 1-70 1.4
CONSTRUCTION EQUIPMENT
1.4.2
Technical Specification (c)
(CONT’D)
(Cont’d)
Passenger Cum Material Hoist The design of the passenger cum material hoist shall be in accordance with BS 4465 or other approved equivalent standards. The payload shall be at least one tonne and the travel speed of the cage shall be at least 25.0 m per minute. For passenger cum material hoist serving buildings of more than 16 storeys, each hoist shall have a minimum of 2 winches. The Contractor shall ensure that the foundations, the masts and tie-backs for the passenger cum material hoist be designed by a PE. The design calculations and detailings shall be certified by the PE. The Contractor shall also ensure that his PE submit a Certificate of Supervision to the SO Rep not later than two weeks after the completion of installation of each hoist. The age of the hoist used on the Site shall not exceed 10 years. The hoist shall be provided and commissioned for use before concreting the sixth storey of each building block of six storeys and above. Provide an overloading device to detect and stop the current if the hoist is overloaded. Provide a siren warning device to warn users that the hoist is ascending or descending. Provide a "one-way" locking device to the swing gate at every landing of the hoist in accordance with the details shown in the Drawings or sketch attached. Provide a bell system for all hoists. The bell shall be loud enough for the hoist operator to hear whenever the hoist is required at a different level. There shall be a bell activation button at every storey level for the purpose of calling the hoist operator to bring the hoist to that level.
(d)
Rough Terrain Forklift The rough terrain forklift shall have a lifting capacity of at least 2 tonnes and a lifting height of at least 3.6 m. The rough terrain forklift shall be provided on the Site not later than the completion of concreting work for the sixth storey slab of the first building block or any other time as instructed by the SO Rep and shall not be removed without his prior approval.
(e)
Formwork System Generally, the Contractor shall provide formwork system in accordance with the Drawings and Specifications. The Contractor shall submit detailed drawings and design calculations of all formwork system to the SO Rep for approval within six weeks from the Letter of Acceptance. Trial setting out of the formwork system shall be carried out on the Site two weeks after approval of the submission. Formwork support system of beams and slabs shall consist of rigid steel props or steel frames of adequate strength.
BLDG12/S01.DOC(70) Sal(151210) (DPD)
Bldg Spec Page 1-71 1.4
CONSTRUCTION EQUIPMENT
1.4.3
Recovery For Non-Provision
(CONT’D)
The Contractor shall be deemed to have included in the Contract Sum for all costs and expenses incurred by him for compliance with the requirements stipulated in this Clause including all subclauses under it. In the event of the Contractor not providing all or any of the specified Construction Equipment to the Site as required under this Clause, including all subclauses under it, without prejudice to the Employer's rights under the Contract, the Contractor shall be indebted to the Employer at the rate or rates specified hereunder and such indebtedness shall be deducted by the Employer from any monies due or becoming due to the Contractor or be recovered by the Employer as a debt from the Contractor : Type Concrete Pump Crane Passenger cum Material Hoist Rough Terrain Forklift Formwork System
Rate Recoverable $100,000 per number $200,000 per number $40,000 per number $60,000 per number $150,000 per set per building block
The above rates shall be deemed to have been fully agreed and accepted by the Contractor and Employer as the costs and expenses allowed by the Contractor for the provision of the specified Construction Equipment. In addition to the abovementioned recovery, the SO Rep may also exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a charge against the Contractor. In the event the SO Rep approves in writing that all or any of the specified Construction Equipment need not be provided by the Contractor, the Contractor shall be indebted to the Employer at the rate or rates specified above in this subclause and such indebtedness shall be deducted by the Employer from any monies due or becoming due to the Contractor or be recovered by the Employer as a debt from the Contractor. In such event, the SO Rep may not impose any charge under Clause 1.6 "Nuisance and Irregularities" against the Contractor. In the event approval in writing is given by the SO Rep for the replacement of a concrete pump with an extra crane over and above the specified requirement for provision of cranes, there shall be no recovery by the Employer from the Contractor. In such event, the additional costs arising out of the replacement shall not be reimbursed by the Employer to the Contractor. Notwithstanding other provisions in this Clause including all subclauses under it, if the Contractor incurs additional costs and expenses over and above the agreed rate or rates specified above in complying with the requirements stipulated in this Clause, the Contractor alone shall bear such additional costs and expenses in full. All differences and/or disputes arising under this Clause including all subclauses under it, (including questions relating to interpretation) shall be determined by the Superintending Officer whose decision shall be final and binding on and conclusive against the Contractor.
BLDG12/S01.DOC(71) Sal(151210) (DPD)
Bldg Spec Page 1-72 1.4
CONSTRUCTION EQUIPMENT
1.4.4
Maintenance
(CONT’D)
All Construction Equipment provided to the Site shall be kept in good working order at all times and the Contractor shall comply with all statutory regulations vis-a-vis the said Construction Equipment. (a)
Mobile Crane Before operating a mobile crane on the Site, the Contractor shall submit the following : (i)
Record of latest overhaul servicing of the crane. The latest overhaul servicing of the crane shall be conducted within one year before transferring it to the Site;
(ii)
Record of checking the connecting devices between parts/components and the condition of parts/components by an Authorised Examiner. Any Defect found in the checking shall be rectified immediately; and
(iii)
Certificate of test/thorough visual examination of lifting equipment by the Authorised Examiner.
The Contractor shall maintain the crane in good working order at all times on the Site. Document and keep all records and certificates of checking and testing in the site office for inspection by the SO Rep upon request. The Contractor shall :
(b)
(i)
Require a licensed crane operator to check the crane daily before operation. licensed crane operator shall have a Certificate of Competence;
The
(ii)
Engage a competent mechanic to conduct servicing of the crane once in every three months; and
(iii)
Engage the Authorised Examiner to carry out test and visual examination on the crane once in every six months.
Tower Crane Before operating a tower crane on the Site, the Contractor shall submit the following : (i)
Record of latest overhaul servicing of the crane. The latest overhaul servicing of the crane shall be conducted within one year before transferring it to the Site;
(ii)
Record of checking the connecting devices between parts/components and the condition of parts/components by an Authorised Examiner. Any Defect found in the checking shall be rectified immediately;
(iii)
Record of checking the installation and functioning of safety devices by the Authorised Examiner; and
(iv)
Certificate of test/thorough visual examination of lifting equipment by the Authorised Examiner.
The Contractor shall maintain the crane in good working order at all times on the Site. Document and keep all records and certificates of checking and testing in the site office for inspection by the SO Rep upon request. The Contractor shall :
BLDG12/S01.DOC(72) Sal(151210) (DPD)
(i)
Require a licensed crane operator to check the crane daily before operation. licensed crane operator shall have a Certificate of Competence;
The
(ii)
Engage a competent mechanic to conduct servicing of the crane once in every three months;
(iii)
Engage the Authorised Examiner to check the installation and functioning of the safety devices once in every six months; and
Bldg Spec Page 1-73 1.4
CONSTRUCTION EQUIPMENT
1.4.4
Maintenance (Cont'd) (b)
(CONT’D)
Tower Crane (iv)
Engage the Authorised Examiner to carry out test and visual examination on the crane once in every six months.
For every extension of height made on the tower mast and before operating the crane with the new height, the Contractor shall engage the Authorised Examiner to conduct test and thorough visual examination on the crane. (c)
Passenger Cum Material Hoist Before operating a passenger cum material hoist on the Site, the Contractor shall submit the following : (i)
Record of latest overhaul servicing of the hoist. The latest overhaul servicing of the hoist shall be conducted within six months before transferring it to the Site;
(ii)
Record of checking the connecting devices between parts/components and the conditions of parts/components by an Authorised Examiner. Any Defect found in the checking shall be rectified immediately; and
(iii)
Certificate of test/thorough visual examination of lifting equipment by the Authorised Examiner.
The Contractor shall maintain the hoist in good working order at all times on the Site. Document and keep all records and certificates of checking and testing in the site office for inspection by the SO Rep upon request. The Contractor shall:
(d)
(i)
Require an authorised hoist operator to check and operate the hoist daily before operation;
(ii)
Engage a competent mechanic to conduct servicing of the hoist once in every three months;
(iii)
Engage the Authorised Examiner to check the connecting devices between parts/components and condition of parts/components once in every three months. Any Defect found in the checkings shall be rectified immediately; and
(iv)
Engage the Authorised Examiner to carry out test and visual examination on the hoist once in every three months.
(v)
The swing gates are to be maintained, checked and certified to be in good working condition by the Authorised Examiner every month.
(vi)
Interlocking gates shall be provided at every lift landing level and they shall comply with the Workplace Safety & Health Act and its Subsidiary Legislation including any amendment or re-enactment thereto.
Authorised Examiner For the purposes of this Clause including all subclause under it, the Authorised Examiner is any person who is approved by the Commissioner for Workplace Safety and Health of the Ministry of Manpower by a Certificate in writing for the purpose of carrying out examinations and tests on lifting equipment in accordance with the Workplace Safety & Health (General Provisions) Regulations.
BLDG12/S01.DOC(73) Sal(151210) (DPD)
Bldg Spec Page 1-74 1.4
CONSTRUCTION EQUIPMENT
1.4.5
Approved Construction Equipment
(CONT’D)
All Construction Equipment used at the Site as specified hereunder shall be obtained from Approved Suppliers registered with HDB. Such Construction Equipment are : (a) (b) (c) (d) (e)
mobile crane; tower crane; gondola; mast climbing platform; and metal scaffold.
The HDB Materials List can be inspected at HDB website ; www.hdb.gov.sg and http://ml.eptc.sg. For Construction Equipment obtained from other sources, such Construction Equipment shall firstly be registered with the HDB before the Contractor can use such Construction Equipment at the Site. Where, such Construction Equipment is used at the Site for a duration of less than a week, the SO Rep may at his sole discretion, waive the aforementioned requirement. Under such a case, there shall be no adjustment to the Contract Sum.
BLDG12/S01.DOC(74) Sal(151210) (DPD)
Bldg Spec Page 1-75 1.5
SAFETY
1.5.1
Site Safety Measures (a)
General Requirement The Contractor shall allow for the compliance with the Workplace Safety & Health Act (hereafter referred to as "the Act" for the purposes of this clause including all subclauses under it) and its Subsidiary Legislation including the provisions of the Workplace Safety and Health (Construction) Regulations (hereafter referred to as "the Regulations" for the purposes of this clause including all subclauses under it) and any amendment or re-enactment thereto. The subsidiary legislations are:(i) (ii) (iii) (iv) (v) (vi) (vii) (viii)
The Workplace Safety and Health (General Provisions) Regulations The Workplace Safety and Health (Registration of Factories) Regulations The Workplace Safety and Health (First-Aid) Regulations The Workplace Safety and Health (Exemption) Order The Workplace Safety and Health (Composition of Offences) Regulations The Workplace Safety and Health (Incident Reporting) Regulations The Workplace Safety and Health (Risk Management) Regulations The Workplace Safety and Health (Workplace Safety and Health Officers) Regulations
Precedent to the commencement of the Works, the Contractor shall first obtain a Certificate of Registration, under the Act and its subsidiary legislation, The Workplace Safety And Health (Registration Of Factories) Regulations. It shall be the duty of the Contractor to comply with all such requirements of the Act and its Subsidiary Legislation, as affect him or any person or persons employed by him, and as related to any work, act or operation performed or about to be performed by him. The Contractor shall not permit any person to do anything not in accordance with the generally accepted principles of safe and sound practice. The Contractor shall ensure a safe environment on the Site at all times. All safety provisions shall be properly maintained and shall not be removed without the written approval of the SO Rep. The Contractor shall ensure that necessary and sufficient precautions are taken by his workmen when safety provisions are used. The Contractor shall not allow any of the safety provisions, to be used unless he has satisfied himself that the provisions are safe. The Contractor shall submit a safety management system to the SO Rep within 14 days from the date of the Letter of Acceptance for approval prior to the commencement of the Works. The submission of the safety management system shall comply with and be kept in the site office and made available for reference at all times. The Contractor shall display safety posters at the site office, site canteen, exit/entry points of buildings and passenger cum material hoist area. The Contractor shall submit drawings, detailings and calculation for all temporary structures as required, certified by his Professional Engineer, for approval at least one week before the commencement of the Works unless otherwise specified. The approval of the SO Rep shall not relieve the Contractor and his Professional Engineer of the need to ensure the adequacy and sufficiency of the safety provisions. The Contractor is deemed to have allowed in the Contract Sum for all cost and expense for the safety provisions and for all additional costs that may arise from amendments to the Act and its Subsidiary Legislation or changes in the requirements of MOM and the HDB. The Contractor shall engage external auditors to conduct 6 monthly audits on the worksite Safety and Health Management System to comply with the Act and its Subsidiary Legislations. In these audits, every year the Contractor shall require the external auditor to use the Construction Safety Audit Scoring System (ConSASS) as an auditing tool to assess the Safety and Health Management System at the worksite. The Contractor shall ensure that the requirements of the Regulations and the requirements specified hereunder are strictly complied with at all times.
BLDG12/S01.DOC(75) Sal(151210) (DPD)
Bldg Spec Page 1-76 1.5
SAFETY
1.5.1
Site Safety Measures (b)
(CONT’D) (Cont’d)
Metal Access Scaffold And Working Platforms The Contractor shall provide, erect and maintain all metal access scaffold for all multi-storey carpark/garage or buildings other than residential of 4 storeys and above or 12.0m in height and above. This requirement may be waived, subject to approval by the SO Rep, where industrialised and semi-industrialised methods of construction together with peripheral safety nets are employed. Under such case, there shall be no adjustment to the Contract Sum. The Contractor shall allow free use of the scaffold by all sub-contractors, specialists, artisans and other tradesmen employed by the Employer or the Contractor. The metal access scaffold shall be of the type approved by the MOM. It shall comply with the requirements of the Singapore Standard Code of Practice for Scaffolding, CP 14 and any amendment or re-enactment thereto. The metal access scaffold shall be prezinc galvanised or other approved by the SO Rep. The metal access scaffold shall be erected, or substantially extended to, or dismantled, by approved scaffold contractor, in accordance with the Factories (Scaffolds) Regulations. The metal access scaffold and any components therein shall be designed according to the CP14 and Factories (Scaffolds) Regulations by a Professional Engineer employed by the Contractor (herein referred to as “PE”) and they shall be removed only with the permission of the SO Rep. The PE’s drawings and calculations shall be submitted to the SO Rep for approval prior to the erection and dismantling. The PE shall satisfy himself that his proposal shall not duly overload the RC structure. The submission shall be submitted before the commencement of the works. The metal access scaffold, for access and finishing work, shall be erected ahead of the structural work (including the construction of water tank rooms), from the second storey and shall be supported by cantilevered platforms erected in accordance with the drawings of the PE. The cantilevered platforms shall project about 1.1m from the edge of the building or any other distance approved by the SO Rep. Where the structure does not allow the metal access scaffold to be erected from the second storey or where the building is less than 12m in height, the Contractor may erect the metal access scaffold from the first storey subject to the approval of the SO Rep. The material used for the metal working platform shall be prezinc galvanised steel and comply with SS 280. The working platform shall be adequately secured to the metal access scaffold frame at the required levels. The connections between metal working platform and metal access scaffold frame, and between the working platforms shall be subjected to the approval of the SO Rep. For any portion of the working platform where the use of metal is not suitable, the Contractor may use timber working platform subject to the approval of the SO Rep. The working platform shall be complete with at least 90mm high coloured toeboards and metal guardrails of at least 1.1m above the platform. The vertical distance between any 2 adjacent guardrails shall not exceed 600mm. Any working platform or workplace and the guardrail immediately above it shall not exceed 600mm. The working platform shall be at least 500mm in width and distance between the edge of the platform shall not exceed 300mm from building edge The Contractor shall provide, erect and maintain an overlying screening net to cover the entire external face of the scaffold. The installation of the net shall follow the erection of the fence closely. A 90mm high toeboard shall be provided at the base of the net. After installation, there shall be no opening between separate sets of the net and any torn net shall be replaced or repaired immediately. The net shall comply with the following requirements: (i) Maximum mesh size : 15mm square (ii) Twine No. : Minimum 350D (iii) Minimum 12 ply (iv) Knot Type : Single or English knot
BLDG12/S01.DOC(76) Sal(151210) (DPD)
Bldg Spec Page 1-77 1.5
SAFETY
1.5.1
Site Safety Measures (b)
(CONT’D) (Cont’d)
Metal Access Scaffold And Working Platforms
(Cont’d)
The overlying screening net shall be installed on the entire external face of the access scaffold and its installation shall follow the erection of the metal access scaffold closely. The SO Rep shall have the right to decide on the colour of the net all at the Contractor’s cost and expense. The metal access scaffold shall be effectively tied to the building structure by means of tiebacks. All tie-backs shall be painted with a bright colour for easy identification. (c)
Prefabricated Mesh Barricade The Contractor shall provide, erect and maintain a vertical prefabricated mesh barricade (hereafter referred to as “mesh barricade” for the purpose of this clause including all subclauses under it) for all peripheral open sides of construction level of building (excluding multi-storey carpark/garage) where a person is liable to fall from height. Mesh barricade shall be of sound construction and produced in the factory and installed at the construction level from the inside of the building. Mesh barricade and its support shall be prezinc galvanised or other approved equivalent by the SO Rep, easily installed and dismantled, and reusable throughout the construction (super-structure) stage. External works of the building, such as painting, touching up works, repair and redecoration, and other minor works, shall be carried out using mechanical suspended scaffold or other vertical access equipment. Where the use of mesh barricade is not feasible, as interpreted by SO Rep, during the construction (super-structure) stage, the contractor can counter-propose localised alternative system other than the use of metal access scaffold Mesh barricade/ counter-proposals for localised alternative system, its vertical support and any components therein shall be in modular sizes and designed according to the Workplace Safety and Health (Construction) Regulations by a PE employed by the Contractor. The PE’s drawings and calculation shall then be submitted to the SO Rep for approval within six weeks from the Letter of Acceptance, before installation and use. Trial setting out of mesh barricade shall be carried out on Site two weeks after approval of submission. The mesh barricade shall be erected ahead of the structural work (including the construction of water tank rooms) from the second storey and held by a supporting system designed by the said PE. The height of the mesh barricade shall be at least 1.1m above the construction level. The Contractor and his PE shall ensure that the substrate at which the mesh barricade is affixed to, can resist the designed imposed loads. The PE shall satisfy himself that his proposal shall not duly overload the RC structure. Where necessary, the Contractor shall provide, erect and maintain an overlying screening net to cover the entire internal face of the mesh barricade. The installation of the net shall follow the erection of the fence closely. Where necessary, a 90mm high toeboard shall be provided at the base of the net from the inside of mesh barricade. After installation, there shall be no opening between separate sets of the net and any torn net shall be replaced or repaired immediately. The net shall comply with the following requirements: (i) (ii) (iii) (iv)
Maximum mesh size (square) Twine No. Knot Type Minimum 12 ply
: 15mm square : Minimum 350D : Single or English knot
The vertical supports of mesh barricade shall be effectively anchored to the building structure. All vertical supports shall be painted with a bright colour for easy identification. The mesh barricade shall be erected according to a pre-determined safe work procedure established by the Contractor, or substantially dismantled, by trained erectors, under the immediate supervision of a competent supervisor. The mesh barricade and its components shall only be erected and dismantled by workers using life-line and safety belts or other equivalent, if not better, means of preventing a fall. The Contractor shall under no circumstance, use the prefabricated mesh barricade and vertical supports for other purposes.
BLDG12/S01.DOC(77) Sal(151210) (DPD)
Bldg Spec Page 1-78 1.5
SAFETY
1.5.1
Site Safety Measures (d)
(CONT’D) (Cont’d)
Personal Protective Equipment The Contractor shall provide and maintain suitable personal protective equipment to all workmen employed on the Site. The Contractor shall ensure that such personal protective equipment comply with the requirements of the Regulations. The Contractor shall also ensure that all equipment are properly used by his workmen during the course of their work. The Contractor shall record the issuance of all equipment to his workmen. The forms shall be kept in the site office and made available for inspection at all times. The colour code of safety helmets provided by the Contractor shall comply with the requirements of the Regulations. Three mirrors of sizes 600 mm x 1500 mm are to be installed for the workers to check their personal protective equipment during Tool Box Meeting. The locations of these mirrors are to be approved by the SO Rep. The Contractor shall provide life-lines and safety harness for workers who are required to carry out work within 2m from any open sides; at or near the external of the building blocks, any floor or top most construction level, lift shafts and void areas or any other locations as directed by the SO Rep all at the Contractor's cost and expense. Approved Personal Protective Equipment (PPE) station shall be set up near the site entrance where the PPE are issued/stored.
(e)
Safety (Anti-Fall) Net The Contractor shall provide and maintain a safety net system to catch person(s) falling whilst working in any location from where he would be liable to fall. The safety net system shall be obtained from suppliers approved by the SO Rep. The Contractor may propose an alternative system, to be certified by his PE, to the SO Rep for approval. The safety net shall comply with SS 292 or other approved standards. The net shall be of sufficient size and strength to catch any person for whose protection it is to be used and the net shall be so located to cover the area of the possible fall. The Contractor shall conduct a sample test on the safety net system, comprising the net and its supporting structures, before it is installed. Subsequent tests shall be carried out when directed by the SO Rep. For all building blocks of four storeys and above, a peripheral safety net system shall be provided. Initially the net shall be installed at the second storey. As construction progresses, it shall be repositioned to follow the topmost working level but shall be kept at not more than 6.0m below it. It shall be removed only with the approval of the SO Rep. Where access scaffolding is used, or any alternative safety measure approved by the SO Rep is used, a peripheral safety net system is not required. The colour of the safety netting shall be approved by the SO Rep. Safety netting of orange colour shall not be used unless such colour is specifically decided by the SO Rep all at the Contractor's cost and expense.
(f)
Working Platforms For Lift Shafts, Central Refuse Chute And Voids The Contractor shall provide working platforms, according to the design of his Professional Engineer, for the erection of lift shafts and void walls except for central refuse chute. The lift shaft and central refuse chute platforms shall effectively cover the voids at alternate storeys. The lift shaft, central refuse chute and void wall platforms shall be left in place until approval is given by the SO Rep to remove them.
BLDG12/S01.DOC(78) Sal(151210) (DPD)
Bldg Spec Page 1-79 1.5
SAFETY
1.5.1
Site Safety Measures (g)
(CONT’D) (Cont’d)
Protective Shelter As Overhead Shelter The Contractor shall provide, erect and maintain protective shelter as overhead shelter at every point of entry/exit to buildings of two more storeys height. The protective shelter shall be constructed immediately below the second storey. It shall protrude at least 3.0m from the building edge. It shall have a clear width of at least 1.5m and a clear height of at least 2.0m as shown in the drawings. If the protective shelter is intended for access by forklift, it shall have a clear width of at least 2.0m and a clear height of at least 3.0m. The contractor shall ensure that the protective shelter rest on a rigid base. The protective shelter shall be aesthetically pleasing, free of rust and does not trap water. The access to, along and egress from the entry/exit points shall be kept free from obstructions and accumulation of oil, grease, water and other substances that may cause slipping and tripping. The protective shelter shall be sufficiently strong enough to support a point load of at least 75 kg. It shall be endorsed in accordance with the relevant statutory requirements by a Professional Engineer. The PE’s drawings, detailings and calculations shall be submitted for the approval of the SO Rep. The protective shelter can be made of curved metal roofing with a diameter of at least 1.5m or pitched metal roofing with a slope of greater than one in two, with timber boarding below support by steel pipes. Alternatively, the Contractor can use the HDB patented protective shelter as shown in the Safety Standard Detail Manual. The Contractor shall source on their own directly from suppliers. The contractor can approach HDB’s Centre of Building Research (CBR) for more details on the protective shelter.
(h)
Peripheral Overhead Shelters The Contractor shall provide peripheral overhead shelters for buildings of more than 15m in height. It shall be erected in place when the construction reaches the fourth storey slab. The overhead shelter shall be at least 2m wide and erected at a height not more than 5m from the base of the building, and inclined so that the outer edge is at least 150 mm higher than the inner edge. The overhead shelter shall be sufficiently strong to support a weight of at least 75kg point load.
(i)
Barricades To Lift Openings, Voids, The Open Sides Of Buildings And Excavations The Contractor shall barricade all lift openings, internal voids and the open sides of buildings and excavations where a person is liable to fall. The barricade shall be at least 1.1m high with 90mm high toeboard and shall have sufficient strength and rigidity to withstand a lateral point load of 50 kg. All services opening shall be fully covered and secured to prevent unauthorised removal.
(j)
Mechanical Suspended Scaffold Mechanical suspended scaffold system shall only be used for touching up, repair and redecoration and minor work. Where mechanical suspended scaffold system is to be used, the Contractor shall first obtain a Certificate of Registration under the Workplace Safety & Health Act from MOM and a written approval from the SO Rep prior to its installation and usage. The mechanical suspended scaffold system shall comply with the requirements of the Singapore Standard Code Of Practice For Suspended Scaffold CP20 and any amendment or reenactment thereto. Where the use of access scaffolding is not stipulated, suspended scaffold may be used for finishing Works. Life-lines shall be provided for the mechanical suspended scaffold users to anchor their safety belts.
BLDG12/S01.DOC(79) Sal(151210) (DPD)
Bldg Spec Page 1-80 1.5
SAFETY
1.5.1
Site Safety Measures (k)
(CONT’D) (Cont’d)
Authorised Operators For Machinery And Vehicles The Contractor shall employ only qualified operators for his site machinery. The operator for the machinery shall possess a Skill Evaluation Certificate (SEC) from the BCA Academy or other approved training centre. For those machinery whereby BCA Academy or other approved training centre does not conduct courses or practical tests for machinery operator, the Contractor shall only authorise an experienced and trained operator who has at least a minimum of 2 years experience in operating the machinery. In the case of vehicles, which are operated within the contract boundary, the authorised operator shall possess a minimum valid Class 3 driving licence from the Registrar of Vehicles (Singapore) or its equivalent from their originating countries. The equivalent of a minimum Class 3 driving licence shall first be verified by the respective embassy in Singapore and thereafter submitted to the SO Rep for approval. The Contractor shall record the particulars of the operators for the machinery and vehicles in the prescribed form and submit to the SO Rep for approval one week before the commencement of the Works. The prescribed form shall be updated and kept on the Site and made available for inspection at all times.
(l)
Enhanced Hoarding Where the buildings under construction are more than 6 stories and less than 30m away from the Site contract boundary within or next to build-up areas, the Contractor shall provide a 6m hoarding with an overhead shelter. The design and position of the enhanced hoarding shall be submitted to the SO Rep for approval. The design and material requirements shall be in accordance with subclause 1.1.52.2 (or as amended) “Erection And Removal Of Temporary Metal Hoarding”. The hoarding shall be cleared away upon the instruction of the SO Rep. The Contractor shall also barricade all unauthorized entries/exits at first storey open sides by using at least 1m high orange PVC netting with steel cables going through the top and midheight of the netting. The steel cables shall act as supports for the barricade.
(m)
Safety Training (i)
Safety Orientation Course The Contractor shall employ workmen who possess valid Safety Orientation Course Certificates. The Contractor shall be required to ensure that his workmen attend a prescribed safety refresher course at an interval of time to be decided by the SO Rep.
BLDG12/S01.DOC(80) Sal(151210) (DPD)
Bldg Spec Page 1-81 1.5.1
Site Safety Measures (m)
Safety Training (ii)
(Cont'd) (Cont'd)
Safety Training Course When directed by the SO Rep, the Contractor shall send his employees/staff as stipulated hereunder to MOM’s accredited training providers for appropriate safety training as shown hereunder : Safety Training Courses Conducted by MOM’s Accredited Training Providers Courses
Applicable To
Specialist Diploma in Workplace Safety and Health / Workplace Safety & Health Officer (WSHO) Training Course
Safety Personnel for registration as Workplace Safety & Health Officer (WSHO)
Construction Safety Course for Project Managers
Chairmen of Safety Committees, Project Managers and Engineers
Safety Management Course
Chairmen of Safety Committees, Managers, Engineers and Supervisory Staff
Advanced Certificate in Workplace Safety and Health
Safety Coordinator
Training Course for Safety Committee Members
Safety Committee Members
Building Construction Safety Supervisor Course
Building Construction Foremen and Supervisors
SIC (Manhole) for Supervisors
Supervisors
Lifting Supervisors Safety Course
Supervisors and Foremen
Industrial First Aid Course
Workers, Safety Personnel and Supervisors
Industrial First Aid Refresher Course
Trained First Aiders
Crawler Crane Operator Course: New entrant programme Refresher programme Familiarisation programme
Crane Operators
Erection of Metal Scaffold
Erectors
Slingers/Riggers Course
Workers, Foremen and Supervisors
Tower Crane Operator Course: New Entrant Programme Familiarisation Programme
Crane Operators
Supervision of Metal Scaffold Erection
Supervisors
Climbing Work Platform Operation
Supervisors, workers and operators
Explosive Powered Tools Operation
Workers and Operators
The safety training shall be applicable to all levels of employees/staff stipulated in this subclause including top management at the work Site. Particular attention shall be given to the needs of young employees/staff. training shall be required where : (1)
Employees/staff are transferred or where employees/staff take on new responsibilities or where a change in the work activity or work environment could arise; and
(2)
There is a change in the work equipment or systems of work in use.
Training shall be repeated periodically to ensure continued competence.
BLDG12/S01.DOC(81) Sal(151210) (DPD)
Further
Bldg Spec Page 1-82 1.5.1
Site Safety Measures (n)
(Cont'd)
Tower Cranes And Other Tall Construction Equipment The Contractor shall comply with all height restrictions on the use of tower crane or other tall Construction Equipment, imposed by the Civil Aviation Authority of Singapore and Ministry of Defence. In addition, the height clearance of tower crane or other tall Construction Equipment shall be submitted to the SO Rep for approval before they are brought to the Site. Force limiting device, speed limiters and moment limit switches shall be installed for all cranes. The Contractor shall submit detailed layout drawings and safety requirement of the tower cranes to MOM and the SO Rep for approval at least one month prior to their installation. The Safety Factor for tower crane shall have a minimum of 1.3, which includes the built-in factor of safety for the tower crane. The Lifting load shall include the weight of the component, the spreader beam and the lifting device. The tip-load shall have the capacity to hoist the heaviest component including the necessary lifting appliances. The slewing radii of the tower cranes shall not overlap, unless the tower cranes are equipped with an anti-collision system. It is not permitted to be hoisted over temporary building structures, outside the contract boundary and other sensitive areas. The slewing limit switch shall be activated to stop the slewing action before the jib slews into the overlap zone. The jib of a tower crane shall not be allowed to slew outside the contract boundary lines without the written approval of the SO Rep. The free standing mast of the tower crane must be certified by the Contractor's PE prior to its use on the Site. The Contractor shall submit detailed drawings and calculations of the type of foundation support and the tie-back for the tower crane, duly endorsed by his PE, together with technical information to the SO Rep for approval. The Contractor's PE shall certify that the free standing height of the mast is structurally adequate and sound before the tie-back is installed. No tower crane shall be installed and supported on the constructed RC structure of a building.
(o)
Access For The Use Of Mobile Crane And Piling Machines Next To Built-Up Area Where the Contractor uses mobile cranes and piling machines on the Site which is next to existing buildings or public roads or MRT lines, the access for the mobile cranes and piling machines shall be of steel plates or reinforced concrete or bituminous pavement as approved by the SO Rep. All such access shall be provided over adequate compacted hardcore base. The Contractor shall provide full access for the movement of the cranes and piling machines and for their lifting or pile driving operations. The access shall be able to distribute the load so as not to exceed the bearing capacity of the underlying materials. The Contractor shall engage a PE to design the access. The drawings and calculations endorsed by the PE shall be submitted for approval by the SO Rep before the construction of the access. The access shall be constructed according to the approved Drawings and maintained in a good condition at all times throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The access shall be inspected by the Contractor's PE prior to its use.
(p)
Warning Signs And Lights The Contractor shall display warning signs of sizes 900 mm x 600 mm at strategic points around the periphery of the Site where trespassing is likely to occur. Such signs shall have the words "DANGER - KEEP OUT" in the four official languages in red on white background with reflective material and approved by the SO Rep. Warning lights shall be placed at similar positions at night to serve as a warning. If work is carried out near public roads, all signage shall comply with the recommendations of the Temporary Road Signage Manual issued by the Land Transport Authority.
BLDG12/S01.DOC(82) Sal(151210) (DPD)
Bldg Spec Page 1-83 1.5.1
Site Safety Measures (q)
(Cont'd)
Mobile Crane The Contractor shall submit layout and details of the crane access to the SO Rep for approval prior to the use of the crane on the access. The Contractor shall ensure and check that the crane access is properly constructed. The Contractor shall keep all records of inspections of the crane access at the Site and produce them for examination when requested by the SO Rep. The boom of the mobile crane with hoisted load shall not be allowed to swing outside the contract boundary without the written approval of the SO Rep. All the hoisting area must be effectively barricaded. The Contractor shall ensure the installation of barriers to warn the crane operator of depressions, excavated areas and other obstructions. Moment limiters shall be installed for all cranes. The Safety Factor for mobile crane shall have a minimum of 1.3, which includes the built-in factor of safety for the mobile crane. The lifting load shall include the weight of the component, the spreader beam and the lifting device. The tip-load shall have the capacity to hoist the heaviest component including all necessary lifting appliances. A Permit-To-Hoist must be obtained before any hoisting operation is carried out. The Contractor shall station a lifting supervisor on the Site to oversee and guide the crane operator during positioning, hoisting and slewing. The cranes shall be tested by an "Authorised Examiner" before its use on the Site irrespective of any valid test certificate. The Contractor shall ensure daily checks are carried out by the crane operator and maintenance checks conducted once every three months. The crane must have overhaul checks before it is used on the Site. Test certificate, overhaul certificates, maintenance certificates, inspection records by the crane operator, data on the Authorised Examiners and the Contractor's site engineer shall be properly documented, kept on the Site and produced for inspection by the SO Rep.
(r)
Crane Operator, Lifting Supervisor, Rigger And Signalman The Contractor shall comply with the Factories (Operation of Cranes) Regulations 1998. He shall appoint at least one full time lifting supervisor to supervise all lifting operations of any crane for the Site. However, where more than one crane is used on the Site, the number of lifting supervisor employed by the Contractor shall be increased as required by the SO Rep. No lifting activity shall be allowed without the supervision of the lifting supervisor. The lifting supervisor shall have a minimum of 3 years of experience in construction work and lifting operations. He must be a site foreman or site engineer and possesses a certificate on Safety Instruction Course for Lifting Supervisor. He shall spend his time fully on all lifting activities and ensure that unsafe conditions are rectified. For lifting operation within the Site which is next to existing buildings, public roads or MRT lines, the crane operator shall have a minimum of 5 years experience in the operation of cranes. For lifting operation within the site not next to existing buildings, public roads or MRT lines, the crane operator shall have a minimum of 2 years experience in the operation of cranes. Riggers and signalmen shall also be appointed for all lifting operations and they must have completed an approved training course. The crane operator, lifting supervisor, rigger and signalman shall carry out their duties strictly according to the abovementioned Regulations and other duties as the SO Rep deems necessary from time to time. The Contractor shall submit a list of crane operators, lifting supervisors, riggers and signalmen with their names, identification card or passport numbers, qualifications and years of experience to the SO Rep for approval one week before the use of the crane. The list shall be updated and kept on the Site at all times. The SO Rep reserves the right to examine the list as and when required.
BLDG12/S01.DOC(83) Sal(151210) (DPD)
Bldg Spec Page 1-84 1.5.1
Site Safety Measures (s)
(Cont'd)
Temporary Staircases The Contractor shall provide and maintain 0.8m minimum wide temporary metal staircases from one working floor to another. The staircases shall be placed against the adjacent staircase walls or formwork of the staircase walls that are under construction. The outer sides of the staircases shall be provided with metal handrails 1.1m above the outer staircase strings. The bottom of the staircases shall be covered fully with metal plate. The Contractor shall engage a PE to design the staircases. The Professional Engineer's drawings, detailings and calculation shall be submitted for approval by the SO Rep before the construction of the staircases.
(t)
Gas Cylinders and Related Equipment The Contractor shall use gas cylinders fitted with a low pressure gauge and a high pressure gauge, a reducing valve with pressure regulator, and safety relief device. The gas cylinders shall not be kept in the same room where welding, cutting or heating is being carried out or placed within five metres of any source of heat. The gas cylinders must always be kept upright in a wheeled-trolley. The hose connecting a gas cylinder to an apparatus for cutting, welding, heating or other related works shall be of good construction and sound material, free from Defect, properly maintained, and not entangled or kinked. A flashback arrester or any other similar device which stops flashback that is acceptable to the Commissioner for Workplace Safety and Health must be fitted at every outlet of a gas cylinder and every inlet of an apparatus. The gas cylinders and hoses shall be colour-coded to conform to SS 152 : Indentification of Contents of Industrial Gas Containers or any amendments thereof. The Contractor shall engage a competent person to check the safety devices referred herein once in every 6 months. The competent person is any person who is competent by education, training and experience on the safety and operational aspects of the use of gas cylinders and related equipment.
(u)
Socket Outlet Assembly The Contractor shall provide, install and maintain the socket-outlet assembly (hereinafter referred to as "SOA" for the purpose of this subclause) for all temporary electrical installations. The SOA shall be manufactured in accordance with the latest edition of CP 88 (Code of Practice For Temporary Electrical Installations in Construction & Building Sites). It shall be designed for wall mounting or fitted with castors so that it can be moved around on the Site. Every electrical equipment used shall be plugged directly into the industrial SOA.
(v)
Others The Contractor shall provide and maintain guards or fences or barriers around excavations, lift pits or other similar potential places of danger to prevent accidents. The guards, fences and barriers shall be of sound material, good construction and possess adequate strength. At the site entrance gate, the Contractor shall provide a gantry fitted with a height control device and a siren to control the height limit of construction vehicle/machinery when they leave the Site. This limit shall comply with the requirements of LTA. The Contractor shall provide and maintain storey number indicators of size 400mm x 400mm at every staircase area and 900mm x 900mm at the metal scaffold enclosing passenger cum material hoist. The indicators shall be displayed at alternate storeys starting from the second storey.
BLDG12/S01.DOC(84) Sal(151210) (DPD)
Bldg Spec Page 1-85 1.5.2
Safety Infringement The Contractor shall include in the Contract Sum for all costs and expenses for complying with the safety requirements. The SO Rep will conduct periodic inspections on the provision of safety measures with the Contractor's site safety supervisor or the Contractor's Representative. The Contractor shall rectify immediately any contravention of or non-compliance with the Workplace Safety and Health Act and its Subsidiary Legislation, Workplace Safety and Health (Construction) Regulations or safety measures specified. All Works or part of the Works may be stopped when the SO Rep considers the working environment or procedure is unsafe for Works to continue. In such event, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor and the Contractor shall not be entitled to any claims for compensation or extension of Time for Completion. If the contravention is not rectified by the subsequent inspection, the SO Rep may exercise his right under clause 1.6 "Nuisance and Irregularities" to impose a further charge against the Contractor. Upon any accident or dangerous occurrence, occurring on the Site, the SO Rep, HDB or any Competent Authority may order a total or partial stoppage of the Works, depending on the nature and extent of the accident/dangerous occurrence, to allow for investigations and/or to carry out remedial measures. Under such cases, the Contractor shall not be entitled to any claims for compensation or extension of Time for Completion. The SO Rep shall, at its absolute discretion, also exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for the following type of incidents occurring in the course of or arising out of or in consequence of the Works :
1.5.3
(i)
Fatal accident, if the SO Rep or Competent Authority is of the opinion that the accident is the result of the defaults, acts, omissions or negligence, in part or in whole, of the Contractor.
(ii)
Other accident which the SO Rep, HDB or Competent Authority is of the opinion that the accident is the result of failure of the Contractor to provide necessary and sufficient safety measures stipulated in the Contract or the Workplace Safety & Health Act and its Subsidiary Legislation, the Workplace Safety and Health (Incident Reporting) Regulations.
(iii)
Dangerous occurrence as classified in the Subsidiary Legislation, Workplace Safety and Health (Incident Reporting) Regulations, Part II if the SO Rep, HDB or the Competent Authority is of the opinion that the dangerous occurrence is the result of failure of the Contractor to provide necessary and sufficient safety measures stipulated in the Contract or the Workplace Safety & Health Act and its Subsidiary Legislation, the Workplace Safety and Health (Incident Reporting) Regulations.
Reporting Of Accidents and Dangerous Occurrence In the case of an accident or a dangerous occurrence as classified under the Subsidiary Legislation, Workplace Safety and Health (Incident Reporting) Regulations, Part II, the Contractor shall notify the Commissioner and HDB within one hour of such accident or dangerous occurrence. Upon receipt of information of an accident or dangerous occurrence, the SO Rep or HDB may at its discretion make a preliminary investigation of the circumstances and record its finding upon such investigation. Notwithstanding the aforementioned requirements, the Contractor shall in addition, make an incident investigation in the form set out in the INCIDENT INVESTIGATION REPORT - HDB and submit it to HDB on a timely basis. The form is obtainable at HDB. Upon submitting the INCIDENT INVESTIGATION REPORT to HDB, the Contractor shall arrange for the injured workman, witnesses and an interpreter, if necessary, to report to HDB to furnish evidence relating to the accident or dangerous occurrence. If the Contractor fails to give any required notice or fails to furnish evidence of the accident or dangerous occurrence as required in this Clause, the SO Rep or HDB may at his absolute discretion exercise his rights under Clause “Nuisance And Irregularities” to impose charges against the Contractor.
BLDG12/S01.DOC(85) Sal(151210) (DPD)
Bldg Spec Page 1-86 1.6
NUISANCE AND IRREGULARITIES If the Contractor is found to have committed any of the following irregularities : (i)
Omitting building materials or labour, reducing the sizes of the materials, using inferior materials; or materials constructed not according to the Specifications or Drawings;
(ii)
Creating nuisance at the Site thereby causing inconvenience to the SO Rep or the public or committing similar acts (such as not complying with site safety requirements, etc.) which are likely to bring the Employer into disrepute;
(iii)
Non-compliance with any part of the Specifications or Drawings, or non-fulfilment of any contractual obligation.
the SO Rep reserves the right to impose on the Contractor, and the Contractor hereby fully accepts and agrees to pay without dispute or question, a charge based on prevailing guidelines set by the Employer but not exceeding $100,000/-, and for contract with a Contract Sum of less than $300,000/-, a charge not exceeding 30% of the Contract Sum per occasion as agreed compensation to the Employer for the inconvenience caused, investigation and administrative expenses incurred by the Employer and for damage to the Employer's reputation and standing generally. Furthermore, the Contractor may be barred from tendering for a specified period. In addition to the above charges, the SO Rep or HDB is empowered either : (a)
to order any irregular work to be removed and made good to the satisfaction of the SO Rep or HDB at the Contractor's own costs and expenses; or
(b)
in lieu of correcting work not done in accordance with the Contract, the SO Rep or HDB may allow such work to remain and shall recover any cost differences between the specified requirements and the non-compliance.
For nuisance committed on the Site, the Contractor shall take immediate action to cease the nuisance committed upon instruction given by the SO Rep or HDB. 1.7
SPECIAL CONDITIONS ON SURVEY WORKS
1.7.1
General Requirements For Land Survey Services The contractor shall engage a registered surveyor at its own cost and expense to provide Land Survey Services to facilitate construction works and to carry out surveys for record purposes or for submission to authority as and when requested by HDB during construction and post construction stage. The cost incurred shall include the purchase of information and equipments required for the survey works. The Contractor shall be held fully responsible for the accuracy of all the survey works carried out by its registered surveyor and for ensuring the works fully comply with the following ; (a)
the technical requirements and standards in the conduct of the surveys as specified in the latest version of the land surveyors board directive on engineering and hydrographic survey practices;
(b)
the technical requirements and standards in the conduct of the surveys as specified in the latest Singapore Land Authority (SLA) directive on cadastral survey practices;
(c)
circulars that are issued from time to time by the Chief Surveyor, Singapore, SLA.
(d)
all field works and office works are executed by the registered surveyor or qualified staff under the registered surveyor direct supervision and direction;
(e)
all documents and survey works pertaining to the survey are certified and dated by the registered surveyor supervising the survey.
BLDG12/S01.DOC(86) Sal(151210) (DPD)
Bldg Spec Page 1-87 1.7
SPECIAL CONDITIONS ON SURVEY WORKS
1.7.2
Engineering Survey Services (Construction Stage)
(CONT’D)
All forms of land survey services required for the purpose to facilitate the construction works or survey works requested by HDB in relation to the construction of the projects are to be performed by the contractor’s registered surveyor. Such surveys shall include the setting out of parcel boundaries, grids, piles position, building blocks, minor sewer and service roads alignments, etc. piles eccentricity checks survey, topographical survey of surrounding services and roads, as-built survey of services and preparation of setting out plans, cross-sectional and longitudinal plans and surveys to monitor ground settlement, where applicable. 1.7.3
“As- Built” Survey (Post Development Stage) The “As-built” survey plan of the parcel is to be submitted to HDB within 2 months from the date of handover of the site to HDB. The survey includes the verification of SVY 21 datum and establishment of horizontal and vertical controls, spot levelling, site features and boundaries details, height of buildings, establishment of at least 3 level control benchmarks (TBM’s) near to the designated site, preparation of cadastral based map information for overlaying onto the topographical plan, including the provision of digital files, DWG format. Details of the surveys, where applicable; (a)
all visible details are to be surveyed;
(b)
samplings and trees where required shall be surveyed and described accordingly;
(c)
for sewer manhole, electrical manholes and inspection chambers, the cover levels and invert levels shall be surveyed. The type of manhole and inspection chambers, direction of flow shall be reflected in the plan;
(d)
for drains, invert levels and coping / top levels shall be surveyed generally at 20m interval. For cascading drain, the coping / top levels shall be surveyed. Covered drains with iron grating shall be surveyed.
(e)
Over-ground electric boxes, lamp / cable posts with numbers, exposed / overhead cables, etc; shall be surveyed;
(f)
Levels of at least 2 extreme corners of the roof including the highest point of the building structure are to be surveyed;
(g)
Spot levels shall be taken generally at 15m interval, at intersection, building corners, permanent features and at all changes of grades. For road, the cross-sectional spot levels are generally at 20m interval;
(h)
Road names and house numbers shall be picked up as appearing on site; and,
(i)
edges of ponds shall be surveyed;
BLDG12/S01.DOC(87) Sal(151210) (DPD)
Bldg Spec Page 1-88 1.8
CONTRACTOR TO VISIT SITE OF WORK The Contractor shall be deemed to have taken note of all conditions for the construction and completion of the Contract, in particular, the following conditions pertaining to this Contract and satisfy himself on and make provision in the Contract Sum : (a)
The nature of sites and soils both above and below ground with respect to various stages of construction in particular the possible existence of boulders/granite underground and other buried materials which have to be removed from site.
(b)
The provision of temporary access for traffic diversion while work is in progress to ensure undisrupted movement of traffic at all times.
(c)
The effect of existing properties, building structures / foundations.
(d)
The availability, supply of and conditions affecting labour within the Time for Completion.
(e)
The effect of other contractors or persons approved by the SO Rep, working within the contract area.
(f)
The probable adverse effect of the weather on the execution of the Contract.
(g)
The effect of execution of works due to the presence of hard soil strata, existing services, etc.
(h)
The means of access to facilitate the transportation and movement of construction equipment.
(i)
The general ground levels, spot levels of the work site.
(j)
The provision of earth drains; silt traps and the requirements to deal with drain diversion.
(k)
All aspects of local conditions, physical or otherwise, at the site that pertains to or affects in any way the construction works required at the site concerned.
(l)
The effect of encountering various existing cables, pipes, sewers, etc. which may require diversion.
(m)
The effect of heavy vehicular and pedestrian traffic.
(n)
The necessary re-instatement of all affected turfing areas and works affected by this contract.
The Contractor must also ascertain for himself the most convenient and expeditious method of carrying out the work. The working conditions and the space to be made available as a work site should be inspected and no claims will be allowed on the ground of lack of knowledge of the conditions under which the work will be executed. The Contractor shall note that all information regarding existing levels given in the drawings only serve as a guide and he shall obtain his own information whenever he is doubtful. No claim by the Contractor for additional payment will be allowed on the ground of any misunderstanding or misinterpretation in respect of any such matter nor shall the Contractor be released fromany risks or obligations imposed on or undertaken by him under the Contract on any such ground or on the ground that he did not or could not foresee any matter which might affect or have affected the execution of the Works.
Section 2/.....
BLDG12/S01.DOC(88) Sal(151210) (DPD)
TECHNICAL SPECIFICATIONS
Bldg Spec Page 2-1 SECTION 2 PILING
2.1
SCOPE OF PILING WORKS The Contract requires the supply of all materials, labours, tools, machinery and everything necessary for the construction and complete installation of one or a combination of the following piling systems under the supervision of the Superintendent Officer's Representative (SO Rep): (a) (b) (c) (d) (e) (f)
H-Section Steel Piling Large Diameter Bored Piling Micro Pile System Jack in Piling System Reinforced Concrete Piling; and Timber Piling
Where the Tender Cost Breakdown of the Form of Tender provides for the rates of the specified piling system to be indicated by the Contractor, the Contractor shall fill in all such tender rates clearly. Where the Tender Cost Breakdown does not provide such rates to be filled in by the Contractor even though the item of work involves piling, such piling work is deemed to be included in the Contract Sum for the said item of work.
2.2
PILING EQUIPMENT/MACHINERY The type of piling machine adopted shall be able to install piles taking into account the headroom constraint and proximity of the piles to the existing building. The Contractor shall provide sufficient piling machines and accessory equipment at any one time throughout the contract period. The use of diesel piling machines is strictly disallowed in the contract. The Contractor shall provide all necessary piling equipment/machinery to overcome obstructions such as hard soil layers, concrete or rocks, etc. such that when these obstructions are encountered the piles can be installed to the required depth for their sound performance.
2.3
EXPERIENCE OF CONTRACTOR/CONTRACTOR'S SPECIALIST FOR PILING WORKS The Contractor shall assess the load capacity of the piles in the various ground conditions encountered. He may engage a Piling Specialist for the piling works. The Piling Specialist so engaged shall be registered under BCA Construction Work Head CR08 and of Financial Grade L5 and above. The Piling Specialist shall also have a minimum of 5 years of relevant experience in large scale piling works and sufficient equipment for the piling works. In addition, the Site Supervisor to be engaged by the Piling Specialist shall have a minimum of 5 years of relevant experience in large scale piling works. The Contractor shall submit the names of the Piling Specialist as well as the Piling Specialist's Site Supervisor and proof of the relevant resources, experience and expertise for approval by the SO Rep. Notwithstanding the approval of the Piling Specialist and Piling Specialist's Site Supervisor by the SO Rep, the Contractor shall be fully responsible for the works. Further, such approval shall not affect, vary or relieve the Contractor's obligations under the Contract. If the Contractor is also registered under BCA Construction Work Head CR08 of Financial Grade L5 and above and with a minimum of 5 years of relevant working experience in large scale piling works, the Contractor may seek the approval from the SO Rep to carry out the piling works himself. In addition, the Contractor shall submit written evidence to show that he has sufficient equipment and the persons to be engaged for the piling Works have had the required experience and expertise.
BLDG12/S02.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 2-2 2.4
WORK SCHEDULES The Contractor shall submit a progress schedule showing the number of piling rigs, the rate of progress and the time required for piling and follow up works to the SO Rep as soon as that site is handed to the Contractor. The Contractor shall adhere strictly to the approved schedule otherwise he shall be liable for Liquidated Damages. The Contractor shall inform the SO Rep in writing the dates of arrival and departure of each piling rig at every site. No piling rig shall leave a site without prior approval of the SO Rep.
2.5
SITE CONDITIONS AND CONSTRAINTS The Contractor shall visit the project site to determine the nature of site conditions and extent of site constraints e.g. poor soil condition. He shall consider the effects of the above condition/constraint may have on his machinery movement, method of pile installation, temporary works or special equipment required, etc. for the completion of foundation works, when he submits his tender.
2.6
PLATFORM LEVEL The Contractor shall check and ensure that the platform level as indicated in the piling plans tallies with the corresponding architectural plans and structural plans. The Contractor shall highlight to the SO Rep if there is difference of platform levels indicated in different sets of plans before commencement of works.
2.7
INFORMATION ON GROUND CONDITIONS Geotechnical information concerning the site shall be provided to the Contractor. However, the SO Rep / HDB accepts no responsibility for the accuracy and/or comprehensiveness of any such information provided. The Contractor shall inspect and examine the site and its surroundings, and carry out all independent investigations, satisfy himself as to the nature of the ground and sub-soil, the form and nature of the site and nature of the Works and obtain all necessary information as to other circumstances which may affect his tender price. If the Contractor wishes to carry out his own ground testing, he shall submit his proposal to the SO Rep for approval prior to such tests and all expenses incurred as a result of the tests shall be borne by the Contractor. All such proposals must be submitted not later than 2 weeks before the tender closing date for the project. The tender closing date will not be extended for any ground testing requested by the Contractor. No claim by the Contractor for additional payment will be allowed on the ground of any misunderstanding or misinterpretation of any such matter or for the Contractor's failure to obtain all necessary information nor shall the Contractor be released from any duties, responsibilities or obligations imposed on or undertaken by him under the Contract on any such ground or on the ground that he did not or could not foresee any matter which might affect the Works.
2.8
CABLES/SERVICES DETECTION The Contractor shall visit and examine the site carefully and ascertain its nature and make provision in the Tender Price for the type of ground conditions, constraints and presence of any underground services. The Contractor is to provide cables/services detecting devices to locate all existing cables/services prior to the commencement of excavation or piling work. He shall engage PUB licensed cables/services detecting companies to carry out all cable/services detection work. The proposed line of excavation or piling work shall be checked for existing services in a systematic manner by making sufficient passes in a grid formation to cover the entire area of work. The Contractor shall notify the SO Rep where mains, pipe or conduit are encountered during excavation and where any excavation is carried out adjacent to or under any existing cable, pipe, structure; or any other such work that may be affected by subsidence, regardless of whether such work is shown on the Drawings or not. If it becomes essential, in the opinion of the SO Rep, the SO Rep may direct and the Contractor shall be paid for this additional work unless in the opinion of the SO Rep such additional work has been necessitated by the Contractor's negligence, lack of foresight or faulty workmanship.
BLDG12/S02.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 2-3 2.8
CABLES/SERVICES DETECTION
(CONT’D)
In the event that damages have been caused to the public services due to the Contractor's work or otherwise, all expenditure for such necessary repairs etc incurred by the relevant public Authorities shall be borne by the Contractor regardless of whether such repairs are due to accident or otherwise. The costs for such repairs shall be deducted from monies due or becoming due to the Contractor or by direct payment by the Contractor to the Authorities. If, in the opinion of the SO Rep, it is essential to permanently divert any cable, pipe or other services, the cost of diversion shall be paid for by the Employer.
2.9
NOISE, VIBRATION, DISTURBANCE AND SAFETY OF EXISTING BUILDINGS/STRUCTURES The Contractor shall comply with the requirements of the Environmental Pollution Control Act and all relevant authorities’ rules and regulations, in respect of work that affects the public. All piling operations and excavation works shall be carried out without unreasonable noise, vibration and disturbance. The Contractor shall bear all risks and responsibilities in carrying out the piling operations and excavation works and shall be responsible during the progress of the piling operation and excavation works for any damage or disturbance to existing or adjoining properties, or annoyance or nuisance to residents and users of these properties. The Contractor shall be responsible for the safety of the existing buildings/structures and shall include in his contract sum the provision and construction of necessary and adequate shoring and supports within existing buildings/structures, to underpin and strengthen the existing building foundations against any adverse effect arising out of the execution of the piling operation and excavation works.
2.10
SITE SURVEY, GROUND MOVEMENT / VIBRATIONS CONTROL MONITORING The Contractor shall engage a Professional Engineer (PE) who will specify the method, procedure, precautions etc, where piling / excavation works are to be carried out close to existing buildings or structures at his own cost and expense. The PE shall study the nature of the proposed piling / excavation works, ground conditions, existing and proposed buildings and structures within the site, existing neighbouring buildings, structures, properties, and gather any other relevant information in order to make the following necessary submissions to the SO’s Rep or other relevant Authorities : (a)
The PE shall submit a vibration monitoring layout plan. The allowable vibration level must be explicitly stated in the submission.
(b)
The PE shall submit his design drawing on retaining works and instrumentation monitoring programme. The allowable ground movements for excavation work must be explicitly stated in the submission.
(c)
The Contractor and his PE shall carry out a pre-construction survey on all the neighbouring properties. A Registered Surveyor has to be engaged in the process if necessary. The Contractor and his PE shall extend a copy of the survey report to the owners of all the neighbouring properties.
(d)
The Contractor and his PE shall carry out crack monitoring to measure movement across cracks in vertical and horizontal directions.
(e)
The Contractor and his PE shall carry out settlement monitoring. When any of the following criteria is reached irrespective of whether damage has occurred, the Contractor shall notify the SO Rep immediately. (i) 5mm settlement or movement between consecutive readings. (ii) 15mm total settlement of any part of a building/structure.
Four sets of the comprehensive reports shall be submitted within two weeks after the completion of the monitoring works. The Contractor and his PE shall be fully responsible on the adequacy of the above designs and submissions. The PE shall be aware of his responsibility as spelt out by BCA’s circulars and announcements in making the above submissions. All of the above requirements are to be complied with before commencement of works. BLDG12/S02.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 2-4
2.11
PROTECTION TO EXISTING FOUNDATION While carrying out any excavation work, the Contractor shall exercise due care and diligence to protect the existing foundation. Exposure of existing footing and piles under the pilecaps shall be avoided to prevent disturbance to the bearing soil or the soil around piles. The costs and expenses for protection during excavation are deemed to have been included in the Contract Sum.
2.12
STANDARD AND CERTIFICATES All materials used in the installation of piles shall be obtained from approved manufacturers. Materials and articles used shall comply with appropriate Singapore Standards (S.S.) where these exist, otherwise British Standards (B.S.) or other approved Standards will apply. Where the standard given in this document has been amended or superseded, the current Standard shall apply. Where British Standards are given in this document, the corresponding Singapore Standards where existing shall prevail. The recommendations in the appropriate Singapore Codes of Practice (C.P.) shall be referred to during the construction where these exist otherwise British Codes of Practice or other approved codes shall apply unless otherwise directed by the SO Rep. In all cases where materials or articles are specified to comply with respective Standards the Contractor shall, if required, obtain from the manufacturers and supply to the SO Rep the appropriate Certificate of Compliance with the Standard.
2.13
TESTING OF MATERIALS The SO Rep may appoint independent persons to carry out test on materials to be used in the works. The cost of conducting any test shall be borne by the Contractor unless otherwise specified. The SO Rep may cause a sample to be taken from each consignment of materials to be tested and the results of such testing shall be accepted as final. Any material test that fails shall be considered not to have fulfilled the requirements. In that event, the SO Rep may, without prejudice to other rights under the Contract, order such further test(s) as he deems necessary, all at the cost and expense of the Contractor. In addition, the whole consignment may be liable to be rejected and shall be removed from site at the Contractor's own expense when directed by the SO Rep. The costs of the failed tests together with all administrative expenses incurred shall be borne by the Contractor. All the tests as and when directed by the SO Rep. must be carried out at HDB’s Engineering Materials Laboratory or Accredited Laboratories
2.14
RESERVED
2.15
REMOVAL OF OBSTRUCTION The Contractor shall allow for at his own cost, excavation in any material to remove obstructions which prevent driving / drilling or which interfere with the proper alignment of the piles, timbering, backfilling, restoration of ground surrounding the piles and any other works necessary to complete the operation to the satisfaction of the SO Rep. No claims for standing time for rigs will be allowed in consequence of any kind.
BLDG12/S02.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 2-5
2.16
PENETRATION AND SIZE OF PILES The Contractor shall be required to install any size of the piles as shown in the specifications or drawings and each pile in the position indicated on the drawings to the required depth. The onus of obtaining the required resistance to withstand the required test load within the limit of settlement shall rest with the Contractor but the piles shall not be installed unnecessarily beyond the depth for them to develop the required test load. Should Contractor find that a longer penetration is required due to poor ground conditions being encountered as work proceeds, this will be permitted only if it is proved to be justified by examination and tests of the soils in the boreholes. The Contractor must also state sound and acceptable basis for determining the penetration required. If ground conditions indicate that the sizes of any subsequent piles as proposed and shown on the drawings are inadequate then the Contractor shall produce sufficient evidence to prove that a larger diameter would be more suitable. Conversely, where a pile is to be constructed in very good ground, the Contractor must produce sufficient evidence to show that the reduced length of pile will be capable of carrying the specified load. However, the Contractor must first obtain the approval of the SO Rep if longer or shorter penetration is required.
2.17
TOLERANCE FROM TRUE POSITION The centre of each pile at the cut-off level shall not deviate from its true position as shown in the drawings by more than 75 mm in any direction. Should the deviation be more than the stated tolerance in any direction, the affected pile is liable to be rejected and compensating piles shall be installed at Contractor's own expense when directed by the SO Rep. All additional cost of amendment in pile cap, beams, etc designed as a counter measure to the pile eccentricities exceeding the permissible tolerance shall also be borne by the Contractor.
2.18
DAMAGED AND REJECTED PILES Damaged piles and piles installed out of position or twisted shall be rejected and/or removed and replacement pile(s) shall be substituted by the Contractor at his own expense even if piles of bigger capacity are required. Piles shall be installed truly vertical and any pile with an inclination exceeding 1 (horizontal) to 75 (vertical) is liable to be rejected and shall be similarly removed and replaced when ordered by the SO Rep at Contractor's own expense. In addition, the Contractor shall also bear the extra cost as a result of rejection and replacement or supplemented by additional pile(s) due to an increase in size of pile caps, strengthening of the ground beam, etc. Piles which have risen or are disturbed as a result of installing adjacent piles shall be reinstated to the original depth and resistance. Otherwise, it shall be replaced by compensating piles at the Contractor's expense.
2.19
PILE VERTICALITY MEASUREMENT The Contractor shall provide all necessary equipments to facilitate the measurement of the verticality of the piles. All such equipments shall be pre-approved by the SO Rep.
BLDG12/S02.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 2-6 2.20
LOAD TESTS (a)
Standard Load Test (SLT) The Contractor shall include in the Contract Sum the number of standard load tests as specified by the SO Rep for the whole Contract. Unless otherwise required under the Contract, Standard Load Test shall be conducted on working piles by loading the piles to twice their nominal working loads. The SO Rep shall decide when testing can commence and the Contractor shall proceed with testing only after the instruction of the SO Rep has been given to him to test the pile. As soon as a test pile has been selected the Contractor shall prepare for the test without delay. All selected test piles must be tested within two weeks from the date of selection. Standard Load Tests shall be carried out on any such working piles as may be ordered by the SO Rep.
(b)
Ultimate load test (ULT) The Contractor shall include in the Contract Sum the number of ultimate load tests (including the installation of the test piles) and the pile instrumentations as specified by the SO Rep for the whole contract.
2.21
ULTIMATE LOAD TEST The Ultimate Load Test (ULT) on a test pile shall be conducted before the installation of the working piles, and/or otherwise directed by the SO Rep. The ULT is conducted to determine the expected settlement and the ultimate capacity of the pile, and to check the pile integrity. It shall be a pile different from the working pile. Unless otherwise required under the Contract, NO Ultimate Load Test shall be conducted on a working pile. For non-instrumented ULT, the pile is tested to 2.5 times nominal working load. For instrumented ULT, the pile is tested to 3 times nominal working load. The Ultimate Load Test on a test pile will be deemed to fail if, (i)
its settlement under the test load (a) (b) (c)
exceeds 25mm at 2 times nominal working load; or continues without further load increment before or at 2.5 times nominal working load; or does not meet other requirements as specified in the relevant clauses of the SS CP4 for Foundations; or
(ii)
any portion of the pile has failed, crumbled or distorted from its original position; or
(iii)
the load test cannot be completed for any reason.
In the event of failure of this ultimate load test on the test pile, instrumented or non-instrumented as the case may be, ONE (1) further test (including the installation of the test piles) shall be carried out at the Contractor's expense. In addition, for bored pile system, the compensating ultimate load test shall be carried out as an instrumented bored pile at the Contractor's expense. If the subsequent test fails again, the ultimate load test results may be used to assess the suitability of the pile type, pile design and layout proposed, or more further tests (including the installation of the test piles) may be ordered by the SO's Rep if deemed necessary all at the Contractor’s cost and expense.
BLDG12/S02.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 2-7 2.22
LOADING OF TEST PILES Adequate facilities and sufficient equipment shall be provided by the Contractor for at least two (2) load tests to proceed simultaneously at any one time. (a)
The test load may be applied to the pile by jacking against kentledge or anchor pile. The clear distance between a test pile and any anchor pile shall not be less than 3 metres. Where piles are in groups, the use of other working piles as anchor piles may be allowed subject to the approval of the SO Rep. Notwithstanding such approval the Contractor shall be solely responsible for making good as the SO Rep considers necessary any damage to such anchor piles which are used as permanent piles.
(b)
Pile top levels of test piles shall be recorded immediately after selection and in any case before the erection of kentledge platform. This shall be done by reading levels on two diagonally opposite corners of the pile top.
(c)
All test equipment such as surveying level, oil pumps and hydraulic jacks shall be accurate and in sound condition. Prior to commencement of test, Certificates shall be submitted to the SO Rep to show the date of last checking for accuracy. The last calibration date of all test equipment must not be more than three months or as directed by the SO Rep.
(d)
The hydraulic pump for the jack shall, when required, be encased in a steel or wooden box under lock and key. The area surrounding the test pile shall be cordoned off by protective fencing.
(e)
In the preparation of all test piles the Contractor shall ensure the rigidity of the supports at all corners of the platform. If piles are required to support the platform they shall be installed at Contractor's own expense.
(f)
If any test is discontinued or fails to reach the specified load due to (a) faulty jack or gauge, (b) unstable support of kentledge, (c) cracking in or damage to the pile, (d) the datums not being set out properly, (e) unstable benchmark or scales, (f) pre-jacking or pre-loading or any other cause, then the test shall be abandoned and the results disregarded. A further test shall be carried out at Contractor's own expense.
(g)
The settlement shall be measured to an accuracy of not less than half mm from a datum which must be on an immovable structure or be on a pile and it shall not be affected by any movement of the ground due to the test loading, driving of piles or any other causes.
(h)
For Standard Load Test, the test load shall be imposed by equal increments at approved intervals of load equivalent to 25% of the working load of the pile with each load increment being maintained for at least 15 minutes until the full test load is reached. This test load at the nominal working load shall be maintained for 24 hours before the operation to load the pile to its full test load (2 times the nominal working load) is continued. The full test load shall remain for a period of no less than 3 (three) days or as directed by the SO Rep. The results shall be plotted to produce a loadsettlement curve.
(i)
For Ultimate Load Test, the test load shall be imposed by equal increments at approved intervals of load equivalent to 25% of the working load of the pile with each load increment being maintained for at least 15 minutes until the full test load is reached. This test load at the nominal working load and at two times nominal working load shall be maintained for 24 hours before the operation to load the pile to its full test load (3 times the nominal working load) is continued. The full test load shall remain for a period of no less than 3 (three) days or as directed by the SO Rep. The result shall be plotted to produce a load-settlement curve.
(j)
All pile load test shall be carried out in compliance with CP4: 2003. Amongst other requirements, a calibrated load gauge and a calibrated pressure gauge shall be used to measure the force exerted on the pile under test.
BLDG12/S02.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 2-8
2.23
FAILURE OF STANDARD LOAD TEST A Standard Load Test shall be deemed to have failed if the settlement exceeds 25 mm at 2 times nominal working load for driving steel piles, large diameter bored piles, jack-in piles, micropiles, precast reinforced concrete piles and timber piles. For pile subjected to negative skin friction, the standard load test can be performed in the normal manner, but with its acceptance subject to satisfaction of an additional criterion that pile settlement at the test load of 1.0 time column load plus 2.0 times negative friction should not exceed 10mm. If a working pile so tested as herein specified, fails to sustain the full standard test load over a period to be decided by the SO Rep, but in any case not less than 3 days, then TWO further tests on other piles in any block at the same area selected by the SO Rep shall be carried out as directed by the SO Rep at Contractor's own expense. Where a pile fails under test, compensating piles, as directed by the SO Rep shall be provided and the group retested if deemed necessary by the SO Rep, the whole of the work shall be carried out at the Contractor's own expense.
2.24
SOUNDNESS OF WORK The Contractor shall be aware that load tests on piles are conducted for the purpose of studying the behaviour of piles and in particular settlement under load. As not every pile can be tested, the Contractor shall ensure that all piles are installed such that the total settlement or differential settlement shall be limited to a maximum angle of 1:500 so that the building to be supported will not be damaged due to settlement. For bored piles in buildings of ten(10) storeys or taller, the Contractor shall monitor and submit the settlement records at various selected columns to the SO's Rep. The acceptance of a few piles which pass the load tests does not relieve the Contractor from the responsibility for the soundness of the whole of the pile foundation. The Contractor shall be solely responsible for ensuring that all the piles are installed to such a depth that the required resistance is obtained.
2.25
ULTIMATE LOAD TEST AND STANDARD LOAD TEST REPORT Three sets of test reports, endorsed by the Contractor's Professional Engineer, shall be submitted to the SO Rep three working days after the completion of the test. The test reports shall contain such detailed information such as background, soil log, details of the test pile, test procedures, full analysis of the test results, etc. The reports must also be properly bound in booklet form. If the pile tested failed to sustain the required load or if the pile top settlement exceeds the permitted settlement specified, the report shall also contain an analysis of the pile behaviour concerning the pile settlement. Recommended measurement on improving the pile performance shall also be included.
2.26
MULTIPLE FAILURE OF WORKING PILES A block containing up to 500 piles will be deemed to have failed if 5 tests therein fail. In the event of such failure, the Contractor shall carry out sufficient further piling in accordance with the contract document as will ensure the safety of the buildings which are to be carried by the piles. The whole of such work shall be executed at the Contractor's expense, and the cost of amending pile caps and ground beams arising out of this, if any, shall be borne by the Contractor.
BLDG12/S02.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 2-9
2.27
CHECKING AND CUTTING OF PILES The Contractor shall include in the Contract Sum, excavation, trimming of the pile, true and level, to the cut-off level and any other necessary works for the completion of the operation. Immediately after piling is completed in a block, the Contractor shall check and record the exact actual position of every pile as compared with the positions indicated on the drawings. Excavation and cutting of piles to the required cut-off levels (+/- 25 mm) shall follow immediately. Test loading of working piles shall commence immediately after a selection is made by the SO Rep and may be carried out before the completion of piling in the block. In the cutting of piles, the Contractor shall employ a Registered Surveyor to be responsible for the measurement of pile eccentricities and cut-off levels, including those for compensating piles. The Contractor shall make available all facilities and equipment for the SO Rep to confirm the measurement All the above works shall take no more than 3 (three) weeks as from the date the last pile is driven in the block regardless of inclement weather or testing time. The Contractor shall ensure that adequate number of licensed surveyors are available at the sites for such work. If the Contractor fails to comply with this requirement, the Employer shall be entitled to employ and pay other persons to carry out the same and all expenses consequent thereof shall be deducted from the monies due to the Contractor without prejudice to the Employer's right to claim any sum over and above monies thus applied.
2.28
PILE PENETRATION AND ECCENTRICITY PLANS Completed pile penetration plans and eccentricity plans (3 copies each) shall be checked and certified by the Contractor's Licensed Surveyor and endorsed by a Professional Engineer directly employed by the Contractor before submitting to the SO rep. The duly endorsed eccentricity plans and penetration plans for each block must be submitted to the SO Rep not more than one month from the date the last pile is driven in the block regardless of inclement weather or testing time.
2.29
SUM AND/OR RATES INSERTED BY THE CONTRACTOR IN THE TENDER COST Breakdown of the Form of Tender shall be the full and inclusive cost and expenses to cover the supply of plant, materials and labour for the execution of piling works in any ground, completely and as specified including but not limited to the following: (a)
All preliminary works on site including the setting up of site office, test cube shed, water supply, washing bay, etc.
(b)
The provision and mobilisation of piling rig to install any size of piles including hammer or auger and all necessary accessories, equipment, tools and appliances brought to the site, erection, movement of piling rig from pile to pile and from building block to other building block within the piling site, dismantling and removal on completion of the work on site.
(c)
The installation of piles to any level below ground level including rocks and to a resistance as specified, including the supply, use and removal of drilling mud or steel casings to support the borehole prior to concreting or cement grouting.
(d)
The setting out of all pile positions in accordance with the drawings.
(e)
To excavate in any material and cut back piles to cut-off level as specified.
(f)
To check the final position and cut-off level of all piles.
(g)
The removal of all spoil, cement slurry and water from site or pile pits as directed by the SO Rep.
(h)
The cleaning of the site on completion.
(i)
The payment of all insurance, water and other charges.
(j)
The observance of all other directions, instructions and clauses contained in all documents forming this tender and the carrying out of the complete work to the satisfaction of the SO Rep and in accordance with the Specifications.
BLDG12/S02.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 2-10 2.30
ADJUSTMENT TO CONTRACT SUM AND PAY LENGTH OF PILES Upon completion, the value of piling works executed by the Contractor shall be determined by the SO Rep. The Lump Sum for the whole of the piling works as entered by the Contractor in the Form of Tender shall then be adjusted based on the value of piling works executed by the Contractor. The adjustment (addition or omission) shall be the net difference between the Lump Sum and the value of piling works executed by the Contractor. The addition or omission amount shall be added to or deducted from the Contract Sum as the case may be.
(a)
For piling works where the Provisional Quantity (in metre) for the respective pile size is shown in the Form Of Tender The value of the piling work executed by the Contractor shall be the product of the total actual pay length and the Basic Rate per metre. The actual pay length of each pile shall be measured from the specified cut-off level of the pile to the end of the pile. The pay length shall be measured to the accuracy of the nearest 10mm. The Basic Rate for the respective pile size shall be derived as follows: Basic Rate = Lump Sum for Respective Pile Size in the Form Of Tender* Provisional Quantity (metre) for Respective Pile Size in the Form Of Tender*
The value of Standard Load Tests (SLT) shall be the product of the actual number of tests and the Basic Rate as derived as follows: Basic Rate = Lump Sum for SLT in the Form of Tender* Provisional Quantity (No.) for SLT in the Form of Tender*
The value of Ultimate Load Tests (ULT) shall be the product of the actual number of tests and the Basic Rate as derived as follows: Basic Rate = Lump Sum for ULT in the Form of Tender* Provisional Quantity (No.) for ULT in the Form of Tender*
Note : * As shown in respective items of the breakdown of Total Lump Sum in the Form of Tender.
(b)
For piling works where the Provisional Quantity (in metre tonne) for the respective pile size is shown in the Form Of Tender The value of the piling work executed by the Contractor shall be the product of the total metretonne and the Basic Rate per metre tonne. The metre-tonne of each pile shall be the product of the actual pay length of the pile and the nominal working load of the pile. The actual pay length of each pile shall be measured from the specified cut-off level of the pile to the end of the pile. The pay length shall be measured to the accuracy of the nearest 10mm. The Basic Rate for the respective pile type shall be derived as follows: Basic Rate = Lump Sum for Respective Pile Type in the Form of Tender* Provisional Quantity (metre tonne) for Respective Pile Type in the Form of Tender*
The value of Standard Load Tests (SLT) shall be the product of the actual number of tests and the Basic Rate as derived as follows: Basic Rate = Lump Sum for SLT in the Form of Tender* Provisional Quantity (No.) for SLT in the Form of Tender*
The value of Ultimate Load Tests (ULT) shall be the product of the actual number of tests and the Basic Rate as derived as follows: Basic Rate = Lump Sum for ULT in the Form of Tender* Provisional Quantity (No.) for ULT in the Form of Tender*
Note : * As shown in respective items of the breakdown of Total Lump Sum in the Form of Tender.
BLDG12/S02.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 2-11
2.31
COMPLETION OF PILING WORK Piling Works to a building block shall only be considered complete if the piles are piled, excavated, cut-off, checked and recorded in the pile layout drawings for eccentricities and levels and compensated for rejected piles.
2.32
H-SECTION STEEL PILING
2.32.1
Hydraulic Hammer Pile Driving Machines The Contractor shall use only hydraulic hammer pile driving machines which are fully enclosed with noise dampening enclosures and the usage of such machine shall comply with all relevant regulations as well as provisions in this Specifications in regard to pollution control. Generator sets for electricity supply and welding purposes shall have adequate housing and exhaust silencer to minimise noise and shall be subjected to the approval of the SO Rep prior to use on site.
2.32.2
Steel Pile Sections The steel pile sections shall comply with the relevant Singapore Standards, where these exist, or the equivalent British Standard BS 4360 for mild steel. Before driving commences, all sections shall be clean and free from any contamination or materials which will impair their strength.
2.32.3
Nominal Working Load The nominal working loads of various sizes of piles are indicated in the Drawings
BLDG12/S02.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 2-12 2.32
H-SECTION STEEL PILING
2.32.4
Length of Steel Pile Sections
(CONT’D)
The length of new steel pile sections delivered to piling site shall be 12 m long. If the Contractor intends to use steel pile sections of other lengths, the approval of the SO Rep must first be obtained prior to their delivery to the stockyard or piling site. 2.32.5
Use of Jointed Sections If the Contractor wishes to drive piles made up of remaining sections from site, he shall obtain written approval from the SO’s Rep first. Where jointed steel sections are proposed to be used for the installation of steel piles, the following conditions must be complied with :-
2.32.6
(a)
Jointed steel sections shall not be used in pile groups of less than 4 piles.
(b)
For pile groups of four or more piles, the number of jointed section piles shall be not more than one out of every four piles.
(c)
The length of each jointed section shall not be longer than 12 metres nor should be shorter than 9 metres, comprising not more than three short sections shop-welded together, each short section being not less than 3 metres. All joints shall have splice plates at both flanges.
(d)
All jointed sections piles shall be straight, free from dents and corrosion pits. They shall be measured and properly recorded before installation.
(e)
All jointed section piles shall be fabricated from sections obtained from the same site. Jointed section piles built up from sections imported from another site shall be strictly prohibited.
Quality of Welded Joints and Welders The Contractor shall ensure and maintain a high standard of quality welded joints. The quality of the welded joint between pile sections depends not only on the quality of the weld material but also on the skill of the worker. The welder shall possess at least National Trade Certificate 3 (NTC 3) for Arc welding issued by a recognised and approved institute. Notwithstanding this, the welder shall be subjected to re-qualifying by approved welding inspectors as and when required by the SO Rep. A high standard of workmanship of welders shall be maintained to ensure a high standard of quality of the welded joints. All pile sections at each piling site must be neatly stacked in the "H" position to facilitate cutting of the 45 degree chamfer. Before commencement of piling, each welder shall execute a sample joint for inspection. If the quality of the welded joint is unsatisfactory, the welder will not be allowed to carry out welding until he has proved by the way of a subsequent demonstration that he can perform a welded joint satisfactorily. During piling, all welded joints of pile sections shall be checked. A welder who produces unsatisfactory welds shall be replaced and shall not be allowed to carry out welding at any other site. The contractor shall fabricate and supply adequate number of weld gauge for use by Consultant’s site supervision staff.
BLDG12/S02.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 2-13 2.32
H-SECTION STEEL PILING (CONT’D)
2.32.7
Record of Steel Pile Driving Records of driving for every steel pile shall be kept by the Contractor and a copy shall be submitted to the SO Rep on site. The records shall include the following: (a) (b) (c) (d) (e) (f) (g) (i)
set temporary compression full length and serial numbers of steel sections reduced level at top of pile reduced cut-off level pay length time of completion inclination of the pile
The form of this record must be approved by the SO Rep before driving commences. The method of measuring the set and temporary compression shall be approved by the SO Rep. The above record must show a series of sets and temporary compressions measured during the process of driving. Once the driving of a pile has commenced, it shall continue until the final penetration or set is reached. Immediately after a pile reaches its final set, the reduced level of the top of the pile section shall be certified so that the exact pay length of the pile may be recorded. 2.32.8
Marking of Steel Sections Serial number and length shall be marked in paint on every steel section on arrival to site. Length of section shall be measured to the nearest 10 mm. Full record shall be submitted to the SO Rep daily for checking.
2.32.9
"Dolly" or Follower Disallowed During Pile Driving "Dolly' or Follower is strictly not allowed to be used during pile driving on site. The SO Rep shall exercise his right under "Nuisance and Irregularities" Clause to impose charges against the Contractor for any noncompliance.
2.32.10
Dynamic Test Pile For Steel H-Pile The Contractor shall engage an independent testing specialist who provides at all times, operate and maintain a set of portable equipment for the dynamic testing of pile foundations. The equipment shall be the latest model of its kind, Model GCPC Pile Driving Analyzer or its equivalent. The equipment shall also be equipped with the latest revision of the CAPWAP programme to perform data analysis of the field data. The CAPWAP programme should include features for interactive or automated mode for calculation and matching of the forces, velocity waves, calculation of CASE capacity, calculation of pile-toe resistance vs toe movement for end-bearing piles, wave equation analysis using pile top measurements, static loadsettlement analysis based on the CAPWAP results and capable of giving both numerical and graphic output and other utilities for the processing of the field data. The Contractor shall ensure that the Hardware and Software owned by the third party testing specialist are in good working condition to the satisfaction of the SO Rep. The Contractor shall submit specifications and details of the Hardware and Software for the SO Rep approval before carrying out the dynamic test pile. If the Contractor fails to make available the Hardware and Software within 2 weeks after notification by the SO Rep on the need to carry out the test, the SO Rep will make the necessary arrangement to engage other testing specialists to carry out the dynamic pile test and CAPWAP Analysis and all costs and expenses thus incurred shall be recovered from the Contractor. The portable dynamic testing equipment should be in a compact unit suitable for rugged use at the piling site. The unit shall contain automatic signal conditioner, printer and a high resolution screen for display. The printer should be capable of producing report quality graphs as well as printout of data in the field. The Contractor shall ensure that qualified personnel viz. an engineer and a technician are available at all times for the operation of equipment and for conducting the test.
BLDG12/S02.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 2-14 2.32
H-SECTION STEEL PILING (CONT’D)
2.32.10
Dynamic Test Pile For Steel H-Pile
(Cont’d)
Three sets of test reports, endorsed by the Contractor's Professional Engineer, shall be submitted to the SO Rep one week after the completion of the test. The test reports shall contain such detailed information such as background, soil log, details of the test pile, test procedures, full analysis of the test results, etc. The reports must also be properly bound in booklet form.
2.32.11
Failure of Dynamic Pile Test A Dynamic Pile Test shall be deemed to have failed if the maximum resistance of pile (RMX) at any time during blow, using a Case Damping Coefficient (J) as approved by the SO Rep, is less than 2 times the nominal working load of a working pile under test. If the force/velocity-time graph taken during the test does not indicate any abnormality, the SO Rep may allow the Contractor to re-tap the pile and another Dynamic Pile Test may be carried out all at the Contractor's cost and expense. If a working pile so tested fails and is rejected by the SO Rep, then TWO further Dynamic Pile Tests on other piles in any building block at the site may be carried out as directed by the SO Rep at the Contractor's cost and expense. In addition, compensating pile(s), as directed by the SO Rep shall be driven all at the Contractor's cost and expense. When the integrity of the pile from a Dynamic Pile Test is doubtful to the SO Rep, the Contractor is required to show proof that the integrity of the pile is acceptable to the SO Rep. Otherwise, compensating pile(s), as directed by the SO Rep, shall be driven all at the Contractor's cost and expense.
2.32.12
Bracing of Steel Piles When penetrations of steel piles are short or when site conditions warrant the need to strengthen the steel piles against movement, the Contractor is required to brace the piles as directed by the SO Rep. The Contractor shall include in his Contract Sum the cost of bracing these steel piles with steel sections or reinforced concrete.
BLDG12/S02.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 2-15 2.33
LARGE DIAMETER BORED PILING
2.33.1
System of Piling The system and equipment offered by the Contractor for installation of large diameter bored piles: (a)
shall be capable of sinking bored holes with a range of diameters between 600 mm and 1800 mm and to a depth ranging from 10 m to 60 m depending on the nature of the ground.
(b)
may include, Flight Auger type system as the principal method for the work in general.
(c)
shall be capable of being modified to deal with whatever strata encountered, by the addition of further cutting or extraction or protective devices as may be required to deal with all ground conditions including: 1. Water bearing ground 2. Soft ground which caves in unless supported 3. Medium stiff or stiff clays 4. Sands or sandstone 5. Coarse gravels 6. Very stiff clays 7. Boulders and granite bedrocks 8. Thinly bedded shales 9. Tree roots or buried trunks
(d)
shall generate the minimum degree of vibration when operating alongside weak structures or until such depth is reached where vibrations may be dissipated without damage to existing foundations.
(e)
shall be capable of sinking and removing casings for the support of the boreholes to whatever depth that may be required (to the full depth of the borehole where necessary) and without disturbance to the ground surrounding the pile.
(f)
shall be capable of under-reaming the bases of the piles.
The Contractor shall be prepared to work in all ground conditions. 2.33.2
Cement All cement used in the works shall be from approved local manufacturers except otherwise permitted by the SO Rep. Where cement is specified it shall comply with SS26 and BS12. The SO Rep may make test of the quality specified at the Contractor's own expense. With each delivery, the Contractor may be required to send to the SO Rep a memorandum of the quantity delivered and the manufacturer's test certificate. Unless otherwise specified, the compressive strength test shall be used to determine the strength of cement.
2.33.3
Aggregates The materials used as aggregates shall be strong, hard, durable and free from clay lumps and organic and other impurities. All materials and grading of aggregates shall comply with SS 31. Notwithstanding the above, fine aggregates for concrete shall be clean well graded sand, free from clay, loam or organic matter. Samples shall be submitted by the Contractor for the approval of the SO Rep prior to their use as fine aggregates. Coarse aggregates for concrete shall be clean crushed granite, well graded between the limits of 5 mm and 20 mm. Samples shall be submitted by the Contractor for the approval of the SO Rep prior to their use as coarse aggregates.
2.33.4
Steel Steel reinforcement shall be obtained from local manufacturer or other manufacturers as may be approved in writing by the SO Rep and shall comply with SS2, SS 18, SS 32, BS 4449, BS 4461, BS 4482 and BS 4483 wherever applicable. All reinforcement shall be free from scale and all loose rust. It shall not be coated with any grease, oil, paint or adhering earth that may impair the bond between the concrete and reinforcement.
BLDG12/S02.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 2-16 2.33
LARGE DIAMETER BORED PILING (CONT’D)
2.33.5
Testing of Concrete For Bored Piling Works Where bored piles are included in the Works, a minimum of 4 cubes shall be cast for every 10m3 of concrete or part thereof for the purpose of compression tests at 7 days strength and 28 days strength. 2 cubes shall be tested at 7 days and the remaining 2 cubes shall be tested at 28 days. The SO Rep shall exercise his rights under clause 1.6 "Nuisance And Irregularities" to impose a charge against the Contractor for every cube which fails to attain the minimum specified strength at 28 days age as specified; in addition, the SO Rep reserves the right to reject the pile and the Contractor shall install compensating piles that will ensure the safety of the building to be supported by the piles. The compensating piles shall be installed all at the Contractor's cost and expense, and as directed by the SO Rep. The test cubes shall be made and cured in accordance with SS 78 and BS 1881. The cubes shall be tested at the HDB’s Engineering Materials Laboratory.
2.33.6
Concrete Strength The compressive strength of the concrete shall not be less than the strength in the following : Class (Grade) of Concrete Grade 35
2.33.7
Compressive Strength N/mm2 7 days
28 days
28
38
Ready-Mix Concrete The Contractor must obtain prior approval from the SO Rep who will, inter alia, require to be satisfied that the propose supplier will adhere to this Specification and that the quality and control of the mix are satisfactory and comply with SS 119 and BS 1926. The SO Rep shall have access to the concrete batching plant of the Contractor's ready-mix concrete supplier during all working hours of the plant. The ready-mix concrete shall comply in all respects with the specified requirements for concrete as outlined in this Specification, and the Contractor shall arrange and pay for the making of all requisite tests. Ready-mix concrete shall only be transported in continuous mixing trucks and comply with the manufacturer's operating standard. Appropriate retarder when used shall be subjected to the approval of the SO Rep. No additional water shall be added to the ready-mix concrete.
2.33.8
Concrete Mixes The Contractor shall submit, for the SO Rep's approval, a chart showing the design mix he proposes to use in the ready-mix concrete. The SO Rep shall at his own discretion, instruct the Contractor to carry out trial mix. For concrete mix used, the Contractor shall inter alia state the weights of cement, granite and fine aggregates, the type and amount of admixture and the water-cement ratio to be used in the mix. Grade 35 concrete shall be used for concreting in the dry and for tremie concreting under water or any other approved water-sealing fluid. In all conditions, the free water-cement ratio shall not be more than 0.5 for Grade 35 concrete. Notwithstanding the above, the slump for concrete measured by the standard slump cone shall be between 100 mm and 150 mm and the cement content in any mix shall not be less than 360 kg/m3. Where concrete is to be placed under water or where pile will be exposed to sea water, the cement content shall not be less than 400 kg/m3. For tremie concreting, the slump for the concrete shall be between 170 mm and 225 mm. The SO Rep reserves the right to instruct the Contractor to modify, alter and improve the concrete mix, if necessary.
BLDG12/S02.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 2-17 2.33
LARGE DIAMETER BORED PILING (CONT’D)
2.33.9
Nominal Working Load For large diameter bored piles, the pile diameters to be adopted shall be from 600mm to 1800mm in increment of 100mm. The nominal working loads of various sizes of bored piles shall be indicated in the Drawings.
2.33.10
Steel Reinforcement and Stirrups For bored piles subjected to compression, the cross-sectional area of the main steel reinforcement and length of the reinforcement cage shall comply with CP4. Details of the steel reinforcement cage are indicated in the drawings. For bored piles subjected to both compression and uplift, the length of the reinforcement cage shall extend to the base of the bored pile. The lap length of the reinforcement shall comply fully with the relevant Singapore Standards CP65 : 1999. The first top rung of stirrups where the reinforcing cage will be lifted shall consists of 3 layers of T10 bars, fully welded to the main steel reinforcing bars. All other stirrups (one layer of T10 bar) shall be spot welded to the main reinforcing bars of the reinforcing cage. The lapping joint for the stirrups shall be 50mm (fully welded) or 200mm (without weld) and the weld of the stirrups to the main reinforcing bars shall be able to withstand all condition of handling, transportation and during concreting. The reinforcing cage should not be distorted in any way during these processes and shall be vertical when lowered into the boreholes.
2.33.11
Plastic Circular Spacers Plastic circular spacers of 55 mm thickness to provide 80 mm cover to the main reinforcement shall be used. The spacers shall be placed at not more than one metre below the top of the reinforcement cage and at not more than 4 m interval along the main reinforcement.
2.33.12
Trial Bore The Contractor shall carry out trial bores by boring outside the pile location at his own expense to determine the required depth or suitability of bored piles as directed by the SO Rep. Sufficient safety measures must be provided to ensure protection against falling or tripping into the bored holes. The bored holes must be covered up immediately after it has been inspected.
2.33.13
Boring and Concreting of Piles (a)
Boring shall be carried down to such soil strata determined from results of trial boring and soil tests carried out previously as agreed by the SO Rep.
(b)
The sides of all boring shall be kept intact and no loose material shall be permitted to fall to the bottom of the bored holes. The Contractor's equipment shall be capable of sinking a steel casing to support and keep the side of the bored hole intact when directed by the SO Rep.
(c)
In cases where soil conditions are sufficiently stiff to hard to dense, and steel casings are not necessary, temporary casings of at least 5 m long shall be placed in the bored holes before inspection of bored holes by the SO Rep. These temporary casings must project at least 1 m above ground to prevent fall of loose materials or persons into the bored holes. All bored holes waiting for concreting shall be set up with the temporary casings at all times.
(d)
All bored holes shall be inspected by the SO Rep on site prior to placing of concrete. All loose material likely to affect the strength of the pile shall be removed forthwith by the Contractor to the satisfaction of the SO Rep.
(e)
The Contractor must provide all facilities to enable the SO Rep to carry out his inspection safely.
BLDG12/S02.DOC(17) Sal(151211) (DPD)
Bldg Spec Page 2-18 2.33
LARGE DIAMETER BORED PILING (CONT’D)
2.33.13
Boring and Concreting of Piles
2.33.14
(Cont’d)
(f)
Holes reamed out at the base shall likewise be clean and firm before placing of concrete.
(g)
If ground water is found in the borehole and it affects the excavation and removal of soil from the borehole, or if it causes the collapse of the sides of the borehole, or if the side collapses irrespective of the presence of water, then steel casing of appropriate length and size shall be installed in the bored hole.
(h)
All concrete placed in boreholes shall be lowered by hoppers with exceptional care so as to prevent segregation. Tremie pipes extending to the full depth of the pile shall be used for concreting under water.
(i)
The top of the pile shall be brought up at least 500 mm above the cut -off level of the pile to permit all laitance and weak concrete to be removed and to ensure that it can be properly keyed into the pile cap. Any defective concrete in the head of the completed pile should be cut way and made good with new concrete well bonded into the old concrete
(j)
All boreholes shall be protected from the possibility of ground surface water entering the hole from the time the boring is completed and ready to be concreted until the pile is complete. No concreting shall commence until the hole has been inspected and the above precautions made.
(k)
Reinforcement cages shall be supported centrally and firmly within the hole so that no movement will occur during the concreting operation
Record of Each Pile A record of each pile shall be kept by the Contractor and a copy shall be submitted to the SO Rep within 1 day after the installation of the respective pile. This record shall include the following information: (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n) (o)
Length of pile measured from cut off level Length of pile measured from ground level Diameter of pile Ground level Cut-off level Length of reinforcement cage Water table below ground level Length of casing Strata of ground penetrated and where boring stops Result of tests on concrete cube Time for commencement and completion of boring and concreting works Grade of concrete used Volume of concrete used and Concrete slump Other information as required by the SO Rep. Dry or tremie concreting
The form of this record must be approved by the SO Rep before piling commences. The Contractor shall also be required to provide log-book for use by the SO Rep for recording of the above information on site. 2.33.15
Piles in Same Group or in Close Proximity The Contractor must submit proposed sequence of installation of piles in a group or in close proximity to the SO Rep for approval. The SO Rep reserves the right to order changes to the approved sequence of piling if he considers it necessary to do so. Generally, no two piles in the same group or in close proximity may be allowed to be bored and/or concreted on the same day, unless with the written approval of the SO Rep.
BLDG12/S02.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 2-19 2.33
LARGE DIAMETER BORED PILING
(CONT’D)
2.33.16
Installation of UPVC Pipe And Wire For Pile Penetration Checking The Contractor shall install in all bored piles an approximately 16mm Nominal Internal Diameter hollow UPVC pipe of approved quality with a prelaid 3mm diameter wire inside the UPVC pipe within each castin-situ pile. The Contractor shall be paid separately for the installation of these UPVC pipes with wires (based on the pile penetration lengths) as a variation to the tender sum. The UPVC pipe with prelaid wire shall be placed from the base of the bored hole to the ground level for checking the length of each completed bored pile immediately after concreting. Upon completion of concreting of the pile, the UPVC pipe shall then be cut about 0.5m below ground level and capped. The UPVC pipe shall include joints and stoppers at the top and bottom ends of the pipe and the 3mm diameter wire shall be prelaid inside it from bottom of the pile to 0.5m above the cut off level prior to capping of the UPVC pipe. The prelaid wire, UPVC pipe thickness, glue length for joints, strength of pipe material and other qualities must be approved by the Superintending Officer's Representative before the commencement of work. Notwithstanding this, the pipe thickness and joint length between pipes shall be not less than 3mm and 150mm respectively. The pipes shall be installed vertically and concrete counterweights shall be used at the base of the UPVC pipe to ensure the verticality of the pipe. The Contractor shall ensure that the pipe is vertical and free from any obstruction which may prevent measurement of its length at a later date. The prelaid wire shall not be removed from the UPVC pipe and the contractor shall facilitate in the measurement of the pile length after the hacking of the bored pile to cut off level. In the event that substantial ground water is present in the borehole and the pile has to be formed by tremie concreting underwater or any other approved fluid, the Contractor shall not be required to install the UPVC pipe with wire. The Contractor shall note that the Employer attaches great importance on the condition of the UPVC pipes and prelaid wires. Where UPVC pipes are found choked or damaged or missing or without the prelaid wires during construction, the Contractor shall not be paid for the installation of these UPVC pipes with wires. In addition, during the conduct of pile penetration checking of selected piles for a block, a UPVC pipe is considered choked if the prelaid wire is unable to be extracted from the UPVC pipe for pile penetration checking. The percentage of chokage of the UPVC pipes based on these selected piles shall be calculated for this block. This percentage shall be deemed as representative of the percentage of chokage of UPVC pipes installed in piles in the entire block. For the payment of UPVC pipes with wires installed for this block, the Contractor shall be paid only for the total length of UPVC pipes with wires installed in the block (excluding UPVC pipes that are found choked or damaged or without the prelaid wires during construction) less the percentage of chokage of UPVC pipes for this block. In addition, an administrative charge may be imposed on the Contractor for the chokage of UPVC pipes.
2.33.17
Pile Integrity Test (PIT) for Bored Pile Where bored piles are included in the Works, the Contractor shall engage an independent specialist testing firm to conduct Pile Integrity Tests on the bored piles. The Sonic Echo method shall be adopted. The total number of tests to be conducted shall be 2 Nos or 2 % of the total number of piles in each building block, whichever is greater. The testing equipment shall be capable of carrying out exponential amplification of the signal with time, if necessary, so that weak reflections from locations at or near the pile toe can be clearly displayed. The Contractor shall provide proper access for the specialist’s testing firm to carrying out the test. The pile shall not be tested until at least 4 days after installation. During preparation, loose concrete, mud or debris, etc shall be removed from the pile head. The pile head shall be trimmed to expose sound concrete and to have flat top surface. The pile shall be tested by means of light blows from the small impact hammer.
BLDG12/S02.DOC(19) Sal(151211) (DPD)
Bldg Spec Page 2-20 2.33
LARGE DIAMETER BORED PILING
(CONT’D)
2.33.17
Pile Integrity Test (PIT) for Bored Pile (Cont’d) The Contractor shall ensure that the test is conducted by qualified personnel i.e. an engineer and a technician. Upon completion of the Pile Integrity Test, the Contractor shall furnish a preliminary report indicating the estimated pile penetration on the same day of the Pile Integrity Test to the SO Rep. Two sets of the final report, to be signed by a qualified testing specialist, shall be submitted within 5 days to the SO Rep. The final report, in printed form, shall include the following: (a) (b) (c) (d) (e) (f) (g)
2.33.18
Contract name and number Block number Pile reference number Pile diameter Date of pile installation and date of testing Graphical representation of the estimated pile shaft profile Qualitative analysis of the pile integrity which cover concrete quality, location and severity of the defect such as discontinuity or change in cross section of the pile, etc.
Instrumented Bored Piles Load Test The Contractor shall install the types and number of instruments as shown in the drawings for conducting the instrumented pile load test as follows:(a)
Weldable type vibrating wire strain gauges, or equivalent, which measure strain in the cast-in-situ concrete bored pile during the load test, shall be used. Each vibrating wire strain gauge shall have, at least, a maximum strain range of + 1500 microstrain, and a thermal coefficient of expansion of 10 x 10 –6 per oC . The pick-up sensor used shall be mounted on top of the vibrating wire strain gauge and shall be of a constant oscillation type, or equivalent.
(b)
8 mm diameter stainless steel telltale rod extensometers to measure the axial compression between the pile and the pile top.
(c)
Heavy-duty signal cables shall be used to connect the pick-up sensors to a terminal box at ground level.
(d)
The vibrating wire strain gauge shall be welded directly onto a single reinforcement bar positioned at the center and extended to the base of the pile. The central bar must be held in position vertically by means of horizontal ties connected to the reinforcement cage and shall be of the same diameter as the main reinforcement bars of the steel cage. The position and number of strain gauges that will be installed in the pile shall be as directed by SO’s Rep.
(e)
The reinforcement bar must be grounded to provide a flat surface before the strain gauges are welded on. The pick-up sensors must be firmly secured on top of the strain gauges by means of suitable clamps. Every strain gauge/pick-up sensor assembly shall be adequately rustproofed and waterproofed.
(f)
The 8mm diameter stainless steel telltale rod extensometers shall be installed vertically in the pile. 12mm internal diameter steel pipe shall be used for the protection of the telltale rod extensometer. An anchor plate must be provided at the toe of the telltale rod. All joints are to be properly welded to avoid grout ingress. A reference head and a depth micrometer must be provided for measuring the relative axial compression of the pile.
(g)
Proper protection must be provided for the strain gauges, pick-up sensors, cables, and telltale rods during all stages in the casting of the pile. The contractor shall carry out function test for the strain gauges and sensors : (i) after installation onto the steel reinforcement (ii) after hoisting and lowering of the steel reinforcement into the bore hole (iii) after concreting the pile
(h)
A Linear Vertical Displacement Transducer (LVDT) shall be placed on a magnetic stand fixed to the pile top and the probe of the LVDT shall be seated on top of a brass reference head at the top of each stainless steel rod. A readout unit shall be used to monitor the movement of the tell-tale extensometers.
BLDG12/S02.DOC(20) Sal(151211) (DPD)
Bldg Spec Page 2-21 2.33
LARGE DIAMETER BORED PILING
(CONT’D)
2.33.18
Instrumented Bored Piles Load Test
(Cont’d)
(i)
Equipment, tools, heavy-duty cables, readout unit and other accessories must be in good working condition and calibrated.
(j)
Test load increments and pile settlement measurement must be carried out in accordance with the testing procedures detailed in Clause 2.20.
(k)
The installation data for every instrument and test results shall be captured and recorded by the contractor’s instrumentation specialist.
(l)
Two sets of the comprehensive reports incorporating relevant soil logs and interpretation of results, to be verified and certified by the contractor’s Professional Engineer involved in the installation of the instruments, shall be submitted to the SO’s Rep within two weeks after the completion of work.
(m)
The Contractor shall be responsible for the security of all the instruments installed.
(n)
The Contractor will carry out at his own cost, another instrumented pile load test as instructed by the SO’s Rep if the test produces erroneous results due to damaged or malfunctioned instruments.
2.34
MICRO PILE SYSTEM
2.34.1
Hydraulic Drilling Rig and Accessories The Contractor shall use only electrically powered hydraulic drilling rigs to minimise noise generated during drilling operation. The slurry circulation tanks shall be used to remove all spoil cement slurry and water from the pile pits. Generator sets for the supply of electricity shall have adequate housing and exhaust silencer to minimise noise and shall be subject to the approval of the SO Rep prior to use on site.
2.34.2
Installation of Micro Piles The installation of the micro piles or any other sizes approved by HDB shall include inter alia the following requirements: (a)
The quality of materials such as Grade 460 steel bar, cement grout, grout additive, splice material, etc must be approved by the SO Rep. Equipment, tools and other accessories must be in good working condition.
(b)
All site safety precautions must be observed and safety measures provided and maintained throughout the installation work.
(c)
Grout shall be mixed from ordinary Portland cement complying to current British or Singapore Standards and clean water supplied from the public mains. Whenever necessary, "Intrusion Aid" grout additive shall be added to the manufacturer's recommendation to improve workability and reduce shrinkage. The grouting shall be executed within such time as may be directed or approved by the SO Rep. The strength of grout shall not be less than Grade 30.
(d)
The installation of every micro pile and the test results of any one piling site shall be captured and recorded and a comprehensive report, to be verified and certified by the Contractor's Professional Engineer involved in the micro pile installation, shall be submitted to the SO Rep within two weeks after the completion of the work at each piling site.
(e)
Any other conditions that may be imposed by the SO Rep to ensure the safety and soundness of each micro pile.
BLDG12/S02.DOC(21) Sal(151211) (DPD)
Bldg Spec Page 2-22 2.34
MICRO PILE SYSTEM (CONT’D)
2.34.3
Nominal Working Load For micro piles, the pile diameters to be adopted shall be from 150mm to 300mm in increment of 25mm. The nominal working loads of various sizes of micro piles shall be indicated in the Drawings.
2.34.4
Boring of Micro Piles For soft and collapsible soils, the boreholes shall be temporarily cased or stabilised with bentonite slurry. Upon reaching rock or firm soil strata, drilling may be continued without casing. Drilling in rock shall be executed with a down-the-hole air hammer. Boring in soil can be done by wet or dry rotary drilling depending on the soil type and site environment. Upon completion of the drilling, the borehole shall be cleaned by flushing out any loose chipping/soil particles from the inside of the casing with water or air.
2.34.5
Main Steel Component of Micro Pile Axial steel component of the micro pile shall be in accordance with the specifications and drawings. The main steel bars shall be joined by splicing. Splicing shall be of approved mechanical splicing. Top anchorage of the micro pile shall consist of extension of the axial steel component of the pile through a steel bearing plate. The circumference of the steel bars through the steel plate shall be securely welded. The contractor shall propose his method of reinforcement splicing or coupling to SO Rep for approval. Upon approval of the method, the contractor shall proceed to fabricate samples of splicing or coupling and send them to an approved laboratory for testing on its tensile strength. The splicing or coupling shall be strong enough such that its tensile strength is higher than the reinforcement. Three samples shall be tested and the results of the tests are to be accepted before installation of working piles. The costs of fabrication of the test samples and testing are to be borne by the contractor.
2.34.6
Grout Mix The proportion of grout according to minimum cube strength shall comply with the following requirements:
Range of Water/Cement Ratio 0.40 to 0.45
Resistance to Crushing (cube strength) 7 days
28 days
24 N/mm2
33 N/mm2
The quantities of cement in the mix shall be measured by weight. Grout shall be mixed on site and shall be pumped into its final position not later than half an hour after mixing. Grout shall be free from segregation, slumping and bleeding. 2.34.7
Grouting Grouting shall be placed using tremie method where grout mix is pumped into the bored hole by grouting pump under low pressure and delivered using PVC hose or galvanised iron pipe in one continuous operation until "good grout" appears at the top of the borehole.
2.34.8
Grout Test 4 test cubes shall be taken from the grout mix of every 3 m3 or a portion thereof for testing purpose for each day when there is grouting works, unless further tests are required due to failure in complying with the specified strength. 2 test cubes shall be tested at 7 days and the remaining 2 cubes shall be tested at 28 days at HDB’s Engineering Materials Laboratory at the Contractor’s expense. The SO Rep shall exercise his rights under clause 1.6 "Nuisance And Irregularities" to impose a charge against the Contractor for every cube which fails to attain the minimum specified strength at 28 days age as specified; in addition, the SO Rep reserves the right to reject the pile and the Contractor shall install compensating piles that will ensure the safety of the building to be supported by the piles. The compensating piles shall be installed all at the Contractor's cost and expense, and as directed by the SO Rep.
BLDG12/S02.DOC(22) Sal(151211) (DPD)
Bldg Spec Page 2-23 2.34
MICRO PILE SYSTEM (CONT’D)
2.34.9
Fabrication of Steel Bar Spiral reinforcement (R6) is fixed around the bars to prevent bursting of grout under load. Lantern centralisers are fixed to the bars at 3 m intervals to ensure sufficient grout cover to the steel bars. Steel spacers are placed at 3 m interval to ensure that the bars are placed vertically.
2.34.10
Pile Integrity Test (PIT) for MicroPile Where micro piles are included in the Works, the Contractor shall engage an independent specialist testing firm to conduct Pile Integrity Tests on the piles. The Sonic Echo method shall be adopted. The total number of tests to be conducted shall be 2 Nos or 2 % of the total number of piles in each building block, whichever is greater. The testing equipment shall be capable of carrying out exponential amplification of the signal with time, if necessary, so that weak reflections from locations at or near the pile toe can be clearly displayed. The Contractor shall provide proper access for the specialist’s testing firm to carrying out the test. The pile shall not be tested until at least 4 days after installation. During preparation, loose concrete, mud or debris, etc shall be removed from the pile head. The pile head shall be trimmed to expose sound concrete and to have flat top surface. The pile shall be tested by means of light blows from the small impact hammer. The Contractor shall ensure that the test is conducted by qualified personnel i.e. an engineer and a technician. Upon completion of the Pile Integrity Test, the Contractor shall furnish a preliminary report indicating the estimated pile penetration on the same day of the Pile Integrity Test to the SO Rep. Two sets of the final report, to be signed by a qualified testing specialist, shall be submitted within 5 days to the SO Rep. The final report, in printed form, shall include the following: (a) (b) (c) (d) (e) (f) (g)
Contract name and number Block number Pile reference number Pile diameter Date of pile installation and date of testing Graphical representation of the estimated pile shaft profile Qualitative analysis of the pile integrity which cover concrete quality, location and severity of the defect such as discontinuity or change in cross section of the pile, etc.
2.35
JACK-IN PILING SYSTEM
2.35.1
System of Piling The jack-in piling system consists essentially of H-section steel piles or Reinforced Concrete piles forced into the ground using a non-impact jacking system. The pile sections used shall comply with the relevant Singapore Standards, where these exist, or the equivalent British Standards. The Contractor shall ensure that when concrete piles are used, they would not be damaged during handling and transportation.
2.35.2
Nominal Working Load The nominal working loads are indicated in the Drawings.
2.35.3
Resistance and Penetration of Piles The resistance of all piles shall be a minimum of 2.5 times the nominal working load of the pile. The Contractor shall install all working piles to such a depth that the required resistance is obtained. The minimum depth of pile shall not be less than 7.0 metres below the cut-off level of the pile or as may be agreed by the SO Rep.
BLDG12/S02.DOC(23) Sal(151211) (DPD)
Bldg Spec Page 2-24 2.35
JACK-IN PILING SYSTEM
2.35.4
Installation
(CONT’D)
During pile installation, the hydraulic pressure of jack corresponding to depth of pile penetration shall be recorded at every 0.5 metre depth intervals. Except for pile joining, each pile shall be jacked in continuously until the required penetration of required resistance as shown on the pressure gauge of the jack is achieved. A maximum jacking pressure of 2.5 times the nominal working load shall be maintained for at least 2 minutes. The final set recorded shall not exceed 10 mm. 2.35.5
Quality of Welded Joints and Welders The quality of welded joints and welders is as provided in subclause “Quality of Welded Joints and Welders” under Clause 2.32.6 of this Specification.
2.36
PRECAST REINFORCED CONCRETE PILING WORK
2.36.1
Penetration Of Driven Piles The pay length of driven piles shall be the actual length measured from the bottom tip to the cut-off level of the driven piles. The penetration of every pile shall be recorded by the SO’s representatives and the Contractor and endorsed by the SO Rep. The concrete pile shall be marked with red paint at every 1m interval to enable easy determination of pile penetration.
2.36.2
Precast Concrete Piles Precast concrete piles can be non-prestressed or prestressed, obtained from the approved supplier. The design, manufacturing, handling, transportation, lifting and driving shall be in accordance with CP4, 'Code of Practice for Foundations'. The position of lifting points shall be clearly specified. The piling system proposed shall be verified by design calculation that the pile section and area of steel required shall be sufficient to safely resist all stresses arising from handling, transportation, driving and lifting, and in no case shall the percentage of area of steel to pile cross-section be less than 1% for non-prestressed concrete pile, and 0.3% for prestressed concrete pile using high tensile strength tendons. The details for splicing of pile sections and method of splicing shall be submitted and for the approval of the SO Rep. Joints shall be designed to resist possible uplift due to nominal eccentric moment of column.
2.36.3
Materials For Precast RC Piles All materials used for precast RC piles shall where appropriate, comply with Section 4 "Structural Concrete" including all clauses and subclauses under it. Minimum 28-day strength of concrete in the piles shall be 40 N per sq mm.
2.36.4
Nominal Working Load For precast reinforced concrete piles, the sizes of the square piles shall be 150mm, 175mm, 200mm, 230mm, 260mm and 300mm. The nominal working loads of precast reinforced concrete piles shall be indicated in the Drawings.
2.36.5
Pile Hammer And Set Where piles are included in the Works, impact hammer, either single-acting or double-acting, or hydraulic hammer shall be used in driving piles. However, diesel drop hammers shall not be used. The hammer shall be capable of producing sufficient kinetic energy to drive the piles to the required set without causing damage. The type of hammer and the height of drop of the hammer shall be first approved by the SO Rep. If hydraulic hammer is used, ensure that the hydraulic hammer provided is suitable for the piling of all sizes of reinforced concrete piles without causing damage. The allowable set for the final 10 blows of piles, which is dependent on factors such as pile size, pile penetration, hammer size and subsoil condition, etc. shall be proposed by the Contractor’s PE and shall be approved by the SO Rep before being adopted as a criterion on the Site. The ultimate resistance of all piles shall be a minimum of 3 times the given nominal working load of the pile section. The onus for obtaining the required resistance shall rest with the Contractor.
BLDG12/S02.DOC(24) Sal(151211) (DPD)
Bldg Spec Page 2-25 2.36
PRECAST REINFORCED CONCRETE PILING WORK (CONT’D)
2.36.6
Construction Equipment And Experience For Driving Piles The Contractor shall submit together with the Tender, a progress schedule and full details of the Construction Equipment to be committed on the Site. A resume showing the experience of the Contractor and operators in piling work shall also be submitted.
2.36.7
Casting Yard At least one month before the commencement of piling Works, the contractor shall submit to the SO Rep for approval of the following : (a) (b) (c) (d)
2.36.8
location and contact number of casting yard; date of casting; type, length and number of piles to be cast; pile design drawing(s) (if alternative systems of piling are used).
Warranty The Contractor shall be responsible for the proper execution of the piling Works in accordance with the Specifications and the pile layout Drawings. Any damage to the super-structure resulting from defective execution of the piling Works shall be made good by the Contractor at his own costs and expenses to the satisfaction of the SO Rep. The warranty period shall be one year after the completion of the superstructure.
2.36.9
Driving Of Piles No pile shall be driven before concrete reaches its 28-day working cube strength. Notwithstanding the earlier achievement of the specified 28-day strength, no pile shall be driven until a period of at least 14 days has elapsed after casting of the pile. Approved piles shall be driven accurately in the correct locations true to line both laterally and longitudinally as indicated in the Drawings. Piles shall be guided at the top and bottom during driving and shall be suitably constrained to maintain their correct position by means of guides. No pile which has been deflected from its course, or has been wrongly aligned may be forcibly brought back to correct alignment except with the written approval of the SO Rep. A dolly shall not be used as an aid to driving a pile to its final penetration unless approval has been obtained from the SO Rep. Where a dolly is used, the allowable set for the final blows of a pile shall be reduced to account for higher energy loss in the dolly-pile head system. The magnitude of the reduction shall be determined by site observation and shall not be less than 25 percent. The centre of each pile shall not deviate from its true position as shown in the Drawings by more than 75mm. The Contractor shall execute and bear the cost of amendment of pile caps, ground beams and other structural work designed to counter pile eccentricities exceeding the permissible tolerance, as directed. Alternately the SO Rep may direct compensating piles to be driven at the Contractor's own costs and expenses.
2.36.10
Raking Pile For raking piles, the piling rig shall be set and maintained to attain the specified inclination. The maximum permissible deviation of the installed pile from the specified inclination shall be 1 in 40.
BLDG12/S02.DOC(25) Sal(151211) (DPD)
Bldg Spec Page 2-26 2.36
PRECAST REINFORCED CONCRETE PILING WORK (CONT’D)
2.36.11
Piling Record Piles shall only be driven in the presence of the SO Rep. The penetration and set of every pile shall be subjected to the approval of the SO Rep. Record of driving for every pile shall be submitted to the SO Rep on site and a copy to be kept by the Contractor. The record shall include the following items : (a) (b) (c) (d) (e) (f) (g) (h)
Set temporary compression penetration from ground level length of pile and size of section ground level cut-off level to the top of pile time of starting and time of completion inclination of the pile
The method of measuring set and temporary compression shall be approved by the SO Rep. The above record shall show a series of sets and temporary compression measured during the whole process of driving. Once the driving of a pile commences, it shall continue until the final penetration or set is reached. 2.36.12
Damaged Or Rejected Piles All piles which are cracked, broken, or damaged in any manner during transportation, handling or driving shall be rejected. All piles driven unduly out of position, or driven out of plumb in excess of 1 in 75, or if no set can be obtained after driving for a considerable length well in excess of estimated penetration based on soil data and site condition, shall be rejected. In situation where a dolly is used, the pile shall be rejected if it does not achieve the allowable set and the full length of the dolly has been utilised to drive the pile.
2.36.13
Compensating Piles All piles driven into ground and rejected shall be replaced with compensating pile or piles at the Contractor's own costs and expenses. The position and number of compensating pile(s) as decided by the SO Rep shall be such that the concentricity of the pile group is not altered. The Employer will only pay the cost for the original number and size of pile(s) in the pile group as shown in the Drawings. In the computation for payment, the size of the original pile as shown in the Drawings and the pay length of the compensating pile shall be taken. If two or more compensating piles are used to replace the rejected pile, the computation shall be based on the size of the original pile as shown in the Drawings and the shortest pay length of the compensating pile (which compensate the particular rejected pile, as decided by the SO Rep). If there are two or more rejected piles in the same pile group and there is no indication which compensating piles are for which rejected piles (as decided by the SO Rep), the computation for payment shall be based on the sizes of the original piles as shown in the Drawings and the two or more shortest pay length of the compensating piles.
2.36.14
Cutting Of Piles Excavate and cut off the pile to the required level shown on the pile layout Drawings or otherwise directed by the SO Rep. Checking and recording of cut-off level shall be followed up immediately. Precast concrete pile shall be stripped to the cut-off level to expose the longitudinal reinforcement bars leaving the dressed head of the pile projecting 75mm into the pilecap. The longitudinal steel shall be left projecting 600mm above the dressed head level and cast into the pilecap. In the cutting of piles, the Contractor shall employ a licensed surveyor to be responsible for the measurement of pile eccentricities and cut-off levels, including those for compensating piles, and to check and endorse the pile eccentricity drawings for submission to the SO Rep. The Contractor shall make available all facilities and equipment for the SO Rep to confirm the measurement.
BLDG12/S02.DOC(26) Sal(151211) (DPD)
Bldg Spec Page 2-27 2.36
PRECAST REINFORCED CONCRETE PILING WORK (CONT’D)
2.36.15
Failure Of Working Load Test A working load test shall be deemed to have failed if the settlement exceeds 25mm at 2 times the nominal working load. If a working test pile fails to sustain the full working test load over a period of not less than 3 days as decided by the SO Rep, then 2 further tests on other piles at the same site selected by the SO Rep shall be carried out. Where a pile fails under test, additional adjacent piles, as directed by the SO Rep, shall be driven and the group re-tested if deemed necessary by the SO Rep, and the whole of the work shall be carried out at the Contractor's own costs and expenses. That part of the Works shall be deemed to have failed if 2 or more piles fail out of a piling area containing up to 150 piles, or 3 or more piles fail out of a piling area containing 151 to 750 piles. In the event of such failure, the Contractor shall, at his own cost and expense, carry out sufficient further piling to the satisfaction of the SO Rep to ensure the safety of the structures carried by the rejected piles.
2.37
TIMBER PILING
2.37.1
Construction Equipment And Experience For Driving Piles Submit together with the Tender, a progress schedule and full details of the Construction Equipment to be committed on the Site. A resume showing the experience of the Contractor and operators in piling work may also be submitted.
2.37.2
Penetration Of Driven Piles The penetration of driven piles shall be the actual length measured from the bottom tip to the cut-off level of the driven piles. The penetration of every pile shall be recorded by the Contractor in the presence of the SO Rep. The timber piles shall be marked with red paint at every 300mm or other suitable interval to enable easy determination of pile penetration.
2.37.3
Timber Piles Timber piles specified shall be from the HDB Materials List and of approved brands/trademarks. Timber piles shall be 100mm x 100mm, 125mm x 125mm, 150mm x 150mm or 175mm x 175mm square sawn timber foundation piles with an allowable tolerance of ±5mm, produced from the species Kempas or Keruing. The safe working load shall be 8.5 N per mm2 in direct compressive stress and with an ultimate resistance of all piles of not less than 3 times the nominal working load. The centre line of pile shall not deviate from the straight line joining the mid points of the butt and toe by more than 25mm for any pile up to 6m in length, or 38mm for pile over 6m in length. Use only timber piles produced under the ISO 9000 or PSB (Singapore Quality Mark/Product Listing Scheme) Certification Scheme Suppliers. Each batch of piles delivered to the Site shall be subjected to random sampling, for testing by an SAC accredited laboratory, in accordance with the following frequency : (i) (ii)
For every contract supply, a minimum of two tests; For supply up to 1,000 metre run, the first test will be carried out from any batch of piles, subsequent test will be made at each interval of 1,000 metre run, the number of test will depend on the quantity of supply but subject to a minimum of two tests for each contract as stated in (i) above.
All piles shall be pressure-treated with copper-chrome-arsenic wood preservative under a pressure of not less than 14.0 kg per cm2, with minimum depth of penetration of preservative of 25mm and with a net dry salt retention in the outermost 25mm of pile of not less than 16kg per m3. All methods of chemical treatment and testing shall be in accordance with SS 72 : 1988 or BS 4072. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each test that fails to comply with the above requirement. In the event that any test by SAC accredited laboratory resulted in failure, remove the batch of piles from which the random sampling is obtained completely from the Site. Should the Contractor negligently or wilfully transport the same batch that had failed previously to the Site again, this act shall be deemed to be an infringement and Clause 1.6 "Nuisance & Irregularities" shall apply.
BLDG12/S02.DOC(27) Sal(151211) (DPD)
Bldg Spec Page 2-28 2.37
TIMBER PILING
2.37.4
Steel Box Joint
(CONT’D)
Join two piles by using a mild steel welded box joint 450mm long made from 4.5mm thick plate and coat with bituminous paint and approved by the SO Rep before use. 2.37.5
Pile Hammer And Set for Pile Driving Use free drop hammer to drive the timber pile. The hammer weight for driving 175mm x 175mm pile shall be 1.5 tonnes, and for driving 150mm x 150mm, 125mm x 125mm or 100mm x 100mm pile shall be 1 tonne. The hammer shall drop a minimum of 1300mm. The acceptable set for the last 10 blows for 175mm x 175mm pile shall be not more than 15mm. The acceptable set for the last 10 blows for 150mm x 150mm, 125mm x 125mm or 100mm x 100mm pile shall be not more than 20mm. The ultimate resistance of all piles shall be a minimum of 3 times the given nominal working load of the pile section. The onus for obtaining the required resistance shall rest with the Contractor.
2.37.6
Warranty The Contractor shall be responsible for the proper execution of the piling Works in accordance with the Specifications and the pile layout Drawings. Any damage or Defect to the inspection chambers and main drain lines resulting from defective execution of the piling Works shall be made good by the Contractor at his own costs and expenses to the satisfaction of the SO Rep.
2.37.7
Driving Of Piles Approved piles shall be driven accurately in the correct locations true to line both laterally and longitudinally as indicated in the Drawings. Piles shall be guided at the top and bottom during driving and shall be suitably constrained to maintain their correct position by means of guides. No pile which has been deflected from its course, or has been wrongly aligned may be forcibly brought back to correct alignment except with the written approval of the SO Rep. The centre of each pile shall not deviate from its true position as shown in the Drawings by more than 75mm. The Contractor shall execute and bear all additional costs of the amendment in pile caps, ground beams, etc designed as a countermeasure to the pile eccentricities exceeding the permissible tolerance, as directed. Alternately the SO Rep may direct compensating piles to be driven at the Contractor's own costs and expenses. During driving, protect the heads of all piles with the helmet of mild steel fitting closely around the pile. A 25mm thick plywood covering the head of the pile shall be contained within the helmet to separate the helmet from the head of the pile. Rigidly & securely join all piles with metal box joints. The joints shall be driven to a tight fit with the pile hammer and spiked to the section of both piles.
2.37.8
Piling Record Piles shall only be driven in the presence of the SO Rep. The penetration and set of every pile shall be subjected to the approval of the SO Rep. Record of driving for every pile shall be submitted to the SO Rep and a copy shall be kept by the Contractor on the site. The record shall include the following items: (a) (b) (c) (d) (e) (f) (g) (h)
Set Temporary compression Penetration from ground level Length of pile and size of section Ground level Cut-off level to the top of pile No. of joints used Time of starting and time of completion
The method of measuring set and temporary compression shall be approved by the SO Rep. The above record shall show a series of sets and temporary compression measured during the whole process of driving. Once the driving of a pile is commenced, it shall continue until the final penetration or set is reached. BLDG12/S02.DOC(28) Sal(151211) (DPD)
Bldg Spec Page 2-29 2.37
TIMBER PILING
(CONT’D)
2.37.9
Damaged Or Rejected Piles All piles which are cracked, broken, broomed, split or damaged in any manner during transportation, handling or driving shall be rejected. All piles damaged during driving, or driven unduly out of position, or driven out of plumb in excess of 1 in 75, or if no set can be obtained after driving for a considerable length well in excess of estimated penetration, where it should set based on soil data and site condition, shall also be rejected.
2.38
PILING WORKS TO LINKWAYS AND PRECINCT PAVILIONS Where piling Works to linkways and precinct pavilions are required as shown in the Drawings, the Contractor shall ascertain the pile penetration lengths required and allow in the Contract Sum for all costs and expenses for providing the piling Works to the requirements specified under the Contract. In ascertaining the pile penetration lengths, the Contractor may, if he wishes, refer to the Soil Investigation Report available from the Employer. However, for the avoidance of doubt, the Soil Investigation Report shall not form part of the Contract or be taken into consideration in the interpretation or construction thereof or of the Contract. The Contractor shall take note that all the information in the Soil Investigation Report are only indicative of the likely soil conditions to be encountered at the Site. The Contractor shall at his own cost, ascertain the actual soil conditions and shall conduct his own site investigations Notwithstanding the pile penetration lengths ascertained by the Contractor, there shall be no adjustment to the Contract Sum for any difference in pile penetration lengths between those actually provided for the Works and those ascertained by the Contractor. However, in the case where any pile as shown in the Drawings is not provided at all, omission by way of variation to the Contract shall be effected. For the purpose of computing such omission amount only, the penetration length of each pile shall be deemed to be 8.0 m.
2.39
PILING METHOD OF STATEMENT The Contractor shall study the soil report and submit the method statement for piling and the type of machinery to be used for the piling works for the approval of the SO Rep within one month of the issue of the Letter of Acceptance.
Section 3/.....
BLDG12/S02.DOC(29) Sal(151211) (DPD)
Bldg Spec Page 3-1 SECTION 3 EXCAVATION
3.1
USE OF SOIL INVESTIGATION REPORT FOR EXCAVATION WORKS The Contractor shall provide all necessary measures, including but not limited to temporary structures, shoring and/or sheet piling, to facilitate the carrying out of excavation Works and/or for heavy vehicular movement within the Site. The cost of such temporary structures, shoring and/or sheet piling, etc shall be deemed to be included in the Contract Sum. Notwithstanding such provisions, the Contractor shall, in the course of excavation Works, take great care to prevent earth movements and/or upheavals in the excavation. The Contractor shall also take precaution to prevent displacement and/or damage to the piles due to any traffic movement from heavy machinery employed on the Site. If any pile in the excavated pit is displaced or if the pile is damaged by earth movement and/or upheavals, the Contractor shall be held accountable for the displacement and/or damage to the piles and shall bear all cost and expenses incurred in remedial Works. The Contractor may, if he wishes to, make reference to the Soil Investigation Report available from the Employer to facilitate the Contractor in ascertaining the temporary structures, shoring and/or sheet piling required. However, the Soil Investigation Report shall not form part of the Contract or to be taken into consideration in the interpretation or construction thereof or of the Contract. The Contractor shall take note that all the information in the Soil Investigation Report are only indicative of the likely soil conditions to be encountered at the Site. The Employer shall not be accountable to the Contractor for the accuracy, adequacy or completeness of the information in the Soil Investigation Report. The Contractor shall ascertain the actual soil conditions and shall conduct his own site investigations and allow in the Contract Sum for all costs and expenses whatsoever arising from and/or out of any inaccuracy, inadequacy or incompleteness of the information in the Soil Investigation Report.
3.2
RESERVED
3.3
DRAINAGE DEPARTMENT'S REQUIREMENTS ON SITE CONTROL The Contractor shall comply with the following site control requirements in addition to those required by the Drainage Department, Public Utilities Board (PUB) : (a)
Submitting all proposals for temporary drains and silt control measures to the Head, Drainage Department for approval before commencement of the Works;
(b)
Providing adequate silt-control facilities including lined temporary drains at the Site boundary surrounding the Site comprising of composite channel drains of adequate capacity (minimum Type C7) to capture the surface run off with proper sump outlets subjected to the prior approval of PUB and the SO Rep, close turfing on both sides of the perimeter drains, silt-trapping devices, turfing, wash-bays incorporating proper discharge outlets, etc. to control silt and mud from the Site to enter the drains;
BLDG12/S03.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 3-2 3.3
DRAINAGE DEPARTMENT'S REQUIREMENTS ON SITE CONTROL
(CONT'D)
(c)
Maintaining regularly all such silt-control facilities to ensure their effectiveness and in a clean, hygienic, pest free and good working condition to the satisfaction of the SO Rep, and desilting all affected drains until Substantial Completion of the Works;
(d)
Ensuring that the execution of the Works shall not disrupt, fill, block or disturb the existing overland flow, existing drains, temporary diversion drains or perimeter cut-off drains;
(e)
Ensuring that runoff within, upstream of and adjacent to the Site can be effectively drained away without causing flooding within the Site or in areas outside the Site;
(f)
Ensuring that discharge consequent to de-watering from basement or trench excavation is channelled into silt trapping devices before reaching existing drains;
(g)
Implementing adequate measures, including the provision of proper barricades between the work areas and existing drains, to ensure that construction materials are not discharged or washed into the drains.
The Contractor shall be responsible for designing and implementing at his own cost and expense, any additional or more stringent measures as may be necessary to achieve satisfactory site control standards as required by the Drainage Department, PUB on surface water drainage.
3.4
EROSION AND SILT CONTROL MEASURES The Contractor shall not allow and be responsible for preventing silt from being washed into drains and canals. The Contractor shall comply with the following requirements strictly : (a)
Treatment Of Silt-Laden Water Ensure that silt-laden water is not discharged directly or by pumping into drains or canals. The siltladen water shall be channelled to silt traps, sedimentation tanks or other measures for removal of silt before discharging into drains or canals.
(b)
(c)
Provision Of Silt Traps And Perimeter Cut-Off Drains (i)
Silt traps, perimeter cut-off drains and other facilities shall be provided to ensure that earth, silt, mud, etc are not discharged into drains or canals. Details of these facilities shall be duly designed and endorsed by a PE engaged by the Contractor. These facilities shall be constructed before the commencement of the Works.
(ii)
Silt traps, perimeter cut-off drains and other facilities shall be desilted and maintained at least once a week or more often if necessary to effectively prevent the discharge of silt from the Site.
Protection Of Exposed Earth Surfaces Provide and carry out close turfing promptly to prevent soil erosion at the Site. All exposed earth surfaces not affected by construction activities shall be planted with turfing on an immediate basis. Where necessary to prevent soil erosion, the Contractor shall also carry out progressive turfing on Site. In cases where turfing is not practical or not effective in protecting exposed earth surfaces which are left bare and undisturbed for more than one month, such surfaces shall be protected from soil erosion by spraying with bitumen based emulsion or other effective methods to be approved by the SO Rep. Notwithstanding the approval of the SO Rep, the Contractor shall ensure that the methods are effective in the prevention of soil erosion.
BLDG12/S03.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 3-3 3.4
EROSION AND SILT CONTROL MEASURES (CONT'D) (d)
(e)
Excavated Material (i)
All surplus excavated materials shall be carted away to the disposal ground immediately. The surplus excavated material shall not be stockpiled on the Site.
(ii)
Earth materials stockpiled on the Site for construction work shall be within properly contained areas and covered to prevent the earth from being washed into drains or canals. The locations for stockpiling the earth shall be subject to approval by the SO Rep. Notwithstanding the approval of the SO Rep, the Contractor shall ensure that earth is not washed into drains or canals.
(iii)
The Contractor shall only carry out trench excavation work provided the rate of construction keeps pace with the rate of excavation.
Treatment Of Mud Slurry Check and ensure that mud slurry from drilling, tunnelling, diaphragm wall construction and jet grouting, etc, are not discharged into drains or canals.
3.5
SURFACE EXCAVATION The Contractor shall grub up and clear all shrubs, vegetable matter, bushes, roots and other obstructions encountered on the Site. No tree shall be removed without written permission from the SO Rep. Any top soil which covers the Site shall be carefully scraped and piled up at a suitable location, with the use of mechanical or manual labour, for subsequent use in turfing or tree planting. The Contractor shall salvage whatever existing top soil there is on the Site, failing which he shall be liable to reimburse the Employer for the loss. No top soil shall be removed from the Site without the permission of the SO Rep.
3.6
SITE FORMATION LEVEL The proposed platform levels for the building platforms and open areas for the Works are as indicated in the Drawings. The existing earth ground levels shall be prepared by the Employer at 300mm below the proposed platform levels, subject to an average tolerance of ±150mm, before the Site is handed over to the Contractor. The Contractor shall top up, fill, consolidate and level up to the proposed platform level as indicated in the Drawings all in accordance with the requirements specified in clause 3.13 "Backfilling". The Contractor shall be deemed to include in the Contract Sum for the cost of all additional works arising from or out of such ±150mm average tolerance as specified. Where excavated earth is not suitable for filling up to the proposed platform levels as indicated in the Drawings, the Contractor shall at his own cost and expense fill up with suitable imported earth approved by the SO Rep.
3.7
EXCAVATION GENERALLY The Contractor shall be deemed to have visited and examined the Site carefully and to have ascertained the nature thereof and the kinds of materials to be excavated, and to have made provision in the Contract Sum to cover for the type of materials to be excavated. Prior to the commencement of excavation, the Contractor shall carry out a pre-construction survey of the neighbouring properties and comply with the requirements of BCA and any other requirements as required by the SO Rep all at the Contractor's cost and expense. The Contractor shall set out the lines and structures for the inspection and approval of the SO Rep. Original ground levels shall also be taken and submitted to the SO Rep for record.
BLDG12/S03.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 3-4 3.7
EXCAVATION GENERALLY (CONT'D) Excavation shall be carried out neatly in accordance with the Drawings, in whatsoever material may be found, including hard rock or other hard material which requires breaking up by pneumatic drills and the excavated materials shall be used as filling if required. The Contractor may be allowed to carry out the excavation by his own methods subject to the approval of the SO Rep. The excavated materials may be temporarily stockpiled on the Site during the course of the Works provided there is sufficient space available and such stockpiling shall not cause obstruction at the work Site and such stockpiling shall be covered to prevent the excavated materials from being washed into the drains and canals. In areas of poor soil, all excavated materials shall be completely removed from the Site. The Contractor shall be held fully responsible for all damages caused by the non-removal or improper stockpiling of excavated materials on the Site. The SO Rep may prescribe and limit the lengths and/or widths and/or depths of excavation to be proceeded with at any one time. Excavation shall not be carried down in the first instance to a depth nearer than 150mm to formation level. The bottoming-up to formation shall be done by hand immediately in advance of placing hardcore, concrete or other Permanent Works unless directed otherwise by the SO Rep. The Contractor shall also take such steps as are necessary, in the opinion of the SO Rep, to prevent damage to the formation owing to exposure to the atmosphere and the trampling of the formation by workmen. Where, in the opinion of the SO Rep, the formation is softened or spoilt by the Contractor, the soft or spoilt areas shall be excavated and filled with Grade 15 concrete at the Contractor's own costs and expenses. No Permanent Works shall be constructed in any excavated area or position until the SO Rep has inspected and approval given to commence further work. The entire excavation Works shall be formed and left complete and as accurate to the widths, levels, contours and slopes or as otherwise directed by the SO Rep. The Contractor may be provided with a site to dump and spread the surplus excavated materials as directed by the SO Rep. Alternatively, the Contractor may be required to dispose of any surplus materials and shall if so required provide lorries for transport and shall make all necessary arrangements for the use of an approved dumping ground and bear all costs and expenses thereof. The Contractor shall not deposit surface excavated materials on private land unless he can produce the written permission of the owner of the land.
3.8
EXCAVATION IN ROCK Any rock or boulders encountered in excavation to the required depths shall be removed by wedging, blasting or other means as the SO Rep may direct, all at the Contractor's own cost and expense. When blasting is required, the Contractor shall obtain prior written permission from the SO Rep. The Contractor shall comply with the Local Laws and Regulations and any requirements imposed by the relevant Authorities with regard to blasting operations. The SO Rep shall be fully informed by the Contractor as to the steps and precautionary measures taken to safeguard the surrounding properties. The Contractor shall be liable for any accident, damage or injury to any person, property or thing, resulting from the use of explosives. Prior to the start of blasting operations, the Contractor, in the presence of the SO Rep, shall conduct a survey of all structures within 120m of the site where blasting is proposed, and any other structures which the SO Rep considers may be affected, in order to determine the existing or pre-blast condition of these structures. Prior to commencing blasting operations, a written report, supported by photographs where necessary, listing any existing defects in the structures, shall be submitted to the SO Rep. When blasting operations are being carried out, any road affected shall be closed to traffic and the appropriate signs erected.
BLDG12/S03.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 3-5 3.9
ERRORS IN EXCAVATION The Contractor shall excavate to such depths only as shown on the Drawings or as directed by the SO Rep. Any excavation done to a greater depth than is necessary shall be filled with concrete of such proportions or with such compacted material to the required formation levels as directed by the SO Rep. The cost of such filling shall be borne by the Contractor.
3.10
EXCAVATION FOR PILE CAPS The Contractor shall excavate for pile caps and complete excavation expeditiously after the piling contractor has cut off excess length of piles. The Contractor shall take care and precaution to avoid damaging or displacing the piles and the Contractor shall be held fully responsible for any damage or displacement to piles in the excavation pits. Any water accumulating in excavated pits shall be pumped dry to facilitate construction of pile caps.
3.11
TEMPORARY COVERS Prior to excavation for footing foundations, the Contractor may erect temporary covers over the area to be excavated to prevent rainwater from getting into the excavations. However, when such temporary covers are instructed to be erected by the SO Rep specifically, they will be paid for as a variation.
3.12
KEEPING EXCAVATIONS DRY The whole of the excavations shall be kept free from water arising from rain, drains, floods or other causes by pumping, bailing, drainage or other means. Should any water get into the excavations, the Contractor shall remove such water, excavate the affected wet soil and fill up the excess excavation with Grade 15 concrete, all at his own cost and expense and to the satisfaction of the SO Rep.
3.13
BACKFILLING The Contractor shall backfill with selected excavated material around foundation excavations, etc up to the required level in layers not exceeding 300mm thick or in such layers as directed and carefully ram and consolidate. Upon approval by the SO Rep, backfilling shall commence as soon as practical and completed expeditiously and without delay.
3.14
DISPOSAL OF SURPLUS EXCAVATED MATERIAL The Contractor shall allow for spreading and levelling on Site or transporting off the Site, all surplus excavated material which remains after completion of backfilling and compaction of excavations, including the surplus excavated material left by the services departments of the relevant local authorities.
3.15
PLANKING AND STRUTTING The term "planking and strutting" shall be deemed to cover whatever method the Contractor adopts to uphold the sides of excavations to prevent damage to adjoining properties, earth movement and injury to workmen. The Contractor shall be held responsible for upholding the sides of all excavations and shall provide all planking and strutting to the satisfaction of the SO Rep. Such planking and strutting shall be designed and supervised by the Contractor's PE
BLDG12/S03.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 3-6 3.16
3.16.1
PRE-TREATMENT OF SOIL FOR PROTECTION OF BUILDINGS AGAINST SUBTERRANEAN TERMITES Over-Riding Clause The Contractor and his Pest Control Operator (the Pest Control Operator hereinafter referred to as the “Specialist”), executing the Works as required in this Clause including sub-clause have to ensure that the Works, goods or materials used shall be suitable and reasonably fit for the purposes for which they are required (hereinafter referred to as the “Performance Requirement”). In the event the Works, goods or materials to be used as specified in this Clause including sub-clauses are upgraded in order to meet the Performance Requirement, the Contractor and his Specialist shall do all necessary upgrading at no extra cost to the Employer, subject always to the approval of the SO Rep, but such approval shall not in any way affect the Contractor and his Specialist’s duties and obligations arising under the Contract.
3.16.2
Scope Of Work Chemically pre-treat the soil for the protection of buildings against subterranean termites. The treatment shall be for residential building blocks and mixed development with commercial building blocks. The ground below multi-storey carparks, linkways, link buildings, precinct pavilions shall not be treated. Other low rise buildings not for residences or storage of merchandise shall not be treated. The areas to be chemically treated shall include: (a)
The entire ground floor slab area prior to the laying of the concrete floor slab. The area below the basement, lift pits and drop-off porch shall be excluded; and.
(b)
All round the building perimeter prior to concreting the apron area. The width of the treatment shall follow the perimeter defined by the apron slab but shall not exceed 2.0 m in width.
The Contractor shall comply with all the requirements of the National Environment Agency (NEA) pertaining to such soil treatment work and such compliance shall form part of the Scope of Work. The Contractor shall also comply with the requirements specified in the Material Safety Data Sheets (MSDS), product labels and instructional materials supplied by the chemical and equipment manufacturers or their licensed representatives. In addition, the Contractor shall submit a detailed Work Method statement, stipulating the strategic work processes control and personnel responsible etc., to the SO Rep for approval prior to commencement of such Works. 3.16.3
Chemical To Be Used The non-repellent active ingredients (AI) and products to be used for the pre-treatment of the soil for works which are within or/and outside Water Catchment areas, shall be those approved by the National Environment Agency (NEA) The Contractor may propose either one of the following active ingredients listed in the table below. Active Ingredient (AI)
Fipronil
Imidacloprid
Thiamethoxam
BLDG12/S03.DOC(6) Sal(151211) (DPD)
Concentration of AI / Dilution rate / Application Rate An aqueous suspension concentrate having an active ingredient (Al) concentration within the range 8.6%w/w to 9.6%w/w of Fipronil. Dilution rate 1:160 Acceptable range of concentration after dilution is 0.05%w/w to 0.07%w/w. Application rate of 5L per m2 or the soil is saturated, whichever occurs first. An aqueous suspension concentrate having an active ingredient (AI) concentration within the range 17.2%w/w to 19.4%w/w of Imidacloprid. Dilution rate 1:400 Acceptable range of concentration after dilution is 0.04%w/w to 0.06%w/w. Application rate of 5L per m2 or the soil is saturated, whichever occurs first. An aqueous suspension concentrate having an active ingredient (AI) concentration within the range 20.1%w/w to 22.5%w/w of Thiamethoxam. Dilution rate 1:240 Acceptable range of concentration after dilution is 0.09%w/w to 0.20%w/w. Application rate of 5L per m2 or the soil is saturated, whichever occurs first.
Bldg Spec Page 3-7
3.16
3.16.3
PRE-TREATMENT OF SOIL FOR PROTECTION OF BUILDINGS AGAINST SUBTERRANEAN TERMITES (CONT’D)
Chemical To Be Used
(Cont'd)
Any other non-repellent active ingredients approved by NEA but not listed above shall be submitted to the SO Rep for approval for use prior application on site (refer to the NEA website: http://app2.nea.gov.sg/soil_Termiticide.aspx for approved list). Prior to the start of each treatment, the Contractor shall propose to the SO Rep the size and the location to be treated. The Contractor shall conduct all the calculations required to ensure accurate application and dilution rates for the termiticide and submit, to the SO Rep prior to the application on the Site. The SO Rep shall be informed for all dilution and mixing procedure by the Contractor. The Contractor is only to mix/dilute the exact amount to be used on the Site. No premixing will be permitted. No mixing offsite prior to its use on the Site will be allowed. All chemicals mixed on the Site MUST be completely used on the Site. No chemical mixed for use on the Site shall be permitted to be removed or disposed off without the approval of the SO Rep. The diluted chemical shall be applied uniformly over the area to be treated. The total volume of flow of diluted chemical used will be measured /metered using a Flow Meter. Other methods for measuring the flow of diluted chemicals will not be permitted. The Contractor shall submit the report to the SO Rep on the Application rate and Dilution rate of the chemicals at the end of each site treatment and/or as directed by the SO Rep. The Report shall contain the following information: Date of Application Amount of Area Treated Amount of Concentrate Termiticide used Amount of Diluted Chemical used Amount of Diluted Chemical unused after the treatment
DD/MM/YYYY XX.XX m2 XX.XX Litres XX.XX Litres XX.XX Litres
This report must be verified and signed by the SO Rep at the end of each treatment.
3.16.4
Chemical Preparation Preparation of chemicals shall be conducted in strict accordance with the Product Labels. All emergency measures shall compile with the recommendation of the Material Safety Data Sheet that will come with each chemical. All necessary Personal Protective Equipment (PPE) required for the chemical preparation and the PPE required for the site will be used at all times. The Contractor shall also ensure that the instructions on handling of the chemicals for the following procedures are in accordance with the published safety information. A declaration document on these safety procedures on handling of chemicals shall also be submitted to the SO Rep for approval prior to the commencement of such works. o o o o o o o o o
Washing of hands Washing of equipment used Calibration of equipment used on site Pre-application Checklist Mixing Procedure Dilution Procedure Amounts of diluents used Type of diluents used All PPE required for the works to be carried out
No work shall commence without these procedures and safety documentations submitted to the SO Rep.
BLDG12/S03.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 3-8
3.16
3.16.5
PRE-TREATMENT OF SOIL FOR PROTECTION OF BUILDINGS AGAINST SUBTERRANEAN TERMITES (CONT’D) Time of Application Treatment shall be carried out immediately before the lean concreting of the floor slabs and apron areas. Soil treatment shall not be carried out when the soil is saturated, eg. during or immediately after rainfall. Verify the ground water table before soil treatment is conducted. For this purpose, the Contractor shall at his own cost and expense, excavate trial holes of more than 0.5m deep measured from the level of the soil to be treated. The Contractor shall submit a report on the ground water table to the SO Rep prior to commencing the soil treatment As required by National Environment Agency (NEA), soil treatment shall not be carried out if the ground water table is 0.5m or less below the level of the soil to be treated, and in such event the Employer is entitled to recover from the Contractor the value of work so omitted by way of a variation order. The variation order shall be priced based on the applicable or analogous or pro-rated rates in the Rates times the untreated area measured flat on plan. Notwithstanding such cost recovery, the Contractor is deemed to have allowed in the Contract Sum for the provision of warranty for the work and the cost recovery shall not absolve the Contractor from his responsibilities to rectify future occurrence of Defect in respect of the work under the warranty. The restriction to soil treatment by virtue of compliance with National Environment Agency (NEA)'s requirements shall not in any way affect or diminish the Contractor’s responsibilities under the warranty. Provided always that in the event chemical pre-treatment of the soil for the protection of buildings against subterranean termites is omitted altogether from the Scope of Work for a building block either on account of National Environment Agency (NEA)'s requirements or by reason of an Authorisation Order, then the provision of a warranty for the chemical pre-treatment of the soil for that building block shall be deemed to be waived by the Employer.
3.16.6
Application Procedure Immediately after the soil treatment is completed, the treated soil shall be securely covered with black polythene sheet. A layer of lean concreting shall be cast on top of the polythene sheet. When it rains during the course of soil treatment, all treated soil shall be covered immediately with black polythene sheet. The coverage shall extend one (1) metre into the untreated areas. The polythene sheet, especially their overlapping parts, shall be properly secured by heavy objects to ensure that all rain water runs into the surrounding temporary drains.
3.16.7
Application Equipment All equipment used in soil treatment shall be in good order and in serviceable condition. A list of all equipment to be used on the Site shall be provided to the SO Rep. Also all these equipment must be accompanied with last service date records prior to their use on the Site.
3.16.8
Provision Of Temporary Drainage Temporary drainage of adequate capacity shall be provided around the whole area to be treated with an outlet connected to a sump.
3.16.9
Quality Control Sampling To verify the concentration of the chemical used, one (1) sample of the chemical shall be taken randomly on each day of application as directed and witnessed by the SO Rep and stored in a one (1) litre container, properly marked with the date and location of the sample taken. The samples taken shall be kept under lock and at a cool and dry location in the SO Rep room. The keys shall be kept by the SO Rep. The SO Rep shall select the required number of samples for concentration test according to the schedule of material tests. The selected samples are to be sent to an accredited/approved laboratory not more than three (3) calendar days after samples taken. The Contractor shall provide at his own cost and expense containers of one litre capacity for the collection of the samples. The sample container must be able to protect its contents against Ultra Violet Light
BLDG12/S03.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 3-9
3.16
3.16.10
PRE-TREATMENT OF SOIL FOR PROTECTION OF BUILDINGS AGAINST SUBTERRANEAN TERMITES (CONT’D)
Failure of Test On Chemical Concentration The SO Rep shall exercise his rights under Clause 1.6 “Nuisance and Irregularities” to take action against the Contractor for each sample that fails to attain within the range of the acceptable concentration as specified in the foregoing requirement in the subclause “Chemical To Be Used. Due care shall be exercised by the Contractor when mixing and preparing the chemical on site. For any areas that were deemed to have failed the minimum concentration, immediate re-treatment by the Contractor is required at no additional cost to the Employer. However, if the slab were already placed and the Chemical Concentration were found to be below an acceptable level, Slab-Injections of the previously used chemicals shall be introduced to the satisfaction of the SO Rep at no additional cost to the Employer.
3.16.11
Approved Pest Control Operators Only Pest Control Operator who is registered with the BCA under the work head for Pest Control shall be engaged to execute the pre-treatment of soil. The Pest Control Operator shall hold a valid letter for the chemical to be used from NEA. In this respect, the Contractor shall submit the name of the Pest Control Operator, proof of BCA registration, letter for the chemical to be used from NEA and the type and details of chemicals to be used (including the rate of application) to the SO Rep for approval prior to commencement of the treatment. In addition, the Contractor shall also ensure that the Pest Control Operator produce a letter of support from the supplier confirming the availability of the chemical to be used for the Works. The SO Rep reserves the right to disapprove the use of the type of chemical and/or the Pest Control Operator so selected by the Contractor. The Contractor shall not be entitled to any claim and there shall be no adjustment to the Contract Sum nor extension of Time for Completion arising from or out of such decision by the SO Rep.
3.16.12
Warranty The Contractor and his Specialist shall warrant the Works on the terms and conditions as stipulated in the Deed of Warranty for Pre-Treatment of Soil for Protection of Buildings Against Sub-terranean Termites as produced in Appendix A1. In this respect, the Contractor and his Specialist shall submit such Deed of Warranty to the Employer or to such other party or such Town Council(s) as the SO Rep may at its sole discretion decide. In the event the Deed of Warranty for part of the Works or for the whole Works is to be submitted to such Town Council(s), the Contractor and his Specialist shall submit such Deed of Warranty as produced in Appendix A1(TC) to such Town Councils. The duly executed Warranty shall be submitted immediately upon request by the SO Rep, and if no such request is made, then at such time when the SO Rep considers the Works have been substantially completed in accordance with the Contract. In the event the Contractor and his Specialist shall fail to execute and submit the Deed of Warranty within the time specified, the SO Rep shall be allowed to withhold 15% of the payment of any sums due to the Contractor in relation to the execution of such Works, subject to the minimum sum of S$5,000/- per Deed of Warranty. However, such sums withheld shall be released to the Contractor upon submission by him of the duly executed Deed of Warranty
3.16.13
Re-treatment During Warranty Period If subterranean termite infestation should occur in the treated buildings within the warranty period, the Contractor shall re-treat the soil using the Post-Construction Soil Treatment method at his own costs and expenses. Drilled holes shall be patched and walls and/or floors refinished. In addition, in the event of additions or extensions to the buildings during the warranty period, the Pest Control Operator and the Contractor shall be informed and shall also execute soil treatment to extend the chemical barrier to cover such additions or extensions. The costs of such extensions of soil treatment shall, however, be borne by the Employer.
BLDG12/S03.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 3-10 3.16
3.16.14
PRE-TREATMENT OF SOIL FOR PROTECTION OF BUILDINGS AGAINST SUBTERRANEAN TERMITES (CONT’D)
Safety Precaution Provide and exercise safety precautions during all treatment processes. Personnel engaged in the soil treatment shall wear protective clothing eg. goggles, long sleeved shirt and long legged trousers or an overall type garment, impervious footwear and gloves as specified in the foregoing requirements. Spray drifts beyond the area to be treated shall be avoided. Every precaution shall be taken to prevent accidental spillage of the chemical. Spillage shall be mopped up with soil or other absorbent materials. The affected soil shall be added to the treated area or kept in plastic bags for disposal at the National Environment Agency (NEA)'s dumping grounds. Signs in the areas of application shall be posted to warn workers and the public that the area has been treated with poisonous chemicals. Unwanted chemicals and containers shall be disposed off safely at the National Environment Agency (NEA)'s dumping grounds.
3.17
FINISHED PLATFORMS, SLOPES AND EMBANKMENTS Platform levels shall be the level at the top of surface drains around the building. The Contractor shall finish the open spaces between buildings with a fall of not less than 1 in 80 towards surface drains. The Contractor shall cut, trim and adjust all slopes and banks to give gradual and regular slopes with no abrupt change of direction, or as directed by the SO Rep.
3.18
SERVICES ROUTES The Contractor shall clear all obstructions from proposed sewer, electrical, water, gas, telephone and Rediffusion services routes and either fill or excavate ground to within 70mm of proposed final platform level as directed by the SO Rep at any time during the Time for Completion and any time period where liquidated damages are imposed under the Contract. Such instructions may be given separately for each of the services at different times and each instruction shall be carried out within seven days.
BLDG12/S03.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 3-11 3.19
ELECTRICAL CABLE PIPES AND TRENCH The Contractor shall excavate and lay 4 no. of 150mm diameter UPVC pipe at a depth of 750mm from the trench in the PowerGrid/SPSL switch room to the position as shown in the Drawings. The pipes shall be laid on 100mm thick mass concrete bed of 600mm width. One end of the pipe shall project 600mm beyond the surface drain or as shown and the other end shall be flushed with the trench. The trench shall be covered with removable RC slabs of 300mm width, capable of supporting a minimum load of 100 kg. Sand shall be provided to fill the trench after installation of the cables into the trench. Excavate and lay 2 no. of 100mm diameter UPVC pipe and 1 no. of 50mm diameter UPVC pipe at a depth of 300mm from the floor of the HDB switchroom to the positions as shown in the Drawings. Pipes used shall be free from leakage, distortion and cracks. Gaps between pipes and trench wall shall be patched up with cement mortar and made watertight. A length of drawn wire strong enough to pull in the cable, shall be provided in each pipe. The drawn wire shall project 600mm at both ends of pipe. All UPVC pipes shall be of at least Class C (wall thickness 6.6mm) type, complying with the requirements of SS 141:1976.
3.20
TELEPHONE CABLE DUCTS The Contractor shall provide and lay where shown 100mm diameter underground UPVC pipes to serve as ducts for telephone cables. Ducts shall turn with gradual bend and continue to extend 600mm beyond aprons, drains and paths outside the building. Provide threading wires for electrical cable ducts. The number of pipes required are as shown in the Drawings.
3.21
DRAIN CASCADES The Contractor shall excavate and lay cascade drains where surface drains flow down steep slopes or banks. Cascades shall not exceed 600mm in length and 300mm in each drop with top of sides finished straight and parallel to slope of ground.
3.22
PUB REGISTERED EXCAVATORS The Contractor shall in addition, engage the services of PUB Registered Excavator Operator only for all excavation Works. In the event the Contractor fails to employ PUB Registered Excavator Operator, no excavation Works shall be allowed.
Section 4/..... BLDG12/S03.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 4-1 SECTION 4 STRUCTURAL CONCRETE 4.1
CEMENT
4.1.1
General Requirements Unless otherwise specified or instructed by the SO Rep, cement shall be of an approved brand and manufacture and comply with the following standards : Type Ordinary Portland Cement Rapid Hardening Portland Cement
Relevant Standard SS EN 197 SS EN 197
High alumina cement shall not be used for any concrete work. When requested by the SO Rep, the Contractor shall produce a certificate showing the date and place of manufacture of the cement. As and when directed by the SO Rep, the Contractor shall, in the presence of SO Rep, be required to take samples for testing. The samples shall be sent for testing at the HDB’s Engineering Materials Laboratory. Any cement failing to comply with the requirements of the relevant standard shall be rejected. The cement shall be fresh and delivered in unbroken bags of the manufacturer or in properly designed bulk containers. All cement delivered in bags shall be stored in a weatherproof dry shed with raised boarded floor of at least 300mm above natural ground level. Cement delivered in bulk tankers shall be stored in properly designed bulk storage tanks. Cement of different manufacture and types shall be kept separate at all times and shall not be used in the same mix. Concrete of different brand of cement shall not be mixed during casting. The SO Rep shall be informed in writing of any change in the source of supply. Consignments of cement shall be used in the order of delivery and any caked or lumpy cement shall not be used. All cement unfit for use shall be removed from site immediately.
4.1.2
Supply From The Contractor’s Source (a)
Certificate Of Compliance The Contractor shall ensure that the quality of his own supply comply fully with the Specifications and Approved Standard. The Contractor shall within one (1) month from the date of the Letter of Acceptance inform and seek the SO Rep’s prior approval in writing of his source of supply together with the following documents: (i) (ii) (iii)
Test Reports showing that the Contractor’s supply is tested according to and in compliance with SS EN 197. If the Contractor’s supply is obtained from a local mill, a copy of the ISO 9000 certification on the mill. If the Contractor’s supply is imported, a letter of supply declaration from the overseas manufacturer.
All test reports shall be the original or certified true copies from a SAC-SINGLAS accredited laboratory. The test reports shall not be dated more than three (3) month from the submission date of the test reports to the SO Rep. Other than due to circumstances beyond the Contractor's control, the Contractor shall not be allowed to change the source of supply at his discretion. The Contractor shall be required to seek the SO Rep’s prior approval in writing for any change in his supply sources, together with the documents laid down hereinabove.
BLDG12/S04.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 4-2 4.1
CEMENT (CONT’D)
4.1.2
Supply From The Contractor’s Source (b)
(Cont’d)
Test Requirements The Contractor shall, in the presence of SO Rep, be required to take and send samples taken from his own supply during the Time for Completion and any time period where liquidated damages are imposed under the Contract for testing at the SAC-SINGLAS accredited laboratory. : The Cement shall be tested in accordance with the Approved Standard for Physical and Chemical Test. The test for Elemental Analysis is not required. The number of tests to be conducted during the Time for Completion and any time period where liquidated damages are imposed under the Contract shall be as follows: Supply Source Local mill with ISO 9000 Local mill without ISO 9000/Imported cement
Number of Test Minimum one test six-monthly Minimum one test quarterly
The Contractor offering from two different supply sources i.e. a local mill and imported cement will have both sources subjected to the test requirements. All costs and expenses in carrying out all the tests and arranging and sending the test samples to the Approved Laboratory as required in the Contract including the cost of samples shall be borne by the Contractor.
4.2
AGGREGATES
4.2.1
General Requirements Fine aggregates shall be uncrushed sand or crushed granite fines complying with SS EN 12620. Where crushed granite fines are used, its percentage of the total amount of fine aggregates shall not exceed 30%. Coarse aggregates shall be crushed or uncrushed gravel, crushed or uncrushed stone complying with SS EN 12620. Coarse aggregates shall not exceed 40mm in size for lean and mass concrete and 20mm for reinforced concrete, unless otherwise specified. All-in aggregates as specified in SS EN 12620 and aggregates derived from limestone or other materials inferior to granite shall not be used. Aggregates shall be stored on clean surfaces in separate stockpiles or bunkers to prevent intermingling of different materials and contamination. Aggregates used for concrete batching plant on site shall be covered with a light roof cover. Fine aggregates shall be tested for moisture content constantly to facilitate moisture compensation during concrete production. The testing shall be carried out based on the Speedy method or other approved equivalent method approved by the SO Rep. The SO Rep reserves the right to draw samples of aggregates from any stockpile at any time and have them tested for compliance with Approved Standards of SS EN 12620, BS EN 933, BS EN 1097, ASTM C295 and ASTM C289. The samples shall be sent for testing at the HDB’s Engineering Materials Laboratory. Aggregates failing to comply with the Approved Standards shall be rejected.
BLDG12/S04.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 4-3 4.2
AGGREGATES (CONT’D)
4.2.2
Supply From The Contractor’s Source (a)
Certificate Of Compliance The Contractor shall ensure that the quality of his own supply comply fully with the Specifications and Approved Standards. The Contractor shall within one (1) month from the date of the Letter of Acceptance inform and seek the SO Rep’s prior approval in writing of his source of supply together with test reports from SAC-SINGLAS accredited laboratories for each source of his supply on the following properties: (i)
20mm Aggregate (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n) (o) (p) (q) (r)
(ii)
Concreting Sand (a) (b) (c) (d) (e) (f) (g) (h) (i) (j)
(k) (l)
BLDG12/S04.DOC(3) Sal(151211) (DPD)
shape; surface texture; particle size distribution - sieving method; flakiness index; shape index; aggregate impact value; aggregate resistance to abrasion; bulk density; particle density and water absorption; clay, silt and dust content; shell content; acid soluble sulphate content; sulphate content; organic impurities; chloride ion content; potential alkali-silica reactivity (chemical method); petrographic examination and other properties as specified by the SO Rep.
particle size distribution - sieving method; clay, silt and dust content by decantation method (not more than 3.00%); organic impurities (lighter than Organic Plate No 3); chloride content (not more than 0.01%); bulk density; particle density and water absorption; assessment of fines; potential alkali-silica reactivity (chemical method); magnesium sulphate soundness; elemental analysis (in percentage): - Silica as SiO2 - Aluminium Oxide as AI2O3 - Iron Oxide as Fe2O3 - Titanium Oxide as TiO2 - Calcium Oxide as CaO - Magnesium Oxide as MgO - Chromium Oxide as Cr2O3 - Sodium Oxide as Na2O - Potassium Oxide as K2O - Sulphate as SO4 - loss on Ignition at 900 0C any other element(s) which may exist in the concreting sand; and other properties as specified by the SO Rep.
Bldg Spec Page 4-4 4.2
AGGREGATES (CONT’D)
4.2.2
Supply From The Contractor’s Source (a)
Certificate Of Compliance
(Cont’d)
(Cont’d)
All test reports shall be the original or certified true copies from a SAC-SINGLAS accredited laboratory. The test reports shall not be dated more than three (3) month from the submission date of the test reports to the SO Rep. Other than due to circumstances beyond the Contractor's control, the Contractor shall not be allowed to change the source of supply at his discretion. The Contractor shall be required seek the SO Rep’s prior approval in writing for any change in his supply sources, together with the documents laid down hereinabove. (b)
Test Requirements The Contractor shall, in the presence of SO Rep, be required to take and send samples taken from his own supply during the Time for Completion and any time period where liquidated damages are imposed under the Contract for testing at the SAC-SINGLAS accredited laboratory. The quality of the aggregates to be supplied shall comply in every respect with the Specifications and Approved Standards, and the conditions, analysis and test requirements laid down in the SS EN, BS EN, ASTM (especially SS EN 12620, BS EN 933, BS EN 1097) classification for concreting purposes. The number of tests to be conducted during the Time for Completion and any time period where liquidated damages are imposed under the Contract shall be as follows: (i)
20mm Aggregate Properties
Frequency of Test
Particle size distribution - sieving method
Minimum one test quarterly
Flakiness index Shape index Aggregate impact value Aggregate resistance to abrasion Bulk density Particle density and water absorption Clay, silt and dust content
Minimum one test six-monthly
Shell content Acid soluble sulphate content Sulphate content Organic impurities Chloride Ion Content Potential alkali-silica reactivity (chemical method) Petrographic examination
Minimum one test
The Contractor shall be required to send their 20 mm aggregate supply for the Mortar-Bar test under ASTM Standard C227 if the need arises.
BLDG12/S04.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 4-5 4.2
AGGREGATES (CONT’D)
4.2.2
Supply From The Contractor’s Source (b)
Test Requirements (ii)
(Cont’d)
(Cont’d)
Concreting Sand Properties
Number of Test
Particle size distribution - sieving method Clay, silt and dust content by decantation method (not more than 3%) Organic Impurities (lighter than Organic Plate No 3) Chloride content (not more than 0.01%) Bulk Density
Minimum one test monthly
Particle density and water absorption Assessment of fines Elemental analysis (in percentage): (i) Silica as SiO2 (ii) Aluminium Oxide as Al2O3 Full list of properties as specified in the subclause “Certificate of Compliance”.
Minimum one test six-monthly
The Contractor offering from two different supply sources will have both sources subjected to the test requirements. All costs and expenses in carrying out all the tests and arranging and sending the test samples to the Approved Laboratory as required in the Contract including the cost of samples shall be borne by the Contractor.
4.3
WATER Potable water supplied by the Public Utilities Board shall be used for mixing concrete, mortar and grout. For cleaning of formwork, reinforcement and curing of concrete, water other than potable water may be used if approved by the SO Rep. The use of seawater shall be prohibited.
4.4
ADMIXTURES When admixture is proposed to be used in concrete mix, furnish information concerning the admixture, admixture acceptance tests and additional information as stipulated in SS EN 934 for approval by the SO Rep prior to the use of the admixture. Admixture used shall comply with SS EN 934 or the relevant British European Standards. Requests for permission to use other types of admixtures not covered by these standards may only be considered when accompanied by full supporting information. Admixture to be used shall be approved by the SO Rep. The Contractor shall provide the SO Rep every facility for inspection and sampling of the admixture(s). The sample(s) shall be kept for reference and shall be sent, if requested by the SO Rep, for admixture uniformity tests in accordance with SS EN 934 or the relevant British Standards.
BLDG12/S04.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 4-6 4.5
STEEL REINFORCEMENT
4.5.1
Description Unless shown otherwise in the Drawings, reinforcement for concrete shall consist of plain mild steel and high yield reinforcement bars complying with SS 2 and welded steel fabric complying with SS 32. Reinforcement shall be free from pitting, loose rust, mill scale, paint, oil, grease, adhering earth or any other material that may impair the bond between the concrete and the reinforcement or that may cause corrosion of the reinforcement or disintegration of the concrete. Where reinforcement is to be welded, it shall comply with CP 65. The Contractor shall obtain the approval of the SO Rep in writing prior to any welding of reinforcement.
4.5.2
Testing The Contractor shall provide the SO Rep every facility for inspection and sampling before any cutting, bending or other fabrication is undertaken. If deemed necessary, the SO Rep may cause samples to be taken from reinforcement already fixed in position. Samples for the tests shall be sent for testing at the HDB’s Engineering Materials Laboratory. For each sample, 3 bars shall be taken for testing. Reinforcement not complying with the appropriate Specifications shall be removed and replaced.
4.5.3
Galvanised Steel Galvanized steel reinforcement as shown in the Drawings shall be hot-dip galvanized in accordance with BS EN ISO 1461. The Contractor shall obtain galvanizing service or galvanized steel reinforcement only from those in the Approved List. The coating weight of zinc shall conform with Table D1 of BS EN ISO 1461. For steel with diameter of 2 6mm and above, the mean coating (minimum) mass shall be 610 g per m and the local coating 2 (minimum) shall be 505 g per m . The coating shall be continuous, smooth and free from flux stains. If the coating appearance of any galvanized reinforcement be found otherwise, such reinforcement shall not be used as a galvanized reinforcement. Store all galvanized reinforcement in a dry and well ventilated place to prevent the formation of white rust on them. Small areas of galvanized coating damaged by welding, cutting or by excessively rough treatment shall be made good by the application of at least two coats of good quality zinc-rich paint with minimum 85% zinc dust, expressed as a percentage by weight of the solid content of the paint. Upon the instruction of the SO Rep, the Contractor shall send at least two samples of the galvanized reinforcement to be tested by a competent authority to determine the coating weight. The coating weight shall be determined using the gravimetric method in accordance with BS EN ISO 1460 and the nominal 3 density of the coating (7.2g/cm ). Certificates of such tests shall be submitted to the SO Rep for verification.
BLDG12/S04.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 4-7 4.6
FABRICATION OF REINFORCEMENT
4.6.1
On Site Fabrication All reinforcement shall be accurately cut and bent to the dimensions and shapes shown in the Drawings. Bends shall be cold-formed by machine or by other approved means which produce a gradual and even bending action. Reinforcement incorrectly bent shall not be used unless the method for straightening and rebending will not cause any cracking, and approval for rebending is given by the SO Rep. Reinforcement shall be securely tied with steel wires. The projecting ends of the steel wires shall be directed away from the formwork so as not to encroach into the concrete cover. Reinforcement shall be adequately supported by approved spacers and chairs to maintain the specified concrete cover. Plastic spacers shall be used for all bottom slab reinforcement. Steel bar chairs bent according to the Drawings or proprietary-type chairs shall be used for top slab reinforcement. The part of the chair that need to rest on formwork shall be coated with plastic for isolation and protection. Other than for slabs, both plastic and concrete or mortar spacer blocks may be used. Concrete or mortar spacer blocks shall be provided with tying wire, and shall not be lower in compressive strength and durability characteristics than the surrounding concrete. All spacers shall be obtained from sources approved by the SO Rep. Sleeve jointing for reinforcement may be used provided that the strength and deformation characteristics have been determined by tests carried out by a competent testing authority and approved by the SO Rep. Fabrication and placing of reinforcement in each part of the Works shall be approved by the SO Rep before any concrete can be placed thereon. Reinforcement shall not be displaced during concreting. Reinforcement projecting from Works being concreted or already concreted shall not be bent without approval by the SO Rep and shall be protected from accidental deformation and damage.
4.6.2
Prefabrication At Factory All column link cages and rectangular column cage reinforcement with T16 main reinforcement bars (except for open links) and all beam cages with beam cage code prefixed with "J" provided to apartment blocks shall be prefabricated in a factory approved by the SO Rep. The rectangular column cage reinforcement shall be prefabricated as welded mesh with the T16 main reinforcement bars welded to and holding in place the column links and bent into column cage reinforcement. The "J" series beam cage shall be prefabricated as welded mesh with the T13 or T16 main reinforcement bars welded to and holding in place the stirrup links and bent into beam cage reinforcement.
BLDG12/S04.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 4-8 4.7
CONCRETE MIXES
4.7.1
Designed Mix For designed mixes, the Contractor shall submit a mix design report covering all concrete mixes to the SO Rep for approval. The designed mix shall comply with the following requirements : Concrete Grade
30
35
40
45
50
Minimum Cement Content (kg per m )
275
300
325
350
400
3
550
550
550
550
550
50
50
50
50
50
0.55
0.50
0.45
0.40
0.40
3
Maximum Cement Content (kg per m ) Maximum % of Fine Aggregate to Total Aggregate Maximum Water to Cement Ratio
For concrete with maximum aggregate size of 14mm and 10mm, the minimum cement content shall be increased by 20 kg per m3 and 40 kg per m3 respectively. In the designing of mixes, a current margin shall be 10 N per mm2. If a current margin other than that recommended is to be used, sufficient valid data shall be made available to the SO Rep for his consideration and approval. Mix adjustment shall be allowed only when sufficient results are available; however, such mix shall comply with the Specifications. In all cases, it is the responsibility of the Contractor to ensure that the designed mix shall be durable, workable and comply with the strength grade requirement as specified or as shown. 4.7.2
Trial Mixes The designed mix with a designed maximum consistency as measured by slump or flow shall be verified by preparation of trial mixes witnessed by the SO Rep. The mix shall be judged for suitable workability as well as strength. A minimum of 18 cubes from three batches shall be taken. The mix may be considered suitable if : (a)
the designed maximum consistency is achieved in accordance with SS 78 or BS 1881 : Part 105 if a flow test is specified; and
(b)
the average strength of the nine cubes tested at 28 days shall exceed the specified characteristic strength by at least 10 N per mm2 or if the nine cubes at an earlier age indicate that it is likely to be exceeded by this amount.
Trial mixes may not be required if concrete is supplied by prequalified ready-mix concrete suppliers approved by the SO Rep. 4.7.3
Mix Adjustment Once the designed mix is approved by the SO Rep, the Contractor shall not be allowed to change the mix without prior approval of the SO Rep. An increase or reduction of cement content by 20 kg per m3 and above, or the percentage of fine aggregate by 5% and above, or any change in the type or dosage of admixture or consistency is considered a change in mix design. This does not constitute a tolerance allowance on the mix design used in relation to the specified requirements. If the Contractor is found to be using a mix design inferior to the approved mix, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.
BLDG12/S04.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 4-9 4.8
BATCHING Cement shall be measured by weight or batched in whole bags if so packed and delivered. Fine and coarse aggregates shall be measured by weight separately. Water shall be measured by volume and due allowance shall be made for the amount of water present in the mass of fine aggregate by deducting this amount from the volume of water to be added during the mixing of concrete. Solid admixtures shall be measured by weight, while liquid or paste admixtures may be measured by weight or volume. The accuracy of the measuring equipment shall be within ±3% of the quantity of cement, water or total aggregate being measured, and with ±5% of the quantity of admixture added before commencement of work and subsequently whenever so directed by the SO Rep, the measuring equipment shall be calibrated with known weights and volume measures.
4.9
MIXING CONCRETE Concrete shall be mixed in a batch type mechanical mixer. The quantity of constituent material in each batch shall not exceed the rated capacity of the mixer. The constituent material shall be thoroughly and continually mixed at the mixing speed specified by the mixer manufacturer until the resulting concrete is uniform in colour and consistency. The mixing time shall be as follows : (i) (ii)
Pan mixer Truck mixer or drum mixer
-
minimum 30 seconds minimum 1.5 minutes for 1 m3 of concrete plus 0.25 minute for each additional 1 m3.
The mixing time shall be reckoned from the time when all the solid materials are in the mixer. No portion of the time required for discharging shall be considered as part of the mixing time. The first batch of concrete fed into the mixer shall have an increase of an appropriate amount of dry mortar similar in proportion to that of the concrete to be mixed and of mixing water for coating the mixer. The mixer shall be emptied completely before being refilled. Mixers which have been out of use for more than 30 minutes shall be thoroughly cleaned before any fresh concrete is mixed. The mixer shall be free from hardened concrete. Worn-off blades or paddles shall be replaced.
4.10
READY-MIX CONCRETE All concrete used in site casting for the Works shall be obtained from pre-approved Ready-Mixed Concrete suppliers. Ready-mix concrete shall comply with SS EN 206. The cement content shall comply with Clause 4.7 "Concrete Mixes" including all subclauses under it. No water in excess of the quantity required in the approved mix shall be allowed to be added to the concrete to increase its workability affected by elapsed time and/or temperature. While it is not being discharged, the concrete shall be kept continuously agitated. The concrete shall be placed in its final position and left undisturbed within two hours from the time when the cement is added to the mix.
BLDG12/S04.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 4-10 4.11
WORKABILITY AND CONSISTENCY The workability shall be such that the concrete can be well compacted, worked into the corners of the shuttering and around the reinforcements, gives the specified surface finish and attain the specified strength. The mix design shall ensure that this workability is obtainable. On each concreting day, workability shall be assessed on the Site at the discharge point of the mixer by means of the slump test in accordance with SS 78. If the measured slump deviates from the agreed value by more than ±25 mm or one third of the required value whichever is greater, the concrete shall be rejected. As an alternative, flow test to BS 1881 : Part 105 or other means of assessing workability may be considered subject to approval by the SO Rep. No water shall be added to the concrete subsequent to the completion of the mixing.
4.12
PLACING OF CONCRETE All concrete shall be transported from the mixer to the place of final deposit as speedily as possible before it has commenced to set, and in no case shall this exceed 20 minutes after mixing. Where retarders are used such interval may be extended subject to the approval of the SO Rep. The method of transit shall be such that it will prevent the segregation, loss or contamination of the ingredients. In the use of concrete pumps, the Contractor shall ensure that the following is complied with : (a)
Pipes shall not be secured to formwork or reinforcement which may be displaced by the pulsating movement of the pipe.
(b)
Pumping shall commence first with blowing of water through the pipeline, followed by cement mortar, both of sufficient quantities and all these shall be discharged away from the area to be concreted.
(c)
When extra sections of pipe are to be added, each length of pipe shall be thoroughly wetted inside but no free water shall remain in the pipe.
(d)
Where the pipeline is exposed to the sun, the line shall be protected against absorption of heat by covering with damp sacking or other approved material during pumping.
Before proceeding to place the concrete, the formwork shall be re-aligned if necessary and water and rubbish therein shall be removed. Immediately prior to placing the concrete, the formwork shall be well wetted and inspection openings shall be closed. Raised gangways for workmen placing and vibrating concrete shall be provided wherever possible and shall be so constructed as to avoid damaging and displacing the reinforcement. Concrete shall be placed in the formwork by shovels or other approved equipment and shall not be dropped from a height nor handled in a manner which will cause segregation. Accumulations of set concrete on the reinforcement shall be avoided. Concrete shall be placed directly in the permanent position and shall not be worked along the formwork to that position. For beams and similar members, concrete shall be placed in a single operation to the full depth. In walls, columns and similar members, the concrete shall be placed in horizontal layers each not exceeding 1m deep. Placing of concrete shall be continuous and temporary interruption shall not normally exceed 30 minutes. At the completion of a specified part, a construction joint shall be made subject to the approval of the SO Rep.
BLDG12/S04.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 4-11 4.12
PLACING OF CONCRETE
(CONT’D)
No concrete shall be placed during wet weather, unless the entire area of pour is covered, or other measures are taken to protect the wet concrete, to the satisfaction and subject to the approval of the SO Rep. All concrete shall be placed in daylight, unless an adequate system of lighting is provided and approval for night work is given by the SO Rep and all relevant authorities prior to commencement of the concreting.
4.13
COMPACTION OF CONCRETE All concrete shall be compacted to produce a dense homogeneous mass. It shall be compacted using approved immersion type mechanical vibrators. Sufficient numbers of vibrators in serviceable condition shall be used on the Site to compact the concrete at the rate at which it is placed, and a minimum of two standby vibrators shall be readily available for emergency use in case of breakdowns. The concrete shall be thoroughly worked into all parts of the formwork and between and around the steel reinforcement. It shall be compacted to give a dense and compact concrete, free from voids of any kind. Steel reinforcement shall be prevented from being displaced or deformed during concreting.
4.14
CURING AND PROTECTION OF CONCRETE After being placed in position, all fresh concrete shall be protected from rain, sun and drying wind, and shall not be subjected to any vibrational disturbance other than that arising from compacting. The exposed surfaces of concrete shall be cured with an appropriate curing compound as approved by the SO Rep. The curing compound shall be applied by mechanical sprayer and comply strictly with the manufacturer's instruction. If the curing compound is exposed to rain or water within 4 hours from the time the application is completed, the Contractor shall re-apply the area affected with appropriate curing compound again. However, the application of the curing compound may be exempted subject to the approval of the SO Rep, if continuous wetting for at least 72 hours by rain on the concrete surface occurs immediately after the concrete sets. This waiver shall not constitute a variation to the Contract. Concrete placed below ground level shall be protected from falling earth and vegetation, and the excavated ground shall be kept free of any water by pumping or other means of drainage. Approved means shall also be taken to protect immature concrete from damage by debris, excessive loading, moving vehicles, mixing with earth or other materials, flotation and other influences that would impair the strength and durability of the concrete. Concrete placed in ground containing deleterious substances shall be free from contact with such ground and with water draining therefrom, during placing and for a further period of 3 days from the time of concrete placing or as otherwise instructed thereafter. Concrete damaged through improper or insufficient curing and protection shall be made good by the Contractor.
4.15
CONSTRUCTION JOINTS Where joints are necessary during concreting, their positions shall be approved by the SO Rep and shall be constructed using expanded mesh as indicated in the Drawings. Before concreting resumes, such joints shall be properly chipped, cleaned and scum and loose aggregates removed therefrom. Immediately before placing new concrete, the joints shall be thoroughly wetted and coated with rich cement grout.
BLDG12/S04.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 4-12 4.16
QUALITY OF CONCRETE WORKS
4.16.1
General Requirements (a)
Testing of Structural Concrete Concrete shall be tested for compliance in strength and durability requirements, except for the following non-structural Works : (a) (b) (c) (d) (e)
Foot paths and paved areas; Ramps and steps; Hardcourts; Inspection chambers and drain lines;and Floor screed
The compressive strength of concrete shall be determined by crushing tests on 100mm cubes. The quality and consistency of the concrete shall be tested as directed by the SO Rep in accordance with BS EN 12390. The Contractor shall provide for slump test or flow test, compressive strength test, core test and any other concrete test as and when required by the SO Rep. (b)
Sampling On each concreting day and for each grade of concrete per concrete mixer, samples shall be taken according to the following rates : (i)
Samples Taken At Sites Where samples are taken at sites, samples shall be taken for every 40 m³ of concrete or part thereof, of each grade of concrete. At least 1 sample shall be taken from each batch chosen by the SO Rep.
(ii)
Samples Taken At Precast Plants And Ready-Mixed Concrete Plant Where samples are taken at ready-mixed concrete plants, for every 40 m3 of concrete or part thereof, at least 1 sample shall be taken from a batch. Each sample cannot be used to represent the Works for more than one Contract or project. The sampling of concrete cubes in the precast plants shall be carried out by the precasters under the Approved Precast Concrete Supplier listed in the HDB Materials List. Notwithstanding the above, the Contractor is still liable for ensuring that the precast components quality satisfies the Drawings and Specifications requirements. In the event that the precast components quality fails to meet the requirements in the Drawings and Specifications, the Contractor shall be liable for the defective precast components. All defective precast components which failed the strength requirement shall be removed or otherwise rectified accordingly to the instructions of the SO Rep at the Contractor's own costs and expenses. No extension of time for completion shall be allowed for the rectification of such works.
A sample shall be a quantity of concrete, consisting of standard scoopfuls, taken from a batch of concrete whose properties are to be determined. The sample shall be taken at the point of discharge from the mixer, agitating truck or mixer truck. These concrete cubes shall be cast to achieve full compaction by using an approved vibrating table. The minimum period required before demoulding these concrete cubes shall be 16 hours.
BLDG12/S04.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 4-13 4.16
QUALITY OF CONCRETE WORKS
4.16.1
General Requirements (Cont'd) (b)
(CONT'D)
Sampling (Cont'd) At least 4 cubes shall be cast from each sample. 2 cubes shall be tested at an early age. The remaining 2 cubes shall be tested at 28 days for compliance purpose. All concrete cubes shall be tested at the HDB’s Engineering Materials Laboratory or other approved accredited testing laboratory with equivalent or better testing facilities, auto-capturing and computerized monitoring system with analysis capabilities. The Contractor shall submit the information pertaining to the proposed laboratory to SO Rep for approval. All contract information and test results shall be uploaded to EPTC e-cube website. The Employer shall recover all testing fees charged by the HDB’s Engineering Materials Laboratory for testing of cubes including those sampled from readymixed concrete plants and precast plant from the Contractor. The Contractor shall provide lockable humid boxes of adequate sizes to store all test cubes for the specified period. The humid boxes shall be placed in a covered area and maintained at a relative humidity of above 95%. The keys to such curing facility shall be exclusively held in custody by a person designated by the SO Rep. The test cubes to be tested at HDB’s Engineering Materials Laboratory shall be collected by the SO Rep from the designated site at regular interval. The SO Rep shall inform the Contractor of the designated collection site and the Contractor shall deliver cubes to the designated collection site on the day of collection. The Contractor shall provide all necessary assistance to hand over the cubes to the HDB’s appointed contractor for the collection of cubes.
(c)
Cube Identification The Contractor shall provide facilities to enable the identification of test cubes by radio frequency or similar means. The Contractor shall provide at least one web-based radio frequency identification (RFID) reader capable of reading the RFID tags on the concrete cubes from a minimum distance of at least 40 mm. The reader must be able to read all 125kHz RFID tags, including tags starting with hex codes of '2800' and ‘2868’. The Contractor shall include the appropriate interfacing software to a web-based controller. The Contractor shall logon to a website of the Employer to register the concrete cube data and tag IDs using the RFID reader. The registration of the cube data and tag IDs shall be done within the same casting day. The appropriate RFID tags shall be placed at the corner of the cubes while the cubes are still fresh. The top surface of the RFID tag shall be level with the concrete cube surface. The Contractor shall protect the RFID tags on the concrete cube while demoulding. For damage or loss of RFID tag, the Contractor shall be charged the replacement cost based on the Employer's purchase price The Employer shall deduct the charges payable by the Contractor from any monies due or becoming due to the Contractor or recover the same from the Contractor as a debt due by the Contractor to the Employer.
(d)
Cover Measurement The Contractor shall provide suitable equipment for the measurement of concrete cover to reinforcement and the in-situ strength of concrete. The Contractor shall carry out measurements for all major structural elements as determined by the SO Rep. The Contractor shall analyse statistically all measurements for each of the major type of structural element. The concrete cover shall comply with the requirements of CP 65. The in-situ strength of the concrete shall be assessed in accordance with BS 6089 where applicable. The strength shall comply with the specified grade, taking into account the variability with in-situ strength.
BLDG12/S04.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 4-14 4.16
QUALITY OF CONCRETE WORKS
4.16.2
Compliance Of Strength Requirement
(CONT'D)
The 28 day strength shall be required for compliance with the strength specified hereunder. The early strength tests shall be required for quality control purposes. For precast concrete, the 3 day strength shall be obtained solely for quality control purpose. Early strength requirements to meet design strength for demoulding, handling and delivery shall be specified by the approved manufacturer of the precast components and approved by the SO Rep. Such strength shall be determined from the additional cubes. The SO Rep shall have the absolute right to reject any precast component should its early strength fails to meet the design strength requirements. Compliance with the specified characteristic strength shall be judged by tests made on cubes at the age of 28 days. Compliance may be assumed if the following conditions are satisfied: (a)
The average strength of the sample and the preceding three samples or the average of the first four samples of the production is greater than or equal to the specified characteristic strength plus half a fixed current margin of 6 N per mm². Thus, the minimum average strength shall be : Grade Minimum Average Strength at 28 days (N per mm²)
(b)
25
30
35
40
45
50
23.0
28.0
33.0
38.0
43.0
48.0
53.0
The sample strength is at least the level specified below : Grade Minimum Individual Sample Strength at 28 days (N per mm²)
(c)
20
20
25
30
35
40
45
50
17.0
22.0
27.0
32.0
37.0
42.0
47.0
The characteristics strength shall meet the requirement of the specified concrete grade.
If a current margin lower than the fixed current margin can be consistently achieved, approval may be sought to lower the strength level as specified in subclause (a) above. For samples taken on the Site, if the sample strength results do not comply with either or both of the requirements specified above, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. All test cubes taken shall be properly stored and the Contractor shall ensure that all test cubes are tested at their respective age. Test cube that are lost shall be deemed to have failed and the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. Payment of charges to the Employer shall not in any way affect, vary or relieve the Contractor's obligations under the Contract. In addition to the payment of charges, the affected concrete Works may be stopped and not be continued until so directed by the SO Rep. No extension to the Time for Completion shall be allowed for such stoppage of the concrete Works.
BLDG12/S04.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 4-15 4.17
TESTING OF HARDENED CONCRETE In the event of non-compliance, the quality of concrete in question shall be interpreted in accordance with BS 5328. For the 28 day strength non-compliance, the quality of the sub-standard concrete shall be estimated by carrying out tests on hardened concrete in the structure. In the event that such tests are not practical, the SO Rep may decide not to carry out any test. The tests may include non-destructive methods, the taking of core samples, load tests or a combination of several methods as follows : Grade
Compressive Strength of Individual Sample 2 (N per mm )
20 25 30 35 40 45 50
14.5 to below 17.0 18.5 to below 22.0 23.0 to below 27.0 27.0 to below 32.0 31.5 to below 37.0 35.5 to below 42.0 40.0 to below 47.0
20 25 30 35 40 45 50
below 14.5 below 18.5 below 23.0 below 27.0 below 31.5 below 35.5 below 40.0
Test on Structure after 28 days ) ) ) ) Non-destructive method and/or core test ) ) ) ) ) ) ) Non-destructive method and core test ) and/or load test ) )
The tests shall be carried out by an accredited laboratory in accordance with CP 65 and assessed in accordance with BS 6089. The results of any such tests shall not nullify the establishment of noncompliance provided that the latter are based on valid cube test results.
4.18
RECTIFICATION OF DEFECTIVE WORK The action to be taken in respect of the concrete which fails to meet either of the requirements in Clause 4.16 "Quality Of Concrete Works" including all subclauses under it and the assessment specified in Clause 4.17 "Testing Of Hardened Concrete" shall be determined by the SO Rep. They may range from : (a)
qualified acceptance in less severe cases with action taken against the Contractor under Clause 1.6 "Nuisance And Irregularities". The Contractor shall provide protective coating against carbonation and other aggressive environment if the affected concrete can be certified to be structurally sound by a PE engaged by the Contractor; or If the average of three core tests falls below the strength level specified in sub-clause 4.16.2(b), or in the event of failure of a load test.
(b)
the Contractor shall carry out at his own costs and expenses any necessary approved remedial measures to the satisfaction of the SO Rep. Remedial measures shall be designed, supervised and certified by a PE engaged by the Contractor at his own costs and expenses; or
(c)
the Contractor shall remove the affected concrete, and the costs and expenses in removing all poor quality concrete shall be the responsibility of the Contractor.
All defective concrete Works such as badly constructed concrete members with poor alignment and plumb, honeycombed and badly formed surfaces shall be removed or otherwise rectified according to the instructions of the SO Rep at the Contractor's own cost and expense.
BLDG12/S04.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 4-16 4.19
FORMWORK
4.19.1
General Requirements (a)
Material The Contractor shall solely use metalforms for the construction of cast-in-situ reinforced concrete structures. Notwithstanding Singapore Standards CP23, other type of formwork material shall not be used, unless expressly specified otherwise or as approved by the SO Rep. In the case where metalforms are not suitable for any part of a structure, the Contractor may propose to use other formwork material which shall provide similar high quality off-form finish as compared with metalforms, all at the Contractor's own cost and expense. The use of such alternative material shall be subject to the approval of the SO Rep and no adjustment to the Contract Sum shall be effected under such case. Unless specified otherwise, all formwork shall comply with Singapore Standard CP 23. It shall be true to the shape and dimensions as shown in the Drawings. The Contractor shall provide appropriate metal formwork system that produces concrete lines and surfaces complying with Grade II requirements of SS CP23. For cases of non-compliance with the foregoing requirements, the SO Rep reserves the right to instruct the Contractor to carry out rectification Works. The form face in contact with concrete shall be free from dirt, adhering grout, projecting nails, splits and other Defect. Formwork shall be coated with an approved form oil which is compatible with the required finish. Such oil shall be insoluble in water, non-staining, not injurious to concrete and shall not become flaky or be removed by rain or wash water. Diesel oil and liquids which retard the setting of concrete shall not be used. The same type of approved form oil shall be used for all Works. The application of the form oil shall be such that no reinforcement is coated by the oil and there shall be no accumulation of the oil on the formwork. Where the use of plywood is approved by the SO Rep, it shall be Phenolic film faced plywood, complying with SS 1 and cut to size from sheets at least 12 mm thick. Formwork to curved surfaces shall be of steel or other material approved by the SO Rep to give a good surface finish.
(b)
Use Of Employer's Metalforms For the use of the Employer's metalforms, Section 5 "Metal Formwork" including all clauses and subclauses under it shall be applicable and the Contractor shall comply with all provisions specified therein. In addition, the Contractor shall also be required to comply with all relevant provisions specified in this clause including all sub-clauses under it.
(c)
Use Of Contractor's Metalforms In the event the Employer is not supplying the metalform, the Contractor shall use his own metalforms or metalforms from suppliers subjected to approval by the SO Rep. The age of the metalforms used on the Site shall not exceed six years from the date of their manufacture. The Contractor shall furnish to the SO Rep with documents to prove that the metalforms provided are as specified, before the construction of the ground floor slab. Where any documents submitted are not the originals, they shall be duly certified by the originating parties.
BLDG12/S04.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 4-17 4.19
FORMWORK
4.19.1
General Requirements (c)
(CONT’D) (Cont’d)
Use Of Contractor's Metalforms
(Cont’d)
The Contractor shall submit details of his proposed metal formwork system for the approval of the SO Rep and comply with the following requirements : (i)
Technical Requirements The proposed metal formwork system shall comply with Singapore Standard CP23 and shall be in every respect rigidly constructed to the shapes and dimensions as shown in the Drawings.
(ii)
Technical Information The Contractor shall submit, within two weeks from the commencement Date of the Time for Completion, the following technical information of his proposed metalforms namely; the grade of steel, steel strength such as tensile strength, yield stress and elongation (including a recent reduced section tensile test certificate), the steel plate thickness, the manufacturing process (including a recent photo of the manufacturing machine) and the name and address of the metalform manufacturer and/or supplier, for the approval of the SO Rep.
(iii)
Testing Of Metalforms
Reduced Section Tensile Test For Contractor self-owned metalforms, the Contractor shall submit, within two weeks from the commencement Date of the Time for Completion, samples of basic types of the metalforms for testing at SAC-SINGLAS accredited laboratory or other approved laboratory or as directed for the reduced section tensile test. Five samples shall be selected by the SO Rep for testing. Reduced section tensile test shall be carried out in accordance with JIS Z2241. The samples shall comply with the minimum tensile strength of 400 N per mm2, minimum yield stress of 245 N per mm2 and minimum elongation of 25%. The minimum steel thickness shall be 2.65 mm. As and when required, the Contractor shall at his own cost and expense, provide a thickness gauge for verification of the steel plate thickness by the SO Rep. The metalforms shall only be approved by the SO Rep upon receiving all satisfactory test results from the laboratory. The SO Rep shall retain the original copy of the test results.
BLDG12/S04.DOC(17) Sal(151211) (DPD)
Bldg Spec Page 4-18 4.19
FORMWORK
4.19.1
General Requirements (c)
(CONT’D) (Cont’d)
Use Of Contractor's Metalforms (iii)
Testing Of Metalforms
(Cont’d)
(Cont’d)
Dimension Test For Contractor's own metalforms or metalforms from suppliers approved by the SO Rep, the SO Rep shall sample metalforms for dimension test. The Contractor shall be required to send samples taken for testing at SAC-SINGLAS accredited laboratory or other approved laboratory or as directed by the SO Rep. The frequency of the dimension test is as follows:
Storey Height Of Building Blocks
No. of Dimension Tests Per Building Block
Building blocks up to 20 storeys
2 tests per building block
Building blocks up to 30 storeys
3 tests per building block
Building blocks up to 40 storeys
4 tests per building block
The metalforms shall be subjected to one re-test. If the result of the re-test does not comply with the requirements, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. In addition to the payment of charges, the affected set of metalform shall be restricted from use at all HDB worksites and the Contractor shall use another set of metalform for the next cycle of form work erection. No extension of the Time for Completion shall be allowed for such replacement of metalforms. (iv)
Method Of Manufacture All metalforms shall be manufactured so that the surface plate and side ribs are formed from the same sheet of metal to a 90 degree bend without any cutting and/or welding. The folding of the 90 degree cold-formed bend shall be completed in one single continuous operation using a continuous series of steel rollers of a roll-forming machine. Only the two end ribs and all the internal ribs shall be welded.
(v)
Maintenance Of Old Metalforms All old metalforms shall be cleaned free of rust, grit, grout stains etc. The method of cleaning shall be by SHOT BLAST only. Such old metalforms shall be repaired to their original shape and condition to the satisfaction of the SO Rep prior to its use. The Contractor shall engage the service of the Cleaning and Repair (C&R) contractor approved by the SO Rep. In addition, the Contractor shall provide documentary proof in the form of a C&R Certificate indicating the C&R contractor and the quantities of cleaned and repaired metalforms to show that such cleaning and repair Works have been carried out.
(vi)
Marking And Identification The Contractor shall seek the approval of the SO Rep on the type of identification mark for their metalforms. In addition, the metalforms shall be engraved with the manufacturer's logo and the date of manufacture, and the identification mark shall be different from those of the Employer's metalforms.
BLDG12/S04.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 4-19 4.19
FORMWORK (CONT’D)
4.19.1
General Requirements (Cont’d) (c)
Use Of Contractor's Metalforms (Cont’d) (vii)
Irregularities Committed If the Contractor uses sub-standard metalforms which do not comply fully with those reference samples approved by the SO Rep as specified in subclause 4.19.1(c) (iii) "Testing Of Metalforms", the SO Rep shall exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor.
(viii)
Metalforms Usage The Contractor shall use form releasing agent approved by the SO Rep for each casting of concrete. The Contractor shall be fully liable and responsible for any consequential loss or damage due to or arising from the usage of his metalforms.
4.19.2
Design Formwork shall be designed to Singapore Standard CP 23 and shall cater for the appropriate method of placing and compacting the concrete. Adequate number of braces, ties and struts shall be provided so that the formwork shall be able to withstand the pressures resulting from whatever method of placing and compacting concrete adopted, and maintain the required position, slope and profile. Metal props shall be used to support formwork, except at irregular places where timber props may be more suitable or practical. Use of timber props shall be subject to approval by the SO Rep. Where the floor to ceiling height exceeds 9.14 m, or where the formwork deck is supported by shores constructed in two or more tiers, or where the dead, live and impact loads on the formwork exceed 732.3 kg per m², the Contractor shall engage a PE to design the formwork structure. The Contractor shall submit the details of the design of the formwork and the supports for approval by the SO Rep. Notwithstanding the approval by the SO Rep, the strength and adequacy of the formwork and supports shall remain the responsibility of the Contractor and his PE.
4.19.3
Construction Formwork shall be constructed sufficiently rigid and tight to prevent loss of grout from the concrete at all stages of placing and compacting. The arrangement of the formwork shall be such that it can be dismantled and removed readily from the cast concrete without causing shock, disturbance or damage. For beams and slabs, the arrangement shall be such that the formwork and supports for the slab soffits and beam sides can be removed without disturbing the formwork and supports of the beam soffits. Where steel props are used, such steel props shall be prezinc galvanised or galvanised by other methods. Obtain approval from the SO Rep before using such galvanised steel props. Supports to an upper floor shall rest on the lower floor only if the lower floor has developed adequate strength to bear the load. If in the opinion of the SO Rep, the lower floor does not have the required strength to carry the supports to the upper floors, then the method adopted to support the formwork of the upper floor shall have to be approved by the SO Rep. All props to a floor which itself supports the formwork of an upper floor shall only be removed 3 days (minimum) after such upper floor is cast.
BLDG12/S04.DOC(19) Sal(151211) (DPD)
Bldg Spec Page 4-20 4.19
FORMWORK (CONT’D)
4.19.3
Construction (Cont’d) Connections in formwork shall be either nailed, screwed, bolted, clamped or otherwise secured. Ties that are anchored against the timber shall pass through a plate washer of at least 50 mm in size and of sufficient thickness so that the load is transferred to the timber without any visible deflection or penetration into the timber. Only cast-in steel spreader ties shall be used to separate and restrain the formwork faces. The voids formed by the removal of the plastic cones after the dismantling of formwork shall be patched up using non-shrink grout. Concrete separators shall not be permitted. The Contractor shall be required to make allowances for any settlement or deflection of formwork which is likely to arise during construction. The soffits of beams and slabs shall be given a camber to allow for deflection after striking of formwork. The magnitude of the camber shall be approved by the SO Rep. Formwork across structure joints shall be erected such that it overlaps adjoining finished concrete by at least 200mm and holds tightly against it. Formwork shall be provided and run continuously at construction joints. Bolts to be permanently installed in concrete, fixing, boxouts, cores and other devices used for forming openings, holes, pockets, recesses and other cavities shall be as rigid as the formwork itself to prevent the leakage of any grout. No holes shall be cut in cast concrete except with the approval of the SO Rep.
4.20
STRIKING OF FORMWORK The minimum period before striking of the formwork for ordinary Portland Cement concrete shall be in accordance with the following table : Type of Formwork
Minimum Period Before Striking
All vertical or side formwork
12 hours
Soffit formwork to slabs and beams
3 days
Props to slabs and beams
14 days
Props to cantilever slabs and cantilever beams
21 days
Remarks ) ) The period shall commence from ) the time of last pour of concrete ) ) After striking of formwork, props ) shall be immediately put up to ) support the structure )
For residential building blocks where metal formwork (HDB Modular Formwork Design System or similar) and Grade 40 concrete and above are specified, the provision of props and re-props shall be as stipulated in the Drawings. Formwork shall be removed gradually without shock or vibration and in the manner and order approved by the SO Rep. After striking of formwork, any honeycombed surface and defective or damaged concrete work arising from improper work procedures shall be immediately made good as directed by the SO Rep and at the Contractor's own costs and expenses. Any remedial measures carried out without the knowledge and approval of the SO Rep shall be liable for rejection and re-execution. All holes formed by tie bolts shall be filled with non-shrink cementitious mortar or grout of a similar or higher grade than the surrounding concrete as specified in Clause 4.26 "Cement Mortar And Grout" including all subclauses under it.
BLDG12/S04.DOC(20) Sal(151211) (DPD)
Bldg Spec Page 4-21 4.21
OPENINGS AND RECESSES Provide openings and recesses in the reinforced concrete structure, including PVC sleeves where required, for the installation of sanitary pipes and fittings, service ducts or pipes, CATV, telecommunication and electrical cables and trunking, as shown in the Drawings. The Contractor shall leave openings in the lift motor room floor to the requirement of the lift contractor or as instructed by the SO Rep. No opening or opening greater than the sizes shown in the Drawings shall be formed without the prior approval of the SO Rep. No coring or hacking of holes through existing structural elements shall be permitted. However, holes not exceeding 20 mm in diameter may be drilled through these elements. If any steel bar obstructs the drilling through of a hole, a new position shall be selected slightly offset to avoid the obstructing bar. Under no circumstances shall any steel bar be cut or removed without the written consent of the SO Rep. For holes with diameter greater than 20 mm, submit drilling proposals to the SO Rep for approval. All openings in slabs shall be formed with sides tapering slightly downwards and trimmed on all sides with mild steel bars as shown in the Drawings. Check and ensure accuracy in the position, alignment, size and shape of all openings and recesses. Otherwise, the Contractor shall make the necessary rectification. Remove all formwork other than PVC sleeves required from openings and recesses after the concrete has set and ensure that the openings are not blocked up. Recesses for vertical electrical trunking shall be finished smooth. Unless otherwise indicated in the Drawings, the Contractor shall seal openings in structural elements such as floor slabs, walls, columns and beams with non-shrink cementitious mortar or grout of a similar or higher grade than the surrounding concrete, after installation of the services by the Contractor or other contractors.
4.22
BUILDING ACCURACY After removal of formwork, the Contractor shall take measurements as directed by the SO Rep to check the deviation of the reinforced concrete Works from specified dimensions shown in the Drawings. All measurements shall be recorded and submitted to the SO Rep. Works complying with Singapore Standard CP 23 Grade II shall be deemed acceptable.
4.23
PERMANENT STRUCTURE JOINTS
4.23.1
General Expansion joints, contraction joints or other permanent structure joints shall be provided in the positions and constructed and sealed with waterproofing materials as detailed in the Drawings. All exposed vertical sides of columns and walls and undersides of beams at expansion joints shall be covered with 0.7mm thick aluminium cover strips fixed with masonry nails at 300mm centres or otherwise as shown in the Drawings. The installation method and the selection, mixing, application and curing of all joint waterproofing materials shall comply with the Drawings and the manufacturers' recommendation. Alternative joint waterproofing materials may be used subject to the approval of the SO Rep. Submit supporting technical information, test reports and samples of the proposed waterproofing materials. All waterproofing materials provided at public access areas shall be protected with non-shrink grout.
BLDG12/S04.DOC(21) Sal(151211) (DPD)
Bldg Spec Page 4-22 4.23
PERMANENT STRUCTURE JOINTS
4.23.2
Waterstops
(CONT’D)
Waterstops shall be as specified in the Drawings and shall be installed and butt jointed according to BS 8007 and the Manufacturer's recommendations. Waterstops shall be securely positioned in the formwork to prevent displacement during concreting. 4.23.3
Sealing Compound (Permanent Structure Joint) For permanent structure joints, sealing compound for external use shall be one of the three generic types namely polyurethane, polysulphide and silicone. They shall comply with ASTM C920 or other approved.
4.23.4
Preformed Flexible Strip Sealant Preformed flexible strip sealant shall comply with the following requirements : (a) (b) (c) (d)
4.23.5
it shall only be used in horizontal joint and be subject to compression throughout its length; Good adhesion; Water resistant; Non-staining
Bitumen/Rubber Cold Applied Membrane Bitumen/rubber cold applied membrane shall comply with the following requirements : (a) (b)
4.23.6
Minimum joint movement capacity of ±10% of joint width at 25°C; Resistant to dilute acids and alkali.
Bituminous Sheeting Bituminous sheeting with fibre shall comply with the following requirements : (a) (b) (c) (d)
Resistant to lime water (no visual effect after two weeks immersion); Maximum water absorption of 10% of dry weight; Minimum tensile strength of 50 kg per cm²; Ozone and ultra-violet resistance.
The strip shall be applied to the joints by burning and affixing on each side of joint to a width not less than 70mm leaving the middle part free to take any movement at the joint without damage. 4.23.7
Polyethylene Foam Backing Rods Polyethylene foam backing rods used as mortar stops in panel joints shall have the following properties : (a) (b) (c) (d) (e) (f)
BLDG12/S04.DOC(22) Sal(151211) (DPD)
Minimum compressibility of 75% of original volume at 25°C: Excellent resilient properties; Density between 35 kg per m³ and 45 kg per m³; Totally resistant to common acids, lubricants and detergents; Totally resistant to water infiltration by capillary action; Suitable for up to 70°C.
Bldg Spec Page 4-23 4.24
APPARATUS The Contractor shall provide the following apparatus for use for all Works on the Site :
4.25
(a)
Concrete slump test apparatus complying with SS 78 or flow test apparatus complying with BS 1881 : Part 105. One set of the apparatus shall be provided for each concreting location;
(b)
Steel or cast iron moulds complete with rod in accordance with SS 78 for casting 100mm concrete test cubes and 100mm mortar or grout test cubes. A minimum number shall be provided such that no stripping of the cube is required prior to the 24 hours setting and hardening period;
(c)
Three measuring cylinders of 250ml capacity, graduated to measure to the nearest 2.0 ml, for determination of silt content (field settling method);
(d)
An approved apparatus for measuring moisture content in fine aggregate;
(e)
One digital concrete rebound hammer equipped with an electronic transducer which converts the rebound of the hammer into an electric signal and displays it in the selected stress units;
(f)
One surveying level or theodolite complete with the necessary accessories;
(g)
One electronic calculator with statistical functions;
(h)
One 5.5m measuring tape; and
(i)
One spirit level.
MASS AND LEAN CONCRETE Mass and lean concrete shall compose of cement, fine aggregates and coarse aggregates in the nominal ratio by weight of 1:2:4. Where, however, a denser and more workable concrete can be produced by a variation in the ratio of fine aggregate to that of coarse aggregates, this ratio may be varied within the limits 1 to 1.5 and 1 to 3, provided that the weights of fine and coarse aggregates, each measured separately, shall nevertheless be equal to the sum of the weights of fine and coarse aggregates appropriate to the nominal mix. The concrete shall be mixed as specified in the foregoing requirements in this Section including all clauses and subclauses under it. Reinforced concrete shall not be laid directly onto earth surfaces. A blinding coat of 40mm minimum thickness of lean concrete shall be laid on well prepared firm ground before any reinforcement is placed in position.
4.26
CEMENT MORTAR AND GROUT
4.26.1
General For structural purposes, cement mortar shall compose of one part cement to one part sand, mixed with water so that water-cement ratio does not exceed 0.4 by weight and cement grout shall compose of cement and water-cement ratio between 0.4 and 0.6, or such other proportions as shall be directed by the SO Rep.
4.26.2
Grouting For Prestressed Concrete Ducts Grouting for prestressed concrete ducts shall be as specified in Clause 7.15 "Grouting".
BLDG12/S04.DOC(23) Sal(151211) (DPD)
Bldg Spec Page 4-24 4.26
CEMENT MORTAR AND GROUT
4.26.3
Precast Concrete Joints
(CONT’D)
Non-load bearing joints between precast concrete components and adjoining structures shall be filled with appropriate grout and/or mortar protected by proprietary sealants and backing rod. They shall be waterproof. Load bearing joints and connection shall be grouted, mortar packed or concreted and these shall be carried out by trained workers. In the case where a joint need not be grouted, mortar packed or concreted immediately, such work shall be completed not later than 28 days after erection. The respective mix design shall be free of lime and chloride. They shall be durable, waterproof, non-shrink and possess strength equal or higher than that of precast concrete. Curing for at least 3 days shall be provided. Designed mixes shall be submitted to the SO Rep for approval. 4.26.4
Testing Method And Compliance For Load Bearing Grout And Mortar The method of sampling and testing prescribed in BS 4551 shall be adopted. The compressive strength shall be determined by crushing test on 50mm cubes. For each casting day and for each grade of grout or mortar, three samples shall be taken from three separate batches. One cube shall be cast from each sample for testing at 28 days. The compliance of the 28 day strength shall be judged, based on the average compressive strength of 3 cubes from 3 samples taken on the same day, in accordance with the strength requirement specified in the Drawings. In the event of non-compliance, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. If the average compressive strength of the 3 cubes is less than the design strength, the quality of the substandard concrete shall be estimated by carrying out appropriate tests on hardened concrete in the structure. In the event that such tests are not practical, the SO Rep may decide not to carry out any test.
4.27
FOUNDATIONS All reinforced concrete footings and pile caps shall be constructed in accordance with the Drawings and to the exact depths required. Provide, maintain and remove any necessary planking and strutting, sheetpiling or cofferdams, and by pumping or other approved means keep the excavations free from water. In the case of loose or disturbed ground, the bottom of excavation for pile caps shall be well rammed and those for footings shall be excavated further to a sound layer. The whole work shall be approved by the SO Rep before it is covered with a blinding layer not less than 40mm thick. The required cover of concrete under the reinforcement shall be entirely above the blinding layer. Excavation for all foundation work shall be carried out in accordance with Section 3 - "Excavation" including all clauses and subclauses under it.
4.28
PILE CAPS Before commencing to construct pile caps, the Contractor shall employ a Registered Surveyor to check and verify the eccentricities and the cut-off levels of all piling work in the ground against pile eccentricity Drawings provided and pile cap details in the Drawings, and shall notify the SO Rep in the event of any discrepancy. Straighten the steel reinforcement projecting above the piles for anchoring pile caps, carry out excavations, erect formwork and temporary timbering for the construction of pile caps.
BLDG12/S04.DOC(24) Sal(151211) (DPD)
Bldg Spec Page 4-25 4.29
LIFT PITS For lift pits below ground level, the concreting to the bottom and walls shall be carried out in one operation without construction joints and bolt holes up to the underside of ground beams and slabs. Forms ties used to connect opposite faces of formwork shall be cast-in steel spreader ties. Concrete separators shall not be permitted. Where in the case water reducing admixture is used in the concrete mix, furnish information concerning the water reducing admixture for approval by the SO Rep prior to its use. Water reducing admixture shall be mixed with the concrete in accordance with the manufacturer's directions and to the satisfaction of the SO Rep. All external wall surfaces of lift pits shall be waterproof by coating with three coats of bitumen solution complying with BS 3416 or other cold applied bituminous coating as approved by the SO Rep. The concrete surface shall be clean and dry before application of the first coat, and ample time for each coat to dry shall be allowed. The total dry thickness of the coating shall be 0.6mm minimum.
4.30
FIRST STOREY SLAB After backfilling and lean concrete to the first storey of residential building block are completed, the Contractor shall engage a licensed registered surveyor to verify the position of all column/wall grid lines and submit such report to the SO Rep. The SO Rep shall be informed of any deviations from the Drawings.
4.31
FLOORS After initial set, the upper surface of cast-in-situ reinforce concrete floors shall be trowelled smooth with a steel float to true level and even surface. No screeding of any kind shall be applied to the floor slabs except where specified otherwise. Care shall be taken to ensure that the steel reinforcement is not displaced or lowered during trowelling. For areas which are to receive rendering or other finishes, the fresh concrete shall be struck off to a level or fall as required using a long timber trowel. The surface shall be densified by a jitterbug tamper or trowelling after the bleeding has stopped in order to eliminate settlement and plastic shrinkage cracks. Before it hardens, it shall be brushed with a stiff broom in one direction to give a rough and tidy surface.
4.32
ROOFS
4.32.1
General Reinforced concrete roofs shall be constructed to fall as shown in the Drawings and finished with power trowelling, leaving the surface smooth and free from mortar droppings. The finished roof slab shall be cured immediately with an approved curing compound. Roof access openings, 900mm x 900mm clear with 200mm upstanding kerbs, shall be constructed at the positions as shown in the Drawings. 100mm x 100mm mortar angle fillet shall be neatly provided around all upstands, pipe supports, RC stumps, walls and ventilating stacks. The finished concrete roof shall be protected against mortar droppings and damages by heavy objects during subsequent work on the roof.
BLDG12/S04.DOC(25) Sal(151211) (DPD)
Bldg Spec Page 4-26 4.32
ROOFS
(CONT’D)
4.32.2
Watertightness And Water Stagnation Test After the completion of all structural work on the roof, the roof slab shall be tested for watertightness and to ensure no water stagnation. Where the reinforced concrete roof is to be protected by a watertight secondary roof, no water test or ponding test will be conducted. The watertightness test shall be carried out by ponding with water to a minimum depth of 25mm for 24 hours. The water used for the test shall be that used for the watertightness test of the RC water tanks. At the end of the watertightness test, the soffit of the slab especially the area around the pipes shall be examined for any dampness or leakage. Immediately after discharging the water off the roof, the top surface shall be examined for any water stagnation. Water collected beyond a layer of 5mm measured from the top surface of the roof in any area is considered a stagnation. After any rectification, hacking and refilling around pipes installed after the first test, the localised area shall be retested at the Contractor's own cost and expense for watertightness, water stagnation or both as deemed necessary by the SO Rep.
4.33
DRIPS Drips shall be formed along edges of soffit to concrete roof slabs, hoods, underside of balconies, cantilevered beams and slabs and other parts of the building where rainwater is likely to adhere in drops.
4.34
RC STRUCTURE CANNOT BE USED AS LIGHTNING PROTECTION SYSTEM Reinforced concrete structure and foundation shall not be used as lightning conductors or earth electrodes. Lightning conductors shall not be embedded in any structural components and steel reinforcement shall not be used as part of the protection system.
4.35
INSTALLATION OF FIBRE OPTIC SENSOR FOR COLUMNS The Contractor shall provide and install encased fibre optic sensors at 10 different 1st storey columns of each building above 10 storeys. Where the columns are precast, the Contractor shall provide such sensors for the precaster to install in the precast columns. The locations of the sensors shall be approved by the SO Rep and as-built drawings indicating actual position of sensors must be submitted upon successful installation. The sensors shall have connecting cables terminating with a socket at the column face to enable the SO Rep to take readings. The Contractor shall submit 3 sets of readings per block to HDB during the construction stage to verify that the sensors are in working condition.
4.36
MONITORING DIFFERENTIAL SETTLEMENT OF COLUMNS For buildings 10 storey or higher and supported on pile foundation, the Contractor shall install and monitor 10 numbers of settlement points per block. The location of the settlement points and the bench marks shall be selected by the SO Rep before installation. These settlement points are to be installed on the first storey columns and they have to be installed before construction works are allowed to proceed for the 2nd storey, unless otherwise instructed by the SO Rep. The instruments and equipment used to take the readings shall have a minimum accuracy of 0.5mm. Readings shall be taken by after the settlement points are first installed and subsequently on every 3 floors, and/or when directed by the SO Rep. In addition, one set of reading is to be taken for the completion of the structural roof slab and another set of reading is to be taken before the building block is handed over. The contractor is required to submit two sets of monitoring reports certified by a Registered Surveyor on the above readings within 1 week after the completion of each reading. The format shall be pre-approved by the SO Rep. The contractor shall take all necessary action to protect the settlement points so that they are not damaged or subject to vandalism throughout the contract period. In the event that the settlement points are damaged, lost and/or vandalized or become defective, the contractor shall install additional points and/or take all necessary remedial action as instructed by the SO Rep.
BLDG12/S04.DOC(26) Sal(151211) (DPD)
Bldg Spec Page 4-27
Section 5/......
BLDG12/S04.DOC(27) Sal(151211) (DPD)
Bldg Spec Page 5-1 SECTION 5 METAL FORMWORK
5.1
5.2
DEFINITIONS "Metalforms" -
shall mean the set of metalforms rented from the Employer including U-clips but excluding the supporting system.
"Workshops" -
shall mean the Employer's Warehouses or appointed maintenance workshop(s).
BUILDING BLOCKS USING METALFORM The Contractor shall use the Employer's metalforms only for the construction of building blocks. The metalforms shall be hired to the Contractor by the Employer and it shall be the responsibility of the Contractor to use and maintain them strictly in accordance with the instructions issued by the SO Rep. The Contractor shall make provisions for his own formwork and accessories for any portion of the building blocks where in the opinion of the SO Rep the use of metalforms is unsuitable. Such situations may occur at curved or bent (other than 90 degrees) members, corners and other parts of the structure. The formwork for such portions shall be made of materials which will result in high quality off-form concrete finish. If, in the opinion of the SO Rep, the concrete surface finish is poor, the Contractor shall carry out rectification Works all at the Contractor's own cost and expense. The charges, terms of hiring and other requirements are specified in Clauses 5.3 to 5.10 (inclusive).
5.3
HIRE RATES, CHARGES & PAYMENT Metalforms shall be hired out at a fixed rate of $1.90 per square metre per month based on the ACTUAL DAILY AREA OF METALFORMS TAKEN BY THE CONTRACTOR. For damage or loss of metalforms and U-clips, the Contractor shall be charged the replacement cost based on the Employer's latest purchase price and the SO Rep reserves the right to destroy the damaged metalforms at no compensation to the Contractor. The decision of the Superintending Officer in this respect shall be final and binding on and conclusive against the Contractor. The Employer shall deduct the amount of hiring costs and other charges payable by the Contractor from any monies due or becoming due to the Contractor or recover the same from the Contractor as a debt due by the Contractor to the Employer.
5.4
HIRING PERIOD The hiring period shall commence on the date of the drawing of Metalforms from the Employer's Metalform Warehouses. The hiring period shall end when the Metalforms are returned to the Employer's Metalform Warehouses. Where during the hiring period, there is delay in the Contractor's construction activities due to the supply of Metalforms which in the opinion of the SO Rep, are deemed to be unavoidable, the hiring charges may be adjusted accordingly and at the sole discretion of the SO Rep. The Contractor must inform the Employer's Metalform Unit of any delay within 2 weeks from the first day of such delay. The details of notice including the number of days delayed and area of metalform affected shall be submitted to the Metalform Unit within 2 weeks from the date of resumption of work. The SO Rep shall endorse on this notice before submitting to the Metalform Unit. If the Contractor does not submit the notice within the above deadline, the SO Rep reserves the right not to consider the Contractor's request for adjustment of the hiring charges.
BLDG12/S05.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 5-2 5.5
IRREGULARITIES COMMITTED Should the Contractor be found to have committed any of the following irregularities : (a)
Subletting or lending the Metalforms or any part thereof to any third party or removing the Metalforms from the site to which it is delivered or consigned, without first receiving written permission from the SO Rep regardless of whether the Contractor has any knowledge of it; or abuse in Metalforms usage or storage, regardless of whether the Contractor has any knowledge of it;
(b)
Using sub-standard metalforms or accessories purchased elsewhere other than from the Employer to replace lost and damaged ones upon returning;
(c)
Using sub-standard metalforms or accessories purchased elsewhere other than from the Employer for use in the Site;
the SO Rep shall exercise its rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor. In addition, the Contractor shall be liable to pay the Employer charges equal to the replacement cost of Metalforms based on the latest Employer's purchase prices. The SO Rep also reserves the right to destroy these sub-standard metalforms found on the Site at no compensation whatsoever to the Contractor if the Contractor does not immediately remove such sub-standard metalforms from the Site.
5.6
PROCEDURE FOR DRAWING OF METALFORMS The Contractor is required to submit to the Employer's Metalform Unit the request for metalform schedule not later than 2 weeks before the delivery date of the Metalforms from the Employer's warehouses. However, the Contractor may request for metalforms with shorter lead time provided the type and quantity requested is available in the warehouse. Based on the request, the Metalform Unit reserves the right to vary the type and quantity based on its availability in the warehouses. The supply of Metalforms will be based on the approved schedule. The Contractor is not allowed to revise the approved metalform schedule in terms of type, quantity and timing. Revision may be granted by the SO Rep in cases where the revision by the Contractor is due to causes beyond his control. Notwithstanding the above, in a situation where the Metalform Unit is not able to supply in full the quantity of certain type(s) of Metalforms, the SO Rep reserves the right to vary the quantity and propose substitute with other equivalent type(s) or combination of metalforms. The SO Rep may direct the Contractor to supplement his requirement from his own sources if the Contractor has objected to the proposed substitution. There shall be no claims for extension of time or whatsoever compensation from the Contractor. To facilitate the planning on the usage of metalform and U-Clip, the Contractor shall feedback to SO Rep on the estimated maximum total quantities of each type of metalforms and U-clips required for each block including MSCP within 2 months after the commencement of the Contract.
5.7
DELIVERY OF FORMWORK The Contractor shall bear all the cost of transportation of the Metalforms from the Metalform Unit's Warehouse or the Workshops to the Site and return the Metalforms to the Metalform Unit's Warehouse or the Workshops at the end of the hiring period, together with a list of the Metalform items hired. Any missing items shall be listed separately. During the delivery of the Metalforms to the Site, the Contractor shall be responsible for and bear the cost of loading, unloading, on-site handling and transportation, arranging, stacking and storing of the Metalforms. Unless notification in writing to the contrary is received by the SO Rep from the Contractor within one week of the Metalforms being delivered to the Site, the Metalforms shall be deemed to be in good order in accordance with the Terms of Contract and to the Contractor's satisfaction.
BLDG12/S05.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 5-3 5.8
USE OF METALFORMS The Contractor shall be responsible for the safe-keeping of the Metalforms and use in a workmanlike manner and return on completion of the hiring period according to the returning schedule. The Metalforms shall not be abused ie. not used in its intended manner, for eg. as bracing or propping of formwork, as walking or working platform. The decision of the SO Rep in this respect shall be final and binding on and conclusive against the Contractor. The Contractor shall be charged for the damage of the Metalforms arising from such abuse, based on the latest Employer's purchase prices. The Metalforms shall be used only at the site as stated in the Delivery Orders. No Metalform shall be allowed to be transferred to another worksite unless prior written approval is obtained from the SO Rep. The Contractor shall remove damaged metalforms and substitute with good ones from the Metalform Unit as and when directed by the SO Rep during construction. The Contractor shall use, for each casting of concrete, form releasing agent approved by the SO Rep. The Contractor shall bear the cost of timber, form ties, form tie holders, plastic cones, hooks, bolts, nuts, washers, anchor bolts & form bracing and propping or any other tools and accessories he may use in conjunction with the use of the Metalforms. The use of such accessories shall be approved by the SO Rep. The Employer accepts no liability or responsibility for any consequential loss or damage due to or arising from the usage of the Metalforms or through non-arrival arising from accident during loading and unloading or transporting of the Metalforms. The Contractor shall fully and completely indemnify the Employer in respect of all claims by any person whatsoever from injury to person or property caused by or in connection with or arising out of the use of Metalforms and in respect of all costs and charges in connection therewith. The Contractor shall be responsible for and bear the cost of building a raised timber platform and tarpaulin covers or equivalent for the safe-keeping and storage of the Metalforms at the Site.
5.9
PROCEDURE FOR THE RETURN OF METALFORMS The Contractor shall comply strictly with the procedures for the return of Metalforms specified hereunder : (a)
Submit returning schedule and quantities to the Employer's Metalform Unit on a per building block basis within 3 weeks from the last date of casting of main roof.
(b)
The Metalforms and accessories for the block (excluding the formwork for water-tank, roof-fascia, pitched roof etc. which are to be cast after the main roof) shall be fully returned within 1.5 months from the last date of casting of main roof; failing which, the SO Rep may treat part or whole of the relevant unreturned metalforms as lost. The decision of the Superintending Officer in this respect shall be final and binding on and conclusive against the Contractor.
(c)
The remaining Metalforms and accessories for the block shall then be returned within 1 month from the last date of casting for the building block; failing which the SO Rep may take the action as specified in (b) above.
(d)
All Metalforms shall be lowered down carefully by mechanical means and no dumping or rough handling is allowed.
(e)
Metalforms returned to the Employer's Workshops shall be packed and strapped in neat bundles of similar sizes and placed on pallets at the Contractor's own expense for easy unloading using forklift. The Contractor shall mark the Metalform with a strip of paint of 100mm width. The colour code to be used can be obtained from the Metalform Unit. Sizes of the pallets shall be in accordance with the instructions of the SO Rep.
(f)
At the receiving Workshops, the Employer's representative shall fill up the metalforms delivery form in triplicate.
BLDG12/S05.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 5-4 5.9
5.10
PROCEDURE FOR THE RETURN OF METALFORMS (CONT’D) (g)
Any amendment or alteration on the delivery form shall be countersigned by the Contractor and the Employer's representative at the receiving ends.
(h)
Metalforms returned to the Workshops which are found to be irreparable will be considered as damaged. An actual counting of such metalforms at the Workshops shall be witnessed by the Contractor. The Contractor shall ensure that he or his representative is present at the time and place so directed by the SO Rep, otherwise, the SO Rep reserves the right to destroy or write-off these damaged Metalforms at no compensation whatsoever to the Contractor.
CLEANING, SERVICING & REPAIR OF FORMWORK The Contractor shall return all the metalforms and the related accessories, as directed by the SO Rep to the Workshops for cleaning, servicing and repair after the completion of the use of the metalforms. The Contractor shall be charged according to the following rates for cleaning, servicing and repair : Items
Rate
(1)
Flat Forms
$ 6.40 per m²
(2)
Inner Corner Forms
$ 6.40 per m²
(3)
L, S-shaped Forms
$ 7.70 per m²
} } Based on surface area in contact } with concrete } }
(4)
Corner Angle Form
$ 7.20 per m²
Based on gross area
The Contractor shall not pay any monies directly to any of the Workshops. The costs for cleaning, servicing and repair shall be deducted from monies due or to become due to the Contractor. Metalforms shall be considered as damaged beyond repair, for example; if they are twisted, severely bent or crushed. The decision of the Superintending Officer in this respect shall be final and binding on and conclusive against the Contractor. The Contractor shall also be charged according to the provisions as specified under Clause 5.3 "Hire Rates, Charges & Payment" for such Metalforms. The SO Rep reserves the right to destroy or write-off these damaged Metalforms at no compensation to the Contractor.
Section 6/.....
BLDG12/S05.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 6-1 SECTION 6 SEMI-PRECAST CONSTRUCTION
6.1
PRECAST CONCRETE COMPONENTS
6.1.1
Area Of Usage Precast concrete components shall be used in areas as shown in the Drawings.
6.1.2
Surface Finishes External surface treatments or finishes of the precast concrete components shall be approved by the SO Rep.
6.1.3
Suppliers The precast concrete components shall be obtained from suppliers approved by the SO Rep. The list of approved suppliers is posted at the following websites: kmo.eptc.com.sg or hdbuilders.com. The Contractor shall submit the names of his suppliers, the written contractual agreements between themselves and the suppliers and the quantities to be supplied by each supplier for the precast concrete components within four weeks from the date of the Letter of Acceptance. The written contractual agreement submitted shall include the detailed breakdown of precast component prices. The Contractor shall not be permitted to change his suppliers without the written consent of the SO Rep.
6.1.4
Safety Measures For Precast Transportation For the precast supply from the Contractor’s appointed sources, the Contractor shall obtain the approval from the relevant authorities as and when necessary for precast transportation. The Contractor shall comply with prevailing traffic regulations and prevent damage to public roads, overhead structures, trees, lamp posts, sign boards, decorations, cables and road related facilities in the precast transportation. The Contractor shall carry out risk assessment and analysis complying with the Workplace Safety and Health (WSH) Act and Regulations for the work procedures related to precast transportation. In this regard, the Contractor shall submit a Safety Manual on precast transportation, which shall include but not limited to the following key activities, for SO Rep’s approval: (a)
Securing of Precast Components The Safety Manual shall include the method to secure precast components on trailer. Trade demonstrations shall be conducted and photographs shall be provided to supervisors and loading workers for better understanding. For precast components to be delivered in horizontal position, sling belts and stoppers shall be provided on the trailer to prevent slipping and toppling of precast components. For precast components to be delivered in vertical position, if galvanised wires and chain block are used, the Safety Manual shall indicate clearly the type and size of wire, type of chain block and the tying method. The Contractor shall provide secondary securing method using chain or sling belt to supplement galvanised wires and chain block if necessary. For trailer mounted with steel frames, the Contractor shall ensure steel frames and the connections to trailers are sound for delivery purpose. The Safety Manual shall include a system of regular checks on the conditions of the steel frames.
BLDG12/S06.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 6-2 6.1.4
Safety Measures For Precast Transportation (b)
(Cont’d)
Loading on Trailer The Contractor shall specify in Safety Manual to avoid over-loading of precast components on trailer. The overall height from ground to the highest point on trailer shall be checked to ensure compliance with the prevailing traffic regulations. In addition, for trailer with steel frame, load balancing of precast components at two sides of trailer shall be checked before leaving the precast factory. For non-compliance found, the driver shall be informed and remedial actions shall be taken before leaving the precast factory.
(c)
Transportation The Contractor shall specify in the Safety Manual that the driver should observe the speed limit and prevailing regulations during the precast transportation. The driving experience of drivers employed for precast transportation shall be specified where necessary to exclude inexperience driver from precast transportation. Continuing road safety education and appropriate disciplinary actions for non-compliances shall also be included in the manual to prevent speeding during transportation. The Contractor shall ensure the transportation fleet like prime-movers and trailers are wellmaintained. The routine maintenance shall include periodic regulatory inspection by the authorities, daily checks by driver on brakes, signal, lighting, tyres. The timber platform shall be in safe condition for the loading workers and the trailer shall be free from loose debris for precast transportation.
6.2
STRUCTURAL PRECAST CONCRETE
6.2.1
Design Structural precast concrete components shall be designed in accordance with CP 65. The Contractor may propose alternative design subject to the written approval of the SO Rep. Joints, connections and sealants shall be designed for protection against water, weather, corrosion and fire so as to provide continued water and weather tightness and structural integrity of the buildings. The positions and capacities of all lifting and erection inserts of precast concrete components shall be carefully considered for all loads induced by manufacturing, lifting, handling, storage, transportation and erection. A minimum safety factor of 3 shall be used to design the lifting and erection inserts, lifting hooks and erection devices. Submit precasting and erection techniques for precast concrete components including structural calculations and details for the lifting and erection devices. Should the load bearing joints and connections be grouted, mortar-packed or concreted, submit respective mix design for approval by the SO Rep and carry out tests in the mix design in accordance with appropriate code or proprietary requirements. Method of installations adopted shall ensure that the joints and connections can be fully grouted, mortar-packed or concreted. Non-load bearing joints between precast concrete components and adjoining structures shall be filled with appropriate grout and/or mortar protected by proprietary sealants and backing rod. The SO Rep may, at his absolute discretion, instruct the Contractor to apply special coatings or epoxy bonding compounds to connections and joints of precast concrete components, be it welded, bolted, dowelled, grouted, mortar-packed or concreted.
BLDG12/S06.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 6-3 6.2
STRUCTURAL PRECAST CONCRETE
6.2.2
Drawings
(CONT’D)
Submit the following drawings for the approval of the SO Rep within one month from the date of the Letter of Acceptance, unless otherwise instructed by the SO Rep : (A)
Shop Drawings (a)
Precast Concrete Components With Shop Drawings Where in the case shop Drawings (denoted by the words "shop drawings" in the drawing title) for precast concrete components are incorporated in the Drawings, the Contractor need not submit shop drawings for approval. Notwithstanding the incorporation of such shop Drawings in the Drawings, the Contractor shall be required to check and/or ensure the following :
(b)
(i)
That the details for such precast concrete components are adequate and suitable for the Works and that there is no discrepancy. The Contractor shall be responsible and bear all costs and expenses for all rejections, reinstatements and reproductions of such precast concrete components directly and/or indirectly resulting from and/or out of any inadequacy, unsuitability and discrepancy in the Drawings;
(ii)
That the handling techniques for precasting, demoulding, storage and transportation adopted shall not over-stress such precast concrete components. It is the responsibility of the Contractor to provide at his own cost and expense, any additional steel reinforcement bars required for his handling techniques to ensure that such precast concrete components are not damaged or over-stressed during handling;
(iii)
Ensure the adequacy and suitability of the size, position and details of lifting and erection inserts and any additional reinforcement bars required for handling and erection purposes shall be submitted to the SO Rep for approval prior to commencement of the production work;
(iv)
That the minimum concrete strength of precast concrete components required for handling, demoulding, storage, transportation and erection are checked and submitted to the SO Rep for approval prior to the commencement of the production work.
Precast Concrete Components Without Shop Drawings Where in the case shop drawings for precast concrete components are not incorporated in the Drawings, the Contractor shall submit shop drawings for such precast concrete components for approval by the SO Rep. The shop drawings shall include the following details :
(B)
(i)
The size, position and details of lifting and erection inserts and reinforcement details;
(ii)
The handling techniques for precasting, storage and transportation;
(iii)
The minimum concrete strength for precast concrete components required for handling, demoulding, storage, transportation and erection.
Mould Drawings Mould drawings showing :
BLDG12/S06.DOC(3) Sal(151211) (DPD)
(i)
Surface treatment of moulds for casting and lifting operation.
(ii)
Method of concrete consolidation and compaction such as external vibration, internal vibration, table vibration, adjusted slump and mix method.
(iii)
Method of curing, demoulding and storage of precast concrete components.
Bldg Spec Page 6-4 6.2
STRUCTURAL PRECAST CONCRETE
6.2.2
Drawings (Cont'd) (C)
(CONT’D)
Erection Drawings Erection drawings showing :
(D)
(i)
Erection sequences and handling requirements.
(ii)
Calculation and position and sizes of backers/shims, temporary props, bracings and their installation method clearly shown.
(iii)
Calculation and details of method of positioning and supporting unconnected precast concrete components including temporary bracings, struts and props.
Waterproofing Joint Drawings Waterproofing joint drawings showing procedure and sequence of installation of sealants on the Site in their relation to erection sequence and handling requirements.
6.3
MANUFACTURING
6.3.1
Concrete Batching Plant The Precaster shall maintain the concrete batching plant in good working order at all times. The concrete batching plant shall be calibrated once in every six (6) months by an accredited laboratory in accordance with SS289. Any errors found during calibration shall be rectified immediately. Proper documentation and records shall be kept in the office in precast plant for inspection by the SO Rep upon request.
6.3.2
Shop Drawings Precast concrete components shall be produced in accordance with approved structural Drawings. Shop drawings shall be based upon the structural Drawings and shall be submitted to the SO Rep for approval as per sub-clause 6.2.2 "Drawings".
6.3.3
Moulds Check and ensure that all moulds, regardless of materials, conform to the shape, lines and dimensions of the precast concrete components to be produced. The moulds shall be sufficiently rigid to produce the casting tolerances and finishes specified. Rubber seal or equivalent shall be used in all horizontal and vertical mould joints to prevent leakage of mortar or cement paste. Moulds shall be designed to prevent damage to concrete from : (a)
restraint as the concrete shrinks;
(b)
the stripping operation when the precast components are lifted from the mould; or
(c)
dimensional changes due to demoulding of prestressed components.
High quality rubber mat shall be used for carrying the tiles of precast components with tile finish.
BLDG12/S06.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 6-5 6.3
MANUFACTURING
(CONT’D)
6.3.4
Manufacturing Requirements Submit proposals for marking identification and date of casting of each precast concrete component for the approval of the SO Rep prior to the commencement of manufacturing. Surface finish requirements shall be consistent with the standard achieved by the use of high quality concrete and properly designed forms or moulds having rigid and smooth surfaces. Such surface finishes including surface airholes shall be to the satisfaction of the SO Rep. Where tile finish is specified, check and ensure uniform width and depth of the groove between the tiles which shall be on the same plane. Prior to mass production of precast concrete components, produce at least one sample of each type of precast concrete component for approval by the SO Rep. The approved sample panel shall be displayed at the precasting yard. The approved sample panel shall be used as the yardstick for the minimum standard and quality to be achieved for all precast panels. The SO Rep may at his absolute discretion require more sample panels to be produced for his approval. Check and ensure that the approved sample panels are not damaged on display. The Contractor shall provide remedial work at his own costs and expenses to precast concrete components that are not satisfactorily finished as decided by the SO Rep. Gross variation from the specified finish may cause rejection of the precast concrete components and the Contractor shall replace the precast concrete components. Allow for the incorporation of all requirements of all trades whose work requires blockouts, recesses, notches, embedded metal work or any other items affecting the precast concrete components involved. All reinforcements shall be positioned in the moulds with the prescribed concrete covers as shown on the Structural Drawings. Approval shall be sought from the SO Rep if such work cannot be incorporated into the precast concrete components. Aluminium window frames, may either be installed on site or cast-in together with the precast concrete components. In all cases the aluminium window frames shall be protected from dirt, grout and other deleterious material by wrapping with self adhesive protective tape. There shall be adequate lapping over the joints of two protective tapes. The protective tapes shall completely adhere to the frame and provide protection to it. In the case of aluminium window frame being installed on site, check and ensure:
6.3.5
(i)
the safety and integrity of the aluminium window frame and that no part of the precast concrete is hacked;
(ii)
the watertightness between the aluminium window frame and precast concrete component.
Manufacturing Tolerances Tolerances for manufacturing and casting of precast components shall be as follows unless otherwise instructed by the SO Rep : (a)
Position tolerances for cast-in items measured from datum line locations as shown on approved Drawings: Inserts, bolts, pipe sleeves etc Flashing relets, at edge of panel Reglets for glazing gaskets Groove width for glazing gaskets Electrical outlets
(b)
: : : : :
±10mm ±6mm ±3mm ±2mm ±13mm
Position tolerances for placement of reinforcement : Reinforcing bars and meshes shall be located within 12mm of the position as shown on the approved shop Drawings, but in casting, no reinforcement shall encroach on the specified minimum cover.
BLDG12/S06.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 6-6 6.3
MANUFACTURING
6.3.5
Manufacturing Tolerances (Cont'd) (c)
(CONT’D)
For casting tolerances, the overall height and width measured at the face adjacent to the mould when cast shall be as follows : 3m or under
:
±3mm
> 3m to 6m
: :
+3mm -5mm
> 6m to 9m
: :
+3mm -6mm
Each additional 3m
:
Angular deviation of plane
:
+2mm per 150mm depth of side mould
Thickness
: :
+6mm -3mm
Openings (cast within one member)
:
+6mm
Out of square (difference in length of two diagonal measurements)
:
3mm per 3m or 6mm total whichever is greater
±2mm per 3m
The casting tolerances specified above shall be compatible with the installation requirements of precast concrete components, which may have attachment of sash, door frames, window frames, louvres sunshades and other materials. (d)
6.3.6
For after casting tolerances, the bowing and warpage shall be as follows: Without intermediate support dimension
:
1 panel 240
With intermediate support dimension
:
1 panel 360
Inspection Of Manufacturing The SO Rep shall have the discretion to inspect the manufacturing plant and the precast concrete components at all times. If the inspection is not conducted at the plant, this shall not relieve the Contractor from his responsibility in manufacturing an acceptable product, and the SO Rep shall at his liberty reject any precast concrete components on the Site not complying with the design requirements even though no plant inspection has been conducted.
6.4
HANDLING The precast concrete components shall be handled and transported in a way consistent with their shapes and design in order to avoid excessive stresses or damages. Precast concrete components shall be lifted only at appropriate points shown on the production and erection Drawings. Check and allow for : (a) (b) (c) (d)
adequacy of design reinforcement to resist handling stresses; provision of additional reinforcement if required; exact number, size and location of lifting inserts or other devices; and Proper supports and support locations for storage and transportation.
Allow for developing handling techniques to ensure that all precast concrete components are successfully fabricated, delivered and installed without causing structural damage, detrimental cracking, architectural impairment, or permanent distortion.
BLDG12/S06.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 6-7 6.5
STORAGE As and when directed by the SO Rep, the Contractor shall store all precast components at the area to be occupied by the multi-storey carpark/garage. After the construction of the foundations and ground beams of the multi-storey carpark/garage, the area shall be backfilled for the temporary storage of precast components. However, construction for Works to the electrical substation (if applicable) can proceed. The Contractor shall ensure that the storage of the precast components shall not cause any damage to the constructed pile caps, column stumps and ground beams. Before recommencing construction Works to the multi-storey carpark/garage, the Contractor shall verify the position and alignment of the column stumps. Any rectification work shall be done to the satisfaction of the SO Rep at the Contractor's cost and expense. Notwithstanding the preceding requirements, the multi-storey carpark/garage and electrical substation (if applicable) shall be Substantially Completed within the Time for Completion. The Contractor shall be deemed to have included in the Contract Sum for all costs and expenses to be incurred by him in compliance with the requirements specified in this clause. The storage area shall be adequate to permit easy access and ready for handling of the stored precast components. It shall have a clean, hard, level and well-drained surface to permit well-organised storage, and to prevent warpage, bowing, chipping, cracking, discolouration, staining or soiling of the precast components. No precast component shall be placed on the ground. They shall be stored with due protection from staining or physical damage.
6.6
ERECTION
6.6.1
Inspection Of Precast Concrete Components All precast concrete components shall be inspected and approved by the SO Rep before erection and after installation. Any unauthorised erection or installation work may be rejected and necessary action taken against the Contractor. Prepare, install and check that the precast components are within the specified erection tolerances prior to calling for inspection and approval by the SO Rep. After the inspection of erected precast components, the SO Rep shall be at liberty to reject any precast components on the Site not complying with the design or specification requirements. No permanent jointing or connection between a precast concrete component and other precast concrete components or in-situ structures shall be carried out without the prior approval of the SO Rep.
6.6.2
Quality Control Only competent workers who are properly trained to handle and erect precast concrete components should be employed. Methods of erection shall be such as to avoid soiling, cracking, chipping and damage to built-in items. Only minor chipping and spalling may be repaired by patching up at the Site after installation, provided this is done to the satisfaction of the SO Rep. Check and ensure the accuracy of location of all bearing surfaces and all anchorages for precast concrete components. Any deviations from the Structural Drawings noted shall be corrected prior to the start of erection. Bearing surfaces, notches, bolts, connection angles or plates shall be checked as to level, line and grade. Whenever inserts or lifting hooks are used for erection purposes, their location shall be checked for compliance with the location as specified in the Structural or Approved Workshop Drawings. Anchorage length and exposed length of lifting hooks shall be checked for compliance with that specified in the design. The inserts or lifting hooks shall be properly secured before casting. If slings are used, the precast concrete components shall be marked so that the slings are placed at the proper locations. Field conditions shall be determined by actual measurement so that precast concrete components and joint sealants installed satisfy design or specification requirements and are within the specified erection tolerances. As and when instructed by the SO Rep, the precast concrete components shall be cleaned and repaired after installation.
BLDG12/S06.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 6-8
6.6
ERECTION
6.6.2
Quality Control (Cont'd)
(CONT'D)
Ensure that good construction practice is adhered to while the precast concrete components are on the Site and bracing or props shall be provided to maintain the required position, stability and alignment of precast concrete components prior to permanent jointing or connection. Each precast concrete component shall be individually adjusted and accurately positioned within the erection tolerances. Horizontal and vertical joints shall be kept correctly aligned and positioned, and uniform joint width shall be maintained as erection progresses. Adjustments or changes in connections, which could induce additional stresses shall be reviewed and approved by the SO Rep. Only qualified welders shall be employed for welded connections. . 6.6.3
Defect And Repair Ensure that no defective precast concrete component shall be delivered. The decision by the SO Rep to reject defective precast concrete components shall be final. The Contractor shall replace the rejected precast concrete components at his own costs and expenses. The rejection criteria shall be made on engineering basis as well as visual appearances. Damaged precast components shall be either patched up or otherwise corrected to the satisfaction of the SO Rep. Method of repairs shall be submitted to the SO Rep for approval before the commencement of repairing work. Major repairs should not be attempted until an engineering evaluation is made to determine whether the precast component will be structurally sound. In the case where localised defective tiles are detected, such defective tiles shall be replaced in accordance with the following suggested method: Two 1mm diameter copper wires shall be glued to the reverse side of each tile with epoxy resin and left to set. Similarly, copper wires shall be fixed 25mm into the concrete surface with epoxy resin. Mortar or cement paste shall then be applied. The tiles shall be tied to the concrete and set in place. In-situ pull out test shall be conducted as and when directed by the SO Rep. All repaired precast concrete component shall be architecturally and structurally acceptable to the satisfaction of the SO Rep.
6.6.4
Erection Tolerance For correct performance and appearance of the structures, check and ensure that the precast components are located in the centre of their theoretical location on the building and adjusted to accommodate adjacent components, proper joint width, and alignment with adjacent precast or in-situ members. Unless otherwise instructed by the SO Rep, the permissible erection tolerances shall be as follows : (a)
(b)
Distance Between Edge Of Panels At Joint For panels with dimensions (normal to the joint) up to 6m
:
±5mm
For each 3m increment in excess of 6m
:
±2mm
: : :
½mm 2mm 9mm
Joint Taper (Panel Edges Not Parallel) Per linear 300mm of joint Minimum allowable Maximum for entire length
(c)
Panel Alignment Alignment of horizontal and vertical joints : Jog in alignment of matching edges : 3mm
BLDG12/S06.DOC(8) Sal(151211) (DPD)
3mm
Bldg Spec Page 6-9 6.6
ERECTION
6.6.4
Erection Tolerance (Cont'd) (d)
(CONT'D)
Location Of Openings In precast concrete components
(e)
±6mm
: : :
±40mm ±20mm ±10mm
Verticality Of Wall Entire height of building 1st to 4th floor Each storey height
(f)
:
Parapet Alignment At Access Balcony Deviation in plan from straight line parallel to specified linear building line : Any interval less than 6m Any 50m length
: :
±1mm per metre ±25mm
: :
±5mm ±25mm
Coping level : Any interval less than 6m Any 50m length (g)
Verticality Of Column Verticality tolerance for columns shall be similar to that for walls.
(h)
Column Alignment At 1st Storey In between columns up to 6m apart : Entire length of building :
6.7
±10mm ±30mm
PRECAST PRESTRESSED CONCRETE PLANK SPECIFICATIONS Provide and install precast prestressed concrete planks as shown : (a)
Design Criteria And Materials For Precast Prestressed Concrete Plank Specifications The design criteria and materials for precast prestressed concrete planks shall be : Low slump concrete shall be used for the production of precast prestressed concrete plank. The strength of concrete at 28 days shall be 40 N per mm², and at transfer shall not be less than 25 N per mm². The use of calcium chloride, ions or other salts is strictly prohibited. The minimum grade of concrete for the cast-in-situ structural topping shall be 40 N per mm². Submit for approval of the SO Rep, the joint details as well as the allowable strands slippage.
(b)
Manufacturing Tolerances For Precast Prestressed Concrete Plank Specifications The manufacturing tolerances shall be as follows :
BLDG12/S06.DOC(9) Sal(151211) (DPD)
(i)
Length
: +3mm
(ii)
Cross-sectional dimensions (width or depth)
: ±1mm
(iii)
Flange thickness
: ±1mm
(iv)
Horizontal alignment (sweep)
: 1.25mm or 1/1,000th of overall length, whichever is greater
Bldg Spec Page 6-10 6.7
PRECAST PRESTRESSED CONCRETE PLANK SPECIFICATIONS (b)
(c)
(d)
(CONT'D)
Manufacturing Tolerances For Precast Prestressed Concrete Plank Specifications (Cont’d) (v)
Position of anchors and inserts
: +2.5mm of centre line location shown on the Drawings
(vi)
Position of strands
: ±2mm
(vii)
End squareness
: ±3mm
(viii)
Blockouts
: ±10mm of centre-line location as shown in the Drawings.
(ix)
Maximum camber deviation allowed
: ±5mm from designed camber
(x)
Difference in soffit level at mid-span between adjacent members or between a precast prestressed concrete plank and an adjacent reinforced concrete slab after installation shall not be more than 3mm.
(xi)
Position of reinforcement designed
: ±10mm primarily for connections
(xii)
Position of handling device
: ±20mm
The following requirements shall be complied with : (i)
Standard underside shall be smooth, dense with no surface holes.
(ii)
Standard top side can have minor chips and spalls but no major imperfections, honeycomb or Defect shall be allowed. The top surface shall be such that it is suitable for composite action with cast-in-situ structural topping.
(iii)
Exposed vertical ends shall be sawn or formed with smooth finish.
(iv)
Major openings or holes shall be provided in accordance with the Drawings. These and any other smaller openings made in the field shall be to the approval of the SO Rep.
(v)
Patching-up will be acceptable provided the structural adequacy of the product and the final appearance are not impaired. Prior to any patching-up work, submit proposal for the execution of such work for approval by the SO Rep. In any event, all patching up work shall be carried out to the approval of the SO Rep.
(vi)
Cast-in structural inserts, bolts and plates as detailed in the Drawings.
Product Delivery, Storage And Handling (Factory) Where precast prestressed concrete planks are included in the Works, the Contractor shall comply with the following:
BLDG12/S06.DOC(10) Sal(151211) (DPD)
(i)
Precast prestressed concrete plank shall be lifted and supported during manufacturing, stockpiling, transporting and erection operation only at the lifting or supporting points, or both, as shown in the Drawings or shop Drawings and with approved lifting devices which shall have a minimum safety factor of 3.
(ii)
All transportation, site handling and erection shall be performed with acceptable equipment and methods and by experienced personnel.
(iii)
All precast prestressed units shall be stored off ground.
(iv)
All precast prestressed units shall be so placed that identification marks can be read.
(v)
Precast prestressed members shall be so stacked that lifting devices are accessible and undamaged.
(vi)
The use of upper member of a stacked tier as storage area for shorter length of precast members or heavy equipment is strictly prohibited.
Bldg Spec Page 6-11 6.7
PRECAST PRESTRESSED CONCRETE PLANK SPECIFICATIONS (e)
(CONT'D)
Erection Where precast prestressed concrete planks are included in the Works, their erection shall comply with the following :
6.8
(i)
Precast members shall be lifted by means of suitable lifting devices at points provided for such purposes. Temporary shoring or bracing shall be provided and they shall have a minimum load factor of 2.0 times the dead load plus construction loads.
(ii)
Members shall be properly aligned and levelled as required by the approved shop drawings. Variations between adjacent members shall be reasonably levelled out by jacking, loading or any other feasible methods acceptable to the SO Rep.
(iii)
Field welding shall be carried out by qualified welders using equipment and materials compatible to the base materials.
(iv)
Precast prestressed concrete members may be drilled or 'shot', provided no contact is made with the prestressing strands. Any spalling resulting therefrom shall be repaired to the satisfaction of the SO Rep.
(v)
Final inspection and acceptance of erected precast prestressed concrete members shall be made by the SO Rep to verify conformity with plans and the Specifications.
PRECAST PRESTRESSED HOLLOW CORE SLAB SPECIFICATIONS Provide and install precast prestressed hollow core slab as shown in the Drawings. The requirements for precast prestressed hollow core slab shall be the same as those specified for the precast prestressed concrete plank except for the following : (a)
Manufacturing Tolerance Position of void - Vertical Horizontal
(b)
6.9
: :
±3mm ±3mm
Erection (i)
Core plugs shall be inserted before erection.
(ii)
All ends of hollow core slabs shall be seated with approved concreting materials to the satisfaction of the SO Rep.
SUBMISSION AND APPROVAL OF SUPPLY AND ERECTION SCHEDULES Submit respective supply and erection schedules detailing the type and quantity of the precast concrete components to the SO Rep for approval as soon as the Site is handed over to the Contractor. Adhere strictly to the approved respective delivery and erection schedules.
6.10
MATERIALS FOR PRECAST CONCRETE WORKS All materials used in the precast concrete works shall be in accordance with Section 4 "Structural Concrete" including all clauses and subclauses under it.
6.11
STRUCTURAL PRECAST AND CAST IN-SITU CONCRETE WORKS Section 4 "Structural Concrete" including all clauses and subclauses under it shall apply for all structural precast and cast-in-situ Works.
BLDG12/S06.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 6-12 6.12
WATER AND WEATHER TIGHTNESS
6.12.1
Waterproofing And Sealant Materials For Joints (i)
General Requirements Batch testing of sealant compounds delivered to the Site shall be carried out as directed by the SO Rep at the Contractor's own costs and expenses. The SO Rep reserves the right to reject the use of any type of sealants if their performance is deemed to be unsatisfactory. The use of membranes and admixtures for grout, mortar or concrete for improving water and weather tightness may be approved by the SO Rep. All sealant materials used at public accessible areas such as access balcony, stair-cases, stair-landings etc shall be protected with non-shrink mortar or grout. Liquid membranes, if used, shall have specified minimum thickness and width for water and weather tightness.
(ii)
Performance Of Waterproofing Materials Waterproofing materials for joints shall be as specified in Section 4 "Structural Concrete" including all clauses and subclauses under it.
(iii)
Application Of Sealant Materials Ensure that joints and joint sealants of precast concrete structures are correctly installed, so as to provide continued water and weather tightness of buildings with minimum maintenance. Joints surface preparation, primers, sealant compounds and backup materials shall be installed to give the highest standard of materials and workmanship; these shall conform to all applicable requirements as specified in the Specifications. Whenever possible, sealants shall be applied with a power-actuated gun. The gun shall have a nozzle of proper size and provide sufficient pressure to completely fill the joints. All compound smears, primers, solvents etc used in caulking and sealing work, shall be immediately and entirely removed from adjacent materials as the work progresses.
(iv)
Joint Width And Sealant Depth After Installation The joint width shall depend on the dimension of the panels and its coefficient of expansion. The maximum joint widths and maximum expansions for the common sealants shall be :
Type of Sealant
Maximum Joint Width (mm)
Maximum Movement in Tension or Compression (%)
Butyl; Acrylic; One Part Polyurethane; Two Parts Polyurethane; One Part Polysulphide; Two Parts Polysulphide;
20 20 20 20 20 20
±10 ±15 to ±25 ±20 ±25 ±25 ±25
The normal design joint widths shall be 10, 14 or 15 as shown in the Structural Drawings. For joints up to 13mm wide, the depth of the sealant shall be equal to the width. For joints over 13mm wide, the depth shall be equal to one-half the width, but not less than 13mm. Sealants installed shall not be less than 6mm wide or 6mm deep.
BLDG12/S06.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 6-13 6.12
WATER AND WEATHER TIGHTNESS
6.12.1
Waterproofing And Sealant Materials For Joints (v)
(CONT’D) (Cont’d)
Sealant Backup Fillers Backup fillers shall be used in joints to control the depth of the sealant, to facilitate tooling of the sealant, and to serve as a bond breaker which prevents the bonding to the back of the joint. Acceptable backup materials shall be those which compress and respond to movements. These include the rod type of sponge materials such as foamed polyethylene, polystyrene, polyurethane, polyvinyl chloride or synthetic rubber. The backup materials shall also be compatible and nonstaining to the selected sealants.
(vi)
Joint Preparation Before sealing the joints, concrete surfaces shall be smooth, clean and free of all mortar dust or other contaminants that may affect adhesion. Sealant and primer shall be supplied by the same manufacturer, and the primer shall be as recommended for the particular sealant used.
6.12.2
Water And Weather Tightness Test The joints in the superstructure shall be subjected to tests for water and weather-tightness. Internal floors shall be tested prior to any tiling work. Testing shall be conducted only when all pipes, trunking, etc have been installed and the penetrations sealed, unless otherwise directed by the SO Rep. (i)
Method and Frequency of Testing Joints shall be tested with the method and frequency as described below: (a)
Structural Roof, Access Balcony Roof And Lift Motor Room Roof Water tightness test shall be carried out on all roofs with precast joints in accordance with Clause 4.32.2 "Watertightness And Water Stagnation Test".
(b)
External Walls For external walls, a continuous jet of water shall be sprayed on the joint corresponding to 600 litres per hour from a water hose having a nozzle velocity of 2m per second and a cone scatter of approximately 60 degrees held at a distance of 1.2m from the wall surface under test. The duration of the test shall not be less than 2 hours. The hose shall be placed with the nozzle in line with the vertical joint and at a level of horizontal joints so that the jet cone will cover a vertical and two horizontal joints as shown in the Drawings. For external walls, the following tests shall be conducted for each building block: Building Height Up to 10 stories Up to 20 stories Up to 30 stories Up to 40 stories Up to 50 stories
Frequency of tests 5 tests for vertical joints, 5 tests for horizontal joints 10 tests for vertical joints, 10 tests for horizontal joints 15 tests for vertical joints, 15 tests for horizontal joints 20 tests for vertical joints, 20 tests for horizontal joints 25 tests for vertical joints, 25 tests for horizontal joints
These tests shall be carried out at any location as instructed by the SO Rep. Water shall not seep into any part of the building during the test. For each test which fails, two additional tests shall be carried out at joint locations as instructed by the SO Rep all at the Contractor's cost and expense.
BLDG12/S06.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 6-14 6.12
WATER AND WEATHER TIGHTNESS
6.12.2
(i)
(CONT’D)
Method and Frequency of Testing (Cont'd) (c)
Gable End Walls All gable end walls shall be tested by spraying water from the top of the walls at the topmost floor level for a duration of 2 hours. The hose shall be placed with the nozzle in line with the vertical joint at the top of the walls. Water shall not seep into any part of the building during the test.
(d)
Refuse Chute All refuse chutes shall be tested by spraying water from the top of refuse chutes. The water shall spray vertically downwards on all internal walls for a duration of 1 hour. No seepage of water from the joints shall be permitted during the test.
(e)
Floor Joints Of Precast Slabs Floor joints of concrete slabs using precast prestressed concrete plank and precast prestressed concrete hollow core slab with minimum 50mm in-situ concrete topping need not be tested. Floor joints of precast slabs using either precast prestressed (or non-prestressed) concrete plank or precast prestressed concrete hollow core slab without in-situ concrete topping or with concrete topping thickness less than 50mm shall be tested. The floors of those areas (or dwelling units) to be tested shall be flooded with water to a depth of 25mm for a period of one hour replenishing when necessary. The areas (or dwelling units) shall pass the test if no dampness or seepage from the dwelling units under test occurs in any adjoining areas (of dwelling units ) or common area during the test. Two units (or dwelling units) per floor shall be tested. The locations of these units (or dwelling units) to be tested shall be decided by the SO Rep. For each unit (or dwelling unit) that fails the water test, two additional units (or dwelling units) shall be selected by the SO Rep for testing.
(f)
Kitchen/Bathroom/Toilet Areas (1)
Carry out water test to the following items prior to any tiling work in accordance with the procedure described below : (i) (ii) (iii) (iv)
`
(2)
All joints between the floor slab and floor traps in the bathroom and kitchen; All joints between the branching off for water closet and floor slab; All floor joints between the precast slabs and walls in bathroom and kitchen; All floor joints between the precast slabs in bathroom and kitchen.
The gratings to floor traps in the bathrooms and kitchens shall be blocked temporarily with polythene sheets or by other suitable means and the floor flooded with about 25mm depth of water at the highest level of the slab. The amount of water shall be maintained for four hours, replenishing when necessary during which the underside of the floor slab shall be checked for signs of leaks. Towards the end of this test, the water will be allowed to drain off. During this process there shall be no sign of chokage in the system.
6.12.2
(ii)
Water Test Failure In the event of failure of a test on any joint, the Contractor shall rectify the joint and repeat the test. This procedure shall be repeated until the tests on the joints comply fully with the passing criteria. Furthermore, the SO Rep reserves the right to reject the use of any waterproofing materials or joint details that perform unsatisfactorily during water tests at no cost to the Employer. Under no circumstances shall the Contractor be allowed to carry out his own water test without the presence of the SO Rep. All water test (specified or not specified) shall be witnessed and certified by the SO Rep as well as the Contractor's Representative.
BLDG12/S06.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 6-15 6.13
HOMOGENEOUS MODULAR CLINKER TILES Homogeneous modular clinker tiles as external wall/slope finishes shall be cast together with precast concrete components as shown in the Drawings.
6.13.1
Submission And Approval Of Samples Provide samples and patterns of clinker tiles to the SO Rep for approval prior to bulk ordering. Failure to provide the samples and/or patterns may render consignments of clinker tiles already received by the Contractor liable to rejection. Check and ensure that the samples and/or patterns submitted are representative of the clinker tiles to be provided.
6.13.2
Inspection And Rejection The SO Rep shall have the power to inspect, examine, check and test the clinker tiles either on the Site or at any factory, workshop or other place where the clinker tiles are being installed, or stored. The Contractor shall arrange to provide all such facilities and cooperation at his own cost and expense as the SO Rep may require in these respects. All consignments of clinker tiles supplied shall be subject to inspection by the SO Rep. Any clinker tiles which do not comply with the requirements of the Specification and the samples and/or patterns submitted by the Contractor shall be rejected. Under such case, the Contractor shall within a reasonable time to be decided by the SO Rep, replace such rejected clinker tiles with clinker tiles that comply fully with the Specifications. The decision of the Superintending Officer shall be final and binding on and conclusive against the Contractor. Prior to the certification of Substantial Completion of the Works, the Contractor shall replace all damaged clinker tiles.
6.13.3
Quality Assurance Check and ensure that the quality of clinker tiles shall comply with SS 301. Provide all means to protect the clinker tile materials before, during and after installation : (a)
Application Of Cement/Sand Mortar & Clinker Tiles The tiles shall be laid on to the prepared rubber mould with the back pattern of the tile facing up in accordance with the tile pattern layout indicated in the architectural Drawings. The quality of the rubber mould shall be such that it can secure the tiles firmly in place and prevent displacement of the tiles during concreting. Prior to pouring the concrete over the entire arrangement of the tiles, the tiles shall be cleaned of deleterious materials that will affect adversely the bonding strength between the tile and the hardened concrete. The wet concrete to be used shall be mixed with water reducing agent strictly in accordance with the manufacturer's instructions. The water reducing agent shall be submitted to the SO Rep for approval prior to its use. Any concreting work carried out prior to approval by the SO Rep shall be rejected.
(b)
Workmanship And Surface Finish Clinker tiles to be used on the external wall faces of the precast concrete components shall be as shown in the Drawings. The colour of the clinker tiles shall be as specified in the Drawings. The clinker tiles shall be free from cracks, crazing, voids, warpage, stones or particles of lime as would affect its safe use and its general appearance. The acceptable texture and uniformity of colour of clinker tiles shall be decided by the SO Rep. When directed by the SO Rep, submit the technical information or reports of clinker tiles to be used.
BLDG12/S06.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 6-16 6.13
HOMOGENEOUS MODULAR CLINKER TILES
6.13.3
Quality Assurance (c)
(CONT’D)
(Cont'd)
Technical Specification Unless otherwise specified, all tests shall be conducted by PSB, SAC-SINGLAS or other approved laboratory in accordance with SS 301. The total number of test specimens required for testing items (i) to (iv) specified below shall be 10. (i)
Dimensional Tolerances Dimensions and their tolerances shall be as follows :
(ii)
Length
:
190mm nominal ±1% tolerance
Width
:
90mm nominal ±1% tolerance
Thickness
:
12mm minimum, the average thickness of each specimen shall not deviate more than ±10% from the average thickness of 10 test specimens.
Straightness Of Sides The maximum deviation from straightness, referred to the length of the side, shall not exceed 0.5%.
(iii)
Rectangularity The maximum deviation from rectangularity of each specimen shall not exceed 1.8% of the nominal dimension.
(iv)
Flatness Of Surface Centre curvature and warpage of the surface shall not exceed 0.5% of the length of the corresponding diagonal. The maximum edge curvature of each specimen shall not exceed 0.5% of the nominal dimension.
(v)
Surface Condition Of Clinker Tiles The products when supplied shall be free from objectional surface blemishes such as projections, depressions, flakes and crazes. The test specimens shall form an area of at least 1 m² with a minimum of 30 tiles.
(vi)
Water Absorption The water absorption capacity on average shall not exceed 3% by weight. Number of test specimens shall be 10.
(vii)
Modulus Of Rupture The average value for modulus of rupture shall be at least 20 N per mm² and minimum single value shall be 17 N per mm². Number of test specimens shall be 7.
(viii)
Colourfastness And Lightfastness The colour of the clinker tiles shall be light-fast. No colour change shall be detectable after exposure to ultra violet radiation for 28 days. Number of test specimens shall be 5.
BLDG12/S06.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 6-17 6.13
HOMOGENEOUS MODULAR CLINKER TILES
6.13.3
Quality Assurance (c)
(CONT’D)
(Cont'd)
Technical Specification (Cont'd) (ix)
Acid Resistance And Alkali Resistance Macroscopic surface examination shall not reveal any visible change for acid resistance and alkali resistance tests. Number of test specimens shall be 5 for each solution.
(x)
Test For Adhesion Bond Strength Between Clinker Tiles And Concrete The test shall include both shear adhesion strength and tensile adhesion strength. 5 test specimens shall be sampled for each test. Test methods and procedures of shear adhesion strength shall comply with ASTM C482-78 except for preparation of test samples. For preparation of test samples, clinker tiles shall be cut to 100mm x 90mm and placed in the base of the moulds with the back pattern of the tiles facing upwards followed by the pouring of wet concrete of similar concrete mix and water reducing agent to be used for the production of the precast concrete components. The load shall be applied perpendicular to the groove line. The characteristic shear adhesion strength at 7 days shall not be less than 2 N per mm². Tensile adhesive strength shall be conducted by PSB, SAC-SINGLAS accredited laboratory or other approved laboratory. The mean tensile adhesion strength at 7 days of each specimen shall not be less than 0.4 N per mm².
6.13.4
Submission Of Test Certificates For Approval Submit test certificates by SAC - SINGLAS accredited laboratory to cover the following items : (a) (b) (c) (d) (e) (f) (g) (h) (i) (j)
Dimensional Tolerances Straightness of Sides Rectangularity Flatness of Surface Surface Condition of Clinker Tiles Water Absorption Modulus of Rupture Colourfastness and Lightfastness Acid Resistance and Alkali Resistance Test for Adhesion Bond Strength Between Clinker Tiles and Concrete.
The test certificates shall be submitted to the SO Rep prior to bulk ordering. In addition, the Contractor shall send the clinker tiles for testing as and when required by the SO Rep. At the time of receiving clinker tiles from the supplier, the Contractor shall check and satisfy himself that the clinker tiles comply with this Specifications, and, if so requested by the SO Rep, shall submit a certificate issued by the manufacturer that the clinker tiles as supplied in the shipment are of the best quality of its kind. 6.14
PRECAST FERROCEMENT SUNBREAKERS
6.14.1
General Unless otherwise specified, the requirements specified in Clauses 6.1 to 6.6 (inclusive), 6.9 to 6.11 (inclusive) and 6.13 including all sub-clauses under them shall be applicable to this Clause including all sub-clauses under it.
6.14.2
Scope Provide and install precast ferrocement sunbreakers complete with fixing accessories to the locations as shown in the Drawings.
BLDG12/S06.DOC(17) Sal(151211) (DPD)
Bldg Spec Page 6-18 6.14
PRECAST FERROCEMENT SUNBREAKERS
6.14.3
Shop Drawings
(CONT’D)
All structural and architectural drawings on this provision shall only serve as a guide. Prepare and submit workshop drawings on all relevant details including :
6.14.4
(a)
Reinforcement detail of sunbreaker panels in elevations and sections.
(b)
Fixing and connection details.
(c)
Necessary steel bolts, hooks or other approved materials required for handling and erection purposes. The size and location of these materials shall be clearly indicated in the details.
Materials (Precast Ferrocement Sunbreakers) (a)
Cement Cement shall be as specified in Clause 4.1 "Cement"
(b)
Fine Aggregates Fine aggregates shall be as specified in Clause 4.2 "Aggregates".
(c)
Water Water shall be as specified in Clause 4.3 "Water".
(d)
Steel Reinforcement Steel reinforcement shall be as specified in Clause 4.5 "Steel Reinforcement" including all subclauses under it. In addition, all welded mesh and steel bar used shall be galvanised in accordance with BS EN ISO 1461. 1.5mm diameter at 25mm spacing wire mesh shall be galvanised with zinc coating of 325 g per m² and 250 g per m2 minimum for average coating and local coating shall have minimum proof stress of 300 N per mm².
(e)
Admixtures Admixtures shall be as specified in Clause 4.4 "Admixtures".
6.14.5
Source Of Material The Welded Mesh Fabric and Fine Mesh Fabric shall be obtained from sources approved by the SO Rep.
6.14.6
Technical Specifications (a)
Mix Design The ferrocement sunbreaker panels shall be cast from a mix design which satisfy the following requirements : (i)
minimum cement to sand ratio by weight of 1:2.
(ii)
maximum water to cement ratio by weight of 0.45.
(iii)
air dry density of hardened concrete (including steel) not less than 2,200 kg per m³.
(iv)
28 days average cube strength from three test cubes shall be not less than 40 N per mm².
The amount of admixture in the mix design shall be in accordance with the Manufacturer's instruction. Before commencing the manufacture of precast ferrocement sunbreaker, submit a proposed mix design to the SO Rep for approval. BLDG12/S06.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 6-19 6.14
PRECAST FERROCEMENT SUNBREAKERS
6.14.6
Technical Specifications (b)
(Cont’d)
Other Properties (i)
Initial Surface Absorption Test (ISAT) shall be carried out in accordance with BS 1881. The hardened panel shall have ISAT value less than that stipulated below : Time (min) ISAT Value (ml/m²/s)
(c)
(CONT’D)
10
30
60
0.100
0.055
0.035
(ii)
Carbonation depth of hardened panel at installation shall be less than 3mm.
(iii)
Cover tolerance shall be such that no more than 3 points per section shall have a cover measurement of less than 5mm, but not less than 3mm.
Finishes The panel shall be cast on a steel base mould with the finish surface cast-face down. The finish surface is the external surface of the sunbreaker elevation where the tile and motifs are located.
(d)
Dimensional Tolerances All tolerances shall be as specified in sub-clauses 6.3.5 "Manufacturing Tolerances" and 6.6.4 "Erection Tolerance".
6.14.7
Manufacturing Process The panel shall be cast flat on a steel base mould. The mortar shall be compacted by vibrators and the top surface shall be steel trowelled smooth. All reinforcement shall be galvanised and adequately supported with approved spacers. After setting and demoulding, the panels shall be marked and neatly stored with easy access and visibility to every piece. All panels must be properly cured. Seek the approval of the SO Rep with respect to the curing method, duration and facilities prior to actual production. The curing method shall be equivalent to 3 days of moist curing. Prior to commencement of the production, at least one sample of the panels shall be produced, erected and installed at site for the approval of the SO Rep. Make adjustments to the manufacturing process or equipment if so directed by the SO Rep. Maintain a record of daily work progress on a proper drawing showing where panels of a particular date of manufacture have been installed.
6.14.8
Quality Assurance Works For Precast Ferrocement Sunbreakers For precast ferrocement sunbreakers, the requirements for inspection and testing, sampling rate and passing criteria shall comply with those requirements for Ferrocement Roof Slabs as specified in Section 14 "Concrete Flat Roof" including all clauses and subclauses under it.
BLDG12/S06.DOC(19) Sal(151211) (DPD)
Bldg Spec Page 6-20
6.15
PRECAST FACADES WITH CAST-IN WINDOW FRAME
6.15.1
Protection Of Cast-In Window Frames The Contractor shall ensure that cast-in window frames are protected from damage before delivery to precast plant. Cast-in window frames shall be protected from dirt, grout, grease, deleterious materials and surface scratch with quality translucent self-adhesive tape of light colour for inspection of window frame quality at precast plant prior to casting, as well as for inspection at site upon the delivery of precast facades. The self-adhesive tape shall be made of durable material that could withstand the weathering. The protective tape shall not stain or stick to the aluminum surface, or leave a sticky surface upon the removal. The Contractor shall ensure that the wrapping with self-adhesive tape is robust to withstand handling during casting, storage and transportation to site. The adhesive tape shall be intact with cast-in window frame along the edges with no visible gaps. The corners of cast-in window frames and intersections of window frame members shall be adequately wrapped with sufficient laps and returns to prevent ingress of concrete grout during casting. All fastening screws, joints and gaps that are in contact with the wet concrete shall be sealed adequately to prevent grout ingress during casting. Cast-in window frames with torn, loose wrappings, and frames with visible gaps at edges that will be in contact with wet concrete shall not be used for casting. The Contractor shall make good or replace the poorly protected window frames at his own costs and expenses.
6.15.2
Quality Control At Window Factory The Contractor shall ensure that adequate quality assurance measures are in place in the production and the assembly of cast-in window frames. The quality assurance checks on surface defects such as dent, scratch and other defects such as dimension out of the manufacturing tolerances, warp, twist, skew, track misalignment, shall be conducted at the window factory before the wrapping up with the protective tape. A label / sticker shall be provided at one location on the internal face of cast-in window frame to indicate the product serial number, window marking (including its orientation such as top, left or right-hand side, if applicable) on each cast-in window frame. This to facilitate down-stream traceability and inspections, and prevent mistake in the placement of window frame in precast production. For sliding window, the Contractor shall provide internal bracing to control the sagging of horizontal aluminum members adjacent to the window opening during handling and precast production process. The cost for measures taken to enhance the window identification, control the alignment of aluminum members during handling and for quality assurance in precast production is deemed to have been included in the tender sum.
6.15.3
Quality Control At Precast Plant
6.15.3.1
Inspection Upon The Delivery Of Cast-In Window Frames The Contractor shall ensure that cast-in window frames delivered to precast plant are of good quality at the point of receiving. The inspections at precast plant shall include, but not limited to inspections on the workmanship of protective wrapping, dimension and surface defects such as dents and scratches.
6.15.3.2
Storage Of Cast-In Window Frames Cast-in window frames shall be stored at a sheltered yard to prevent deterioration of protection system due to weathering. The storage shall be demarcated, barricaded and raised to prevent soiling, contacting with deleterious materials and accidental damage.
BLDG12/S06.DOC(20) Sal(151211) (DPD)
Bldg Spec Page 6-21 6.15
PRECAST FACADES WITH CAST-IN WINDOW FRAME
6.15.3.3
Care And Protection During Casting And Transportation
(CONT’D)
The Contractor shall ensure cast-in window frames are handled with care during the production process. At least an experienced engineer, supervisor and a team of skilled workers shall be assigned for the production of precast facades with cast-in window frame, repair and delivery. Any part of cast-in window frames which is in direct contact with the dummy frames, bracings and stoppers of the mould system, additional protective material shall be provided to prevent any premature damage to the cast-in window frames. Additional protection may be needed to prevent grout leakage at the corners. To avoid excessive staining due to dropping of fresh concrete, protective measure shall be taken to cover the window frames during the casting process. For the transportation from precast plant to site, the Contractor shall ensure adequate measures are provided at the critical contact points between the precast facades and the steel frames on the trailers to prevent damage to the cast-in window frame. Before casting, the Contractor shall exercise due diligence and care in the precast production to ensure that the orientation of cast-in window frame is checked when it is placed on the mould. The position of the cast-in window frame shall also be measured and checked against the approved precast shop drawings before casting. Upon the demoulding of precast facades, the orientation, position of cast-in window frame and the clearance between the aluminum members shall be measured to detect any possible sagging or bulging occurred during the casting. 6.15.3.4
Water-Tightness Test The Contractor shall provide the equipment, labour and material to conduct water-tightness test at the precast plant to ensure there is no water seepage at the interface joint between the cast-in window frame and adjacent concrete. The water-tightness test shall be carried out using a continuous jet of water sprayed on the joint/interface with a nozzle and water hose. For each window, four points shall be selected for testing and each point shall be sprayed for 20 minutes. The location of test shall be selected by the SO Rep. The velocity of the water at each nozzle shall be 2m per second. The capacity of the water delivered from each nozzle shall be 600 litres per hour. The nozzle shall be held at a distance 1m away from the joint/interface and pointed towards the joint/interface horizontally. 10% of the precast facades with cast-in window frame shall be tested for the water-tightness at the interface joint. The Contractor shall carry out the water-tightness test as soon as the precast production is commenced to ascertain the initial casting workmanship, as well as the performance of the cast-in window frames. The SO Rep shall decide on the window type or window configuration and the location on window frame to be tested. The SO Rep reserves the right to adjust the percentage of testing depending on the quality and performance cast-in window and the test results.
6.15.3.5
Functional Test For quality assurance, the Contractor shall check the functionality and the performance of cast-in window frames randomly at the early stage of the project. This is to ensure that any inadequacy of the bracing system can be detected early. For sliding windows, the inner frames shall be installed for repeated sliding operations to check for smoothness, alignment and safety in operation. For casement and top-hung windows, the inner frames shall be tested by repeated opening and closing to check for smoothness, alignment and safety.
6.15.4
Inspection And Protection Of Precast Façade With Cast-In Window Frame At Site
6.15.4.1
Inspection Upon Delivery Of Precast Facades With Cast-In Window Frame When precast facades with cast-in window frame are delivered to site, the Contractor shall check the condition of the cast-in window frames before installation.
6.15.4.2
Protection of precast facades with cast-in window frame The precast components with cast-in window frame delivered to site are protected with the translucent self adhesive tape. At site, the Contractor shall provide additional protective material like bubble wrap of minimum thickness of 5mm or any other materials which are equivalent in performance and subject to the approval of SO Rep to further protect the cast-in window frames from impact and abrasive forces.
BLDG12/S06.DOC(21) Sal(151211) (DPD)
Bldg Spec Page 6-22
6.15
PRECAST FACADES WITH CAST-IN WINDOW FRAME
(CONT’D)
6.15.5
Submission Of Window Shop Drawings And Delivery Of Cast-In Window Frames To Precast Plant The Contractor shall submit the window shop drawings timely to SO Rep for approval within a reasonable timeframe from the date of the Letter of Acceptance. The timeframe for window shop drawing submission shall tie in with the approved master construction programme for the initial delivery schedule of precast components to prevent any delay in the precast supply. The Contractor shall deliver mock-up cast-in window frames to precast plant to facilitate the mould fabrication at the window opening. The timeframe for the delivery of mock up window frames shall be carefully planned to tie in with the initial delivery schedule of precast components to site and tie in with the approved master construction programme. The Contractor is obliged at no extra cost to HDB to provide the mock up frames, make improvements in the protective wrapping including increasing the number of layer if required to enhance grout tightness, and on window frame construction where necessary. The Contractor shall ensure sufficient lead time in the delivery of the cast-in window frames meant for mass precast production, and for building up of the initial component stocks at precast plant to meet the delivery subsequently. The Contractor shall plan the schedule diligently and take note of the expected initial precast components delivery schedule for each block in the project, and tie in with the approved master construction programme.
6.15.6
Mould Design And Fabrication Timeframe The mould supplied by the Contractor shall facilitate the production of precast facades with cast-in window frame. The moulds shall be robust and durable without causing misalignment of track, twisting, skewing and warpage of cast-in window frame during casting and demoulding. The Contractor shall design the bracings and stoppers as part of the mould system. The bracings and stoppers shall be provided adequately at appropriate spacing to prevent misalignment and warping of cast-in window frame during casting. The Contractor shall order and fabricate required moulds diligently to tie in closely with the site progress and the cast-in window frame delivery schedule. Mould fabrication and production planning shall be submitted to the SO Rep as and when requested.
6.15.7
Preparation And Viewing Of Sample Panel The Contractor shall arrange for sample panel with cast-in window frame for SO Rep to assess the quality of the finished product prior to full-scale production. The Contractor shall bear the costs of rectifications, improvement and/or reproduction of sample due to the rejection of sample panel.
6.15.8
Repair Of Damaged Window Frame For repair works involving the removal of concrete at the interface joint between the cast-in window frame and adjacent concrete, the water-tightness test shall be conducted after the repair is completed to ensure the joint is water-tight. The Contractor shall consider the accessibility and the safety aspects when the rectification is required at site and/or precast plant. A method of statement of the repair shall be submitted to the SO Rep for approval before the rectification of defective cast-in window frame at precast plant and/or site is carried out.
Section 7/.....
BLDG12/S06.DOC(22) Sal(151211) (DPD)
Bldg Spec Page 7-1 SECTION 7 PRESTRESSED CONCRETE
7.1
GENERAL The following specifications on Prestressed Concrete shall be treated as additional clauses to those required under Section 4 "Structural Concrete" including all clauses and subclauses under it.
7.2
CONCRETE MIX Only specially designed concrete mixes complying with the requirements specified in the Drawings shall be used for prestressed concrete work. Submit, for the approval of the SO Rep, details of the concrete mix proposals at least 6 weeks in advance of concreting work so as to allow strength tests from trial mixes to be made. Trial mixes shall be repeated until a satisfactory mix as regard to the cube strength and workability has been achieved. Once the SO Rep has approved the mix, it shall be used for that work and no departure shall be made from it either in properties of materials or in their relative proportions unless authorised by the SO Rep who may require further trial mixes to be made. All sampling and testing of constituent materials, fresh and hardened concrete, shall be carried out in accordance with the provisions of the appropriate Singapore or British Standard. If the strength of cube test results representing the prestressed concrete work fails to achieve the required strength, the Contractor shall be subject to charges and shall carry out further tests and/or rectifications to ascertain the in-situ strength of concrete as specified under Clause 4.16, 4.17 and 4.18 including all subclauses under them. Notwithstanding that all tests have been complied with, member which cracks during or after prestressing operations to an extent which in the opinion of the SO Rep renders it unfit for its purpose in the work shall be removed from the work and replaced.
7.3
PRESTRESSING STEEL The prestressing steel, wire or strand used in prestressing tendons shall comply with the requirements of BS 2691, BS 3617, BS 4486, BS 4757 and BS 5896. High tensile steel wires or high tensile steel strands shall be supplied in coils of a sufficiently large diameter so that it shall retain its physical properties and shall be reasonably straight when unwound from the coils. A copy of the Manufacturer's test certificates covering each coil of prestressing steels to be used shall be provided to the SO Rep. If test certificates relating to the material is not available, the Contractor shall arrange for testing of samples. The SO Rep may require the Contractor to carry out further test on the steel of each batch. All such testings shall be carried out by an approved testing authority. All wires or strands shall be cut from certified coils. Keep proper records so as to enable identification of the wires with the coil from which they are cut. The manufacture and assembly of tendons shall be done in accordance with the best quality of workmanship appropriate to the prestressing system being used. Tendons shall be made to the required length plus an allowance, where applicable, at each end for stressing operation. Splicing of strands or wires forming a tendon shall not be permitted. Flame cutting of wire or strand within 80mm of where tendon will be gripped by the anchorage or jacks shall not be permitted. Care shall be taken to ensure that the flame does not apply on the anchorage or on the tendon, within 25mm of the anchorage. A durable metal label on which shall be stamped the length of the tendon and the coil number of the wire or strand used, shall be tied to each tendon. Care shall be taken that tendons of any type are not damaged, kinked or bent. Tendons shall be kept free from loose or thick rust, oil, grease, tar, paint, mud, or any other deleterious substances but a thin film of rust will be permitted.
BLDG12/S07.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 7-2 7.4
ANCHORAGE DEVICES Anchorage devices shall be subjected to the approval of the SO Rep. Each anchorage device shall be capable of transmitting a force not less than the ultimate tensile strength of the tendon without overstressing the concrete. Spiral or other reinforcement specified by the manufacturer as being required for this purpose shall be considered part of the anchorage devices and shall be of the size and dimensions recommended by the Manufacturer for the prestressing system being used. Certificates of origin shall be provided for all anchorage devices. No damaged or defective anchorage devices shall be used. All steel parts shall be protected from corrosion and all threaded parts and fittings shall be protected by wrappings or plugs until used. The anchorage devices shall be kept free from mortar, loose rust, grease, tar, paint, oil, mud or any other coatings.
7.5
SHEATHING All Sheathing shall be subject to the approval of the SO Rep. Sheathing shall be of the type suitable for the prestressing system to be used and shall be strong enough for withstanding the placing and compaction of the concrete without suffering damages or deformation. Internal and external diameters of sheathing shall be within the limits specified in the design or approved by the SO Rep. The sheathing and all splices shall be mortar tight. Steel sheathing shall be galvanised or lead coated. The Manufacturer's value for the friction coefficients of the proposed sheathing shall be stated by the Contractor. Enlarged portions of the sheathing at couplings or anchorages shall be of sufficient length to provide for the extension of tendons. Grout holes shall be provided at both ends of the sheathing and shall be at least 10mm diameter. Each of the grouting holes shall be equipped with a plug valve or similar device capable of withstanding a pressure of 1 N per mm² without loss of water, grout or air. Additional vents, with plug valves, shall be provided at suitable points in the sheathing, including high and low points, for the purpose of bleeding air and water to ensure the complete filling of the duct with grout. The number and location of these additional vents shall be as specified in the design. Sheathing for prevention tendons shall consist of plastic tubing or other approved material of a quality, diameter and thickness approved by the SO Rep. Sheathing shall continue through end forms for at least 25mm.
7.6
PLACEMENT OF TENDONS (a)
Post-tensioned Tendons Unless otherwise stated in the Drawings or approved by the SO Rep, tendons shall be sheathed and placed in position prior to concreting. Where permanent tendons cannot be placed, temporary tendons or other methods approved by the SO Rep shall be used to stiffen the sheathing. Tendons shall be handled with care and shall be pulled through the sheathing in such a manner as to avoid damage or contamination to either the tendon or the sheathing. Sheathing shall be securely fixed at points sufficiently close together to maintain a smooth tendon profile throughout the length of the tendon within a tolerance of 3mm of the position shown. If in the opinion of the SO Rep, the sheathing is liable to be damaged or deformed during concreting work, the Contractor shall take additional precautions to maintain the position and shape of the sheathing. Any temporary opening in the sheathing shall be plugged and all joints between sheathing and any other part of the prestressing system shall be effectively sealed to prevent the entry of mortar, dust, water or other deleterious matter. Sheathing shall be neatly fitted at joints without projection or reduction of diameter, and the joints shall be mortar tight. Immediately after the whole of the concrete has been placed, all tendons therein shall be pulled back and forth for about 300mm to ensure that they are perfectly free inside the sheaths. Ducts stiffened by temporary tendons shall be checked by passing through a tendon identical with the permanent tendon.
BLDG12/S07.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 7-3 7.6
PLACEMENT OF TENDONS (CONT'D) (a)
Post-tensioned Tendons (Cont'd) Unless otherwise specified, the minimum concrete cover to the outside surface of any sheathing shall be 50mm for beam soffits and 40mm elsewhere. This minimum cover shall be increased by 15mm for members in contact with earth or water or over salt water and by 25mm for members in contact with salt water. Each anchorage device shall be set square to the line of the corresponding prestressing tendon and shall be positioned securely to prevent movement during concreting. The anchorage devices shall be cleaned to the satisfaction of the SO Rep. Any mortar or concrete which adheres to the bearing or wedging surfaces shall be removed immediately. Provision shall be made for covering anchorages with reinforced concrete after completion of stressing. The minimum cover shall be 50mm over the anchorages and 40mm over the reinforcement.
(b)
Pretensioned Tendons Tendons shall be located as shown on the Drawings and suitable devices shall be provided to ensure that the correct positioning of the tendons is maintained during casting. When tendons are being placed, particular care shall be taken so that the tendons shall not come into contact with the oiled surface of the forms or be otherwise soiled. Any oil, etc which might collect on the tendons shall be removed by cleaning the affected tendons with a petrol-soaked rag or by other approved methods. The anchorages shall be such as to prevent any slip during the casting or curing operations. Unless as shown otherwise in the Drawings, the concrete cover to the surface of any tendon shall not be less than twice the tendon diameter or 25mm whichever is the greater. Such minimum cover shall be increased by 15mm for members situated in earth or water or over salt water.
7.7
CONCRETING Concrete in one precast unit shall be placed in one operation continuously without interruption. The Contractor shall provide such protective cover as and when required to avoid stoppage due to sudden rain. No unit shall be removed from the mould or erected until sufficiently matured to ensure that no damage shall be done to the unit. For post-tensioned construction, where necessary, temporary openings shall be provided in the formwork to enable placing and adequate compaction of concrete, especially around and underneath sheathing and anchorages. Care shall be taken to avoid damaging the sheathing. Vibrators shall not come into contact with the sheathing and if the sheathing is damaged during concreting, the whole or a portion of the concrete cast may be rejected by the SO Rep. Sheathing shall be cleaned out within half an hour of completion of each concreting operation by blowing oil-free compressed air through the length of the sheathing. The concrete shall be moist cured until the prestress is applied.
7.8
CONCRETE STRENGTH AT TRANSFER No post-tensioning of tendons or the release of pretensioned tendons shall take place until the concrete has attained the minimum strength required as stated in the Drawings or as specified. These requirements shall be ascertained from tests on concrete cubes made and cured under the same conditions as the concrete member. Sufficient cubes shall be made so that if the stipulated strength is not achieved, further cubes will be available for such additional testing as may be required.
BLDG12/S07.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 7-4 7.9
TENSIONING EQUIPMENT All tensioning equipment shall be approved by the SO Rep prior to use. Hydraulic pumps shall be power driven and the power unit shall be so adjusted that the rate of extension of the tendon is within the limits recommended or as directed by the SO Rep. Dynamometers, and each set of equipment comprising pump, jack and pressure gauge shall be calibrated as directed by the SO Rep and the true force determined from the calibration. Dynamometers, pressure gauges and scales shall permit force and elongation to be determined within an accuracy of 2%. Pressure gauges shall only be used as a substitute for dynamometers and shall be concentric scale gauges complying with the requirements of BS 1780 which requires gauges to be accurate to within 1% of their full capacity. They shall be selected so as to be used between the 50% and 90% of their full capacity and shall not be less than 200mm in diameter. Where pressure gauges are used, a suitable device shall be fitted so as to protect the gauge against sudden release of pressure. Provision shall also be made by such means as a "tee" connection, for the attachment of a second gauge which shall be attached and used as a check whenever so requested by the SO Rep.
7.10
TENSIONING PRECAUTIONS All tensioning operations shall be carried out in the presence of the SO Rep in accordance with the best practice applicable to the particular prestressed method proposed. The tensioning operation shall be performed only by personnel trained and experienced in this type of work. Care shall be taken during tensioning to ensure the safety of all personnel engaged on the work and of other persons in the vicinity. Jacks shall be secured in such a manner that they will be restrained should they loose their grip on the tendons. No person shall be permitted to stand behind the jacks or close to the line of the tendons while tensioning is in progress. The operation of jacks, the measurements of elongation and associated operations shall be carried out in such a manner and from such positions that the safety of all concerned is ensured. During actual stressing operations warning signs shall be prominently displayed. Where, in the opinion of the SO Rep, there is danger to the general public or to property, special precautions in the form of substantial barrier shall be required.
7.11
TENSIONING FORCE Unless otherwise specified, the tensioning forces required shall be that shown in the Drawings. The tensioning force applied to any tendon shall be determined by direct measurement of the force and checked by measurement of the elongation of the tendon. The secant modulus determined from test samples or shown on test certificates shall be used when interpreting the measurement of elongation. Allowance shall be made for any anticipated draw-in at the anchorage devices on release of the jack, for elastic shortening of the member and for anticipated losses due to stressing of subsequent tendons. The final forces in each tendon, as measured by the dynamometer, shall be within an accuracy of plus or minus 3% of the values stipulated. If, on completion of tensioning each tendon to the required force, the check measurement of elongation differs from its required value by more than 5%, the SO Rep may direct that some or all of the following steps be taken : (a)
Recalibration of equipment;
(b)
Testing of tendon material to check secant modulus;
(c)
Tendons released and restressed (secant modulus applicable to second stressing to be adopted);
(d)
Lubrication of tendons to reduce friction losses. Only water soluble oils shall be used in ducted systems and these shall be washed out before grouting;
(e)
Where only 1 jack is used previously, the tendon shall be tensioned from both ends using 2 jacks;
(f)
Other methods as directed by the SO Rep.
BLDG12/S07.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 7-5 7.12
PRETENSIONING The abutments and casting beds for pretensioning of tendons shall be strong enough to withstand the required total prestressing force with adequate safety. The abutments shall be so constructed as to provide protection at all times against injury or damage caused by slipping occurring in anchorages during or after tensioning. Provisions shall be made for free and adequate movement of the member at points of support in the direction of the expected shortening due to prestress without impairing the rigidity of the forms during casting operations. Where necessary, provision shall be made in the design of the casting bed for the use of external vibrators. In the case where tendons are to be deflected, submit details of the proposed layout for each line of tendons together with values for the portion of the force to be provided by the initial tensioning and for the portion which will be provided by the elongation resulting from subsequent deflection of the tendons. Tensioning shall not commence until the SO Rep has approved the values submitted. Special care shall be taken to apply tensioning force smoothly at an even rate and to determine its value with considerable accuracy. Tendons shall be marked for measurement of elongation and shall also be marked at both the jacking and dead ends of the stressing bed so that any slip may be observed. Should a slip of any of the tendons in a group of tendons tensioned together occur, the tensioning of the whole group shall be released, tendons reset, and the whole group tensioned again. Alternatively, the tensioning of the group of tendons can be completed without the slipped tendon(s) which can be subsequently tensioned. The prestressing force shall be transferred from the jack to the abutment of the stressing bed immediately the required force (or elongation) has been reached and the pressure in the jack shall be relaxed before any other operation commences. Tendons shall be deflected, where shown in the Drawings and the required force maintained, by use of approved fixing devices strong enough to hold the tendons firmly in their proper positions especially during concreting and curing, until the concrete has attained the required strength. In order that the required force is maintained after the tensioned steel has been anchored, an allowance shall be made in assessing the value of the applied force for loss of stress due to yield in the anchorages and for slip when the steel is wedged after tensioning. In long line beds, due consideration shall be given to the friction caused by the varying shape and number of diaphgrams. Prior to concreting, a check shall be made of the accuracy of alignment of forms and of the distance centre to centre bearings, overall length, width, positioning of end blocks, tendons, sheathing and anchorages and their connections, reinforcement, bearings, dowels and any other fittings shown in the Drawings. Concreting of a member shall not commence until the approval of the SO Rep has been obtained. Prior to transfer of the prestressing force from the abutments of the casting bed to the members, all tendons shall be tested for tightness and any loose tendon found shall be reported to the SO Rep who will decide whether the members are acceptable. All tendons shall be marked at each end of every member so as to check the draw-in and any slip of the tendons. The procedure of release shall be continuous and shall be performed in the shortest possible time without interruption. The prestress shall be transferred to the members in such a manner that the tendons are released gradually and, preferably, simultaneously. The method of transferring the prestress and the equipment proposed shall be approved by the SO Rep prior to use. The SO Rep shall be present at every occasion of releasing tendons. After prestress has been transferred to the members, the tendons between the members shall be severed working along the line from the point or points of release. Every effort shall be made to avoid injury to the concrete.
BLDG12/S07.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 7-6 7.13
POST-TENSIONING The process of prestressing each member shall be continuous, the tendons being stressed in the order indicated in the Drawings, and the operation completed without interruption in as short a time as possible. No member shall be left partially prestressed without the permission of the SO Rep unless the Drawings require the member to be prestressed in stages. In general, tensioning shall proceed symmetrically to avoid lateral distortion and development of tension on one side. At no time shall the permissible stresses in concrete and steel be exceeded. Tendon ducts shall be cleaned out by blowing compressed air through them and anchorages shall be thoroughly cleaned prior to commencement of tensioning. The protruding ends of tendons shall be cleaned of any coating, such as rust, mortar, oil or mud which would lessen the grip of wedges of anchorage devices. Tendons shall be checked before tensioning to see that they are free to move inside the duct. Special care shall be taken to set the jacks accurately in the line of the tendon. The force which is applied initially to take up the slack of the tendon shall be sufficient to seat the jack firmly but shall not exceed the amount normally associated with the particular method of post-tensioning. After taking up the slack, the tendon shall, where possible, be accurately marked at both ends and elongations or draw-in measured from these markings. When requested by the SO Rep readings of force and elongation shall be taken at stages during the tensioning of a tendon and plotted to determine the zero error in measuring elongation. Where tendons consist of a number of individual components, each component shall be marked so that any slip may be observed. In the case of slipping of one or more components or tendons of a group tensioned together, the SO Rep may permit a compensating increase in the elongation of the remaining tendons of the group provided that the jacking force does not exceed 80% of the minimum ultimate tensile strength of the remaining tendons. In the case of a tendon breaking or slipping after tensioning, the tendon shall be released, replaced if necessary, and restressed. Under no circumstances shall the maximum jacking force exceeds the rated capacity of the jacking equipment used, or 80% of the specified minimum ultimate strength of the tendon whichever is less.
7.14
TENSIONING RECORDS All tensioning data shall be recorded and submitted to the SO Rep for checking and retention : (a)
Pretensioned Tendons The following data relating to the prestressing operation shall be recorded :
(b)
(i)
Identification numbers of dynamometers, gauges, pumps and jacks;
(ii)
Force applied if dynamometer is used; alternatively, pump or jack pressure and area of piston;
(iii)
Elongation remaining after anchoring.
Post-Tensioned Tendons The following data, where applicable, shall be recorded :
BLDG12/S07.DOC(6) Sal(151211) (DPD)
(i)
Identification number of each dynamometer, gauge, pump and jack;
(ii)
Identification particulars of tendons;
(iii)
Initial forces (or pressures) when tendons are marked for measurement of elongation;
(iv)
Final forces (or pressure) and elongations obtained on completion of tensioning;
(v)
Elongation remaining after release of jacks;
(vi)
Elongations obtained at intervals during tensioning, together with corresponding forces (or pressures), if and when required by the SO Rep.
Bldg Spec Page 7-7 7.15
GROUTING After post-tensioned tendons have been tensioned and anchored they shall be pressure-grouted as soon as practicable. The grout mix and the method of mixing and injecting the grout shall be approved by the SO Rep before grouting is commenced. The pressure at which the grout is to be pumped into the duct shall be approved by the SO Rep and shall not normally exceed 0.7 N per mm². The grout shall preferably be either a neat cement grout with a water to cement ratio not exceeding 0.4 or cement mortar (1:1 3/4 by weight). An approved expanding plasticising admixture shall be used. Grout shall be mixed in a high speed mechanical mixer, for at least 2 minutes, until a uniform colloidal consistency is produced. Mixing by hand shall not be permitted. Pumps shall be capable of continuous operation with little pressure variation and shall have a system for recirculating the grout whilst actual grouting is not in progress. Pumps shall be fitted with a pressure gauge and shall be capable of delivery at pressures up to 1.0 N per mm². All equipment, especially piping, shall be thoroughly washed with clean water after each series of operations and more frequently if necessary. Grouting shall not be carried out while the shade temperature exceeds 38°C. All ducts and holes shall be thoroughly flushed out with clean water followed by compressed air. Grout shall be injected into each duct at a speed between 300mm and 600mm per second. A continuously steady flow of grout shall be maintained until the duct is completely filled and pure grout issues from all vents and from the far end and until all entrapped air has been expelled. The vents shall be progressively closed as required to ensure the complete filling of the duct. The grout pressure shall then be held at the required value for at least 1 minute after which the grouting end shall be plugged. All vents and ends shall be kept closed until final setting of the grout has taken place. When directed by the SO Rep, duct openings shall be inspected 2 or 3 days after grouting and topped up if necessary. If serious leaks occur, the grouting shall be stopped, the duct flushed clean with water and the leakage plugged before continuing with grouting. If a blockage occurs, pumping may be quickly transferred to the far end of the duct if there are sufficient vents to ensure that the duct will be filled with grout. Alternatively, ducts may be flushed with clean water to clear the blockage. The Contractor shall be responsible for the complete filling of the ducts with grout. If several blockages occur the grout mix may be rejected and a new mix designed. On completion of grouting and after the grout has hardened sufficiently, any vents or grouting tubes which extend to the surfaces of the concrete shall be cut off 25mm below the concrete surface and the recess plugged with concrete. Tendons shall be cut back to give, when recesses are concreted, a minimum of 25mm cover. Wire stubs (if any) may be bent into the recesses. Recesses shall be concreted, or, when shown in the Drawings, shall be filled monolithically when other cast-in-place concrete is placed. Complete records shall be kept on all grouting of ducts and a copy of the records submitted to the SO Rep.
7.16
PRESTRESSED MEMBERS Workmanship displayed in the construction of prestressed members shall be of the highest order and every endeavour shall be made to obtain accuracy of dimensions. The dimensions and shape stated in the Drawings shall be taken to apply to the structure at the time of its completion when under self weight alone. Except where stated otherwise in the Drawings or approved by the SO Rep, the dimensions and profile of the formwork shall compensate for deformations due to prestress, etc so that the dimensions and profile of the completed structure will conform to the Drawings. Submit details of the magnitude of these deformations and the proposed method to allow for them. Construction of formwork shall not commence until the approval of the SO Rep has been obtained.
BLDG12/S07.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 7-8 7.16
PRESTRESSED MEMBERS (CONT'D) For precast members, the date of casting, length of member and the identification number required by the SO Rep shall be marked on every member. When requested by the SO Rep, the word 'TOP' and/or lifting positions shall also be marked on the member. All accepted members shall be clearly identified by marking in the presence of the SO Rep. Members shall not be lifted or handled until fully stressed. At all times, and especially during transportation, members shall be secured in proper positions by means of suitable packing pieces and braces. Members shall not be braced against one another but shall be provided with independent bracing. Members shall be handled, lifted and supported carefully at the positions and in the manner required by the Drawings. Where no method of lifting is shown in the Drawings, submit for the approval of the SO Rep, details of proposals for lifting the members and once approved no other method shall be used during the whole period of construction except with the permission of the SO Rep. Precast members shall be supported on timber bearers or other approved means, over their full width. The ground or space between the bearers supporting the members shall be carefully cleared and levelled so as to prevent the member from being accidentally supported other than on the approved bearers. The bearers themselves shall be supported on firm foundation and, every precaution shall be made to prevent subsidence from occurring. Members shall not be stacked on top of one another except when approved by the SO Rep who shall determine the manner of stacking and the maximum number of layers or height of the stacking. Each layer shall be separated from the next layer by bearers. No precast member which is manufactured outside the Site shall be delivered to the Site without the permission of the SO Rep. The granting of permission shall be dependent on each individual member exhibiting satisfactory workmanship and finish and complying with the tolerance on dimensions and prestressing force. In addition, test loading, if specified, and concrete strength tests of representative members shall satisfy the requirements specified.
Section 8/.....
BLDG12/S07.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 8-1 SECTION 8 HOUSEHOLD SHELTER
8.1
SEMI-PRECAST HOUSEHOLD SHELTER The Contract primarily requires the Contractor to construct semi-precast household shelters. The Contractor shall comply with all requirements specified herein in this Section including all clauses and subclauses under it. (a)
Approved Supplier The precast panels of household shelters hall be obtained from a supplier approved by the SO Rep. The list of approved suppliers is posted on the Internet (www.eptc.sg) under HDB’s Materials List (ML). The Contractor shall submit the written contractual agreement between himself and his supplier within two weeks from the date of the Letter of Acceptance.
(b)
Precast Concrete Works The requirements specified in the clauses and subclauses under Section 6 "Semi-Precast Construction" shall apply for all structural precast Works.
(c)
Manufacturing Of Precast Components The precast component of the household shelters shall be fabricated with proper quality control and shall be fabricated in accordance with the approved Drawings. The door frame for the blast door shall be cast in together with the precast panel. A removable steel bracing frame (Dummy Door) to prevent the door frame from warping shall be used during concreting. The door leaf shall be installed on the Site at a later stage as decided by the SO Rep. In all cases, the blast door frames shall be protected from dirt, grout and other deleterious materials by wrapping with plastic sheets or other means to provide protection to the door frames. The Contractor shall ensure the correct alignment and positioning of the door frame, ventilation sleeve and plate units and openings for electrical services. Where honeycombs or segregation occur in the concrete, these shall be made good only by pressure grouting with the approval of the SO Rep. No plastering shall be allowed on the internal surfaces of the household shelter. Prior to mass production of the precast panels for the household shelters, the Contractor shall produce at least one sample of each type of precast panel together with the blast door installed for approval by the SO Rep. The approved samples shall be displayed at the factory or on the Site if precast on Site. These approved samples shall be used as references for the minimum standard and quality to be achieved for all the precast panels of the household shelters. The Contractor shall provide remedial work to any precast panel of the household shelters that are not satisfactorily finished as decided by the SO Rep. Gross deviation from the specified finish may result in the rejection of the precast panel. The SO Rep shall reject any precast panel of the household shelter including those already delivered to the Site, if it is found that such precast panel does not comply with the Drawings and/or Specifications.
BLDG12/S08.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 8-2 8.1
SEMI-PRECAST HOUSEHOLD SHELTER (CONT'D) (d)
Transportation And Site Storage The precast panels of the household shelters shall be delivered to the Site in a proper manner. The Contractor shall ensure that the precast panels are able to withstand any distortion in the shape during lifting, transportation and installation. They shall be handled in such a manner so as to avoid excessive stress or damage. The Contractor shall ensure proper site access and shall supply all necessary tools and equipment for the efficient transportation of the precast panels to the designated location at the Site. The storage area shall be adequate to permit easy access and ready for the handling of the stored precast panels. It shall have a clean, hard, level and well-drained surface to permit well-organised storage, and to prevent warpage, bowing, chipping, cracking, discolouration, staining or soiling of the precast panels. No precast panel shall be placed directly on the ground without proper support. They shall be stored with due protection from staining or physical damage.
(e)
Installation The Contractor shall provide all necessary tools and equipment such as cranes, temporary staging, etc for the efficient installation of the precast panels. The installation procedure shall be submitted to the SO Rep for approval and shall be strictly adhered to thereafter. The Contractor shall exercise good construction practice and stringent control to ensure that the household shelter is constructed properly according to the Drawings and/or Specifications. No hacking of the concrete of precast panels shall be allowed.
8.2
CAST-IN-SITU CONCRETE WORKS (a)
The requirements specified in Section 4 "Structural Concrete" including all clauses and subclauses under it shall apply for all cast-in-situ Works.
(b)
The Contractor shall ensure the correct alignment and positioning of the ventilation sleeve and plate units and openings for electrical services where required.
(c)
The Contractor shall exercise good construction practice and stringent control to ensure that the household shelter is constructed properly in accordance with the Drawings and/or Specifications. No hacking of the concrete of household shelters shall be allowed. Concrete unevenness, if required to be made good, shall be ground smooth by using grinders only. Where honeycombs or segregation occur in the concrete, these shall be made good only by pressure grouting with the approval of the SO Rep. No plastering shall be allowed on the internal surfaces of the household shelter.
8.3
BLAST DOOR (a)
Approved Supplier The household shelter blast doors shall be obtained from a supplier approved by the SO Rep. The list of approved suppliers is posted on the Internet (www.eptc.sg) under HDB’s Materials List (ML). The Contractor shall submit to the SO Rep, the approved blast door shop drawings and the written contractual agreement between himself and his supplier within two weeks from the date of the Letter of Acceptance.
BLDG12/S08.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 8-3 8.3
BLAST DOOR (CONT'D) (b)
Fabrication Of Blast Door The blast doors shall be fabricated according to the details as shown in the approved shop Drawings with good quality and workmanship acceptable to the SO Rep.
(c)
Inspection/Testing Of Blast Doors The Contractor shall allow for the inspection and testing of the blast doors by the SO Rep during the course of fabrication. Blast door shall be selected on the Site by the SO Rep for inspection/testing. The Contractor shall cut them open to check for compliance with the approved shop Drawings and/or Specifications. Water-tightness tests shall be carried out on the door (closed and fully locked with the door frame) to a minimum depth of 25 mm water for a period of 2 hours. Any seepage of water through the door or gasket after the 2 hour period shall be considered a failure.
(d)
Steel Sections For components such as blast door frame, blast door leaf cladding panels and internal frame of the door leaf, uncoated mild steel sheets to ASTM A366 or BS 1449 or other approved standards subject to the approval of the SO Rep shall be used. Such components shall be treated with approved Cathodic Electro-Deposition (CED) primer and tested to the requirements stipulated in subclause 18.29.1. For other mild steel sections (such as for small movable parts in the locking mechanism, if any), grade 43A to BS 4360 or other approved standards subject to the approval of the SO Rep shall be used. Such other mild steel sections shall be protected from corrosion by a method approved by the SO Rep. Small areas of corrosion protection coating damaged by welding, cutting or bending shall be made good by the application of at least two coats of good quality zinc-rich paint with a minimum of 85% zinc dust, expressed as a percentage by weight of the solid content of the paint, or other method approved by the SO Rep.
(e)
Locking Bolts and Shear Pins Locking bolts and shear pins shall be of stainless steel to AISI Type 316.
(f)
Gasket The material for the gasket shall be Neoprene or EPDM rubber and shall meet the requirements of Type 2 closed cell expanded rubber, either grade 2A3 or higher; or grade 2B3 or higher as specified in Table 2 of ASTM D1056; or other approved
(g)
Spray Painting To Blast Door Leaf The blast door leaf which is Cathodic Electro-Deposition (CED) primed shall be spray finished with 2 coats of approved enamel paint. Prior to the application of the enamel paint, the surfaces shall be clean, dry and free from grease, oil or other foreign matter. A full colour range of the enamel paint shall be submitted for selection and approval by the SO Rep.
BLDG12/S08.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 8-4
8.3
BLAST DOOR (CONT'D)
(h)
Painting To Blast Door Frame Painting to Blast door frame which is Cathoidc Electro-Deposition (CED) primer shall be painted on the Site with 2 coats of approved enamel paint. Prior to the application of the enamel paint, the surfaces shall be clean, dry and free from grease, oil or other foreign matter. A full colour range of the enamel paint shall be submitted for selection and approval by the SO Rep. The CED primer shall comply with the following requirements:
Performance / Properties
BLDG12/S08.DOC(4) Sal(151211) (DPD)
Test Method
Requirement
Adhesion
ASTM D3359
5B
Scratch Resistance
SS 5 : Part F2
Shall withstand scratch test load of 2000g
Pencil Hardness
ASTM 3363
2H shall be the hardest pencil that do not scratch the film
Dry Film Thickness
SS 5:Part B1
20 microns 5 microns
Resistance to Salt Water Spray
SS 5:Part G1
1000 hrs: 10 ml/min
Rheological Properties
ASTM C639
Vertical displacement 0.3 N/mm2 28 days => 1.0 N/mm2 28 days => 1.0 N/mm2 At 28 days => 1.0 N/mm2 Circulating oven : 70 + - 2 degree C for 14 days => 0.5 N/mm2 after not less than 30 mins After 28 days storage under standard conditions 2.5mm (minimum)
Grouting To Tile Joints Approved tile grouts shall be used to fill the joints between floor tiles. They shall be used in all floor tiling Works to residential units and common areas except for water tanks. The grouts shall have good working characteristics, low shrinkage and good adhesion to the sides of the joints. They shall be suited for the width of the joints and intended use of the tiling application. The Contractor shall submit the brand and method of application to the SO Rep for approval prior to the commencement of the tiling Works. The Contractor shall submit samples of the grouts to the SO Rep for selection of colours to match the tiling Works.
BLDG12/S19.DOC(21) Sal(151211) (DPD)
Bldg Spec Page 19-22 19.7
LAYING OF CERAMIC FLOOR TILES
19.7.8.1
Material
(CONT’D)
The proprietary grouts shall be modified by the inclusion of various polymer additives. They shall be easy to prepare, apply and clean up at the Site. A sample for each type of grouts shall be taken at the Site and tested at an accredited laboratory according to the following requirements : Tile grout for joint width up to 4mm S/N
Characteristics
Test Method
Performance Criteria
1
Shrinkage
EN 12808-4
2 mm/m
2
Water absorption
EN 12808-5
2g (after 30 min) 5g (after 240 min)
3
Compressive strength (After dry storage)
EN 12808-3
4
Abrasion resistance
EN 12808-2
5
Flexural strength (After dry storage)
EN 12808-3
15 N per mm² minimum 35 N per mm² maximum 2000 mm3 3.5N per mm²
Tile grout for joint width above 4mm S/N
Characteristics
Test Method
Performance Criteria
1
Shrinkage
EN 12808-4
2 mm/m
2
Water absorption
EN 12808-5
2g (after 30 min) 5g (after 240 min)
3
Compressive strength (After dry storage)
EN 12808-3
15 N per mm² minimum 35 N per mm² maximum
4
Abrasion resistance
EN 12808-2
1000 mm3
5
Flexural strength (After dry storage)
EN 12808-3
3.5N per mm²
The grouts shall be light-fast and colour-fast. Their colours shall not fade or show inconsistent tones for the whole tiling Works.
BLDG12/S19.DOC(22) Sal(151211) (DPD)
Bldg Spec Page 19-23 19.7
LAYING OF CERAMIC FLOOR TILES
19.7.8
Grouting To Tile Joints
19.7.8.2
Application
(CONT’D)
(Cont’d)
The proprietary grouts shall be stored and used in accordance with the manufacturer’s instructions. The potential risk of staining shall be verified by applying the grout to a few tiles in a small trial area. Coloured grouts shall be cleaned off promptly in accordance with the manufacturer’s instructions as it may be difficult to remove them from matt glazed tiles, tiles with textured surfaces and some unglazed tiles. The grouting shall be provided in accordance with the following : (i)
The grouting shall commence within 7 days upon completion of tile fixing;
(ii)
Ensure that all building dust and debris are removed from the open joints;
(iii)
Mechanically mix the grout in accordance with the manufacturer's instructions;
(iv)
Spread the grout with a rubber squeegee or grouting trowel, working back and forth over the area until the joints are completely filled;
(v)
Remove surplus grout from the tiles with the aid of a rubber squeegee or grouting trowel and a damp, but not wet, cloth;
(vi)
Tool the joints with a piece of wood or other material of suitable size and shape;
(vii)
After the grout has dried, the tile surface shall be cleaned and given a final polish using a clean, dry cloth.
All grout joints shall be uniformly finished. Cushion edge tiles shall be finished evenly to the depth of the cushion.
19.7.9
Other Materials Any other material not specifically described but required for a complete and proper laying of the ceramic floor tiles shall be provided by the Contractor at its own cost and expense, but subject to the approval of the SO Rep.
19.7.10
Cleaning Up Upon completion of grouting, thoroughly clean all the exposed surfaces of the ceramic tiles. The tiles shall thoroughly be cleaned before the handing over. The Contractor shall use tile-cleaning agents to clean all finished surfaces. The tile cleaner shall be an effective blend of penetrants which could instantly penetrate deep into mortar and scale on tiles surface and remove the mortar completely. The tile cleaner shall be safe to use and does not harm or burn the skin. The tile cleaner shall be prepared and used according to the manufacturer's instructions.
19.7.11
Damage And Replacement In the event of any damage to the ceramic tiles and accessories, the Contractor shall immediately make all repairs and replacements necessary to the satisfaction of the SO Rep all at the Contractor's cost and expense.
BLDG12/S19.DOC(23) Sal(151211) (DPD)
Bldg Spec Page 19-24 19.7
LAYING OF CERAMIC FLOOR TILES
19.7.12
Testing Of Tensile Pull-Out Strength
(CONT’D)
The Contractor shall conduct tensile pull-out tests on floor tiles according to the Schedule Of Material Tests. Each test shall determine the tensile pull-out strengths of five randomly selected pieces of tiles within a room. The joint around the tile shall be cut to the depth of the joint before the pull-out test. The test shall be conducted within 21 to 28 days after fixing the tiles. The average tensile pull-out strength of the 5 tiles tested shall achieve a minimum of 0.20 N per mm². In addition, the individual tensile pull-out strength of each tile shall not be less than 0.16 N per mm². The first test for each building block shall be conducted at the early stage of floor tiling Works. The remaining tests shall be spread out and be carried out progressively.
19.20
FINISHED FLOOR LEVEL AT JUNCTIONS BETWEEN DIFFERENT TYPES OF FINISHES Unless otherwise specified the finished floor level at junctions between different types of finishes must be flushed.
19.20.1
Dividing Strips To provide and fix minimum 10X3mm thick stainless steel or brass strips insert to joints where there is a change in materials, change in pattern, interfaced joint between living room tiles and kitchen tiles, and wherever it is indicated on the drawings or as directed by the SO Rep. The stainless steel strips insert is to be embedded in cement mortar and finished flush with finished floor level.
Section 20/.....
BLDG12/S19.DOC(24) Sal(151211) (DPD)
Bldg Spec Page 20-1 SECTION 20 WALL FINISHES
20.1
APPROVED MATERIALS FOR PLASTERING AND SKIMMING WORKS
20.1.1
Mortar Mix For Plastering Works The Contractor shall use premixed mortar system or prepacked mortar listed in HDB’s Materials List for all plastering works on brick walls, solid block walls and RC surfaces. Plastering of RC surfaces shall be restricted to internal surfaces only. The premixed mortar system shall be a fully automated system that stores, conveys and mixes mortar for instant application. The prepacked mortar shall be in bag form and shall be mixed mechanically according to the manufacturer's recommendation. The Contractor shall submit a work method statement to the SO Rep for approval. The premixed mortar system or prepacked mortar shall be formulated with at least 0.80% of pure polymer by mass. The premixed mortar system or prepacked mortar shall comply with the following performance requirements and product specification when subjected to the specified laboratory testing : Prepacked Mortar Mix S/No
Type of Evaluation
Testing Method
Tensile Adhesion Strength
Tensile adhesion strength test according to HDB method on a sample cured for 14 days under shaded ambient condition. Twelve spots on the sample slab shall be tested.
Shear Adhesion Strength
Shear adhesion test according to HDB method on a sample cured for 14 days under shaded ambient condition. Six spots on the sample slab shall be tested.
3
Average Shrinkage
ASTM C 531 – 2000
4
Compressive Strength – 28 days
5
Consistence Retentivity
6
Water Retentivity
7
Setting Time
8
9
1
2
Requirement Average strength 2 > 0.75 N per mm Individual strength 2 > 0.60 N per mm Average strength 2 > 1.00 N/mm Individual strength 2 > 0.70 N/mm < 0.10% 12 - 20 N/mm
2
BS 4551 : Part 1 : 1998 > 65% > 95%
BS 4551 : Part 1: 1998
> 240 mins 360 mins
Polymer Content
Thermal Gravimetric Analysis & SDTA
0.80% min. by mass
Product Identification Analysis
Fourier Transformed Infrared Spectrophotometric Analysis
The chemical blueprint shall match the record of the approved product
Initial set
< 500 mins
Final set
HDB may instruct the contractor to conduct site sampling of the prepacked mortar for testing to determine the pure polymer content by Thermal Gravimetric Analysis & SDTA to be conducted by an accredited laboratory. The pure polymer content of the site sample shall exceed 0.64%, i.e. 80% of the specified content for production. The 20% margin allowed for acceptance of individual test result has taken into consideration that it will be difficult to achieve perfect distribution of the polymer in the production and the tolerance for test accuracy. Prepacked mortar with pure polymer content less than 0.64% shall be removed from HDB's Materials List. The Contractor shall remove all unused prepacked mortar with deficiency in pure polymer content from the site. To avoid delay to the building works, the Contractor is required to use only those prepacked mortar listed in HDB’s Materials List and subject to the approval of the SO Rep. The Contractor may be required by the SO Rep to remove all works that used the prepacked mortar with deficiency in pure polymer content. BLDG12/S20.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 20-2 20.1
APPROVED MATERIALS FOR PLASTERING AND SKIMMING WORKS
20.1.2
Skimming Materials
(CONT’D)
The Contractor shall use prepacked external skim coat listed in HDB’s Materials List for skimming works on external RC surface. The skimming works on other areas shall use prepacked internal skim coat listed in HDB’s Materials List. The prepacked skimming materials shall be mechanically mixed with the amount of water as specified by the manufacturer. The prepacked internal skimmed coat shall be formulated with at least 1.0% of pure polymer by mass and shall comply with the following performance requirements and product specification when subjected to the specified laboratory testing : Prepacked Internal Skim Coat
S/No
1
Type of Evaluation
Tensile Adhesion Strength Test
Testing Method
Requirement
Tensile adhesion strength test according to HDB method on a sample cured for 14 days under shaded ambient condition. Twelve spots on the sample slab shall be tested.
Individual strength 2 > 0.60 N per mm
Average strength 2 > 0.80 N per mm
2
Average Shrinkage
ASTM C 531 – 2000
< 0.10%
3
Compressive Strength – 28 days
BS 4551 : Part 1 : 1998
7 - 12 N/mm
4
Water Retentivity
BS 4551 : Part 1 : 1998
> 95%
5
Setting Time
BS 4551 : Part 1: 1998
> 240 mins 360 mins
i)
Initial set
2
< 500 mins
ii) Final set 6
Polymer Content
Thermal Gravimetric Analysis & SDTA
1.0% min. by mass
7
Product Identification Analysis
Fourier Transformed Infrared Spectrophotometric Analysis
The chemical blueprint shall match the record of the approved product
The prepacked external skim coat shall be formulated with at least 2.0% of pure polymer by mass and shall comply with the following performance requirements and product specification when subjected to the specified laboratory testing : Prepacked External Skim Coat S/No
1
2
Tensile Adhesion Strength Test
Tensile adhesion strength tests after accelerated weathering for 100 cycles* of alternate heating and cooling.
3
Average Shrinkage
4
Compressive Strength – 28 days
5
Water Retentivity
6
BLDG12/S20.DOC(2) Sal(151211) (DPD)
Type of Evaluation
Setting Time
i)
Initial set
Testing Method Tensile adhesion strength test according to HDB method on a sample cured for 14 days under shaded ambient condition. Twelve spots on the sample slab shall be tested. Tensile adhesion strength tests after accelerated weathering for 100 cycles* of alternate heating and cooling. Twelve spots on the sample slab shall be tested. * Each cycle consist of 4 hours of heating by UVA 340 lamps at 60C and then 10 minutes of intermittent water spray to produce a thermal shock. ASTM C 531 – 2000 BS 4551 : Part 1 : 1998
Requirement Average strength 2 > 0.80 N per mm Individual strength 2 > 0.60 N per mm
Loss of strength < 15% (compared to 14-day strength under normal condition)
< 0.10% 7 - 12 N/mm
2
> 95% BS 4551 : Part 1: 1998
> 240 mins 360 mins < 500 mins
ii) Final set
7
Polymer Content
Thermal Gravimetric Analysis & SDTA
2.0% min. by mass
8
Product Identification Analysis
Fourier Transformed Infrared Spectrophotometric Analysis
The chemical blueprint shall match the record of the approved product
Bldg Spec Page 20-3
20.1
APPROVED MATERIALS FOR PLASTERING AND SKIMMING WORKS
20.1.2
Skimming Materials
(CONT’D)
(Cont’d)
HDB may instruct the contractor to conduct site sampling of the prepacked internal and external skim coat for testing to determine the pure polymer content by Thermal Gravimetric Analysis & SDTA to be conducted by an accredited laboratory. The pure polymer content of the site sample shall exceed 0.80% for prepacked internal skim coat and 1.60% for external skim coat, i.e. 80% of the specified content for production. The 20% margin allowed for acceptance of individual test result has taken into consideration that it will be difficult to achieve perfect distribution of the polymer in the production and the tolerance for test accuracy. Prepacked internal skim coat with pure polymer content less than 0.80% or external skim coat with pure polymer content less than 1.60% shall be removed from HDB's Materials List. The Contractor shall remove all unused prepacked internal skim coat or external skim coat with deficiency in pure polymer content from the site. To avoid delay to the building works, the Contractor is required to use only those prepacked internal or external skim coat listed in HDB's Materials List and subject to the approval of the SO Rep. The Contractor may be required by the SO Rep to remove all works that used the prepacked internal skim coat or external skim coat with deficiency in pure polymer content.
20.2
CONTROL OF PLASTER THICKNESS ON RC SURFACE The overall thickness of plastering on RC surface shall not exceed 18mm. If the structural Works are constructed with good alignment and surface condition, application of a thinner coat of plaster or skimming is acceptable. The finished surface shall be smooth and true to plane and shape.
20.3
PLASTERING TO RC SURFACE The RC surface shall be cleaned, using high-pressure water jet, such that the surface are free of dust, residue form oil and organic growth prior to the application of the plaster. The Contractor shall allow the Resident Technical Officer to check the background preparation before plastering. The prepacked mortar mix can be applied to the RC surface without spatterdash. The first coat of the plaster to the RC surface shall be of a thickness between 5 to 8mm and shall be pressed hard onto the surface during application. For better bonding of the second coat, the first coat shall be lightly scratched and allowed to cure for at least 12 hours before the application of the second coat.
20.4
ADHESION STRENGTH OF PLASTER ON RC SURFACE The Contractor shall conduct site pull-out tests on plasters applied on concrete surface according to Schedule of Materials Tests. The first test at each building block shall be conducted at the early stage of plastering Works. The remaining tests shall be spread out and be carried out progressively. Each test shall cover five randomly selected spots to be conducted within 14 to 28 days after plastering. The test spots shall be cored to a diameter of 50mm for the pull-out test. The average tensile pull-out strength of the five spots shall achieve a minimum value of 0.50 N per mm2. However, no individual strength shall fall below 0.40 N per mm2.
BLDG12/S20.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 20-4 20.5
SKIMMING TO THE EXTERNAL SURFACE OF REINFORCED CONCRETE MEMBERS The surface of all reinforced concrete members forming part of the external facade shall be constructed to good alignment and verticality such that no plastering is required to provide a good aesthetic appearance. Where there are minor surface unevenness or blemishes, the RC surface shall be skim-coated with approved external skimming materials. The skimming can be applied in one or two coats up to a total thickness not exceeding 6mm. This requirement shall be applicable to external RC members of all storeys, including the ground floor void deck structures.
20.5.1
Workmanship Of RC Works The verticality of the peripheral RC members and internal RC members shall comply with the following tolerance, in accordance to Grade II tolerance of SS CP 23. Allowable variation From The Plumb Type Of RC Members/Surfaces Within Each Floor
For Any Continuous Height Of 10 Storeys
Exposed continuous column corners or other conspicuous lines (External)
10mm
20mm
Corner or surface of columns and walls etc with continuity broken by beams or nibs or other protusions (External)
10mm
40mm
Column and Wall (Internal)
10mm
NA
The maximum allowable variation from the plumb for the entire building height shall be 40mm. The horizontality, alignment and evenness of the ceiling, slab and beam shall comply with the following tolerance : Type Of RC Members/Surfaces
Allowable variation from horizontality /alignment
Allowable variation for evenness of surface
Beam
10mm
NA
Ceiling
Lesser of 3mm per 1.0m or 20mm
NA
Slab
NA
±10mm from structural floor level
To achieve the required structural workmanship, the Contractor shall be required to : a)
regularly check and maintain their formwork to be in a good and acceptable condition;
b)
ensure proper and adequate bracing and strutting;
c)
conduct thorough checking of plumb and alignment before casting.
BLDG12/S20.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 20-5 20.5
SKIMMING TO THE EXTERNAL SURFACE OF REINFORCED CONCRETE MEMBERS (CONT’D)
20.5.2
Measurement Of RC Works At least fourteen(14) days before commencement of Works, the contractor shall submit to the SO Rep for his approval the measurement plan and survey methods. The areas of the Works to be measured and incorporated into the measurement plan and survey methods shall, inter alia, include the following : (a)
Verticality and alignment of corners of every building block
(b)
Verticality and alignment of columns
(c)
Verticality of walls
(d)
Straightness, horizontality, alignment and evenness of beams and slabs
The Contractor shall engage a competent person to carry out measurements of the plumb and alignment of all external & internal columns, external and internal walls and external corners of the building blocks. This measurement shall be carried out for every storey, including the first storey. The Contractor shall be required to use a precision laser plummet capable of shooting a vertical laser beam for up to 100mm in range and at an accuracy of at least 5 seconds; and a precision multidirectional laser marker capable of beaming right angle lines for up to 30m in range and has an accuracy of at least 3mm at 10m horizontal and vertical distances. Proper records of the RC verticality measurements shall be submitted to the SO Rep within one month after casting of the RC members or any other period as instructed by the SO Rep. The Contractor shall highlight in their report all deviations that exceed the tolerance. Upon completion of the finishing work, the Contractor shall carry out another measurement of the building block. Proper records of all measurements made on the various areas of Works shall be kept by the Contractor. The Contractor shall when directed by the SO Rep submit the records of measurements made in respect of every building block before seeking his approval to proceed with the next stage of the Works
20.5.3
Rectification Of Misalignment And Surface Defects The Contractor shall carry out structural rectification to the external RC members with poor alignment and plumb, poor construction joint, honeycombed and badly formed surfaces to the satisfaction of the SO Rep all at the Contractor's cost and expense. The structural rectification of such Defect shall commence not later than two months after casting. The Contractor shall rectify minor bulging or depression on the RC surface, which does not affect the reinforcement cover, with the following method : (a)
trim and roughen the surface,
(b)
clean the surface with pressure jetting
(c)
apply approve bonding agent to the surface
(d)
patch the areas with approved polymer modified mortar.
For serious structural Defect or misalignment, the Contractor shall be required to submit a PE proposal for the rectification work subject to the approval of the SO Rep. 20.5.4
Application Of External Skimming Skimming shall not commence until the surface has been properly prepared and cleaned with water jet. The Contractor shall allow for the inspection of the surface preparation prior to the skimming application. Upon completion of the skimming Works, the Contractor shall carry out another measurement of the building blocks. All measurement data shall be submitted to the SO Rep.
BLDG12/S20.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 20-6 20.5
SKIMMING TO THE EXTERNAL SURFACE OF REINFORCED CONCRETE MEMBERS (CONT’D)
20.5.5
Testing Of External Skimming The Contractor shall conduct tensile pull-out tests on the external skimming at each building block according to the Schedule Of Material Tests. Each test shall cover five randomly selected spots of skimming with age between 14 to 28 days. The average tensile pull-out strength of the 5 spots, of 50mm cored diameter each, shall exceed 0.50 N per mm2. In addition, the individual tensile pull-out strength of each spot shall not be less than 0.40 N per mm2. The first test at each building block shall be conducted in the initial stage of skimming Works. The remaining tests shall be spread out and be carried out progressively.
20.6
CONTROL OF PLASTERERS The Contractor shall employ workers that are capable of producing good workmanship for plastering and skimming Works. They shall possess Skills Evaluation Certificate on plastering works from local institutions. A list of these workers shall be submitted to the SO Rep for pre-screening and approval before they are allowed to commence work. These workers are also required to wear identification pass upon approval by the SO Rep. The pass shall be easily distinguishable from other pass used at the Site, by their colour, size or pattern.
20.7
ARRISES AND ANGLES IN PLASTERING AND SKIM COAT (WITHIN FLATS) All arrises, internal angles, etc. shall be straight plumbed. All internal angles and external angles shall be formed with proprietary PVC plaster angle beads to the SO Rep. approval. Internal angles and external angles shall include the interface of ceilings, walls and beams etc. Square PVC angle beads shall have a face flange minimum 20mm wide that subtends a 90 degrees angle and shall have a short reveal of 2 mm on the front edge for the finishing skim coat. The face flange shall be perforated and its surface tooth formed to hold and receive the plaster and skim coat. The entire length of the PVC angle beads shall be clean and straight, any damaged or used beads shall not be recycled. Samples of the PVC angle beads shall be submitted to the SO Rep. for approval prior to ordering and commencement of skim coat or plastering work on site. An approved sample of the PVC angle beads shall be displayed in the material sample room.
20.8
MAKING GOOD All making good of defective plaster shall be carried out in rectangular areas, the edges undercut to form dovetailed key and finished flush with face of surrounding plaster. Cut out and make good all cracks, blisters and other Defect and clean the whole of the work on completion.
20.9
PARTIALLY OR WHOLLY SET PLASTER No partially or wholly set plaster shall be allowed to be used or remixed.
20.10
DRIPS AND GROOVE Drips and grooves shall be formed to give a clean clear and straight surface free from loose sandy mortar.
BLDG12/S20.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 20-7 20.11
LAYING OF CERAMIC WALL TILES
20.11.1
Wall Tiling Method The Contractor shall carry out wall tiling according to the following procedure : (a)
Clean the background to remove all laitance, dust, oil or other substances that affect the bonding of rendering. The background shall be washed using water jet.
(b)
Apply rendering to the background to a finished thickness not exceeding 10mm to achieve a flat and even surface. The background shall be first dampened to prevent excessive absorption of water from the rendering before its placing. The rendering shall be increased to a finished thickness not exceeding 18mm to allow for concealment of water piping.
(c)
Allow the rendering to set for at least 12 hours.
(d)
Apply a layer of bedding mortar onto the rendered substrate and spread another layer as thin as possible on the full back of the tiles before placing tiles in position. The keys, frogs or depressions at the back of the tile shall be completely filled with mortar before fixing.
(e)
Place each tile and tap it firmly into position to ensure that each tile makes contact over its whole area. Tile spacers shall be used for laying of wall tiles to achieve consistent joint width. The tile spacers to be used shall be approved by the SO Rep prior to the commencement of the tiling works.
(f)
Adjust the position of any tile within 5 minutes of fixing. The grouting to the tile joints shall commence within 7 days after fixing the wall tiles. Dust or foreign materials shall be removed from the joints. The grout shall be wet mixed mechanically before application. It shall be spread with a grout spreader (rubber squeegee or grout trowel), working back and forth over the area until the joints are completely filled. Excess grout shall be removed with the aid of a spreader and a damp (not) wet cloth. After the grout has stiffened slightly, tool the grout with a piece of wood or other suitable tool to a consistent depth and shape. After the grout has dried, the tile surface shall be cleaned and given a final polish using a clean, dry cloth.
20.11.2
Prepacked Mortar For Mortar Bed The Contractor shall use approved pre-packed mortar mix for rendering to concrete surface and block walls to receive the wall tiles. Potable water supplied by PUB shall be used for mixing the mortar. The pre-packed mortar mix shall be mixed mechanically according to the manufacturer's recommendation. The pre-packed mortar mix shall comply with the following performance requirements, as stated in clause 20.1.1 when subjected to the specified laboratory testing.
20.11.3
Tile Adhesive The Contractor shall use pre-approved tile adhesive and shall submit the brand and method of application to the SO Rep for approval prior to the commencement of the tiling works. The tile adhesive shall be applied onto the surface of rendered wall and then notch-trowelled to a finishes thickness not exceeding the manufacturer’s recommendation. The area of application shall not exceed 1m2. in each application. The tile adhesive shall also be spread uniformly over the back of each tile to fill deep keys and all remaining depressions. The tile shall then be placed into the position and be tapped firmly to ensure its full contact with the adhesive. The tile adhesive shall be stored and used in accordance with the manufacturer’s instructions. The normal set tile adhesive shall comply with the following requirements specified in Clause 19.7.7 “Tile Adhesive”.
BLDG12/S20.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 20-8 20.11
LAYING OF CERAMIC WALL TILES
20.11.4
Testing Of Tensile Pull-Out Strength
(CONT’D)
The Contractor shall conduct tensile pull-out tests on wall tiles according to the Schedule Of Material Tests. Each test shall determine the tensile pull-out strengths of five randomly selected pieces of tiles within a room. The joint around the tile shall be cut to the depth of the joint before the pull-out test. The test shall be conducted within 21 to 28 days after fixing the tiles. The average tensile pull-out strength of the 5 tiles tested shall achieve a minimum of 0.20 N per mm². In addition, the individual tensile pull-out strength of each tile shall not be less than 0.16 N per mm². The first test for each building block shall be conducted at the early stage of wall tiling Works. The remaining tests shall be spread out and be carried out progressively. 20.12
COLOUR GLAZED CERAMIC WALL TILES INSIDE DWELLING UNITS
20.12.1
General Provide and lay colour glazed ceramic wall tiles to locations as specified in the subclause “Schedule Of Colour Glazed Wall Tiles “ hereunder and at other locations as shown in the Drawings.
20.12.2
Approved Colour Glazed Wall Tiles The type of colour glazed wall tiles provided by the Contractor to locations specified in the sub-clause "Schedule Of Colour Glazed Wall Tiles" hereunder shall be subject to the approval of the SO Rep. The SO Rep shall have the absolute prerogative to select the type of colour glazed wall tiles and no adjustment to the Contract Sum shall be made. Notwithstanding any approval by the SO Rep, the Contractor shall ensure that all colour glazed wall tiles comply with the requirements specified in this clause including all sub-clauses under it. The colour of glazed wall tiles for such locations as specified in the schedule of the said subclause shall be BLUE and/or PINK and/or BEIGE and/or GREY. Provide samples of colour glazed wall tiles with the colour range as specified for selection and approval by the SO Rep.
20.12.3
Testing Requirements (a)
Test Samples And Methods All test samples shall be randomly chosen from the same batch of delivery by the SO Rep. The test methods shall be in accordance with SS 483 : 2000 (Annex L) unless otherwise stated.
(b)
Test Certificate And Compliance Requirement Provide test certificates by a testing laboratory accredited under SINGLAS to cover the tests mentioned in this clause and all other tests mentioned in the testing schedule.
BLDG12/S20.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 20-9 20.12
COLOUR GLAZED CERAMIC WALL TILES INSIDE DWELLING UNITS (CONT’D)
20.12.4
Technical Specifications Dimensional and surface quality requirements and physical and chemical properties shall be accordance with SS 483 : 2000 (Annex L) unless otherwise stated : (a)
Dimensions Nominal Length Nomianal Width Thickness
: : :
200mm 200mm 7mm
: : :
250mm 200mm 7mm
: : :
300mm 200mm 7mm
: : :
300mm 300mm 7mm
or Nominal Length Nomianal Width Thickness or Nominal Length Nomianal Width Thickness or Nominal Length Nomianal Width Thickness
The dimensional tolerances shall be as follows :
(b)
(i)
Length
:
Average length of each tile (2 or 4 sides) shall not deviate by more than 0.3% from the average length of 10 test specimens.
(ii)
Width
:
Average width of each tile (2 or 4 sides) shall not deviate by more than 0.3% from the average length of 10 test specimens.
(iii)
Thickness
:
Average thickness of each tile shall not deviate by more than 0.5mm from the average thickness of 10 test specimens.
Surface Quality The tiles shall be free from objectionable surface blemishes such as projections, depressions, flakes, hairline cracks and bubbles. The tiles shall be level and regular in size with properly formed corners and shall not be warped or deformed in any manner.
(c)
Physical Properties The water absorption shall be a maximum of 18%.
BLDG12/S20.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 20-10 20.12
COLOUR GLAZED CERAMIC WALL TILES INSIDE DWELLING UNITS (CONT’D)
20.12.4
Technical Specifications (Cont’d) (d)
Chemical Properties (i)
Staining Test The procedure for carrying out the test is as follows : Allow 3 or 4 drops of each of the test solutions (Methylene blue solution, 10g/L and Potassium permanganate solution, 10g/L), to fall on a fresh part of the test specimen. Place an approximately 30mm diameter convex watch glass on the applied drop in order to spread it to an approximately circular area. Allow to remain for 24 hours and then rinse the surface with running water and wipe with a damp cloth. If a stain remains, thoroughly clean with a solution of the standard cleaning agent. Performance Criteria The stain on the test specimen shall be able to be cleaned by cleaning solution.
(ii)
Reverse Staining Test The procedure for carrying out the test is as follows : (a)
Five full pieces of tiles shall be selected and checked to ensure that there are no Defect or damages. The tiles shall also be checked for signs of tonality difference.
(b)
Dry the tiles in a ventilating oven at 105oC for 48 hours.
(c)
With the top or glazed surface facing downwards, “pond” the biscuit (ie. back of the tile) with potable water over a circular area of 50mm diameter and with a water height of 25mm. At interval of every 5 minutes, inspect with the naked eye or prescription glasses if usually worn and under sufficient light intensity (> 300 lux), the top or glazed surface for signs of dark patches up to a total “ponding” duration of 30 minutes.
(d)
Repeat the aforementioned test on another five pieces of tiles but using methylene blue solution diluted at 2g of methylene blue per litre.
Performance Criteria The tiles shall not show any sign of dark patches on the top or glazed surfaces.
20.12.5
Schedule Of Colour Glazed Wall Tiles Provide and lay colour glazed wall tiles to locations as specified below including any other areas not specified but as shown in the Drawings. Accommodation 3-Room, 4-Room, 5-Room
BLDG12/S20.DOC(10) Sal(151211) (DPD)
Location ) ) ) )
Kitchen Kitchen/Dining Bath/WC WC
Bldg Spec Page 20-11
20.13
LISTELLO TILE TO BATH/WC OF DWELLING UNITS Where required under the Contract, provide and lay one course of matching Listello tiles to all bath/wc of residential units including other areas as shown in the Drawings. The type of Listello tiles provided by the Contractor shall be subjected to the approval of the SO Rep.
20.14
CERAMIC WALL TILES (NON RESIDENTIAL UNITS AND COMMON AREAS)
20.14.1
General Provide and lay first quality, first choice wall tiles to locations as specified in the subclause “Schedule Of Ceramic Wall Tiles “ hereunder and at other locations as shown in the Drawings.
20.14.2
Testing Requirements (a)
Test Samples And Methods All test samples shall be randomly chosen from the same batch of delivery by the SO Rep. The test methods shall be in accordance with SS 483 : 2000 ( Annex J ) unless otherwise stated.
(b)
Test Certificate And Compliance Requirement Provide test certificates by a testing laboratory accredited under SINGLAS to cover the tests mentioned in this clause and all other tests mentioned in the testing schedule.
20.14.3
Technical Specifications Dimensional and surface quality requirements and physical and chemical properties shall be accordance with SS 483 : 2000 ( Annex J ) unless otherwise stated :(a)
Dimensions Nominal Length Nominal Width Thickness
: 200mm : 200mm : 8mm
The dimensional tolerances shall be as follows :
BLDG12/S20.DOC(11) Sal(151211) (DPD)
(i)
Length
:
Average length of each tile (2 or 4 sides) shall not deviate by more than 0.75% from the average length of 10 test specimens.
(ii)
Width
:
Average width of each tile (2 or 4 sides) shall not deviate by more than 0.75% from the average length of 10 test specimens.
(iii)
Thickness
:
Average thickness of each tile shall not deviate by more than 5% from the average thickness of 10 test specimens.
Bldg Spec Page 20-12 20.14
CERAMIC WALL TILES (NON RESIDENTIAL UNITS AND COMMON AREAS)
20.14.3
Technical Specifications (Cont’d) (b)
(CONT’D)
Surface Quality The tiles shall be free from objectionable surface blemishes such as projections, depressions, flakes, hairline cracks and bubbles. The tiles shall be level and regular in size with properly formed corners and shall not be warped or deformed in any manner.
(c)
Physical Properties The water absorption shall be a maximum of 6%
(d)
Chemical Properties (i)
Colour Fastness And Light-Fastness
:
The tiles shall be light-fast and no colour change shall be detectable after exposure to ultra-violet radiation for 28 days.
(ii)
Reserve Staining Test
:
The procedure for carrying out the test is as follows : (a)
Five full pieces of tiles shall be selected and checked to ensure that there are no Defect or damages. The tiles shall also be checked for signs of tonality difference.
(b)
Dry the tiles in a ventilating oven at 105oC for 48 hours.
(c)
With the top or glazed surface facing downwards, “pond” the biscuit (ie. back of the tile) with potable water over a circular area of 50mm diameter and with a water height of 25mm. At interval of every 5 minutes, inspect with the naked eye or prescription glasses if usually worn and under sufficient light intensity (> 300 lux), the top or glazed surface for signs of dark patches up to a total “ponding” duration of 30 minutes.
(d)
Repeat the aforementioned test on another five pieces of tiles but using methylene blue solution diluted at 2g of methylene blue per litre.
(e)
Performance Criteria The tiles shall not show any sign of dark patches on the top or glazed surfaces.
20.14.4
Colours, Patterns And Textures Provide a full range of colours, patterns and textures of wall tiles for the SO Rep to select from. The SO Rep shall have the absolute prerogative in his selection and no adjustment to the Contract Sum shall be made for difference in colour pattern and texture within each category of tiles.
20.14.5
Accessories Provide and lay all accessories in matching size and colour to the approval of the SO Rep.
BLDG12/S20.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 20-13 20.14
CERAMIC WALL TILES (NON RESIDENTIAL UNITS AND COMMON AREAS)
20.14.6
Schedule Of Ceramic Wall Tiles
(CONT’D)
Provide and lay glazed ceramic wall tiles to locations as specified below including any other areas not specified but as shown in the Drawings. Accommodation
All Housing Blocks
Eating House
Lock-Up Shop, Shop, Market Produce Lock-Up Shop
Mini-Market Restaurant (Family) Market Produce Shop 20.14.7
Location Walls at upper floor lift lobbies Walls at centralised Refuse chute hopper Wash areas at void deck Refuse Chute Chambers Walls in toilet adjoining Utility Room at ground floor lift lobby Refreshment Areas Stalls Toilets/Bath/WC Bin Areas Wash Areas Bath/WC Display Areas Preparation Areas Bin Areas Walls and Columns Toilets Bin Areas Toilets Display Area WC
Tile Spacers
Tile spacers shall be used for laying of wall tiles and floor tiles to achieve consistent joint width. The tile spacers to be used shall be approved by the SO Rep before commencement of the tiling works. 20.15
POLISHED HOMOGENEOUS WALL TILES Provide and lay 300mm x 300mm x 9mm (Nominal Size) polished homogeneous wall tiles to locations as specified below : Accommodation All Housing Blocks
Location Walls of ground floor lift lobbies. Wall enclosures at letter box including low walls defining the ground floor lift lobby.
Provide full range of colours and texture of polished homogeneous wall tiles for the SO Rep to make a selection. The SO Rep shall have absolute prerogative in his selection and no adjustment to the Contract Sum shall be made for differences in colour and texture.
20.16
WORKSHOP DRAWINGS Provide complete sets of workshop drawings showing the laying patterns of ceramic floor tiles and wall tiles in kitchen, kitchen/dining, bath/wc, lift lobby, courtyard and other locations where tiling work are indicated. The workshop drawings shall include plans, elevations, detailed sections and other relevant details required by the SO Rep. These drawings shall be submitted to the SO Rep for approval prior to the laying of ceramic floor tiles, ceramic wall tiles and white glazed wall tiles. The ceramic floor tiles shall be laid with tile joints that coincide with the joints of wall tiles and to the approval of the SO Rep. Section 21/.....
BLDG12/S20.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 21-1 SECTION 21 ELECTRICAL, TELEPHONE AND BROADBAND COAXIAL CABLING INSTALLATIONS
21.1
WORK BY LICENSED ELECTRICIAN All electrical installation Works shall be carried out by a Licensed Electrician (LE) respectively and shall comply with all current Codes-of-Practice, Bye-Laws, Requirements and Regulations of the relevant Authorities.
21.2
Reserved
21.3
OPENINGS/RECESSES FOR METAL TRUNKINGS Further to Clause 4.21 "Openings And Recesses" and subclause 1.1.27 "Contractor's Work In Connection With Subsidiary Contracts", ensure that all these openings are flushed with the ceilings and align with each other and with the building lines. Ensure that the recesses are continuous and on the same plane from floor to floor.
21.4
METAL TRUNKING FOR TELEPHONE AND BROADBAND COAXIAL CABLE SYSTEMS Metal trunking shall be complete with slotted brackets for the fixing of telephone and broadband coaxial cables inside the trunking. Slotted brackets shall be welded to the base of the trunking and shall be three numbers per floor or to the requirements of the Relevant Authorities. Where there are no lead-in pipes to link riser ducts to MDF or TER, the contractor shall provide horizontal metal trunkings. The size of metal trunking to be used shall be in accordance to the latest Code of Practice for Info-Communications Development Facilities (COPIF) in Building issued by InfoCommunications Development Authority (IDA) or as shown in the drawing. Any discrepancy in the drawings with COPIF shall be brought up to the SO Rep for decision. The horizontal metal trunking shall be complete with slotted brackets for the fixing of telephone and broadband coaxial cables inside the trunking. Slotted brackets shall be welded to the base of the horizontal trunking and shall be spaced not more than 300mm centres. The horizontal metal trunking shall have provisions for cabling from lead-in risers to riser ducts with no lead-in pipes and to the requirements of the Relevant Authorities. The horizontal metal trunking shall also be provided to link riser ducts to the MDF or TER for broadband coaxial cabling where required by relevant Authorities. The thickness of mild steel sheet used in the fabrication of trunking shall not be less than those specified hereunder : Nominal Thickness Of Mild Steel Sheet Thickness Of Body Material
Thickness Of Cover Material
1.6mm
1.4mm
Construct metal trunking to the details as shown in the Drawings. All metal trunkings shall have removable covers extending over the entire lengths as shown in the Drawings. The covers shall be fixed to the trunking by means of brass screws or stainless steel or steel screws protected with a finish of zinc coating against corrosion. All welded parts shall be smoothened. All surfaces of the metal trunkings shall be painted with two coats of approved anti-rust undercoat and two finishing coats giving an overall coating thickness of not less than 45 microns. Alternatively, oven-bake powder coating will also be accepted. The colour of the finishing coats shall be Off White to BS 10B15. Each metal trunking shall be protected during delivery and during installation from scratches to the painted surfaces. Submit samples of metal trunkings to the SO Rep for approval before commencing installation. The samples shall be checked to conform to dimensions, material quality, colour and finishing requirements. Approved samples shall be retained as basis of delivery and shall be considered as part of delivery. Unless specified otherwise, all materials, supports, fixings, attachments and other items associated with and necessary for the complete installation, together with all the work involved shall be provided. BLDG12/S21.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 21-2 21.5
MAIN DISTRIBUTION FRAME (MDF) ROOM, TELECOMMUNICATION EQUIPMENT ROOM (TER) FOR OPTICAL FIBRE CABLE INSTALLATION AND TELECOMMUNICATION RISERS All UPVC (SS 272) lead-in pipes to MDF room, Telecom Equipment Room and Telecommunication risers shall be encased in concrete as shown in the Drawings. All bent pipes, straight pipes and trunkings shall comply with the COPIF requirements. All bent pipes, straight pipes and trunkings shall be installed as shown in the Drawings. The number of lead-in pipes to MDF room, TER and Telecommunication riser ducts shall comply with COPIF requirements and/or as shown in the drawings. All pipes terminating inside the Telecommunication riser shall flushed against the wall and rise up to a minimum height of 1.0m.
21.6
AUTHORITIES REQUIRMENTS All provision and installation for telecommunication and broadband coaxial cabling systems shall comply with all statutory rules, regulations and Code of Practice for Info-Communications Facilities in Building (COPIF) issued by Info-Communication Development Authority of Singapore (IDA).
21.7
FACILITY FOR NEXT GENERATION NATIONAL BROADBAND NETWORK (NGNBN) The contractor shall provide the facility to support the NGNBN in accordance to the latest Code of Practice for Info-Communication Facilities (COPIF) in Building issued by Info-Communication Development Authority (IDA) or as shown in the tender drawing. Any discrepancy in the drawings with the COPIF shall be brought up to the SO Rep for decision.
Section 22/.....
BLDG12/S21.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 22-1 SECTION 22 GLAZING
22.1
FIXED AND ADJUSTABLE GLASS LOUVRED VENTS Unless otherwise specified, glass louvre used externally shall be obscured wired rough cast glass of thickness 6mm 0.3mm and housed at least 10mm at each end. Glass blades shall not have clearance at each end exceeding 3mm. All exposed edges of the glass louvre shall be ground mechanically to a consistent smooth finish.
22.2
CLEANING GLASS On completion, clean all glass inside and outside, replace all cracked, broken or defective glass and leave the whole Works in good condition to the satisfaction of the SO Rep.
Section 23/..... BLDG12/S22.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 23-1 SECTION 23 PAINTING AND DECORATING
23.1
GENERAL
23.1.1
Paint The paints used shall be manufactured by an approved Specialist and shall be approved by the SO Rep. All paint shall be delivered to the Site in their original containers and the containers shall not have been opened before. Unless otherwise specified, all paint shall comply with the relevant Singapore Standards shown below and their latest amendments : Standard SS7:1998 SS34:1998 SS37:1998 SS38:1998 SS150:1998 SS345:1990 SS494:2001
Type of Paint "Gloss Enamel Finishing" "Undercoat for Gloss Enamel" "Aluminium Paint" "Aluminium Wood Primer (Leafing and Non-Leafing)" "Emulsion Paint" "Algae Resistant Emulsion Paint for Decorative Purposes" "Lead and Chromate-free Primer"
Before the commencement of any painting work, provide and submit colour charts of approved paint to the SO Rep for the selection of colour scheme. All water based algae resistant emulsion paint shall comply with SS 345:1990. All enamel paint shall be synthetic enamel paint unless otherwise approved by the SO Rep.
23.1.2
Mixing Of Paint During the progress of work, the SO Rep may at his discretion obtain samples of paint being used on site for testing. Should paint used in this Contract be found to be adulterated or over-diluted, the SO Rep shall exercise its rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. In addition, all such paint shall be removed from the Site and replace the same with paints that meet the prescribed standards. All work executed with paint which fails to meet the prescribed standards shall be burnt off or otherwise removed and the work shall be re-executed at the Contractor's own cost and expense to the satisfaction of the SO Rep.
23.1.3
Workmanship Unless otherwise specified, all paints shall be applied in accordance with the Manufacturer's recommendations and instructions. All paints for priming coats, undercoats and finishing coats used for the work shall be of the same brand and from the same manufacturer. Where available, undercoats shall be of different shades to correspond with the shade of the finishing coat. Provide sample panels of paintwork showing the shade of the respective coats. All external paintwork shall be executed under dry condition and the surface to be painted shall be dry before the paint is applied. The whole of the interior and exterior surfaces of the building including the ceilings and soffits shall be cleaned down thoroughly and all cracks and blemishes made good prior to the commencement of the painting work. After the completion of each coat of painting work, the SO Rep shall be notified before the application of the next coat.
BLDG12/S23.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 23-2 23.2
EXTERNAL PAINTING
23.2.1
Over-Riding Clause The Contractor and his Specialist executing the Works as required in this clause including all sub-clauses under it have to ensure that the Works, goods or materials used shall be suitable and reasonably fit for the purposes for which they are required (hereinafter referred to as "Performance Requirement"). In the event the Works, goods or materials to be used as specified in this clause including all sub-clauses under it are upgraded in order to meet the Performance Requirement, the Contractor and his Specialist shall do all necessary upgrading at no extra cost to the Employer, subject always to the approval of the SO Rep, but such approval shall not in any way affect the Contractor's and his Specialist's duties or obligations arising under the Contract.
23.2.2
Water Based Algae Resistant Emulsion Paint (a)
Type And Location The water based algae resistant paint shall comply with SS345:1990 and shall be PSB Marked. Unless otherwise specified, all colours of paint to be used shall be approved by the SO Rep. and to comply with BS 4800:1972 "Paint Colour for Building Purposes". Unless otherwise specified or instructed by the SO Rep, all plastered, skim coated and concrete surfaces of all exterior surfaces of the external walls which are subject to weathering including walls, ceilings and other surfaces of the ground floor void decks shall be finished with one coat of water based sealer and two coats of water based algae resistant emulsion paint. Sealer coat and two coats of water based algae resistant emulsion paint shall not be diluted. The whole paint system shall be obtained from the same paint manufacturer. Allow for different colour tones for all undercoats to distinguish the different coatings. Should the finished paintwork be found to be unsatisfactory, ie. brushy work, unevenness in applications, original stains, etc., repaint the same with additional coat or coats to the satisfaction of the SO Rep. External painting to parapet walls, refuse chutes, columns and beams shall cover up to and including returned surfaces. External painting to exterior surfaces of external walls shall cover up to and including returned surfaces stopping at a convenient point to be directed by the SO Rep.
(b)
External Painting To Electrical Sub-Station/Utilities Centre/Dustbin Compound For electrical sub-station/utilities centre/dustbin compound, the external painting works shall be executed with three coats of water based algae resistant emulsion paint.
(c)
Touch-Up Coat Painted surfaces which have to be overcoated by touch-up work should not be confined to the affected spots only. The whole panel of the wall or area affected by touch-up shall be repainted to match the colour tone of the finished coat.
(d)
Painting Of Sample Units At the appropriate time prepare the exterior of one or more typical flat unit for each type of flats to receive the paint and inform the SO Rep to select his colour scheme. Paint the sample units, changing colours as directed, until the SO Rep is satisfied with the workmanship and/or colour scheme.
BLDG12/S23.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 23-3 23.2
EXTERNAL PAINTING (CONT'D)
23.2.2
Water Based Algae Resistant Emulsion Paint (Cont'd) (e)
Warranty The Contractor and his Specialist shall warrant the Works on the terms and conditions as stipulated in the Deed of Warranty For External Painting as produced in Appendix A5. In this respect, the Contractor and his Specialist shall submit such Deed of Warranty to the Employer or to such other party or such Town Council(s) as the SO Rep may at its sole discretion decide. In the event the Deed of Warranty for part of the Works or for the whole Works is to be submitted to such Town Council(s), the Contractor and his Specialist shall submit such Deed of Warranty as produced in Appendix A5(TC) to such Town Council(s). The duly executed Warranty shall be submitted immediately upon request by the SO Rep, and if no such request is made, then at such time when the SO Rep considers the Works have been substantially completed in accordance with the Contract. In the event the Contractor and his Specialist shall fail to execute and submit the Deed of Warranty within the time specified, the SO Rep shall be allowed to withhold 15% of the payment of any sums due to the Contractor in relation to the execution of such Works, subject to the minimum sum of S$5,000/- per Deed of Warranty. However, such sums withheld shall be released to the Contractor upon submission by him of the duly executed Deed of Warranty.
23.2.3
Acrylic Emulsion Paints Unless otherwise specified, all external plastered, skim coated and concrete surfaces, except those subjected directly to weathering as mentioned earlier, shall be painted with one coat of water based sealer and two subsequent coats of approved acrylic emulsion paint. Sealer coat and two coats of acrylic emulsion paint shall not be diluted. The whole paint system shall be obtained from the same paint manufacturer. External surfaces to be painted with acrylic emulsion paint shall include all surfaces except those within the enclosing walls of the dwelling units, switch rooms, motor rooms, pump rooms, water tank compartment and other enclosed spaces. However, walls and ceilings of the private balcony and/or service balcony of dwelling units and common access corridors shall be considered as external surfaces to be painted with acrylic emulsion paint. Technical specification for the water-based sealer:
Test Method
Properties/ Performance
Requirement
1
Colour
-
White or light grey
2
Non-volatile matter
SS 5 :Part B2
3
Through-dry time
ISO 9117 75±10µm wet film thickness
Min 35% by weight of paint Max 4 hours
4
Opacity (contract ratio)
SS 5:Part E2
Min 70%
5
Lead content
SS 5:Part C6
Max 0.01%by weight of dried paint film
6
Coating adhesion
ASTM D3359 Method A (X-cut) One coat of sealer of 75±10µm wet film thickness and two coats of SS 345 paint at 75±10µm wet film thickness per coat on grade 40 concrete
Coating shall achieve a rating of at least 4A
BLDG12/S23.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 23-4 23.2
EXTERNAL PAINTING (CONT'D)
23.2.3
Acrylic Emulsion Paints (Cont'd) Technical specification for the water-based sealer: (Cont'd)
7
23.3
Properties/ Performance Alkaline resistance
Test Method
Requirement
SS 5: Part G2 0.1 M NaOH solution for 1 hour
Coating shall show no blistering, wrinkling or lifting when examined immediately, and after 30 minutes recovery
8
Water permeability, 14 days
SS 500 Appendix B 75±10µm wet film thickness
Coating shall display no yellowing, blistering, sweating or disintegration of paint
9
Water immersion resistance, 500 hours
ISO 2812-2 One coat of sealer of 75±10µm wet film thickness and two coats of SS 345 paint at 75±10µm wet film thickness per coat on cement panel. Remaining surface coated with epoxy paint.
Coating shall show no blistering, wrinkling or lifting
PAINTING OF INTERNAL SURFACES (a)
Internal Surfaces Of Dwelling Units Unless otherwise specified or instructed by the SO Rep, all plastered, skim coated and concrete surfaces of internal walls and ceilings of dwelling units shall be painted with two coats of approved white emulsion paint. The first coat may be with thinning of up to 20% of clean water by volume. The second coat shall not be diluted. The method of painting for these two coats, with the exception of the two coats for the ceilings of the toilets and kitchens, shall be by means of an appropriate portable airless spraying equipment as approved by the SO Rep. No compressed air shall be used to assist the spraying. The two coats for the ceilings of the toilets and kitchens may be painted by using rollers.
(b)
Other Internal Surfaces Unless otherwise specified, all plastered, skim coated and concrete surfaces of internal walls and ceilings of shops, shoplets, eating houses, living quarters, switch rooms, lift motor rooms, pump rooms, water tank compartments, stores, MDF rooms, electrical substations and areas other than dwelling units shall be painted with three coats of approved emulsion paint. The first coat may be with thinning of up to 20% of clean water by volume. The second and third coats shall not be diluted.
(c)
BLDG12/S23.DOC(4) Sal(151211) (DPD)
The emulsion paint shall be of those qualities approved by the SO Rep.
Bldg Spec Page 23-5 23.4
PAINTING OF WOODWORK
23.4.1
Preparation All joinery and finished woodwork shall be properly cleaned down, knotted, stopped, sand-papered smooth and primed. Two coats of wood preservative shall be applied to the back of doors frames and window frames and other woodwork abutting masonry work. The wood preservative shall be "Solignum", "Creosote" or other approved.
23.4.2
Painting Unless otherwise specified, surfaces of all woodwork shall be prepared and painted with one priming coat, one undercoat and one finishing coat of approved enamel paint.
23.4.3
Wood Varnish To Main Entrance Doors Varnish coatings on fire-rated and non fire-rated main entrance doors shall be finished off-site under a factory environment with a minimum of three coats of clear varnish, in semi-gloss finish or other approved finish. The varnish finish shall be approved by the SO Rep. The door with completed varnish shall comply with the requirements as follow :
23.4.4
Performance Accelerated Weathering :SS5: Part G4
Requirements Max 35% Gloss Loss
(400 hours)
No de-lamination, blistering or other defects
Surface Preparation All pin holes and recesses on the main entrance door and bedroom door surfaces shall be filled and stopped with putty. The door surfaces shall be properly sanded smooth by mechanical means and cleaned prior to the application of wood varnish.
23.4.5
Wood Varnish The main entrance door and bedroom door surfaces shall be finished off-site under a factory environment with a minimum of three coats of clear varnish, in semi-gloss finish or other approved finish. The varnish shall be approved by the SO Rep. The varnish shall comply with the requirements as specified hereunder :
Substrate
Application Method/Film Thickness
SS 5 Part B4:1987
NA
NA
b) Keeping qualities
SS 5 Part B6:1987
NA
NA
c) Fineness of grind
SS 5 Part B13:1987
NA
NA
d) Dry film thickness
SS 5 Part B1:1985 (Method 5)
Test Varnish Only a) Condition in container
BLDG12/S23.DOC(5) Sal(151211) (DPD)
Test Method
Burnished tinplate
3 coats by brush
Requirements
No coagulation, precipitation, or separation of components, free from foreign particles ; No coagulation, precipitation, or separation of components, free from foreign particles ; Maximum 30 microns ; Minimum 50 microns ;
Bldg Spec Page 23-6 23.4.5
Wood Varnish (Cont’d)
Test
Test Method
Substrate
Application Method/Film Thickness
Requirements
Varnish Only (Cont’d) e) Surface drying time
SS 5 Part D2:1985
Burnished tinplate
Metered bar/ wft 50 microns
2 hrs maximum;
f)
ISO 9117:1990
Burnished tinplate
Metered bar/ wft 50 microns
6 hrs maximum;
g) Gloss at 60 deg.
SS 5 Part E1:1985
Glass plate
Metered bar/ wft 50 microns
25 - 50 gloss units;
h) Flash point
SS Part B15:1987
i)
Washability
SS 5 Part F5:1992
Burnished Glass
Metered bar/ wft 80 microns
3000 cycles with no wear-off
j)
Scratch Resistance
SS 5 Part F2:1988
Burnished tinplate
Metered bar/ dft 25 microns
Minimum 1000g
k) Accelerated weathering (500 hrs dry cycle)
SS 5 Part G4:1992
Burnished tinplate
Metered bar/ dft 25 microns
Maximum gloss loss 30%
l)
SS 150 Appendix C
NA
NA
No growth
Through dry time
Mildew resistance
23.4.6
Reserved
23.4.7
Reserved
BLDG12/S23.DOC(6) Sal(151211) (DPD)
NA
NA
23C minimum
Bldg Spec Page 23-7 23.5
PAINTING OF FERROUS METAL WORK
23.5.1
Preparation Of Surface Remove all dust, rust, scale, grease and oil before painting.
23.5.2
Painting Unless otherwise specified, paint all exposed metal surfaces with one coat of lead and chromate-free primer, one undercoat and one finishing coat of approved enamel paint. Primer to mild steel door frame shall be approved cathodic electrodeposition primer. Unless otherwise specified, paint all metal surfaces in contact with or embedded in concrete, masonry work, etc, except for concrete reinforcement, with one coat of lead and chromate-free primer. Paint stainless steel, brass and aluminium Works only if specified.
23.6
PAINTING OF PIPES Allow for the painting of all sanitary, water and gas installation pipes, rainwater downpipes, balcony waste discharge stacks and all services pipes including water supply pipes (except for stainless steel pipes and pipes in the water tank compartment). Unless specified otherwise, the colour shall match with the general background colour tone of the building to the satisfaction of the SO Rep. Paint pipes and trunking as specified hereunder and including other types of pipes and trunking not so specified but as shown in the Drawings. Type Of Pipe / Trunking
Paint Coat Required
UPVC pipes and fittings
Two coats of enamel paint unless specified otherwise. However, those within trunking, stacks/ceiling and service ducts need not be painted)
UPVC trunking for electrical wiring, water and gas pipes outside residential units
Two coats of acrylic emulsion paint to match the general background colour tone. However, those within service ducts need not be painted
Galvanised steel pipes and fittings
First coat Second coat Third coat Fourth coat
Ductile iron pipes and fittings including supports
Two coats of lead and chromate-free primer followed by two coats of enamel paint.
Ductile iron pipes and fittings for water distribution mains including supports on roof level
Two coats of approved ceramic insulation coating.
Copper gas pipes including fittings
Two coats of white enamel paint or other colour to match the background as instructed by the SO Rep.
Stainless steel, copper and brass pipes
No painting required unless specified otherwise.
BLDG12/S23.DOC(7) Sal(151211) (DPD)
-
one coat of polyvinyl butyral etching primer; one coat of lead and chromate-free primer; one coat of undercoat for enamel paint; one finishing coat of enamel paint.
Bldg Spec Page 23-8 23.7
PAINTING TO EXTERNAL REINFORCED CONCRETE SLOPING ROOF OF CENTRAL REFUSE CHUTE CHAMBER The external reinforced concrete sloping roof of the central refuse chute chamber shall be painted with water based algae resistant emulsion paint in accordance with Clause 23.2 "External Painting" including all subclauses under it.
23.8
DISPOSAL OF SPENT PAINT The Contractor shall ensure that all spent paint and waste water from the washing of paint brushes/instruments are properly disposed off. The disposal of spent paint and waste water/waste solvent shall be in accordance with MEWR guidelines. The Contractor shall provide the necessary 220-litre drums and engage a licensed industrial toxic waste collector to collect the drums for proper disposal. The Contractor shall put up a consignment note to the Pollution Control Department.
23.8.1
Solvent Based Enamel Paint All spent paint and waste solvent (generated from washing) shall be collected in 220-litre drums. There shall be no discharge of spent paint and/or waste solvent/waste water (generated from washing) into the sewerage system. The drums shall be in good and sound conditions so that they can be transported safely for proper disposal by the licensed industrial toxic waste collector. The drums shall be properly labelled and stored within a curbed area to prevent spillage. The drums shall be covered to prevent fire hazard and smell nuisance.
23.8.2
Water Based Emulsion Paint All spent paint and waste water (generated from washing) shall be collected in 220-litre drums. There shall be no discharge of the spent paint and/or waste water (generated from washing) into the sewerage system. The drums shall be in good and sound conditions so that they can be transported safely for proper disposal by the licensed toxic industrial waste collector. The drums shall be properly labelled and stored within a curbed area to prevent spillage.
23.9
SCAFFOLDING Provide and erect scaffolding over all faces of the building blocks for the application of paint. Scaffolding shall not be removed until the painted surfaces are inspected by the SO Rep and until the test results of the paint samples taken out for testing are known.
23.10
CLEARING UP ON COMPLETION All areas stained by paint including but not limited to floors, staircases, aprons and public areas and drains shall be thoroughly washed and removed upon completion of the Works before handing over to the Employer. All debris and superfluous materials shall be cleared away.
Section 24/.....
BLDG12/S23.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 24-1 SECTION 24 UNDERGROUND PIPE SYSTEM FOR LOW TENSION RETICULATION CABLE, TELECOMMUNICATION AND BROADBAND COAXIAL CABLE
24.1
LOW TENSION RETICULATION PIPE SYSTEM The Contractor shall provide and install underground pipe system for Low Tension (LT) reticulation cables as shown in the Drawings.
24.1.1
Unplasticised Polyvinyl Chloride (UPVC) Pipes
24.1.1.1
Materials All UPVC pipes shall be Class B in accordance with SS 141:1976. The material from which the pipe is produced shall be unplasticised polyvinyl chloride (UPVC) to which shall be added suitable lubricants, pigments, stabilizers and pastes. These additives shall not constitute a toxic hazard and shall not impair its chemical and physical properties. The UPVC pipes shall be grey in colour and shall have a socket at one end. The pipe wall shall be homogenous throughout and the internal and external surfaces shall be clean, smooth and reasonably free from grooves, blisters, dents and heat marks. The ends shall be clearly cut and square with the axis of the pipe.
24.1.1.2
Dimensions The dimensions of the UPVC pipes and plug shall be as shown in the Drawings for underground piping system.
24.1.2
Pipe Installation (a)
General The pipeline shall be straight and level where possible. In case a straight run is not possible the radius of curvature shall be determined on the Site by the SO Rep.
(b)
Gradient Of UPVC Pipes Under-Crossing Other Services Unless otherwise specified or shown in the Drawings or directed by the SO Rep on the Site, the gradient of UPVC pipes under-crossing other services shall be : Pipe Size 155mm
(c)
Gradient 1:12
Preparation Of Bottom Of Trench A layer of 150mm thick hardcore bed well blinded with granite dust shall be provided to areas that have muddy, clay or soft soil. The hardcore shall consist essentially of crusher run/stones blinded with sufficient blinding material to aid consolidation.
(d)
Flared-Mouth Pipes Flared-mouth pipes shall be used for entry into draw pit or for pipes which terminate directly in the ground. All the ends of flared-mouth pipes shall be sealed with end plugs to prevent entry of earth or cement.
BLDG12/S24.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 24-2 24.1.2
Pipe Installation (Cont'd) (e)
Construction Method The first layer of concrete with A6 welded steel mesh shall be placed to the required thickness on the prepared trench bottom. The bottom layer of pipes shall be laid using spacers at 1.5m intervals to maintain the spacing between pipes. Ensure that a minimum gap sufficient for the specified concrete thickness remains between the outside of pipes and the side of trench or trench shuttering where used. The next layer of concrete shall then be placed to the prescribed thickness before the second layer of pipes are laid. The final layer of concrete shall be reinforced with A6 welded steel mesh. The concrete shall be evenly placed around the duct and each batch, as it is placed, shall be properly compacted without creating unbalanced side thrust against the pipe. The final layer of the concrete shall be thoroughly trowelled. PVC cover plates shall be anchored on the final layer of concrete. Ready mixed concrete shall be used. However, if the concrete required is less than 2 m3, hand mix concrete is allowed. Mechanical vibrator shall be used to ensure that the gaps between pipes are filled with concrete.
(f)
Rapid Hardening Cement When pipes are laid in conditions where backfilling is required to be carried out immediately, an approved type of rapid hardening cement additive compound shall be used with the concrete.
(g)
Nylon Ropes in Pipes A nylon/polyethylene rope (minimum diameter 7mm) acceptable by the SO Rep shall be provided in each pipe to facilitate cable pulling after pipe testing.
(h)
Protection of Cables During the boring of pipe entries into existing structures, or during the demolition and rebuilding of the joint hole, the Contractor shall take such measures as directed by the SO Rep to protect the cables. Such measures may include the following :
(i)
(i)
Any movement of existing cable shall be carried out under the direction of the SO Rep.
(ii)
Cables shall be protected against mechanical damage at pipe entries and inside joint hole by packing them with sandbags to act as a cushion when any movement occurs.
Pipe Testing On completion of pipe laying (including compaction and backfilling) between any two joint holes or more, a cylindrical brush and a mandrel as shown in the Drawings shall be passed through each pipe in both directions to test the pipe and to remove any foreign matter which may have entered. The cylindrical brush and mandrel shall be supplied by the Contractor. The mandrel shall follow the brush to minimise possible scouring or breaking of the pipes. The testing shall be carried out under the direction of the SO Rep before the section of pipes are accepted.
BLDG12/S24.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 24-3 24.1.3
PVC Cover Plates
24.1.3.1
Materials All cable cover plates shall be of standard lengths of 1.0 m. Each cover plate shall be nominal 172.4mm in width and 2.0mm in thickness. The length and breadth may have a tolerance of 5 mm. The cable cover plates shall be made of high impact resistance polyvinyl chloride without plasticizer (UPVC). Use of regenerated PVC, or Polyethylene or PP is strictly forbidden. Each cable cover plate shall be linked to the adjacent cover plates at both ends to form a continuous chain. The colour of the plate shall be black in accordance with BS 381c colour code and shall remain permanent and non-fading. The materials and the colour of the cable cover plates shall be resistant to chemical influences likely to be encountered when buried in the ground. The cable cover plates shall be designed, manufactured and tested in accordance with the latest revision of the following standards or their equivalent :
(a) (b) (c) (d) 24.1.3.2
Description Impact Test Tensile Strength Vicat Softening Temperature Accelerated Ageing
Standard Clause 7.3 of E6530 (Austrian Standard) Clause 7.4 of E6530 (Austrian Standard) ASTM D1525 ASTM D3045
Requirements The PVC cover plates shall have the following properties : (a)
Three fully processed specimens tested for their impact strength shall not have more than 3 cracks respectively (5 drop hammer tests per specimen). The drop hammer shall not penetrate the specimens more than 100mm for more than 3 times in a series of 15 drop hammer tests. If these requirements are not met, the same test series are repeated on the specimens from the same lot. Should the specimens tested in the second series of tests also fail to meet the requirements, the whole test is deemed to have failed.
(b)
The longitudinal connections (linking mechanism) of the fully processed specimens shall withstand a tensile strength of minimum 100 newtons.
(c)
The Vicat softening temperature of the fully processed samples shall not be less than 72°C (Rate A at 50°C 5°C per hour).
(d)
The fully processed specimens shall be aged at 70°C for 168 hours. Aged specimens shall also be tested for their tensile strength in the longitudinal connections. The change in properties shall be less than 25% of the original value.
The cable cover plates shall be type tested by PSB or an SAC accredited laboratory in accordance with the above requirements. 24.1.3.3
Installation of UPVC Cable Cover Plates The cable cover plates shall be laid end to end directly over the pipes as shown in the Drawings. Ensure that the cable cover plates are properly secured together.
24.1.4
Markers For Draw Pit On completion (including backfilling, compacting and turfing) of the draw pits which are not located within the road, approved markers as shown in the Drawings shall be installed to indicate the corners of the draw pit. For draw pits which are located within the road, such markers need not be provided.
BLDG12/S24.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 24-4 24.1.5
Backfilling For Underground Pipe System All trenches excavated for the provision of underground pipe system for Low Tension (LT) reticulation cables shall be backfilled as follows :
24.1.6
(a)
For trenches which are located within the road, backfill from the completed pipe level to the subgrade of the road with granular materials such as sand/granite fines or quarry dust.
(b)
For trenches which are not located within the road, backfill to the level required under the Contract with good dry earth approved by the SO Rep.
Energisation Of Electrical Sub-Station By PowerGrid The Contractor shall expedite and complete all underground pipe system work timely to facilitate the laying of all necessary reticulation cables by PowerGrid or other utilities Services Provider within the Site boundary. The electrical sub-station is targeted to be energised by the Services Provider at least 12 weeks before the date of Substantial Completion of the first building block in the Works or otherwise advised by the SO Rep. The Contractor shall incorporate such work arrangement requirements in the programme for the Works or revised programme for the Works, submitted under the Contract. All costs and expenses incurred for complying with the provisions of this subclause shall be deemed to be included in the Contract Sum.
24.2
TELECOMMUNICATION PIPE AND BROADBAND COAXIAL CABLE SYSTEM The Contractor shall provide and install underground pipe system for telecommunication and Broadband coaxial cables as shown in the tender Drawings. The installation of Telecommunication and Broadband Coaxial Cable Pipe System shall comply with all statutory rules and regulations, and in accordance to the latest Code of Practice for Info-Communications Facilities in Buildings (COPIF).
24.2.1
Unplasticised Polyvinyl Chloride (UPVC) Pipes
24.2.1.1
Materials All UPVC pipes shall comply with all requirements as specified in SS.272; 1983 The material to produce the pipes shall be unplasticised polyvinyl chloride (UPVC). When joining pipes, suitable lubricants, pigments, stabilizers and pastes shall be used. These additives shall not constitute a toxic hazard to the environment and shall not change in its chemical and physical properties. The UPVC pipes shall not be darker than the grey colour and shall have a socket at one end. Each length of pipe shall be clearly, indelibly and continuously marked at intervals of not more than 1.0m using a distinctive colour with the description of Manufacturer’s identification/110mm UPVC pipe/Date/Month/Year/SS272. The pipe wall shall be homogenous throughout and the internal and external surfaces shall be clean, smooth and reasonably free from grooves, blisters, dents and heat marks. The ends shall be clearly cut and square with the axis of the pipe.
BLDG12/S24.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 24-5 24.2.2
110mm Nominal Diameter UPVC Pipe Installation
24.2.2.1
Dimensions Of 110mm Nominal Diameter UPVC Pipe The dimensions of the UPVC pipes and coupling for the underground piping system shall be as shown hereunder :
Item
Pipe
Coupling
24.2.2.2
Length
Max Wall Thickness
Min Wall Thickness
Max External Diameter
Min External Diameter
Internal Diameter at the Edges
Internal Diameter at the Center
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
6000+50 -0
3.6
3.2
110.4
110
-
-
180 ±2
3.6
3.2
-
-
110.5+0.2 -0
110+0 - 0.2
General (a)
All pipelines are to over-cross sewer lines.
(b)
The crowns of all pipelines are to be laid at least 600mm below the invert level of Civil Engineering drains.
(c)
No pipe is to be cast in the base or wall of the drains.
(d)
The pipeline shall be straight and level where possible. Where a straight run is not possible, the radius of curvature shall be determined by the SO Rep.
(e)
All rectification Works instructed by the SO Rep to meet all requirements shall be carried out at the Contractor’s cost and expense.
(f)
The following items shall be submitted to the SO Rep for verification of tests conducted on the Manholes and Pipelines : (i) (ii) (iii)
Completion Certificate Summary of Manhole and Pipeline Length Pipe Testing Report/Manhole Survey Record
The Contractor shall assist the SO Rep in all verification work to ensure all tests are properly conducted. The Contractor shall perform more tests if the SO Rep deemed necessary all at the Contractor's cost and expense. (g)
24.2.2.3
Upon completion of the pipe laying works, the Contractor shall submit As-Built drawings of the project site to the SO Rep, in addition to the items listed in subclause 24.2.2.2(f) above.
Gradient Of UPVC Pipes Under-Crossing Other Services Unless otherwise specified or shown in the Drawings or directed by the SO Rep on the Site, the gradient of UPVC pipes under-crossing other services shall be : Pipe Size 110mm
BLDG12/S24.DOC(5) Sal(151211) (DPD)
Gradient 1: 6
Bldg Spec Page 24-6 24.2.2
110mm Nominal Diameter UPVC Pipe Installation (Cont’d)
24.2.2.4
Preparation Of Bottom Trench The trench shall be excavated to the required width and depth; the bottom of the trench shall be free from stone, levelled and well punned. The pipe shall be laid at the depth specified to the details shown in the COPIF unless otherwise specified. A layer of 150mm thick hardcore bed well blinded with granite dust shall be provided to areas that have muddy, clay or soft soil. The hardcore shall consist essentially of crusher run/stones blinded with sufficient blinding material to aid consolidation.
24.2.2.5
Flare-Mouth Pipes And Coupling Flare-Mouth UPVC pipes shall be used for entry into manhole wall unless otherwise specified. The outer surface of the pipe shall be roughened with glass paper or sandpaper and a coat of solvent cement applied for its length in the manhole wall. All the ends of flared-mouth pipes shall be sealed with end plugs to prevent entry of earth or cement.
24.2.2.6
Construction Method (a)
Where UPVC of less than 16-Ways are to be laid, they shall be encased in Grade 20 concrete to a minimum thickness of 50mm as shown to the details in the COPIF.
(b)
Where UPVC are to be laid in multiple formation, polypropylene spacers shall be used at a maximum spacing of 1.5m apart to allow clearance between adjacent pipes.
(c)
The starting end of the pipe shall be blanked off with a board or boards to prevent foreign objects from entering the pipes. When joining multiple pipes, all pipe ends and the interior of the collar shall be thoroughly cleaned with a dry rag followed by a liberal coating of solvent cement. The collar shall then be pushed into the first pipe by hand. A suitable wooden batten is then placed across the remote end of the collar and tapped with a hammer until it is engaged midway. The next length of pipe shall then be engaged to the collar and similarly tapped until fully engaged.
(d)
The first layer of concrete shall be placed to the required thickness on the prepared trench bottom. The bottom layer of the pipes shall then be laid (using the spacer to maintain the spacing between pipes where applicable) such that a minimum gap, sufficient for the specified concrete thickness, remains between the outside pipes and the side of the trench or trench shuttering where used. The next layer of concrete shall then be placed to the prescribed thickness before the second layer of pipes are laid. This process shall be continued until the final layer of concrete is laid to the specified thickness. The concrete shall be evenly placed around the duct and each batch, as it is placed, shall be properly compacted without creating unbalanced side thrust against the pipe. Where ready mix concrete is used, the placing of concrete up to three layers of pipe in a single batch is allowed, provided 12mm size diameter vibrators are used to consolidate the concrete filling the spaces between the pipes. For pipeline encased with 100mm thick concrete, each batch shall be well compacted and worked around the pipe and vibrated using a vibrator. The space between the pipes shall be properly tamped with a 12mm diameter rod to ensure that the concrete is properly filled. The final layer of concrete shall be thoroughly trowelled.
(e)
When pipes are laid under conditions where backfilling is required to be carried out immediately, approved type of rapid hardening cement additive compound shall be used with the concrete.
(f)
All spaces alongside the pipe shall be filled with stone free earth and hand punned to a compacted thickness of not less than 100mm above the top of the pipe barrel.
(g)
Where the pipe is recessed into the wall of the manhole, the outside surface of the pipe shall be roughened with glass paper or sandpaper and a coat of solvent cement applied for its length in the manhole wall.
(h)
Pipes shall be laid at a minimum depth of 1.2m below the final ground level or as otherwise directed.
BLDG12/S24.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 24-7 24.2.2
110mm Nominal Diameter UPVC Pipe Installation (Cont'd)
24.2.2.6
Construction Method (Cont'd)
24.2.3
(i)
Pipes shall be in straight run. When bending is unavoidable, the bend shall be gradual and smooth. No ‘S’ bend is allowed.
(j)
A 90 degree upturn when changing from a horizontal to a vertical plane shall be done with approved type factory made bend pipe. The pipe shall be clipped and flushed against the wall and shall rise to a height of 1.0m above ground level unless otherwise directed.
(k)
A nylon/polyethylene rope shall be provided in each pipe to facilitate cable pulling after pipe testing and this shall be drawn in together with the proposed cable. The rope shall be of 4-core or multistrand type with overall diameter of 6.0mm in coil of 200m. In all lead-in pipes, the rope shall extend to the first manhole to allow pulling of cables in the manhole.
Standard Manholes (a)
The details of the standard manholes are shown in the COPIF. The presence of unforeseen obstructions in the ground, or adverse ground conditions, may necessitate the construction of a type other than that specified, or a modification of one or more of the dimensions stipulated in the COPIF. The SO Rep shall advise the Contractor of any modifications required. The Contractor shall not carry out any modification without the approval of the SO Rep.
(b)
Before any concrete is placed : (i)
The bottom of the excavation must be properly levelled and consolidated.
(ii)
The bottom shall be kept dry by providing a sump hole as shown in the COPIF to accommodate a water pump, and a layer of 150mm thick hardcore material shall be provided where necessary.
(c)
Pipes shall be cast in situ as construction of manhole proceeds. Pipe ends shall be trimmed and entries made clear of raw edges which may damage cables, if flared mouth pipe is not used.
(d)
Pipes shall enter the manholes in the manner as shown in the Drawings or as directed by the SO Rep. The pipes shall enter the manholes at such depths as to ensure a minimum clearance of 350mm from the roof and base and 150mm from the walls at the sides unless otherwise specified.
350mm 150mm
150mm 350mm
(e)
BLDG12/S24.DOC(7) Sal(151211) (DPD)
Rawl plugs, channel brackets and anchor irons and earth rods shall be fixed in the manhole as shown in the COPIF or in such other positions as determined by the SO Rep.
Bldg Spec Page 24-8 24.2.3
Standard Manholes (Cont'd) (f)
Manholes shall be constructed at a depth to allow a 230mm thick grade 30 concrete shaft wall with the following height (measured from the roof to the top of the cover) as shown : Manhole Code JX 2 MX 1 and MX 2 MX 3 and MX 4
Height (mm) 250 shown in the details in the COPIF 400 shown in the details in the COPIF 1200mm with single layer of steel fabric reinforcement shown in the details in the COPIF
Where X = C denotes that heavy-duty manhole frame and cover shall be used. Where X = F denotes that medium duty manhole frame and cover shall be used. Concrete for filling the recess of the frame and cover shall be of grade 30 concrete and shall be flushed with the top of the cover. For heavy duty without frame and cover, the concrete shall be filled up to the ribs without covering the ribs.
24.2.4
(g)
Manhole walls shall be fair faced and not rendered. All projections shall be removed and cavities filled with cement mortar. The walls shall not be coated with cement or cement sand wash.
(h)
The floor shall be given a 20mm rendering of cement mortar with a fall towards the sumphole from all directions.
(i)
Only approved formwork shall be used in manhole construction.
(j)
Manholes or other structures shall be located outside the Drainage Reserve and at a minimum clear distance of 1m from the wall of an existing culvert, or 2.5m from the boundaries of the Drainage Reserve.
(k)
Manholes should be located within the turfed area where feasible. The top level of the manholes should match the final road level or the surrounding ground level as decided by the SO Rep.
(l)
The position of the manholes and pipelines should not conflict with the drains, sewer lines, sewer manholes, electrical pipelines and draw pits.
(m)
Completed manholes shall be pumped clear of water and made ready for the SO Rep to inspect.
Manhole Frame & Cover (a)
Manhole frame and cover shall be obtained from suppliers who have obtained certifications from the PSB or other accredited product certification bodies that these items comply with SS 30 Grade A1 or Grade B for heavy duty or medium duty respectively. The manhole cover shall not bear the name of any licensees.
(b)
Medium duty frame and cover shall be fixed onto manhole constructed within turf or footpath areas.
(c)
Heavy-duty frame and cover shall be fixed onto manhole constructed within carriageway or car park.
(d)
Voids in the frame and cover of heavy-duty type are to be filled with grade 30 concrete, well tamped, levelled off, and cured before use.
(e)
The manhole frame and cover shall be placed on top of manhole shaft, with a minimum width of 150mm and a minimum depth of 150mm and grade 30 concrete haunching all round the frame. The frame and cover shall be fixed in such a manner as to be level with the surrounding area.
(f)
Manhole covers near to building edges or road edges shall be aligned with these edges.
BLDG12/S24.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 24-9 24.2.5
Pipe, Manhole And Trench Testing Upon completion of pipe laying works, the Contractor shall make arrangements with Public Telecommunication Licensees (PTL) / Telecommunication System Licensees (TSL) through the Telecommunication Facility Co-ordination Committee (TFCC) to have the pipe tested in accordance with the following procedures.
24.2.5.1
24.2.5.2
Pipe Testing Of 110mm Nominal Diameter UPVC Pipe Between Manholes (a)
On completion of the pipe laying (including compaction of the backfill) between any two manholes or sites thereof, a cylindrical brush and standard Mandrel (see details in the COPIF) or a Quad No.5 cable of minimum 2m length shall be passed through each bore in both directions to test the pipe and to remove any foreign matter which may have entered. The Contractor shall provide the test mandrel and brush. The mandrel shall follow the brush to minimize possible scouring or breaking of the pipe. The testing shall be carried out under the direction of the SO Rep before the section of pipes is accepted.
(b)
When the building of manhole(s) is/are deferred until after the completion of a section of pipe included in the Works, the last 2m of each bore shall be tested. The SO Rep shall first make a visual check with the aid of a torchlight or similar means of illumination. Any foreign matter shall be removed from the pipe.
(c)
The Contractor shall test and install draw-wires or nylon ropes in all newly laid pipes including one way pipe. (nylon/polyethylene rope of 4-core or multi-strand type with overall diameter of 6.0mm in coil of 200m).
(d)
Testing of encasement of the pipe shall be subjected to approval by the SO Rep.
Manhole Testing (a)
Cube Test When instructed by the SO Rep, the Contractor shall furnish the required numbers of 100mm cubes of concrete for manhole construction to be prepared and tested for its compressive strength in accordance with SS 78:1972. A minimum of one such test shall be conducted per ten manholes. The minimum works cube strength of concrete shall be as shown hereunder :
(b)
Grade 20
-
14N per mm2 after 7 days 20N per mm2 after 28 days
Grade 30
-
20N per mm2 after 7 days 30N per mm2 after 28 days
Core Test After the concrete has hardened, the SO Rep may at his discretion, instruct the Contractor to drill sample(s) of concrete from manhole walls or floors or roofs and send such sample(s) for core test in accordance with BS 1881 all at the Contractor's cost and expense.
24.2.5.3
Water Proofing The Contractor shall take all necessary actions to ensure that after the completion of pipe laying and manhole construction, there shall be no leakage such as seeping, dripping or flowing of water through manhole walls, roof, floor and pipe entries.
BLDG12/S24.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 24-10 24.2.5
Pipe, Manhole And Trench Testing (Cont'd)
24.2.5.4
Testing of Trench The Contractor shall arrange all the necessary equipment and manpower to carry out tests on the constructed trenches on any of the following : (a)
the depth of covering;
(b)
the concrete encasement;
(c)
the trench base construction;
(d)
the compaction test of the backfilling material and the subgrade;
(e)
quality test of backfilling and reinstatement materials;
(f)
the fabric reinforcement.
The Contractor shall rectify Works that are not carried out in accordance with the Specifications. All test results shall be certified by the SO Rep. 24.2.5.5
Backfilling For Underground Pipe System All trenches excavated for the provision of underground pipe system for telecommunication and Broadband coaxial cables shall be backfilled as follows : (a)
For trenches that are located within the road, backfill shall be from the completed pipe level to the subgrade of the road with granular materials such as sand/granite fines or quarry dust. The backfilling shall be properly compacted.
(b)
For trenches which are not located within the road, backfill to the level required under the Contract with good dry earth approved by the SO Rep.
Section 25/.....
BLDG12/S24.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 25-1 SECTION 25 CHILDREN’S PLAYGROUND, FITNESS STATION AND HARDCOURT
25.1
GENERAL Construct badminton court, sepak takraw court, volley ball court, basket ball court, fitness station, and children's playground, complete with play equipment, play sculpture, sand filling; or concrete base with line markers, table and concrete benches in numbers and to positions as shown in the Drawings. Details and finishes shall be as shown and as specified in this Section including all clauses and subclauses under it.
25.2
SETTING OUT Set out outline of playground, courts, fitness station, or position of play equipment and obtain approval from the SO Rep before proceeding further. Allow for shifting and making adjustment when directed by the SO Rep.
25.3
LEVELS Levels of playground and equipment shall be based on finished ground level adjourning and not necessarily on finished platform level shown on the Drawings. Check on site in all cases to ensure that rainwater collected on these playground can be discharged into nearby drains. Adjust levels where necessary.
25.4
GROUND BASE After removal of the top layer of the soil, the ground shall be well consolidated mechanically before laying hardcore. Consolidate again, filling more hardcore to make up to level. Should ground be soft, obtain the decision of the SO Rep on the necessity for piling work.
25.5
CONCRETE STRUCTURE
25.5.1
Construct concrete structure of Grade 25 concrete as specified in Section 4 "Structural Concrete" including all clauses and subclauses under it.
25.5.2
Bases of playgrounds shall be hardcore base of an average net thickness of 100mm, consolidated hardcore, blended and topped with 50mm thick crusher run (6-40mm) and compacted to a net thickness of 100mm and to a fall 1:50 or as shown in the Drawings. Provide expansion joints to positions and details as shown.
25.5.3
Hardcourts And Multi-Purpose Courts Where hardcourts and multi-purpose courts are included in the Works, these shall be constructed strictly in accordance with the Drawings. The slab shall be a minimum of 150mm thick reinforced with wire mesh D8 placed 35mm from the top surface. The Grade 30 concrete shall be cast as specified in Section 4 "Structural Concrete" including all clauses and subclauses under it. Contraction joints shall be introduced into the slab at a spacing of 9500mm or as shown in the Drawings. It shall be formed by a saw-cut after the concrete has aged for at least one day. The depth of the saw-cut shall be at least 40mm. For multi-purpose courts, a 25mm expansion joint shall be formed strictly in accordance with the Drawings at the half-court line.
BLDG12/S25.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 25-2 25.5.3
Hardcourts And Multi-Purpose Courts (Cont'd) The slab shall be finished with 3 passes of power trowel done without sprinkling of cement dust, cement grout or water onto the surface. The trowelling shall be completed before the concrete set. Ensure a sufficient team of workmen to complete the job. The concrete shall be immediately cured for seven days with approved curing compound or other approved methods. The basketball court stand shall be constructed in accordance with the Drawings. Concrete footing shall be as shown in the Drawings. All joints shall be fully welded to a neat and smooth finish. 50mm thick nylon cushion padding shall wrap round the standpost to the height as shown in the Drawings. The backboard shall be 18mm clear acrylic sheet and shall be fixed to the angle support with 6mm diameter stainless steel counter sunk screws and at intervals as shown in the Drawings. All galvanised steel pipes, angles and supports shall be treated with one coat of polyvinyl butyral etching primer and one coat of approved zinc chromate primer and then painted with one coat of undercoat and one finishing coat of approved enamel paint. All court lines shall be painted with polyurethane paint in bright red, orange, blue or white as indicated. Samples of polyurethane paint showing the colour range as specified shall be submitted to the SO Rep for approval. The Contractor shall ensure that the steel structure are adequately and effectively protected from lightning strike. The lightning protection system shall be in accordance with the Drawings.
25.6
CONCRETE PIPES Concrete pipes shall be of the dimensions as shown in the Drawings & conforming to BS 556.
25.7
PRECAST SLABS Precast slabs around edges of playground shall be 300mm x 300mm x 100mm thick of Grade 30 concrete as specified in Section 4 "Structural Concrete" including all clauses and subclauses under it and cast in steel moulds. Lay slabs on 1:3 cement mortar bed with 25mm gaps between slabs. Fill these gaps with 5 to 10mm graded granite chippings.
25.8
SUB-SOIL PIPES All sub-soil pipes shall be installed at areas as indicated in the Drawings. All sub-soil pipes shall be of perforated UPVC sub-soil pipes conforming to BS 4962 : 1989 or SS 272 UPVC pipes with perforations as shown in the Drawings. All sub-soil pipes shall be wrapped with approved non-woven geotextile fabric and encased with washed sand as shown in the Drawings. All sub-soil pipes shall be laid in 1:100 gradient (minimum) and with uPVC pipe joint fittings. The maximum length of sub-soil pipe shall be 25m. For perimeter open drains with depth of 400mm and above, the diameter of the sub-soil pipes shall be 150mm. Where the depth of the perimeter open drain < 400mm, the diameter of the sub-soil pipes shall be 100mm. Under such case, consult with the SO Rep before proceeding. All sub-soil pipes shall be connected to sumps and drains at the outlet. Upon completion of laying of all subsoil pipes, the Contractor shall prepare and submit 3 copies of as-built drawings to the SO Rep. Geotextile fabric shall be non-woven type and approved by SO Rep. The tensile strength of geotextile shall be minimum 7.0kN/m and flow rate shall be 80 -150 litres/sq.m/sec. Submit test report and sample for the approval of SO Rep before installation on the Site.
BLDG12/S25.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 25-3 25.9
PLAY EQUIPMENT AND OUTDOOR FITNESS EQUIPMENT
25.9.1
Play Equipment Fabricate all playground equipment as shown and complying with SS 457:2007. Install these equipment in the positions and in accordance with the details as shown in the approved shop drawings. The Contractor shall produce program for submission of shop drawings, and seek SO Rep approval on installation time frame. The Contractor shall provide shop drawings, manufacturer’s component installation drawings, mounting details with PE endorsement and third party certification by International Play Equipment Manufacturer’s Association (IPEMA) or other equivalent as approved by SO Rep to Consultant Qualified Person (QP) for approval. The third party certificate by IPEMA shall indicate the model of the approved play equipment. The Contractor shall follow strictly to the manufacturer’s instructions and procedures for the installation of each play structure designed. The play equipment shall be supervised and inspected by the Contractor and the Consultants QP. The Contractor produce inspection checklist, certificate of supervision and other related records on play equipment upon request during the site audit. Upon handing over the playground including play equipment, the Contractor shall engage the Certified Playground Safety Inspector (CPSI) to inspect and certify the installed play equipment complied with relevant standards. The Contractor shall submit a Performance Compliance Certificate in the format as shown in Appendix A46, together with the approved drawings, to the SO Rep. The CPSI shall indicate the name and the registration no. on the drawings with the Performance Compliance Certificate.
25.9.2
Outdoor Fitness Equipment Fabricate all outdoor fitness equipment as shown and complying with SS 534:2007. Install this equipment in the positions and in accordance with the details as shown in the approved shop drawings. The Contractor shall produce program for shop drawings, approvals and installation time frame. Contractor and Consultants to strictly follow specialist’s instructions and installation methods and ensure shop drawings include details of fixings and footings. Modification by main contractor and/or specialist to shop drawings shall be re-submitted to Consultants for verification. The installation shall be in accordance with the approved shop drawings and shall be supervised by the Consultants. The finished product shall be inspected by the Contractor, Specialist, sub-contractor and the Consultants EPDM rubber flooring shall be as specified in Clause 25.10 “Cast-in-situ EPDM Rubber Flooring for Children’s Playground”. Upon handing over the fitness equipment, the Contractor shall submit a Performance Compliance Certificate in the format as shown in Appendix A48 to the SO Rep.
25.10
CAST-IN-SITU EPDM RUBBER FLOORING FOR CHILDREN’S PLAYGROUND
25.10.1
Over-Riding Clause The Contractor and his Specialist executing the Works as required in this clause including all sub-clauses under it have to ensure that the Works, goods or materials used shall be suitable and reasonably fit for the purposes for which they are required (hereinafter referred to as "Performance Requirement"). In the event the Works, goods or materials to be used as specified in this clause including all sub-clauses under it are upgraded in order to meet the Performance Requirement, the Contractor and his Specialist shall do all necessary upgrading at no extra cost to the Employer, subject always to the approval of the SO Rep, but such approval shall not in any way affect the Contractor's and his Specialist's duties or obligations arising under the Contract.
25.10.2
Concrete Base The concrete base shall be finished in accordance with the manufacturer’s requirements with the necessary drainage and falls before laying the cast-in-situ rubber flooring.
BLDG12/S25.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 25-4 25.10
25.10.3
CAST-IN-SITU EPDM RUBBER FLOORING FOR CHILDREN’S PLAYGROUND
(CONT’D)
Cast-In-Situ Rubber Flooring The wet-pour rubber flooring for the children’s playground consists of a tw0-layer system, comprising of a base mat of Styrene Butadiene Rubber (hereinafter referred to as “SBR” for the purposes of this clause including all subclauses under it) rubber granular and a top surface of Ethylene Propylene Dienemonomer (hereinafter referred to as “EPDM” for the purposes of this clause including all subclauses under it). The completed rubber flooring shall be free from Defect, such as blistering, fissure, peeling, delamination, disintegration, unevenness and discolouration. The performance of the rubber flooring surfacing shall comply with SS 495:2001. (a)
Polyurethane Binder The binding agent shall be a solvent free single component Methylene Diphenyl Isocyanate (hereinafter referred to as “MDI” for the purposes of this clause including all subclauses under it) based, moisture curing binder. It shall be Toulene Diphenyl Isocyanate (hereinafter referred to as “TDI” for the purposes of this clause including all subclauses under it) free. The binder shall be “Flexilon 1102”; “Stobielast S133/S134”; “Tennek TPB 4811 (2c)”; “Incorez 902/023”; “Poly 8112C”; or other approved, polyurethane binder.
(b)
EPDM Top Layer The EPDM shall be peroxide cured only. The typical physical properties of the peroxide cured EPDM shall be as follows: Hardness (IRHD) Tensile (Mn/m²) Elongation at break (%) Specific Gravity
65 ±5 > 4.2 > 650 1.58 ± 0.03
EPDM pigment synthetic rubber granules (size 1 –4mm) shall be coloured EPDM and must be UV stable. Strand, shave, chipped or shredded rubber is not acceptable in the top layer. A minimum of 10mm thick top layer EPDM rubber surface shall be a seamless surface. The colours and design shall be submitted to the SO Rep for approval prior to its installation. The EPDM shall be “BRG”; ”MRI; or other approved. (c)
Base Layer The base layer shall be a precise combination of black granular rubber SBR (size 4 to 10 mm) mixed with binder. The thickness of the SBR base rubber shall be minimum 65mm thick.
(d)
Thickness The total thickness of the cast-in-situ EPDM rubber flooring shall not be less than 75 mm thick.
25.10.4
Method Of Installation The system shall be laid-in-situ on top of the concrete base and trawled to provide an even, seamless. porous, slip resistance and resilient rubber flooring. (a)
Surface Preparation All surfaces are to be laid to fall and shall be clean and dry before commencement of the Works. The new concrete base shall be allowed to cure for a minimum of seven days prior to the commencement of the rubber flooring.
(b)
SBR Base Rubber SBR base rubber granules shall be thoroughly mixed by mechanical mixer with the polyurethane binder and laid onto the concrete slab. A minimum ratio of 100:12 by weight, between the rubber granules and binder shall be mixed on the Site. The SBR rubber layer shall be minimum 65mm thick . The screed shall be trowelled to form a uniform and seamless layer. A roller is required to roll the surface to maintain an equal density surface throughout.
BLDG12/S25.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 25-5 25.10
25.10.4
CAST-IN-SITU EPDM RUBBER FLOORING FOR CHILDREN’S PLAYGROUND Method Of Installation (c)
(CONT’D)
(Cont'd)
Curing For Base Rubber The surface shall be cured in ambient temperature for a minimum of 12 hours before proceeding to the next layer.
(d)
EPDM A minimum thickness of 10mm EPDM layer is laid on a SBR rubber base. A minimum ratio of 100:18 by weight between the EPDM rubber and binder shall be mixed. The screeding shall be cast-in-situ screeding and hand trowel to maintain a seamless application.
(e)
Curing For EPDM The surface can be walked on only after 18 hours. However, the playground shall only be opened for public usage after 5 days when full curing is achieved. Proper barricade shall be provided during the process of curing.
(f)
Edges The surface edges shall be flush with adjacent areas or tapered to provide a safe and barrier-free transition.
25.10.5
Performance Requirements Where cast-in-situ EPDM Rubber flooring for children's playground is included in the Works, test certificates for the performance requirements specified hereunder shall be submitted to the SO Rep for approval. The performance requirements and test methods for impact absorbing playground surfacing shall comply with SS 495:2001. (a)
Resistance To Abrasive Wear The cast-in-situ surfaces shall exhibit the performance specified hereunder : (i) (ii)
(b)
Wear index shall be less than 1.0; Wear ratio (p) shall be not less than 1.0 and not more than 3.0
Slip Resistance The minimum slip resistance measured in any direction of test, under either wet or dry conditions shall not be less 40.
(c)
Resistance To Indentation The residual indentation (r), after 24 hour recovery, shall not be more than 5.0mm. after removal of the load and after allowing for 24 hour recovery, none of the specimens tested shall exhibit any cracking, splitting or perforation around the point at which the load was applied.
(d)
Ease Of Ignition The greatest radius of effects of ignition shall not exceed 35mm and shall thereby be classified as having a “LOW radius of effects of ignition”.
(e)
Critical Fall Height Critical fall height of impact absorbing surfacing shall comply with SS 495:2001.
Before handing over the playground including playground equipment, contractor is required to conduct impact attenuation test at site to comply with SS 495:2001 and shall submit Performance Compliance Certificate, together with test report attached in the format as shown in Appendix A46, to the SO Rep.
BLDG12/S25.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 25-6 25.10
25.10.6
CAST-IN-SITU EPDM RUBBER FLOORING FOR CHILDREN’S PLAYGROUND
(CONT’D)
Warranty The Contractor and his Specialist shall warrant the Works on the terms and conditions as stipulated in the Deed of Warranty For Cast-In-Situ EPDM Rubber Flooring For Children’s Playground as produced in Appendix A6. In this respect, the Contractor and his Specialist shall submit such Deed of Warranty to the Employer or to such other party or such Town Council(s) as the SO Rep may at its sole discretion decide. In the event the Deed of Warranty for part of the Works or for the whole Works is to be submitted to such Town Council(s), the Contractor and his Specialist shall submit such Deed of Warranty as produced in Appendix A6(TC) to such Town Council(s). The duly executed Warranty shall be submitted immediately upon request by the SO Rep, and if no such request is made, then at such time when the SO Rep considers the Works have been substantially completed in accordance with the Contract. In the event the Contractor and his Specialist shall fail to execute and submit the Deed of Warranty within the time specified, the SO Rep shall be allowed to withhold 15% of the payment of any sums due to the Contractor in relation to the execution of such Works, subject to the minimum sum of S$5,000/- per Deed of Warranty. However, such sums withheld shall be released to the Contractor upon submission by him of the duly executed Deed of Warranty.
25.11
BONDING OF SPRING ROCKERS (PLAYGROUND) All spring rockers in playground shall be electrically bonded to weldmesh in accordance to SS 555. The Contractor shall ensure proper bonding is done.
25.12
EQUIPOTENTIAL NETTINGS Equipotential nettings shall be provided for playground, hardcourt, fitness station with reinforced concrete base in accordance to SS 555 : Part 3 Clause 8.3.3. The Contractor shall ensure electrical continuity of the weldmesh/BRC used to form the equipotential surface and that all metallic poles and elements within the surface are properly bonded to the weldmesh/BRC. The Contractor shall capture all the necesssary photographs to prove that equipotential nettings are provided and equipment and metallic fixtures are bonded. These photographs, with dates shown, shall be submitted to the Consultant for approval and record. In addition, the Consultant's LEW or PE shall submit a certification form (HDB-TM(M&E)-EQNET) as produced in Appendix A47 to HDB to confirm equipotential nettings have been provided for the playground/hardcourt / fitness station in accordance to SS 555 upon completion of the work.
Section 26/.....
BLDG12/S25.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 26-1 SECTION 26 TREE PLANTING AND TURFING
26.1
PLANTING TREES AND SHRUBS
26.1.1
General The work generally includes :
26.1.2
26.1.3
26.1.4
(a)
Preparation of plant bed and tree hole including soil supplements.
(b)
The search, selection, supply, delivery and planting of nursery plants.
(c)
Protection, maintenance, guarantee and replacement of all plant materials and mulched beds.
Quality Of Workmanship And Materials (a)
All materials shall be approved by the SO Rep prior to use on the Site. Materials shall be obtained from approved sources/or suppliers.
(b)
All materials and workmanship shall be of the best quality.
(c)
All plant materials supplied shall be free of pest disease, discolouration and damage. Plants shall be well branched with vigorous shoots. The root system of each plant shall contain a good proportion of fibrous roots.
Inspection (a)
All materials shall be subjected to inspection and approval by the SO Rep.
(b)
Inspection and approval of plants on delivery shall be for quality, size and variety only and shall not in any way impair the right of rejection for failure to meet other requirements during the planting or at the time of inspection for final acceptance.
Submission (a)
Samples Submit samples of each of the following type of materials to be approved except where specified otherwise : Topsoil Materials for planting mixtures Materials for staking, guying and wrapping Fertilizers
(b)
Request for Substitution If substitutions for the plants listed in the plant schedule are required, submit request for substitution approval in writing within six weeks from the date of the Letter of Acceptance.
(c)
Photographs of Plant Material Within six (6) calendar months from the commencement date of the Time for Completion, submit two (2) complete sets of photographs of all plant material subject to inspection. All photographs shall be labelled and representative of the plant materials specified.
(d)
Maintenance Reports and Schedule During the Maintenance Period, submit monthly reports describing the work completed for the previous month and the work to be accomplished in the following month.
BLDG12/S26.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 26-2 26.1.5
Horticultural Supervisor The Contractor shall employ a competent, experienced (min 2 years) and qualified horticultural supervisor (minimum Certificate of Ornamental Horticulture or equivalent) to be stationed full time at the Site and for the full duration of the Works required under this Section including all clauses and subclauses under it, who shall receive and act upon instructions given by the SO Rep, and such instructions given to the horticultural supervisor shall be deemed to have been given to the Contractor.
26.1.6
Notice Of Works The Contractor shall inform the SO Rep at least 24 hours in advance of his intention to commence any of the following operations : setting out; excavation; backfilling; plant delivery and planting.
26.1.7
Topsoil All topsoil shall be of good quality, free from rubbish, roots, stumps or other extraneous matter, be friable and porous in texture. The texture content shall be 40-50% sand, 20-25% clay and 20% approved organic matter.
26.1.8
Sub-Soil The clay content of the sub-soil which is the strata found just below the top soil layer shall not be greater than 45%.
26.1.9
Unwashed Sand The unwashed sand shall be free of any debris, stones or other foreign material.
26.1.10
Soil Conditioner Soil conditioner shall be peat, cocopeat, organic compost, or other approved fibrous organic matters suitable for mixing with soil to make a friable growing medium for plants.
26.1.11
Lightweight Aggregate Lightweight aggregate shall be clean clinker of low-density inert material of vermiculite or volcanic scoria, expanded shale/clay or other porous material weighing not more than 500 kg per m3.
26.1.12
Water-Holding Medium Water-holding medium is an absorbent copolymer water crystal that increase the water-holding capacity of any soil mixture to at least 15 times its own weight.
26.1.13
Setting Out (a)
The Contractor shall set out the Works in accordance with the Drawings or as directed by the SO Rep.
(b)
Any discrepancies between the Drawings and actual conditions on the Site shall be notified to the SO Rep before commencement of the Works. If the Contractor fails to notify the SO Rep on any such discrepancies, all costs and expenses of any adjustment, amendment, resetting and realignment of the setting out shall be borne by the Contractor.
(c)
The location of trees, palms and shrubs shall be laid out and pegged by the Contractor on the Site to be inspected by the SO Rep before further commencement of the Works. The pegs shall be painted to indicate sizes of holes/pits as follows: Holes / Pit Sizes 0.5m x 0.5m x 0.5m 1.0m x 1.0m x 1.0m 1.5m x 1.5m x 1.0m
BLDG12/S26.DOC(2) Sal(151211) (DPD)
Colour Indication Yellow Not Painted Red
Bldg Spec Page 26-3 26.1.13
Setting Out (Cont'd) (d)
26.1.14
The shape, pattern and layout of flower beds shall be demarcated and drawn by the Contractor on the Site. The Site shall be inspected by the SO Rep before further commencement of the Works.
Hole For Planting Holes for planting shall be decided by the SO Rep. All holes excavated shall be inspected and approved by the SO Rep before backfilling soil mixture. All excavated and unwanted materials shall be removed from the Site. The Contractor shall allow in the Contract Sum for excavating clayish subsoil, broken concrete, rubble or other material when excavating holes for tree planting as no claim for extras shall be entertained for excavation in difficult or hard ground. Holes for planting shall be of the following sizes :
26.1.15
(a)
Minimum 1.0m x 1.0m x 1.0m deep for planting of tree saplings
(b)
Minimum 1.5m x 1.5m x 1.0m deep for the planting of semi-mature (instant and 30-litre bag and above) trees and fruit trees
(c)
Minimum 500mm deep for flower beds or trenches to areas as shown in the Drawings
(d)
Minimum 500mm x 500mm x 500mm deep for planting of shrubs and foliage plants
Soil Mixture for Backfilling (a)
Waterlogged Hole If there is underground water or the hole is waterlogged, necessary action or measure shall be taken to rectify the waterlogged condition
(b)
Soil Mixture All planting holes shall be backfilled with 3:1 topsoil, soil conditioner and 1kg per m3 of granular fertilizer NPK (15:15:6:4) or 4:2:1 subsoil, unwashed sand and soil conditioner with 1kg per m3 of granular fertiliser NPK (15:15:6:4) well mixed to a level 250mm higher than the adjacent ground level at time of filling.
(c)
Soil Mixture For Roof Garden All close bottom planter shall be backfilled with 4:2:2:2 topsoil, unwashed sand, soil conditioner lightweight aggregate and 20g per m3 of water-holding medium and 1 kg per m3 of granular fertilizer NPK (15:15:6:4). They shall be well mixed off-site before backfilling into the planter. The finished level of the soil mixture to be flushed with the top of the lower planter wall.
(d)
Soil Mixture Used For Instant Tree All planting holes for transplanted instant trees/palms/shrubs shall be backfilled with only topsoil.
(e)
Soil Mixture For Fruit Trees Similar soil mixture shall be used. The excavated earth shall be used to constructed earth mound averaging 50 mm high and 1750mm wide along the edge of the holes all round.
26.1.16
Purchase Of Trees The Contractor shall purchase the trees/palms/shrubs etc. from his own source.
BLDG12/S26.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 26-4 26.1.17
26.1.18
Plant Protection (a)
All plant materials shall be carefully protected and if necessary wrapped in the nursery during the lifting, awaiting transportation, unloading and during storage on the Site.
(b)
Any evidence of unsatisfactory protection to roots, stems, branches and leaves will result in the plants being rejected. Unprotected plants shall not be transported during hot weather and all plants shall be kept moist during transportation and storage. No plant shall be left on the Site unplanted for more than two (2) days.
Plant Quality (a)
All trees, palms, shrubs and other plants delivered to the Site shall be of the specified size, free of pests and diseases and undamaged. Plants shall be well branched with bushy foliage.
(b)
All the general conditions of plants delivered to the Site shall be to the satisfaction of the SO Rep and approved by him before planting out onto the Site in accordance with the Drawings or as directed by the SO Rep.
(c)
The SO Rep shall reserve the right to reject undersized, unhealthy, unspecified, damaged, injured, diseased, infested or any other plants not in accordance with the Contract and to the satisfaction of the SO Rep during the entire period including the Maintenance Period and Defects Liability Period of the Contract.
(d)
The Contractor shall immediately remove and replace all rejected plants at his own cost and expense.
(e)
The plant size shall be measured on the day of planting at the Site in accordance with the Drawings or as directed by the SO Rep in writing.
(f)
Plants not complying to the specified sizes shall be rejected and rectified by the Contractor. All associated costs involved including plant material cost shall be charged and deducted from any monies due to the Contractor, if he fails to rectify.
(g)
All trees, palms and shrubs shall possess the natural characteristics and growth habit typical of its variety and species to the satisfaction of the SO Rep.
(h)
All trees, palms and shrubs where required under the Contract shall comply with the descriptions and requirements specified hereunder: "Instant Trees" Instant trees are semi-matured trees especially prepared in advance for transplanting. Instant trees shall have the specified minimum clear and upright straight tree trunk of the specified height and girth with at least 3 branches and a well developed secondary branch system. "Big Saplings" Big saplings are medium-sized nursery grown trees having a single straight stem and unbroken leader with an overall height as specified. The stem shall be fully furnished with an evenly spread and balanced lateral branches and shall be of the specified girth measured at 0.5m from the ground "Saplings" Saplings are small sized nursery grown trees having single straight stem and unbroken leader with an overall height as specified. The stem shall be fully furnished with evenly and balanced lateral.
BLDG12/S26.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 26-5 26.1.18
Plant Quality (Cont'd) (h) (Cont'd) "Edible Fruit Trees" Edible fruit trees shall be of minimum height of 1.2m or as specified. They shall be marcotted or grafted saplings especially as follows: Pouteria caimito (Abiu) - Grafted Persea americana (Avocado) - Grafted Achras zapota (Chiku) - Marcotted Durio zibethinus (Durian) - Grafted Psidium guajava (Guava) - Grafted or Marcotted Artocarpus heterophyllus (Jackfruit) - Grafted Eugenia aquea (Jambu Air) - Marcotted Citrus microcarpa (Lime) - Grafted Mangifera indica (Mango) - Grafted Nephelium lappaceum (Rambutan) - Grafted Annona muricata (Soursop) - Grafted Averrhoa carambola (Starfruit) - Grafted Artocarpus incisus (Breadfruit) - Grafted "Single-stemmed Palms" Single stemmed palms shall have a straight trunk of the specified height measured from the root collar. The heads of the palms shall be balanced with at least five fronds and evidenced of one new shoot. "Clustered Palms" Clustered palms are palms which naturally grow as a multi-stemmed clump by sending out suckers. Such palms shall have a minimum of three suckers each and have a specified overall height measured from the root collar. They shall have at least three fronds on each stem and evidence of one new growing shoot per stem. "Shrubs" Shrubs are woody perennials of generally multi-stemmed and bushy habit and shall have a minimum height measured from the ground level to the top of plants as specified. Such shrubs shall be well balanced and bushy with strong developed fibrous root systems, and shall be pruned in advance as required to achieve the specified height tolerances. Branches shall break from the base of the plant just above the root collar, and shall be well furnished with leaves right down to the ground level unless otherwise specified by the SO Rep. All plants shall be grown in containers of suitable dimensions for the species. "Herbaceous Plants" Herbaceous plants are non-woody perennials usually of a clump forming habit. Such plants shall have well-developed main stem or stems with good symmetry, and a healthy root system. Clump of herbaceous plants shall include rhizomes, corns, tubers or roots with soil undisturbed by lifting with evidence of growing shoots emerging above the soil level. All herbaceous plants shall be grown in containers unless specified as being produced by an alternate method.
BLDG12/S26.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 26-6 26.1.18
Plant Quality (Cont'd) (h)
Cont'd "Groundcover" Groundcover plants are low growing or prostrate shrubs or herbaceous plants whose habit are to totally cover the soil. All groundcover species shall be evenly balanced to allow equal growth in all directions. Plants shall have fully developed roots and leaves. All plants shall be grown in containers. "Climbers" Climbers are plants whose growth habit are to climb upwards by means of twining stems, tendrils or clinging roots. Such plants shall have at least two leader shoots up to the specified height or length and a vigorous root system. All plants are to be grown in containers.
26.1.19
26.1.20
Planting Techniques (a)
Where trees/palms are planted in turf or shrub areas, plant trees and palms before the turfing or shrub planting operations. Where shrubs are planted in turfed areas, plant the shrubs before the turfing work.
(b)
The Contractor shall handle the plant in such a manner so that the ball of soil surrounding the roots is not broken. The plant should be firmly held by the pot, plaster bags, containers, etc.
(c)
The Contractor shall ensure that trees, palms and shrubs are properly removed from their pots, containers, plaster bags, etc and securely planted in the ground. The Contractor shall straighten the plants whenever directed by the SO Rep.
(d)
All plants shall be planted with their collars levelled with the ground and covered with soil as directed by the SO Rep.
(e)
All plants shall be planted to accommodate the spreading root system of the plant to the same soil depth as in the nursery and shall be well watered before removing them from the containers The plants shall be positioned upright and the soil firmed around the roots.
(f)
For large areas, the outer rows are to be set out first to ensure that the correct shape of the bed is established. The remaining plants shall then be evenly distributed to cover the planting area. The SO Rep shall be notified in advance if there are too many or too few plants to fill the area required, and an assessment of the laying out adjustments will be directed accordingly.
(g)
The laying out of plants shall be completed and approved before planting into the soil bed can commence.
(h)
Small shrubs, groundcovers and herbaceous plants shall be planted in pockets formed by a trowel or hand spade. The pocket shall be deep enough and wide enough to accommodate the root ball of the plant. The plants shall be placed upright in the planting pockets and make firm into the ground by treading or hand pressure. All plants shall be watered thoroughly immediately after planting.
Tree Support (a)
To Tree Sapling Tree saplings shall be supported immediately as directed after planting. The supporting stakes shall be in 75mm diameter Bintangore pole or other approved material, minimum 3.0m long and driven vertically 1.2m deep into the ground without injuring the rootballs and projecting 250mm above the crown of the sapling. Fasten tree saplings to the supporting stakes by rubber or PVC hose and tie wires. Tying wire shall be No. 20 SWG galvanised wire, threaded through 10mm diameter rubber or plastic hose and be wound around the tree trunk in a single loop. The tree trunk shall be secured at a point just above its branch and also at a point just 500mm above ground level.
BLDG12/S26.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 26-7 26.1.20
Tree Support (Cont'd) (b)
To Semi-Mature/Mature/Instant Tree (Tripod Support) For semi-mature/mature/instant tree, 3 tree stakes of Bintangore poles shall be evenly spaced around the tree to form a tripod system to support the transplanted tree at about two thirds of its height or under the main fork. The tree stakes of Bintangore poles are driven at least 0.5m into the ground at an angle. 2 layers of gunny sack or similar material shall be wound around the tree trunk where it meets the supporters. The meeting point of the supporters are tightened up with galvanised wire to form a sturdy tripod support system. The support system shall be checked monthly and be removed after 6 months when the tree becomes stable.
26.1.21
Tree Guards Provide tree guards to trees planted as specified by the SO Rep. The pattern of the tree guard shall be decided by the SO Rep.
26.1.22
Tree Shade Provide shading to mangosteen, rambutan or other sensitive fruit trees as directed by the SO Rep. Nylon netting or other approved with 60% to 70% shading effect shall be used to cover the top of the tree guard and upper 500mm of its four sides.
26.1.23
Transplanting Existing Trees (Instant Tree) Where required under the Contract, transplanting of existing trees shall be carried out as follows : (a)
Branch Pruning Prune branches or pollard the tree as directed by the SO Rep. Paint all cuts with fungicidal sealant.
(b)
Rootballs All trees/palms, shrubs to be transplanted shall have an earth rootball of a minimum diameter ranging from 3.5 to 7.5 times the diameter of the tree trunk measured at 1.0m above ground level or to the size to be decided by the SO Rep. This shall be done by excavating a trench about 0.8m deep around the tree at an appropriate distance. All protruding roots shall be cut and painted with a fungicidal sealant. Excavated trees shall be transplanted within the same working day unless otherwise directed by the SO Rep.
(c)
Tree Pits To avoid delay, the new pit for the tree transplant shall be ready before the tree is brought to the new location. The pit shall be at least 0.5m wider and 0.25m deeper than the rootball to allow for incorporation of topsoil beneath the root. The minimum tree pit dimension shall be 1.5m x 1.5m x 1.0m deep. All planting holes for instant tree shall be backfilled with good quality approved topsoil to a level 250mm higher than the adjacent ground level at the time of filling.
(d)
Lifting And Transporting The tree shall be lifted by motor crane or other lifting machinery of appropriate capacity. Every precaution including rootball securely wrapped by moisten canvass and angle bar frame or other approved materials shall be taken to prevent damage to the rootball during the loading and transporting of the tree to the new location.
(e)
BLDG12/S26.DOC(7) Sal(151211) (DPD)
Before unloading a tree into position, the depth and diameter of the rootball shall be measured and adjustment made to the pit. The tree shall be set in the hole, orientated, depth adjusted and planted with minimum delay. The tree shall be planted to its former depth. Backfilling shall then be firmly consolidated to eliminate air pockets under and around the roots. Tripod shall be provided to keep it firmly in position if required.
Bldg Spec Page 26-8 26.1.24
Tree Pruning Trees with dead, rotten or crossed branches shall be pruned to maintain a clear stem up to the specified height using the methods described below. The pruning operation shall be carried out by an experienced worker with appropriate tools and equipment under the supervision of the Horticultural Supervisor :
26.1.25
(a)
Pruning shall be done with a cut just above and sloping away from an outward facing healthy bud;
(b)
Removal of branches shall be done by cutting flush with the adjoining stem and in such a way that no part of the stem is damaged or torn;
(c)
Ragged edges of barks shall be trimmed with a sharp knife;
(d)
Any cut or wound over 25mm diameter shall be painted with an approved sealant such as "Arbrex" or other approved after trimming; and
(e)
All pruning shall be cleared and removed from the Site after pruning.
Maintenance Of Trees, Shrubs And Ground Covers, Etc Planted trees, shrubs and ground covers, etc. shall be maintained prior to handing over to the Employer and shall be further maintained for another 6 months from the date the planting is handed over to the Employer by performing and/or providing the following :
26.1.25.1
Watering (a)
Trees 20 litres of water per tree shall be watered as and when directed by the SO Rep.
(b)
Landscaped Site 10 litre of water per m2 of the landscaped site shall be watered as and when directed by the SO Rep.
(c)
Method Watering shall be carried out by using rubber hose fitted with an adjustable spraying head/gun to wet the soil thoroughly.
26.1.25.2
Soil-Loosening (a)
Ornamental Tree Saplings For ornamental tree saplings, the weeding circle shall be loosened to a depth of 75mm using a garden fork.
(b)
Shrub/Foliage/Landscaped Site For shrub/foliage/landscaped site, the weeding area shall be spiked to a depth of 100mm using a garden fork.
26.1.25.3
Weeding (a)
Ornamental Trees For ornamental trees, weed to 1.0m diameter around the sapling tree base using hand trowel or weeding hoe. Weed out an annular band of 50mm around mature or semi-mature tree base using hand trowel or weeding hoe or approved weedicide.
BLDG12/S26.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 26-9 26.1.25
Maintenance Of Trees, Shrubs And Ground Covers, Etc (Cont'd)
26.1.25.3
Weeding (Cont'd) (b)
Fruit Trees For fruit tree saplings, spread 100mm of mulch consisting of dry shredded leaves, grass sword, wood chips, cocopeat or compost over the 1.0m diameter weeding circle. Spray weedicide on the edge of the mulched area (50mm band) using a knapsack sprayer equipped with a "drift-shield". The mulched area shall be weeded monthly. For semi-mature and mature fruit trees, a weeding annular band of 200mm around the tree base shall be maintained by weeding operation.
(c)
Shrub/Foliage (Individually Planted) A weeding circle of 0.5m diameter around individually planted shrub/foliage shall be manually weeded using a hand trowel or weeding hoe.
(d)
Landscaped Site The Landscaped site shall be weeded using a hand trowel or weeding hoe.
(e)
Hedge An annular band of 0.5m diameter around the base of the hedge shall be weeded using a hand trowel or weeding hoe.
26.1.25.4
Fertilising (a)
Ornamental Trees Sapling Fertiliser NPK Mg (15:15:6:4) shall be broadcasted at a rate of 375g per ornamental tree sapling within the weeding circle 120mm away from the stem. Semi-Mature/Mature Trees For semi-mature/mature ornamental trees, fertilizer NPK Mg (12:12:17:2) shall be inserted at a rate of 0.5kg per 250mm girth into holes 300mm deep and at 500mm apart along the dripline.
(b)
Fruit Tree Saplings Less Than 1 Year Old For fruit tree saplings less than 1 year old, fertiliser NPK Mg (15:15:6:4) shall be placed under the mulch at a rate of 300g per tree, 120mm away from the stem. Saplings/Semi-Mature Trees For fruit tree saplings/semi mature fruit trees, fertilizer NPK Mg (15:15:6:4) shall be broadcasted at a rate of 0.5kg per tree within the drip zone away from the stem. Matured Trees (Flowering/Fruiting) For mature (flowering/fruiting) fruit trees, fertilizer NPK Mg (12:12:17:2) shall be broadcasted (on level ground) or shall be pocketed (on slope) at 1.0 kg per tree as directed by the SO Rep within the drip zone away from the stem.
(c)
Shrub/Foliage For shrub/foliage, fertilizer NPK Mg (12:12:17:2) shall be broadcasted at 50g per m2, with the weeding circle 100mm away from the stem.
BLDG12/S26.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 26-10 26.1.25
Maintenance Of Trees, Shrubs And Ground Covers, Etc (Cont'd)
26.1.25.4
Fertilising (Cont'd) (d)
Landscaped Site/Hedge For landscaped site/hedge, fertilizer NPK Mg (12:12:17:2) shall be broadcasted at 50g per m2 as directed by the SO Rep.
(e)
Climber/Creeper For climber/creeper, approved foliar fertilizer shall be sprayed as directed by the SO Rep.
26.1.25.5
Trimming Trees shall be trimmed as directed by the SO Rep including performing and/or providing the following :
26.1.25.6
(a)
Trim and remove all extra leader.
(b)
Trim and remove all side branches from the main trunk measured 3.0m from the ground for trees along footpaths, carparks and roadside.
(c)
Trim and remove all dead, broken, diseased and unwanted branches/shoots.
(d)
Trim and remove all overlapping branches rubbing each other.
(e)
Remove and clear from the Site all trimmed vegetation.
(f)
Paint all cut surfaces exceeding 25.4mm with 2 coats of anti-fungus wound sealant.
Pest Control (a)
Vegetative Stage Of Trees For vegetative stage of trees, the top and bottom of tree leaves shall be thoroughly sprayed. Respraying shall be done if it rains within 6 hours after spraying. Approved pesticides are : Pesticides Dimethoate Deltamethrin White Summer Oil Abate 1% Sand Granules Benomyl Captan Thiram Terrazole Copper Fungicide (Metalic Copper) Mancozeb Captafol Omite Tenac (sticker)
(b)
40% EC 1.25% EC 80% EC 50% EC 50% UP 80% UP 24% EC 50% 80% WP 39% EC 30% WP
Fruiting Stage Of Fruit Trees For fruiting stage of fruit trees, brown paper or raffia bags shall be used for the control of fruit fly 3 to 4 weeks after flowering for Chiku, Chempedak, Guava, Jackfruit, Jambu Ayer, Mango, Pomelo and Starfruit. Approved brown paper and raffia bags shall be used to bag the fruits as follows : Fruit Chiku; Starfruit Guava; Mango Jambu Ayer; Pomelo Chempedak Jackfruit
Size of Bag 150 x 150mm 150 x 300mm 400 x 400mm 400 x 500mm 500 x 800mm
Material of Bag Brown Paper Brown Paper Brown Paper Brown Paper or Raffia Brown Paper or Raffia
Remove and clear from the Site all rotten fruits on trees or on ground. BLDG12/S26.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 26-11 26.1.25
Maintenance Of Trees, Shrubs And Ground Covers, Etc (Cont'd)
26.1.25.6
Pest Control (Cont'd) (c)
Shrubs/Foliage Etc For shrubs/foliage etc, immediately spray with approved pesticides after the infestation is spotted. Continue such spraying until the infestation is controlled.
26.1.25.7
Maintenance Planted trees shrubs and ground covers, etc shall be maintained by adjusting tree tie, making good damaged tree guards, adjusting tripod support including providing and/or performing other reasonable work. The Contractor shall allow in the Contract Sum for all costs and expenses for maintaining all planted trees, shrubs and ground covers, etc provided under the Contract for a further period of six months commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as "Maintenance Period" for the purposes of this section including all clauses and subclauses under it) by providing and/or performing the following : Operation
26.1.25.8
26.1.25.9
Frequency
Soil Loosening
Monthly
Weeding
Monthly
Watering Pest Control Fertilising Pruning Adjusting tree ties
Daily Monthly Monthly Monthly Monthly
Damaged/Missing Tree Guards, Supporters, Trees, Shrubs, Ground covers, etc.
To be replaced/repaired as directed by the SO Rep.
) ) and/or to be carried ) out as directed by ) the SO Rep. )
Warning Sign (a)
The Contractor shall display sufficient warning signboards at strategic locations on the Site during the progress of tree pruning/spraying of pesticide works, as directed by the SO Rep.
(b)
The Contractor shall also seal off the Site with red and white plastic tapes as an additional safety precaution during the execution of the Works.
(c)
The signboard shall measure 1000mm long x 600mm wide using aluminium plate with reflective sheeting and reflective wordings "DANGER - TREE PRUNING IN PROGRESS" OR "DANGER PESTICIDE SPRAYING IN PROGRESS". A sample of the signboard shall be submitted to the SO Rep for approval before using them on the Site.
Working Hours Of Tree Pruning The Contractor shall carry out routine tree pruning/trimming operation within the following hours : Monday to Friday Saturday
: :
7am to 3pm 7am to 12 noon
No routine tree pruning/trimming shall be carried out outside the above hours except otherwise instructed by the SO Rep. 26.1.25.10
Updating Of Landscape Plan The Contractor shall update a landscape plan within one month after final planting and to provide 6 sets of updated landscape plans to the SO Rep.
BLDG12/S26.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 26-12 26.2
TURFING
26.2.1
Site Preparation And Turfing The Contractor shall allow for turfing Works, forming slopes and platforms with even surfaces to the levels as shown in the Drawings. Clear away loose stones, gravels, tree stumps and building debris. Seek the approval of the SO Rep before commencing turfing Works.
26.2.1.1
Soil For Site Formation The soil used for backfilling shall be original clean earth and the topmost 600 mm shall be soil with a clay content of not more than 45%.
26.2.1.2
Soil Scarification For Compacted Site The top layer shall be scarified or loosened to 100mm deep for the whole Site and graded to fall towards drains or as instructed by the SO Rep all at the Contractor’s cost and expense.
26.2.1.3
Site Gradient The Site shall be graded to fall towards drains at a minimum ground gradient of 1 in 70 or as instructed by the SO Rep all at the Contractor’s cost and expense.
26.2.2
Site Control Tests And Testing Instruments Provide all necessary labour, plant, Construction Equipment, tools, instruments etc. for carrying out all checking and testing of Site Works. The Contractor shall be deemed to have allowed for all costs and expenses to comply with the requirements as specified, in the Contract Sum. No claim for compensation or extras shall be paid for any work carried out by the Contractor in connection with such Works.
26.2.2.1
Number Of Soil Test The number of soil samples shall be 1 per 500 m² subject to a minimum of 3 samples.
26.2.2.2
Percolation Test Procedures for Percolation Test on dry soil sample are as hereunder specified:
26.2.2.3
(a)
Randomly select a spot where the test is to be conducted;
(b)
Dig a hole measuring about 400mm x 400mm x 600mm deep;
(c)
Fill the hole with water up to the top;
(d)
Cover the hole;
(e)
After 24 hours, observe whether or not all the water has drained off. The drainage performance of the soil is acceptable if no water remain in the hole.
Jar Test The procedures for Jar Test on dry soil sample are as hereunder specified:
BLDG12/S26.DOC(12) Sal(151211) (DPD)
(a)
Fill a 250 ml measuring cylinder with water up to its two-third level;
(b)
Pour in a teaspoon of washing detergent;
(c)
Shake the contents well;
(d)
Pour in the soil sample until the water level rises to the 250 ml mark;
(e)
Shake the contents well;
(f)
Place the measuring cylinder on a level bench and gently tap until the surface of the sand is level;
Bldg Spec Page 26-13 26.2.2
Site Control Tests And Testing Instruments (Cont'd)
26.2.2.3
Jar Test (Cont'd) (g)
Take measurement of the sand level;
(h)
After 3 hours of standing, take measurement of the height of the silt visible above the sand-silt interface;
(i)
After 24 hours of standing, take measurement of the height of the clay visible above the siltclay interface;
(j)
Work out the percentage of clay, silt and sand.
26.2.3
Soil Mixture
26.2.3.1
All topsoil shall be of good quality, free from rubbish, roots, stumps or other extraneous matter, be friable and porous in texture. The texture content shall be 40-50% sand, 20-25% clay and 20% approved organic matter.
26.2.3.2
The soil mixture shall be three (3) parts of topsoil with one (1) part of soil conditioner and 1kg per m3 of granular fertilizer NPK (15:15:6:4) or 4:2:1 subsoil, unwashed sand and soil conditioner with 1kg per m3 of granular fertilizer NPK (15:15:6:4).
26.2.4
Thickness Of Soil Mixture The minimum thickness of soil mixture shall be 150mm (including 25mm of original soil attached to the turf) at the time of construction. A 125mm layer of soil mixture shall be spread over the prepared surface, followed by the planting of fresh turf.
26.2.5
Turfing Materials Provide turfing materials of size 300mm x 300mm with about 25mm of original soil adhering to the roots, be of good quality, free from pests or diseases and of vigorous growth. The type of turf shall be Cow Grass (Axonopus Compressus) The turf shall be planted promptly to avoid desiccation.
26.2.6
Planting Turf Sods shall be laid within 24 hours upon delivery, in brick-like patterns. Sods shall be firmly sunken into the ground with their edges in contact but without stretching or overlapping or gap. Water turf immediately after planting until the turf is thriving.
26.2.7
Rolling When the level of the completed turfing Works is undulating or uneven, the turfed areas except those on steep slopes shall be properly rolled out with a garden roller of weight not more than 150 kg or with other approved means. The turfing shall give a uniform even surface on completion. Rolling shall be carried out when the turf is established after the second grass cutting.
26.2.8
Temporary Fencing Provide and fix temporary barricade to all turfed areas comprising 50mm x 50mm x 1.65m long Balau timber posts spaced at 2.4m centres with one end driven 450mm into the ground. Corner and end posts shall be strutted by 2 no. of 50mm x 50mm x 1.65m Balau timber post. Run 10mm diameter nylon ropes diagonally and horizontally across the top and bottom of the barricade.
BLDG12/S26.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 26-14 26.2.9
Maintenance The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services, as specified hereunder, to the turfing Works during the Time for Completion and any time period where liquidated damages are imposed under the Contract, and for a further period of six months commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this clause including all subclauses under it) by providing and/or performing the following :
26.2.10
26.3
(a)
Watering with a volume of 10 litres per m2 daily for the first two weeks after planting and when necessary or as directed by the SO Rep all at the Contractor's cost and expense;
(b)
Weeding where and when necessary or as directed by the SO Rep all at the Contractor's cost and expense;
(c)
Replacing dead turf or re-turf bare areas;
(d)
Fertilising before handing over, and on the 3rd and 6th month of the Maintenance Period;
(e)
Cutting grass fortnightly.
Safety Measures For Grass-Cutting Machines (a)
Provide all safety precaution to eliminate danger to the workmen, the general public and the property of others.
(b)
All mechanised driven or walk behind grass-cutting machines used shall be installed with suitable protective guards of steel or other approved materials to eliminate splinters and flungoff objects from causing damage. Under no circumstances shall the protective guards be removed from machines in operation.
(c)
Hand held open blade rotary machine shall not be allowed to be used without approved guards.
(d)
The grass-cutter shall wear safety boots, goggles, helmets and safety vest. When these safety requirements are not complied with, the Contractor's foreman or the SO Rep shall instruct the grass-cutter to stop work.
(e)
Before grass-cutting commences, the public shall be kept at least 10 metres radically away from the grass-cutter and a signboard shall be erected on the Site with the wordings "DANGER KEEP OFF. GRASS CUTTING WORK IS IN PROGRESS".
(f)
The grass-cutting blade shall be securely fixed to the machine. When the machine is in continuous use, regular checks shall be made. The blade shall be kept in good condition. A worn-out blade shall be replaced immediately.
(g)
The bolts and nuts which are fastened to the cutter blade shall be checked before the machines are operated to prevent the blade from flying off.
SUMP Sump for sub-soil drainage shall be constructed to the size and in the position as shown in the Drawings.
BLDG12/S26.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 26-15
26.4
USE OF NON-POTABLE WATER The Contractor shall allow in the Contract Sum for all costs and expenses incurred in the collection, storage, transportation and use of non-potable water, when directed by the SO Rep, for watering turf, trees and shrubs. Non-potable water can be collected free of charge from the MEWR Sewage Treatment Works. These Sewage Treatment Works are located at : (a) (b) (c) (d) (e) (f)
Ulu Pandan Sewage Treatment Works Kim Chuan Sewage Treatment Works Seletar Sewage Treatment Works Kranji Sewage Treatment Works Bedok Sewage Treatment Works Jurong Sewage Treatment Works
The Contractor shall use water tankers or water-tight tanks mounted on trucks to collect the nonpotable water from any of the above MEWR Sewage Treatment Works. The tank is preferred to have a minimum capacity of 9000 litres. The Contractor must also ensure that unused non-potable water is returned to the Sewage Treatment Works for proper disposal and not discharged into open drains in water catchment areas. The Contractor shall submit detailed particulars of their water tankers or tank mounted trucks to the SO Rep who will then obtain an authorization letter from MEWR for the registered tanker to collect non-potable water. The Contractor shall submit detailed justifications to the SO Rep for not using non-potable water for watering turf, trees and shrubs, after direction has been given by the SO Rep to do so.
Section 27/.....
BLDG12/S26.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 27-1 SECTION 27 MULTI-STOREY CARPARK
27.1
GENERAL Construct multi-storey carpark to details as shown in the Drawings. In addition to complying with the requirements in the Specifications, the Contractor shall also be required to comply with the requirement specified in this section including all clauses and subclauses under it.
27.2
WATER REDUCING ADMIXTURE FOR REINFORCED CONCRETE SLAB/CONCRETE TOPPING AT CARPARK ROOF DECK OF MULTI-STOREY CARPARKS Water reducing admixture shall be used for the reinforced concrete slab/concrete topping at the roof deck level. The application shall be in accordance with the manufacturer's recommendations and instructions. Check and ensure that the admixture shall not affect the strength or other properties of the reinforced concrete. The admixture shall comply with SS EN 934 or relevant British Standards and shall be approved by the SO Rep.
27.3
HALF-HOUR FIRE-RATED TIMBER SURFACE FINISHED COMPOSITE DOORS TO STAIRCASE OF MULTI-STOREY CARPARK (A)
Over-Riding Clause The Contractor executing the Works as required in this clause including all sub-clauses under it has to ensure that the Works, goods or materials used shall be suitable and reasonably fit for the purpose of complying with the required fire-rating (hereinafter referred as "Performance Requirement"). In the event the Works, goods or materials to be used as specified in this clause including all sub-clauses under it are upgraded in order to meet the Performance Requirement, the Contractor shall do all necessary upgrading at no extra cost to the Employer subject always to the approval of the SO Rep, but such approval shall not in any way affect the Contractor's duties or obligations arising under the Contract.
(B)
General Provide and install half-hour fire-rated timber surface finished composite doors complete with door frames and ironmongery to staircase of multi-storey carpark. The half-hour fire-rated timber surface finished composite doors, door frames and ironmongery shall be provided as a complete system complying with SS 332 : 2007. The complete system shall have PSB test certificates, PSB labels and shall be certified under PSB Product Listing Scheme Class 1A or 1B. Details of the half-hour fire-rated timber surface finished composite doors shown in the Drawings shall serve as a guide.
(C)
Shop Drawings And Sample Prior to the installation, submit workshop drawings and PSB test certificates for the approval of the SO Rep. Further, install a complete sample on the Site for the approval of the SO Rep before full implementation.
(D)
Ironmongery Provide and fix all ironmongery required to complete the whole Works in accordance with the following schedule subject to the approval of the FSSD. All ironmongery shall comply with SS 332 : 2007 and shall be at least half-hour fire-rated. The brand names specified in the schedule shall serve as a guide to the respective quality and profile of ironmongery required.
BLDG12/S27.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 27-2 27.3
HALF-HOUR FIRE-RATED TIMBER SURFACE FINISHED COMPOSITE DOORS TO STAIRCASE OF MULTI-STOREY CARPARK (CONT'D) (D)
Ironmongery (Cont'd) Unless otherwise specified, the grade of stainless steel shall be AISI Grade 304 . Schedule Of Ironmongery
(E)
(a)
4 no.
Stainless steel hinges.
(b)
1 no.
Door closer shall be listed in PSB Product Listing Scheme Class 1A. Approved slim line door closer with cushioned back checking action shall be of silver colour.
(c)
1 no
Stainless steel pull handles. The diameter shall be 18mm minimum and the length shall be approximately 225mm.
(d)
1 no.
Stainless steel push plate of size 300mm x 150mm. The thickness shall be 1.2mm minimum. The word "PUSH" shall be engraved and painted on the push plate
(e)
1 no.
"Alsecure" ASI/BC002/SS Ball Catch; or “Tiki” ACCORD RC/002 SS Roller Catch; or “YTL” BC002 SS Ball Catch or other approved stainless steel Ball Catch or Roller Catch.
Certificates The Contractor shall submit to the SO Rep certificates as documentary proof that the complete system of the fire-rated timber finish composite door including door frames and ironmongery installed are of at least half-hour fire-rated in all aspects approved by the FSSD.
(F)
Surfaces The surfaces of doors shall be in accordance with Clause 15.9 "Timber Doors".
(G)
Moisture Content The moisture content of timber for all timber components shall be in accordance with Clause 15.9 "Timber Doors".
27.4
HALF-HOUR FIRE-RATED TIMBER SURFACE FINISHED COMPOSITE DOORS TO LIFT MACHINE ROOM FOR MULTI-STOREY CARPARK
27.4.1
Over-Riding Clause The Contractor executing the Works as required in this clause including all sub-clauses under it shall ensure that the Works, goods or materials used shall be suitable and reasonably fit for the purpose of complying with the required fire-rating (hereinafter referred as "Performance Requirement"). In the event the Works, goods or materials to be used as specified in this clause including all sub-clauses under it are upgraded in order to meet the Performance Requirement, the Contractor shall do all necessary upgrading at no extra cost to the Employer subject always to the approval of the SO Rep, but such approval shall not in any way affect the Contractor's duties or obligations arising under the Contract.
27.4.2
General Where half-hour fire-rated timber doors to lift machine room are shown in the Drawings, the Contractor shall provide and install half-hour fire-rated timber surface finished composite doors to the lift machine room complete with timber door frames and ironmongery. The half-hour fire-rated timber surface finished composite doors, timber door frames and ironmongery shall be provided as a complete system complying with SS 332 : 2007. The complete system shall have PSB test certificates, PSB labels, FSSD approval and certified under PSB Product Listing Scheme Class 1A or 1B.
27.4.3
Shop Drawings And Sample The details shown in the Drawings shall serve as a guide. Prior to the installation, provide shop drawings, PSB Product Listing Scheme certificates, PSB test reports, PSB and FSSD approval for the approval of the SO Rep. Further, a complete sample shall be installed on the Site for the approval of the SO Rep before full implementation.
BLDG12/S27.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 27-3
27.4
HALF-HOUR FIRE-RATED TIMBER SURFACE FINISHED COMPOSITE DOORS TO LIFT MACHINE ROOM FOR MULTI-STOREY CARPARK (CONT'D)
27.4.4
Ironmongery Provide and fix all ironmongery required to complete the whole Works in accordance with the following schedule subject to the approval of the FSSD. All ironmongery shall comply with SS 332 : 2007 and shall be at least half-hour fire-rated and approved by FSSD. The brand names specified in the schedule shall serve as a guide to the respective quality and profile of ironmongery required. Provide and fix ironmongery in accordance with the following schedule:
27.4.5
(i)
4 no. 102mm x 76mm x 2mm stainless steel butt hinges for each door leaf.
(ii)
1 no. "Accord" 0706C/1404/1591B or “BLIY” N-27-FIR US 32D or other approved half cylinder mortice lockset with stainless steel lever handles on rose or on back plate on both sides (shall comply with CP 2:2000, the door shall be opened from the outside only by the use of key and shall not require a key to open it from within the machine room).
(iii)
1 no. Brass rebated part.
(iv)
1 no. 200mm x 20mm wide stainless steel lever action flush bolt in satin finish (box type).
(v)
1 no. 300mm x 20mm wide stainless steel lever action flush bolt in satin finish (box type).
(vi)
1 no. Door closer shall be listed in PSB Product Listing Scheme Class 1A. Approved slim line door closer with cushioned back checking action shall be of silver colour.
(vii)
1 no. Approved stainless steel selector.
Grade Of Stainless Steel Unless otherwise specified, the grade of stainless steel shall be AISI Grade 304.
27.4.6
Certificates Submit certificates to the SO Rep to certify that the complete system of the fire-rated timber surface finished composite doors including door frames and ironmongery installed are of at least half-hour firerated in all aspects approved by the FSSD.
27.4.7
Surfaces The surfaces of doors shall be in accordance with Clause 15.9 "Timber Doors".
27.4.8
Moisture Content The moisture content of timber for all timber components shall be in accordance with Clause 15.9 "Timber Doors".
27.5
HANDRAILS, PIPE SUPPORTS AND EXPANDED METAL TO PARAPET OF MULTI-STOREY CARPARK Provide and fix hot dipped galvanized steel handrails and pipe supports as shown in the Drawings. The hot dipped galvanised steel handrails and pipe supports shall be in accordance with the requirements specified in Section 17 "Structural Steelwork" including all clauses and subclauses under it. Provide and install "Bestal" BMM 3060 or "Emco" SM 3060; or other approved hot dipped galvanised steel expanded metal to parapet. The expanded metal shall be of the following nominal size : SWM LWM Thickness Strand Width
BLDG12/S27.DOC(3) Sal(151211) (DPD)
= = = =
42 mm 115 mm 3 mm 6 mm
Bldg Spec Page 27-4 27.5
HANDRAILS, PIPE SUPPORTS AND EXPANDED METAL TO PARAPET OF MULTI-STOREY CARPARK (CONT'D) All metal strips and screws used for fixing shall be of hot dipped galvanised steel. The details of the expanded metal shall be as shown in the Drawings. The handrails, pipe supports and expanded metal shall be fabricated and assembled in the factory unless otherwise specified. All exposed surfaces shall be straight and smooth. All joints shall be fully welded and no spot welding shall be used in the Works. All welds shall be finished smooth and secured. All galvanised steel surfaces shall first be treated with one coat of polyvinyl butyral etching primer and one coat of lead and chromate-free primer and then painted with one undercoat and one finishing coat of enamel paint. The finishing colour shall be approved by the SO Rep.
27.6
RAILING, PIPE SUPPORTS AND BALUSTERS TO STAIRCASE OF MULTI-STOREY CARPARK Provide and fix hot dipped galvanised steel railings, pipe supports and balusters as shown in the Drawings. The hot dipped galvanised steel railings, pipe supports and balusters shall be in accordance with the requirements specified in section 17 "Structural Steelwork" including all clauses and subclauses under it. All exposed surfaces shall be straight and smooth. All joints shall be fully welded and no spot welding shall be used for the Works. All welds shall be finished smooth and secured. All galvanised steel surfaces shall first be treated with one coat of polyvinyl butyral etching primer and one coat of lead and chromate-free primer and then painted with one undercoat and one finishing coat of enamel paint. The finishing colour shall be approved by the SO Rep.
27.7
GALVANISED STEEL L-ANGLE TO ALL CORNERS OF COLUMNS AND WALLS Provide and fix galvanised steel L-angle and mild steel flat to all internal corners of columns and walls (next to driveways and ramps including 500mm walls) to the dimensions and details as shown in the Drawings. The L-Angle shall be flushed against the finished surfaces of walls or columns. Paint galvanised steel angles with two coats of luminous paint approved by the Land Transport Authority. The colour shall be approved by the SO Rep.
27.8
SIGNBOARDS All signboards and letterings shall be as shown in the Drawings. These shall be installed at positions as decided by the SO Rep or as stated in the Drawings.
27.9
TRAFFIC SIGNS Traffic signs shall be of retro-reflective material and of brightness as approved by the Land Transport Authority. Letterings, plates and details shall be as shown in the Drawings. Galvanised steel pipes specified in the Drawings shall comply with SS17. Samples of the traffic signs shall be approved by the SO Rep.
27.10
PAINTING (A)
External Painting And Warranty Paint all external plastered, skim coated and concrete surfaces with water based algae resistant emulsion paint in accordance with Clause 23.2 "External Painting" including all subclauses under it. The Contractor and his Specialist shall warrant the work on the same terms and conditions as stipulated in the Deed of Warranty For External Painting as produced in Appendix A5 and/or A5(TC) as decided by the SO Rep.
BLDG12/S27.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 27-5 27.10
PAINTING (CONT'D) (B)
Internal Painting Paint all internal plastered, skim coated and concrete surfaces with one priming coat and two subsequent coats of approved acrylic emulsion paint. The priming coat may be with thinning of up to 20% of clean water by volume. Subsequent coats shall not be diluted.
(C)
Painting Of Sample Prior to the commencement of the painting work, submit the colour chart of approved paint to the SO Rep for selection of colour scheme. The Contractor shall then paint one or more panels of the multi-storey carpark parapets for the approval of the SO Rep.
27.11
TRAFFIC LINES, ARROWS AND DIRECTIONAL ARROWS ON FLOORS Unless otherwise specified, all traffic lines, arrows and directional arrows on floors shall be of reflectorised thermoplastic road marking as approved by the Land Transport Authority. The thermoplastic material shall comply with SS 498:Part 1:2002 "Specifications for Hot Applied Thermoplastic Road Marking Materials". The reflectorised thermoplastic road marking shall be provided strictly in accordance with the supplier's instructions. Samples shall be approved by the SO Rep before full implementation.
27.12
CAR PARKING BAYS Paint white lines, red lines, numbers and letterings of the parking bays as shown in the Drawings or as instructed by the SO Rep. Unless otherwise specified, the paint shall be quick drying chlorinated rubber based and shall comply with the requirements specified in SS221 2002 ""Specification for Road Marking Paint".
27.13
FORMWORK TO MULTI-STOREY CARPARK In addition to complying with the requirements specified in Clause 4.19 "Formwork" including all subclauses under it, the Contractor shall also comply with the following requirements for formwork to MultiStorey Carpark/Garage : (a)
Propping to the slabs and beams at the lower floor deck shall not be removed until the slabs and beams of the upper floor deck have been cast for 3 days.
(b)
The Contractor shall check and ensure that propping to the slabs and beams is adequate at all times.
BLDG12/S27.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 27-6
27.14
WATERPROOFING MEMBRANE AT PLANTER BOXES AT TYPICAL DECK OF MULTI-STOREY CARPARK
27.14.1
Scope of Work The Contractor shall provide and lay liquid applied Flexible Non-Cementitious (Water-Based) Waterproof Membrane, as listed in HDB’s Materials List or other approved Flexible Water-Based Waterproof Membrane to all the sides (internal surfaces) of the planter boxes. All the surfaces shall be examined for defects, and the waterproofing treatment shall be applied on sound concrete.
27.14.2
Preparation Work Concrete surfaces shall be clean from all scale, laitance, loose material, mould oil, curing agents, cracks and honeycombs. The structure shall be ponded prior to the waterproofing treatment to allow identification and rectification of cracks and honeycombs by grouting.
27.14.3
Application The liquid applied Flexible Non-Cementitious (Water-Based) Waterproof Membrane shall be applied in three coats to obtain a minimum dry film thickness of 1.5mm. The subsequent coats shall only be applied after the first coat has dried.
27.14.4
Testing and Checking After completion of the waterproofing work but prior to the laying of screed or other infill material, the planter boxes shall be tested for water-tightness by ponding by plugging all outlets; and flooding it, with clean water, to the full height of the planter box. There shall be no leakage after a flooding period of at least 48 hours. In areas where leaks are observed during test periods, such areas shall be recoated with the application of additional membrane material. Recoated areas shall be re-tested and further re-coated until such recoated areas pass the water test.
27.14.5
Protection Immediately after the approval by the SO Rep of water test, the Contractor shall apply a skim coat to all the sides (internal surfaces) of the planter boxes to prevent damages to the waterproofing membrane.
Section 28/..... BLDG12/S27.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 28-1 SECTION 28 ELECTRICAL SUB-STATION/UTILITIES CENTRE/DUSTBIN COMPOUND
28.1
ELECTRICAL SUB-STATION
28.1.1
General Electrical Substation shall be deemed to include Electrical Substation, Ring Main Substation, Transformer Room, Generator Room, Tank Storage Room and all other utility rooms for electricity transmission, whether located separately or within a building block. Where metal roofing is used, it shall be as specified in Clause 13.3 "Metal Roofing And Insulation Sheet" including all subclauses under it.
28.1.2
Construction Time Commence work immediately when site is handed over and shall complete the electrical substation including fencing as shown, not later than the Expiry of the Time for Completion as specified in the Contract. Where no such date is stipulated, the substation including fencing shall be completed not later than six calendar months before the Expiry of the Time for Completion of the earliest phase of the contract or the Expiry of the Time for Completion of the earliest dwelling block if the Works is to be completed as a single phase.
28.1.3
Cable Room of Electrical Substation Where shown in the Drawings, the cable room shall be cast in waterproof concrete with precaution taken to render it watertight. In the case where the water table is high, provide drainage for the cable room after consulting with the SO Rep.
28.1.4
Cable Ducts Provide and lay 155mm UPVC pipes in numbers, positions and lengths as shown and encased all round with mass concrete to serve as cable ducts. All UPVC pipes shall be of at least Class C type complying with the requirement of SS 141 or other approved by PowerGrid. Both ends of the UPVC pipes shall be sealed with removable water-tight plugs. The cable ducts shall be extended at least 600mm beyond the apron and adjacent drain. Prior to the laying of ducts, check the ground conditions and should the ground be soft, inform the SO Rep who shall decide whether piling is required or not.
28.1.5
Cable Trenches, Drains And Switch Gear Floor Openings Cable trenches, drains and switch gear floor openings shall be provided with removable heavy duty A1 chequer plates or heavy duty GS gratings as shown in the Drawings capable of supporting a minimum load of 100 kg. Depth of trenches shall be as shown in the Drawings. After the completion of cable installation by PowerGrid, all entries shall be sealed and water tight to the requirements of PowerGrid. Sand or granite chips shall be provided to fill cable trenches.
28.1.6
Concrete Paved Areas Surrounding concrete paved area within fence shall be 75mm thick 1:2:4 concrete reinforced with 1 layer No. A6 welded steel fabric on 100mm consolidated hardcore.
BLDG12/S28.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 28-2 28.1.7
Reinforced Concrete Drain And Crossing Construct length of surface drain in reinforced concrete to details as shown. Precast concrete drain covers shall be 75mm thick reinforced with 2 layers No. A6 welded steel fabric or approved reinforcement with main reinforcement spanning across drain.
28.1.8
Hollow Glass Blocks Build hollow glass block panels shown in the Drawings and in accordance with the Manufacturer's printed instructions. The size of the glass block shall be 150mm x 150mm x 100mm and approved by the SO Rep. Fix 'EXMET' 60mm No. 20 or other approved reinforcing strip at every second course. Carry reinforcements into brickwork or leave dowel bars of 4mm galvanised wire in reinforced concrete structure to lap with reinforcement. Mortar shall be in accordance with Clause 12.1 "Mortar Mix For Block And Brickworks" and pointed with white Portland Cement. Paint openings around panel with bitumen before laying glass blocks.
28.1.9
Bronze Anodised Extruded Aluminium Vents To Electrical Substation Provide and install bronze anodised extruded aluminium vent together with all necessary components to all electrical substations as indicated in the Drawings. The aluminium frames and louvre blades shall be extruded with the minimum thickness of 2.3mm and finished with 25 microns (minimum) anodic coating
28.1.10
Finishing To Internal Floors, Landings And Steps All internal floors except basement landing, steps and transformer plinth shall be provided with 50mm thick cement rendering including a smooth 20mm thick granolithic finish of 1 part cement, 1 part fine granite chippings and 1 part sand with the addition of approved hardener all mixed in accordance with the Manufacturer's printed instructions. All walls and columns shall be provided with minimum 18mm cement plastering.
28.1.11
Time For Rendering Allow for carrying out rendering after PowerGrid has installed their floor frames, switch gears and equipment which may be some time after the sub-station is handed over to PowerGrid after the Date of Substantial Completion for the sub-station. The PowerGrid Engineer-in-charge shall be notified prior to final rendering of the switch room floor.
28.1.12
Finish To Flat Roof Lay screed to flat roof with minimum fall of 1 in 60 of 1:3 cement:sand mix gauged with approved waterproofing compound to the Manufacturer's printed instructions. Screed shall be minimum 18mm thick.
28.1.13
Painting External And Internal Walls And Ceiling Paint all vents, fascias, columns and beams, skimmed and plastered surfaces as specified in Section 23 "Painting And Decorating" including all clauses and subclauses under it.
28.1.14
Final Coat Painting And Touching Up Allow for waiting until PowerGrid has installed sub-station equipment before applying final coat of painting and touching up. This work may not be carried out within the Time for Completion of this part of the Works.
BLDG12/S28.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 28-3 28.1.15
Electrical Installation (A)
General Provide and install electrical installation and fittings shown including earthing systems for the electrical installation. Installation shall be carried out by a licensed electrician to the satisfaction of the SO Rep and complying with the requirements of PowerGrid. All wiring shall run in galvanised steel exposed conduits (not smaller than 20mm diameter) with spacer bar saddles and bases to BS EN ISO 1461.
(B)
Application For Testing The installation shall be tested/verified by and to the requirements of HDB's Plan Approval (M&E/Testing ) Unit and approved by the SO Rep before handing over to PowerGrid. For all tests, at least seven (7) working days advance notice shall be given to the SO Rep.
(C)
Retesting Any omissions or Defect or faults detected during the day of testing shall be rectified and the Contractor shall arrange for re-testing within three working days from the date of the last test.
28.1.16
Ironmongery All ironmongery shall be as shown in the Drawings.
28.1.17
Fence And Gate Where shown in the Drawings, fencing shall be carried out in accordance with Section 12 "Brickwork And Blockwork" including all clauses and subclauses under it. The gates shall be hung on clay brick piers and run on rollers over rails all as shown in the Drawings. Chainlink perimeter fencing shall be of the PVC. covered type (green or grey) wire mesh. The base support of the fencing shall be embedded in 150mm concrete kerb. Ironmongery to gate shall be as shown in the Drawings.
28.1.18
Painting Fence And Gate Paint all metal work and gate as specified in Section 23 "Painting And Decorating" including all clauses and subclauses under it.
28.1.19
Catch For Trap Door In Switch Room Floor Provide and fix brass hook and eye for trap door.
28.1.20
Cat Ladder And Handle Provide and fix mild steel cat ladder and handrail as shown.
28.1.21
Hot Dipped Galvanised Steel Handrail (Electrical Sub-station) Provide and fix hot dipped galvanised steel pipe handrail to locations as shown in the Drawings. Dimensions of hot dipped galvanised steel handrail, pipe supports and balusters shall be as shown in the Drawings. All exposed surfaces shall be straight and smooth. All joints shall be fully welded and no spot welding shall be used for the Works. All welds shall be finished smooth and secured. All galvanised steel surfaces shall first be treated with one coat of polyvinyl butyral etching primer and one coat of lead and chromate-free primer and then painted with one undercoat and one finishing coat of enamel paint. The finishing colour shall be approved by the SO Rep.
BLDG12/S28.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 28-4 28.1.22
Doors To Electrical Substation (A)
Extruded Anodised Aluminium Doors Provide and fix extruded natural anodised aluminium doors with anodic coating not less than 25 micron (including all components, shoot bolt etc) as shown and in accordance with the detailed Drawings.
(B)
Acoustic Doors To Generator Rooms Provide and fix extruded natural anodised aluminium doors infilled with 38mm thick rockwool insulation material of density 150 kg per m³ (±10% tolerance). The noise reduction coefficient shall be NRC 0.76 within the sound range of 180-2800 Hz. Moisture resistance shall not be more than 0.2% by volume. The rockwool shall be non-combustible with fire hazard indices at Class O. Where rockwool is shown in the Drawings, the rockwool shall be of "Bradford Rockwool, FibertexR60"; or other approved. Doors (including all components, shoot bolt etc) shall be of natural anodised aluminium of anodic coating not less than 25 micron and constructed to resist any water penetration into the cavity of the door. Provide and fix heavy duty door hinges capable of bearing 80 kg of load per leaf. The Drawings shown shall serve as a guide. Submit workshop drawings showing all the detailed sections, plans and relevant details and accessories to the SO Rep for approval prior to installation.
28.2
UTILITIES CENTRE/DUSTBIN COMPOUND
28.2.1
General Construct Utilities Centre/Dustbin Compound to details as shown in the Drawings unless specified otherwise. Timber benches, shelves, notice board, lockers, etc., shall be provided and fixed to locations all as shown in the Drawings.
28.2.2
Floor Slab The floor slab shall be cast in Grade 40 structural concrete. Compliance criteria and specifications shall follow Section 4 "Structural Concrete" including all clauses and subclauses under it. The slab shall be finished with a minimum 3 passes of a power trowel strictly without sprinkling of cement dust, cement grout or water. Provide a sufficient team of workmen to finish the work before final set. The slab shall be immediately cured for seven days with approved curing compound or other approved methods. The surface shall be hardened with approved liquid hardeners strictly in accordance with the Manufacturer's instruction. The liquid hardeners shall have zinc and/or magnesium fluorosilicates as its active ingredients. The scupper drain shall be finished with rendering of 1 part cement to 3 parts sand by volume. The rendering shall be laid to fall towards water outlets. The rendered surface shall then be finished with two coats of liquid hardeners (with zinc and/or magnesium fluorosilicates as its active ingredients).
28.2.3
Finish To Reinforced Concrete Flat Roof Provide and lay screed of 1:3 cement:sand mix gauged with approved water-proofing compound to the Manufacturer's instructions to reinforced concrete flat roof with minimum fall of 1 in 180. Screed shall be of a minimum of 18mm thick.
BLDG12/S28.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 28-5 28.2.4
Roller Shutter To Utilities Centre/Dustbin Compound (i)
Motorised Roller Shutter For Door Height Four (4) Metres And Above Provide and install motorised roller shutter complete with channel guide, shutter motor, angle bolts, bottom rail and other necessary components in accordance with the Manufacturer's instructions to utilities centre/dustbin compound of door opening height 4 metres and above unless otherwise specified : (a)
Material The motorised roller shutter shall be of 0.8mm thick minimum galvanised steel or 1.6mm thick natural anodised aluminium interlocking slats with end clips to secure slats laterally or 0.5mm thick minimum Zincalume steel curtain permanently lock-seamed to form a continuous curtain. Provide a seamless PVC weatherseal at the base of the rail. Secure the curtain top and wrap it around the drum assembly. Provide box housing of similar material with the curtain to house the entire drum assembly and integral chainwheel complete with galvanised steel chain or other approved for manual operation. Provide perforation slots of 100mm x 25mm spaced at 400mm apart to approximately the top one-third of the curtain height to the approval of the SO Rep. Provide edge-treatment to prevent metal to metal contact between the curtain and the guides during operation.
(b)
Coating Aluminium shutter shall be natural anodised to 25 microns (minimum). Zincalume steel and galvanised steel shutter shall be finished with 25 microns (minimum) colorbond silicone modified polyester coating. The finishing colour of the coating shall be selected by the SO Rep.
(c)
Power Supply And Operation System Tap the power supply for the motor from a 10 Amperes TPN isolator in the utilities centre/dustbin compound. Connect with electrical wiring from the isolator to the motor. Provide a built-in auto-stop safety device to the system so that the roller shutter shall automatically stop when it is obstructed during the closing operation. Provide push-button switches enclosed in a weatherproof control box and mount it outside at 1.6m measured from the floor to the base of the control box and on the right hand side of the utilities centre/dustbin compound viewing from the front. Provide the control box with Camlock model "L & F" A/CR 11 or 16 with key no. 01/3S/N65; or other approved. The control box shall contain "Up", "Down", and "Stop" buttons. Indicating arrows pointing upwards and downwards shall be marked indelibly beside the "Up" and "Down" buttons. The motorised roller shutter shall stop immediately after the end of "Up" or "Down" operation.
(d)
Workshop Drawings The details shown in the Drawings shall serve as a guide. Submit workshop drawings showing all the detailed sections, plans and relevant details and accessories to the SO Rep for approval prior to the ordering of the system.
(ii)
Manually Operated Roller Shutter For Door Height Below Four (4) Metres Provide and install zincalume steel or galvanised steel or natural anodised aluminium roller shutter complete with channel guides, angle bolts, bottom rails and other necessary components in accordance with the manufacturer's instructions to utilities centre/dustbin compound of door opening height below four (4) metres unless otherwise specified. (a)
Material The roller shutter shall be of 0.8mm thick minimum galvanised steel or 1.6mm thick natural anodised aluminium interlocking slats with end clips to secure slats laterally or 0.5mm thick minimum Zincalume steel curtain permanently lock-seamed to form a continuous curtain. Provide a seamless PVC weatherseal at the base of the rail. Secure the curtain top and wrap it around the drum assembly. The drum assembly shall consist of suitably graded oiltempered torsion springs secured to drumwheels moulded from engineering plastics. Provide box housing of similar material with the curtain to house the entire drum assembly and integral chainwheel complete with galvanised steel chain or other approved for manual operation.
BLDG12/S28.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 28-6 28.2.4
Roller Shutter To Utilities Centre/Dustbin Compound (Cont'd) (ii)
Manually Operated Roller Shutter For Door Height Below Four (4) Metres (Cont’d) (a)
Material (Cont’d) Provide perforation slots of 100mm x 25mm spaced at 400mm apart to approximately the top one-third of the curtain height to the approval of the SO Rep. Provide edge treatment to prevent metal to metal contact between the curtain and the guides during operation. Locking device with master key shall be provided at waist level.
(b)
Coating Aluminium shutter shall be natural anodised to 25 microns (minimum). Zincalume steel and galvanised steel shutter shall be finished with 25 microns (minimum) colorbond silicone modified polyester coating. The finishing colour of the coating shall be selected by the SO Rep.
(c)
Operation System The shutter shall be hand chain operated. The raising and closing of the shutter shall be 250mm minimum per metre chain-pull.
(d)
Workshop Drawings The details shown in the Drawings shall serve as a guide. Submit workshop drawings showing all the detailed sections, plans and relevant details and accessories to the SO Rep for approval prior to the ordering of the system.
28.2.5
Bronze Anodised Extruded Aluminium Vents To Utilities Centre/Dustbin Compound Provide and install bronzed anodised extruded aluminium vents together with all necessary components as indicated in the Drawings. The aluminium frames and louvre blades shall be extruded with the minimum thickness of 2.3mm and finished with 25 microns (minimum) anodic coating.
28.2.6
Ceramic Floor Tiles Provide and lay 200mm x 200mm x 8mm thick glazed ceramic floor tile to wash area and toilet all as shown in the Drawings. The qualities shall be as specified in Clause 19.4 “Ceramic Floor Tiles (Common Areas and Non-Residential Units)”
28.2.7
Key Boards Provide and install one 1200mm x 1200mm keyboard consisting of Kapor frame, plywood backing, plywood door panel all as shown in the Drawings for every block of Utilities Centre. Provide angle hooks for keys fixed 75mm centres both ways and 2 no. brass hangers to each board. Paint woodwork according to Section 23 "Painting And Decorating" including all clauses and subclauses under it).
Section 29/..... BLDG12/S28.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 29-1 SECTION 29 EATING HOUSE
29.1
FLOOR FINISHES Except for the "Store" and "room" the whole floor of Eating houses shall be finished in ceramic tiles as specified in sub-clause 19.4.5 "Schedule Of Ceramic Floor Tiles". Tiles shall continue up doorways to abut external floor rendering. The colour and pattern of the tiles shall be approved by the SO Rep. The quality and laying of the tiles shall be as specified in Clause 19.4 "Ceramic Floor Tiles (Common Areas and Non-Residential Units) " and Clause 19.7 “Laying Of Ceramic Floor Tiles” including all subclauses under them.
29.2
CERAMIC TILE WALL (EATING HOUSES) Except for the "store" and "room", all internal surfaces of walls and columns in the refreshment area and stalls of eating houses shall be finished with 200mm x 200mm x 8mm glazed ceramic wall tiles to a height of 2100mm above reinforced concrete floor level. Where shown in the Drawings, provide and lay 200mm x 200mm x 8mm glazed ceramic wall tiles to a height of 600mm above the stainless steel sink and draining board or to the window cill height if the sink and draining board is located along the window. Provide and lay 200mm x 200mm x 8mm glazed ceramic wall tiles to kitchen, toilets/bath/wc, bin area and wash area. The height of glazed ceramic wall tiles shall be as shown in the Drawings. All glazed ceramic wall tiles shall be of the quality as specified in Clause 20.13 "Ceramic Wall Tiles (NonResidential Units and Common Areas)" including all subclauses under it.
29.3
BRICK/BLOCKWORK AND PLASTERING Construct walls as shown in the Drawings and as specified in Section 12 "Brickwork And Blockwork" including all clauses and subclauses under it. Plastering where shown shall be as specified in Section 20 "Wall Finishes" including all clauses and subclauses under it.
29.4
PAINTING Painting shall be as specified in Section 23 "Painting And Decorating" including all clauses and subclauses under it.
29.5
DOORS AND IRONMONGERY Doors to eating houses shall be as shown in the Drawings, complete with ironmongery as specified in Section 16 "Ironmongery" including all clauses and subclauses under it.
29.5.1
Timber Doors All timber doors where shown in the Drawings shall be constructed as specified in Section 15 "Carpentry And Joinery" including all clauses and subclauses under it. Sizes are nominal. Plywood panels shall be of grade 2 moisture resistant quality.
29.5.2
PVC Doors Extruded PVC doors to common water closets and bathroom shall be as specified in Clause 15.15 "Full Panel Extruded PVC Swing Doors". Except for bath/w.c. in room and main entrance door to toilets, each common w.c. door shall be fixed with a pair of aluminium alloy eyes for hanging on to mild steel hooks and rides built into masonry. Provide and fix plastic male and female toilet signs with thickness and sizes all as shown in the Drawings.
BLDG12/S29.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 29-2 29.6
PREPARATION TABLES Construct preparation tables in Grade 25 and 100mm thick in-situ concrete slabs reinforced with one layer of No. A6 welded steel fabric supported on 90mm thick solid concrete block wall finished with 200mm x 200mm x 8mm (nominal size) thick ceramic tiles with mosaic cove tiles for returned edges all as shown in the Drawings.
29.7
COOKING SLABS Where shown, cooking slabs shall be constructed and finished as specified in Clause 29.6 "Preparation Tables".
29.8
FAN HOOKS Cast fan hooks into positions as shown, bent out of 13mm diameter mild steel rod to ceiling of eating houses.
29.9
EXHAUST FAN OPENING Provide opening for exhaust fans in positions shown and trim with Kapor frame rebate and bead. Fill with 12mm thick calcium silicate boards. Paint frame and panel as specified in Section 23 "Painting And Decorating" including all clauses and subclauses under it.
29.10
EXTRACTOR FANS AND DUCTS Extractor fans and ducts are not included in this Contract unless as specified otherwise.
29.11
ALUMINIUM ROLLER SHUTTER Where shown in the Drawings, provide and install aluminium roller shutters to eating houses as specified in Clause 18.8 "Aluminium Roller Shutter".
29.12
ALUMINIUM CASING TO DISCHARGE STACKS/PIPES AND ALUMINIUM SHEET COVERING Where shown in the Drawings, the aluminium casing to discharge stacks/pipes enclosure and aluminium sheet covering shall be constructed with 50mm x 25mm x 1.2mm thick aluminium frame and lined with 1.2mm thick (18 SWG) natural anodised aluminium sheet. The anodic coating shall be 15 microns minimum. Access panels shall be provided as shown in the Drawings and at the positions of the cleaning eyes.
29.13
ADJUSTABLE AND FIXED GLASS LOUVRES Where shown in the Drawings, provide and install bronze anodised aluminium frame adjustable and fixed glass louvres. The anodic coating shall be 25 microns minimum. Glazing shall be in accordance with Section 22 "Glazing" including all clauses under it.
29.14
PLYWOOD SHELVES Where shown, the 19mm thick plywood shelves to store shall be supported by 31mm x 31mm x 1.2mm thick mild steel hollow sections.
BLDG12/S29.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 29-3 29.15
METAL ROOFING AND INSULATION Where shown in the Drawings, the metal roofing and the insulation shall be provided and laid as specified in Clause 13.3 "Metal Roofing And Insulation Sheet" including all subclauses under it.
29.16
SUSPENDED CEILING Provide and fix 1200mm x 600mm x 16mm thick non-combustible mineral fibre board to stalls with aluminium T section and be supported by 14 SWG galvanised steel hanger wire all as shown in the Drawings. Each panel shall be reinforced with 2 no. of spline glued to the back of the board.
Section 30/.....
BLDG12/S29.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 30-1 SECTION 30 MISCELLANEOUS (BUILDING)
30.1
GROUND FLOOR FACILITIES Provide and fix the facilities (eg. table tennis table, kiosks, tables, benches etc.) at 1st storey all as shown in the Drawings. Painting to timber and metal work shall be as specified in Section 23 "Painting And Decorating" including all clauses and subclauses under it.
Section 31/.....
BLDG12/S30.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 31-1 SECTION 31 FABRICATION AND PROVISION OF REFUSE BINS, LITTER BINS, BULK CONTAINERS AND TROLLEYS
31.1
SCOPE OF WORKS The scope of work in this Contract comprises: (i)
Fabrication and delivery of 250-litre refuse bins;
(ii)
Fabrication and delivery of post/wall mounted polyethylene litter bins (including installation);
(iii)
Fabrication and delivery of six-bin trolleys, 0.7 cubic metre rectangular bulk refuse containers model "E" and bulk containers frame model "EF"; and
The required no. of bins and frames shall be as specified in the table below: Facility 0.7 cubic metre Bulk Container Utility Centre Refuse Room Bulky Refuse Room where there are ground floor units Every 3 blocks Every deck for MSCP Every 80 parking lots for Surface Car Park
31.2
Items
Frame for Bulk Container 250-litre Refuse Bin 250-litre Refuse Bin Six-Bin Trolley Wall Mounted Litter Bin Post Mounted Litter Bin
Quantity Required Per Facility 1 1 2 2 1 2 1
GOODS (a)
In the specifications, the expression "the Goods" shall unless the context otherwise requires, means the six-bin trolley and the 0.7 cubic metre bulk refuse container model "E", bulk container frame model "EF", the 250-litre refuse bins and the post/wall mounted polyethylene litter bins.
(b)
Every six-bin trolley, 0.7 cubic metre bulk refuse container model "E" and bulk container frame model "EF" accepted by the Superintending Officer's Representative shall be assigned a serial number. The Contractor will be notified on the beginning serial number of the respective type of goods within a reasonable period and the subsequent serial number shall then be assigned by the Contractor on the same format and set at one unit increment. Each serial number shall be engraved at the spot directed by the Superintending Officer's Representative and of a size approved by the Superintending Officer's Representative.
(c)
All components for incorporation into the Works shall be in metric units. However, if any components are not available in metric units its equivalent in imperial units may be used subject to the approval of the Superintending Officer's Representative and such a substitution will not constitute a variation to the Contract.
BLDG12/S31.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 31-2 31.3
POST / WALL MOUNTED POLYETHYLENE LITTER BIN
31.3.1
Dimensional Details Each post/wall mounted polyethylene litter bin shall be provided complete with separate hood, ash-tray, aluminium inner liner, bin body and mounting brackets. (a)
Bin body and hood The bin body and hood shall be designed and manufactured to withstand strong sunlight and extremes in temperature without fading or cracking. (i)
Material Linear medium density or high density polyethylene. No rework material shall be used. The density of the material shall be within the range of 0.935 to 0.965 g/cm3. The melt index of the material shall be within the range of 1.0 to 8.0 g/10 min. The bin shall be opaque and have the feature of being impact - resistant and ultra-violet stabilised such that it can withstand continuous use under long hours of strong direct sunlight without any adverse change to its physical and mechanical properties and performance.
(ii)
Capacity 25 - 40 litres (without hood)
(iii) Height 450 - 550 mm (without hood) (iv) Width 360 - 450 mm (bin body) (v)
Depth 240 - 350 mm (bin body)
(vi) Thickness 2.8 mm (minimum) and meeting all other Specifications (vii) Ash-Tray 120 mm diameter x 60 mm height x 0.8 mm thick reflective finished stainless steel of AISI Grade 304 with 3 Nos of 5 mm diameter equally spaced holes at base and 175 mm x 95mm stubbing plate (Optional). The ash-tray shall be securely fixed to the top of the hood and shall not affect the aesthetics of the bin adversely. The hood should be firmly fitted to the bin body but also allows for easy emptying of the contents from the bin as and when necessary. The hood should only have one side opening with a minimum breadth of 110mm and minimum length of 200mm, and shall be fastened to the bin body by a 400mm long stainless steel chain or other method of fastening which is to be approved by the Superintending Officer's Representative.
(b)
Aluminium liner (i)
The liner shall not be less than 0.8mm thick
(ii)
The liner should fit the inner part of the bin with room for easy fitting
(iii) The liner shall have a fitted handle for lifting (iv) The liner shall be detachable (v)
BLDG12/S31.DOC(2) Sal(151211) (DPD)
All corners of liners shall be rounded
Bldg Spec Page 31-3
31.3
POST / WALL MOUNTED POLYETHYLENE LITTER BIN (CONT’D)
31.3.1
Dimensional Details (Cont’d) (c)
Bracket (i)
Material
:
26 mm (wide) x 5 mm (thick) galvanised bracket bent to shape and size as shown in Appendix A49 Drawing No. CMU-LB-01, and secured with galvanised bolts and nuts.
(ii)
Strength :
The bracket should be able to support the bin body with a full load of up to 15 kg.
(iii) Paint
31.3.2
31.3.3
:
The bracket shall come with a coat of approved red lead primer to surfaces of bracket, nuts and bolts etc and two coats of good quality aluminium paint.
Design (a)
The internal form and surface of the bin shall be such that it will not trap the contents.
(b)
There shall be no sharp edges anywhere on the bin.
(c)
The internal and external surfaces shall be smooth and non porous, free from cracks, splits, dents, distortion, blisters, voids, air bubbles and other surface blemishes or defects.
(d)
It shall be substantially uniform in colour. The Contractor shall make available 2 choices of colour, the hues of which shall be approved by the Superintending Officer's Representative.
(e)
The litter bin shall be sufficiently stiff such that its shape and form is maintained when subject to continuous use over a long period of time.
(f)
Six (6) numbers of 10 mm diameter holes are to be provided at the base of the post mounted litter bin to drain off rainwater.
Installation The Contractor shall install the post/wall mounted polyethylene litter bin in the manner specified in the Drawings (as shown in Appendix A49) at locations designated/ instructed by the SO Rep. The polyethylene litter bin shall be installed in the following manner: (a)
Wall Mounting 26 mm (wide) x 5 mm (thick) galvanised brackets bent to shape and size as shown in the Drawings (as shown in Appendix A49), are clamped to the bin with bolts and nuts. Wall plug or ramset bolt shall be used for mounting the bin to wall.
(b)
Post Mounting 26 mm (wide) x 5 mm (thick) galvanised brackets bent to shape and size as shown in the Drawings (as shown in Appendix A49), are clamped to the bin with bolts and nuts. Hose clips shall be used for mounting the bin to post.
(c)
The Contractor shall ensure that the mounting of the brackets for post mounted bin shall not obstruct the lamp posts terminal box cover to facilitate maintenance when required.
(d)
The Contractor shall ensure the mounting would keep the bin upright and minimise any strain on the bin body.
The Contractor shall include in the Contract Sum for the cost to remove and cart away the existing brackets and bins during the replacement with new bins. For new installation of bins, there shall be no cost adjustment to the contract price.
BLDG12/S31.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 31-4
31.4
LOGO The Litterman logo shall be hot foiled stamped on the outer face of the litter bin body.
31.5
250-LITRE LOW DENSITY POLYETHYLENE REFUSE BIN
31.5.1
Materials The refuse bins shall be manufactured from formulated and compounded linear low-density polyethylene for use with normal household refuse except hot ashes. No rework material shall be used. The density of the material shall be within the range of 0.926 to 0.940 g/cm3. The melt index of the material shall be within the range of not less than 1.0 to 8.0 g/10 min. The carbon black content shall not be less than 0.5% and shall provide optimum protection against ultraviolet light degradation. The finely divided carbon black shall have mean particle sizes of less than 25nm and shall be well dispersed. The carbon black shall be melt-compounded. No dry blending of carbon black is permitted.
31.5.2
Dimensional Details Of 250-Litre Refuse Bin Dimensional Specification
Unit
Bin Sizes
Overall Height
(mm)
740
Overall Width
(mm)
700
Overall Length
(mm)
700
Tolerance
(mm)
10
(Litres)
250
(kg)
9.0
Minimum Wall Thickness
(mm)
4.0
Minimum Base Thickness
(mm)
6.0
Minimum Capacity Minimum Weight (Excluding Handles)
31.5.3
Design (a)
Body The refuse bin shall be designed such that its internal form and surface will not trap refuse when it is being emptied as shown in the Drawings (as shown in Appendix A49). The internal and external surfaces of the refuse bin shall be smooth and reasonably free from surface blemishes and contamination, air bubbles, blisters and voids, and shall be substantially uniform in colour. The refuse bin shall have no sharp edges and shall be moderately stiff such that its shape and form is maintained when subject to continuous use over a long period of time.
(b)
Base The base of the refuse bin shall be designed to withstand regular dragging during refuse collection time. It shall also be designed to withstand impact from falling refuse. When tested in accordance with the method described in Clause 31.5.4, there shall be no visible weakening and no permanent distortion or splitting to the base or main body of the refuse bin. Eight holes of 10mm diameter shall be provided at the base to allow sullage water to drain out. The holes shall be located such that they will not affect the physical properties or performance of the bin in any way.
BLDG12/S31.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 31-5
31.5
250-LITRE LOW DENSITY POLYETHYLENE REFUSE BIN
31.5.3
Design (c)
(CONT’D)
(Cont’d)
Handles for Refuse Bins Each refuse bin shall be fitted diametrically opposite with two solid cylindrical drop handles, situated above the centre of gravity of the empty bin. Each handle shall be shaped so as to give a hand hold. The handle shall be 95 mm long and have a diameter of at least 9 mm. It shall be made of metal and protected against corrosion. Each handle shall be fitted to the wall of the refuse bin with four bolts such that the wall of the bin is sandwiched between the front and back plates. The back plate shall be of 3 mm minimum thickness in one piece and shall measure not less than 60 mm x 120 mm. The front plate shall be of 2 mm minimum thickness in one piece and shall measure not less than 60 mm x 120 mm incorporating an approved design for housing the drop handles of the refuse bin. The front, back plates and bolts and nuts shall be galvanised and protected against corrosion. When tested in accordance with the method described in Clause 31.5.4, there shall be no visible weakening of the attachments and no permanent distortion or splitting to the main body of the refuse bin. The refuse bin shall also be designed with two recessed finger grip positioned vertically below the drop handles. The recessed finger grip is approximately 130 mm from the base of the bin. It shall be shaped so that there are no sharp corners or edges.
31.5.4
Tests The following two tests shall be carried out on samples randomly selected from a batch delivered to the Site. The Contractor shall have the test rig(s) and test loads available for the tests. He shall perform the tests in the presence of the as and when directed by the SO Rep. If a sample fails any of the tests, all the refuse bins in that batch delivered to the Site shall be rejected. The rejected bins shall be removed from the Site immediately. The Contractor shall ensure that no rejected bin is delivered to the Site. The Contractor shall also ensure that the batch number of the rejected bins is not used again. Te required tests shall be as specified below: (a)
Test for Strength of Handles The refuse bin shall be filled with the appropriate test load of 65 kg. Put the loop (refer to the Drawings as shown in Appendix A49) through the handle that is to be tested and on to the cross bar of the test rig. The filled bin is raised using an inelastic rope and a quick-release hook attached to the handle that is being tested such that there is 300 mm slack on the loop as shown in the Drawings (as shown in Appendix A49). After the filled bin has come to rest, the quick-release hook is disengaged allowing the filled bin to fall freely. At all times, the filled bin must not come into contact with the ground. The procedure is repeated for the other handle. Test Load A test load of 65 kg shall be used for the handle test. Pass Criteria There shall be no visible weakening of the attachments and no permanent distortion or splitting to the main body of the refuse bin.
BLDG12/S31.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 31-6 31.5
250-LITRE LOW DENSITY POLYETHYLENE REFUSE BIN
31.5.4
Tests (b)
(CONT’D)
(Cont’d) Test for Impact Strength of the Base The base of the bin shall be placed on a flat concrete surface. A test load of 65 kg shall be raised to a height of 2 m above the centre of the bin and allowed to fall freely on the base of the bin. Repeat the test two more times. The test load shall consist of free flowing solid material contained in a test bag of diameter 25cm with a hemispherical bottom as shown in the Drawings (as shown in Appendix A49). Pass Criteria There shall be no visible weakening and no permanent distortion or splitting to the base or main body of the refuse bin.
31.6
EMBOSSING ON BINS The date of production (month and year) and batch number (in running order) shall be embossed on one face of the refuse bin as shown in Appendix A49 Drawing No. CMU-RB-01. Each letter or number shall be 25 mm by 20 mm.
31.7
SIX-BIN TROLLEY
31.7.1
Design and Detailing The Drawings show the design and detailing of the six-bin trolley and the Contractor shall conform to the dimension, capacity and design of the six-bin trolley as shown in the Drawings (as shown in Appendix A49).
31.7.2
Welding All weldings must be continuous unless otherwise specified or approved by the SO Rep. No spot welding shall be used for completion of the Works. The welding edges shall be smoothly and securely finished. If in the opinion of the SO Rep that certain portion of the weld should be reinforced, the Contractor shall execute and complete the work as instructed by the SO Rep all at the Contractor's costs and expenses.
31.7.3
Wheel (a)
The six-bin trolley shall be supported by two (2) numbers of 280mm diameter solid-tyre wheels at the sides and one (1) number of 180mm diameter swivel castor wheel at the front as indicated in the Drawing (as shown in Appendix A49). Each wheel shall have a minimum load carrying capacity of 200kg.
(b)
The types and models of wheel to be used shall be subject to the approval of the Superintending Officer's Representative.
(c)
All screws, bolts, nuts and washers used to secure the wheels in position must be galvanised steel. Should any of these be found rusty within the warranty period, the Contractor should replace it at his own cost.
(d)
The types and models of wheel shall be subject to the approval of the Superintending Officer's Representative. The tenderer shall attach all relevant technical details and catalogues of the types of wheel to be used in his tender.
BLDG12/S31.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 31-7 31.8
0.7 CUBIC METRE BULK REFUSE CONTAINER MODEL "E" AND BULK CONTAINER FRAME MODEL "EF"
31.8.1
Design and Detailing The Drawings show the design and details of the container and frame and the Contractor shall conform to the dimension, capacity and design of the container and frame as shown in the Drawings (as shown in Appendix A49) or any drawings from time to time issued or approved in writing by the SO Rep.
31.8.2
Welding All weldings must be continuous unless otherwise specified or approved by the Superintending Officer's Representative. No spot welding shall be used for completion of the Works. The welding edges shall be smoothly & securely finished. If in the opinion of the Superintending Officer's Representative that certain portion of the weld should be reinforced, the Contractor shall execute and complete the work as instructed by the Superintending Officer's Representative at his own costs and expenses.
31.8.3
Wheel (a)
The 0.7 cubic metre bulk refuse container model "E" shall be fitted with four (4) Numbers of 180mm diameter swivel castor wheels, two of which shall have foot lever brakes. Every castor wheel shall be welded to a thick packing plate as shown in the Drawings (as shown in Appendix A49) or be fitted to the 0.7 cubic metre bulk refuse container using galvanised steel nuts, bolts and washers approved by the Superintending Officer's Representative. The minimum load capacity of each wheel shall not be less than 170 kg.
(b)
The bulk container frame model "EF" shall be fitted with five (5) Numbers of 100mm diameter swivel castor wheels, three with a minimum load capacity of 180 kg and two of 70 kg. Every castor wheel shall be bolted securely to the frame.
(c)
The types and models of wheel to be used shall be subject to the approval of the Superintending Officer's Representative.
(d)
All screws, bolts, nuts and washers used to secure the wheels in position must be of galvanised steel. Should any of these be found rusty within the warranty period, the Contractor should replace it at his own cost.
(e)
The types and models of wheel shall be subject to the approval of the Superintending Officer's Representative. The offeror shall attach all relevant technical details and catalogues of the types of wheel to be used in his offer.
31.9
PAINTING OF GOODS
31.9.1
General (a)
All painting shall be done in accordance with the relevant Singapore Standard, British Standard and Codes of Practice and shall be suitable for tropical climate. No painting shall be carried out during damp or inclement weather.
(b)
The minimum drying or curing time in between coats and the method of application of primer and paint shall be in accordance to the paint manufacturer's recommendation for the particular paint being applied. In the case of two-part paint, the mixing ratio shall likewise be according to the manufacturer's recommendation.
(c)
Each coat of paint shall be of a different colour from the preceding coat. The Contractor shall submit a sample of the paint system for the Superintending Officer Representative's approval within 10 days from the date stated in the Letter of Acceptance of Tender. The colour of the finishing coat shall be approved by the Superintending Officer's Representative.
(d)
In the event that paint used is found or suspected to be adulterated or unsatisfactory, the Contractor shall bear the costs of tests carried out to validate such findings.
(e)
The Contractor shall submit the paint manufacturer's technical specifications, product data sheet and application instructions together with the tender otherwise the tender may be rejected.
BLDG12/S31.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 31-8 31.9
PAINTING OF GOODS
31.9.2
Six-bin Trolley (a)
(CONT’D)
Surface Preparation Before carrying out the painting, the six-bin trolley shall be pre-treated by degreasing and followed by blast-cleaning to a quality agreed by the Superintending Officer's Representative. Application of coating shall be carried out immediately after the said trolley has been thoroughly cleaned.
(b)
Paint System Painting of the six-bin trolley shall consist of one coat of self-cured inorganic zinc-rich primer of at least 50 microns and top coated with two coats of bituminous paint of film thickness 30 microns, measured when the paint is completely dry.
31.9.3
Bulk Container Frame Model "EF" (a)
Surface Preparation All steel surfaces to be painted shall be thoroughly degreased with water-based oil and grease remover, and washed with fresh clean potable water to remove all emulsified residues, dust and other contamination and foreign matters. All welded areas shall be completely removed of welding flux slag, flux fumes, heat oxides and weld splatter. All sharp edges, weld seams, millscales and heat oxides shall be ground. All loose rust, non-adherent millscales shall be thoroughly removed by power tool cleaning. The Contractor shall ensure that all surfaces to be painted are thoroughly dry and well cleaned, free from all dirt, rust scales and loose millscales before applying the following paint system.
(b)
Paint System The bulk container frame model `EF' shall be painted with 1 full coat surface tolerant high build epoxy primer of 120 microns dry film thickness within four hours of cleaning and in any case before any visible rusting or contamination of the surface occurs, provided that all other conditions for painting to proceed are met. One full coat polyamide-cured high build epoxy mastic of 100 microns dry film thickness shall then be painted over the priming coat.
31.9.4
0.7 Cubic Metre Bulk Refuse Container Model "E" (a)
Surface Preparation All steel surfaces to be painted shall be thoroughly degreased with water-based oil and grease remover, and washed with fresh clean potable water to remove all emulsified residues, dust, zinc salts, and other contaminants and foreign matters. All welded areas shall be completely removed of welding flux slag, flux fumes, heat oxides and weld splatter. All sharp edges, weld seams, millscales and heat oxides shall be ground. All damaged and defective steel surfaces shall be cleaned with power tool. The Contractor shall ensure that all surfaces to be painted are thoroughly dry and well cleaned before applying the following paint system.
(b)
Paint System The bulk refuse container Model "E" shall be painted with one touch up coat surface tolerant high build epoxy primer of 100 microns dry film thickness to all damaged and defective steel areas and one full coat phosphoric acid based wash coat on steel surfaces within four (4) hours of cleaning and in any case before any visible rusting or contamination of the surface occurs, provided that all other conditions for painting to proceed are met. One full coat polyamide-cured epoxy pigmented with micaceous iron oxide of 100 microns dry film thickness and one full coat polyamide-cured high build epoxy mastic coat of 100 microns dry film thickness shall then be painted over the priming coat.
BLDG12/S31.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 31-9 31.9
PAINTING OF GOODS
31.9.5
Coating to 0.7 Cubic Metre Bulk Refuse Container Model "E" and Bulk Container Frame Model "EF" (a)
(CONT’D)
Surface Tolerant High Build Epoxy Primer It shall be a two-component epoxy aromatic amine-cured coating containing at least 80% volume solids and aluminium paste pigmentation. It shall have good chemical and solvent resistance and a long overcoating time of up to six (6) months. The high film thickness shall be achievable by brush application.
(b)
High Build Epoxy Mastic It shall be a two-component epoxy polyamide-cured coating containing at least 60% volume solids and chemical and weather resistant pigments. It shall have excellent chemical and solvent resistance.
(c)
Epoxy Micaceous Iron Oxide Primer It shall be a two-component epoxy polyamide-cured coating containing at least 65% volume solids and micaceous iron oxide. It shall have excellent durability, toughness and abrasion resistance. Its maximum overcoating time shall not be less than six (6) months.
(d)
Etch Solution For Galvanised Surfaces It shall be a phosphoric acid based wash coat of pale blue colour designed for use over new or untreated galvanised surfaces so as to provide good adhesion for subsequently applied paint. During application, the surface shall blacken with an even appearance. The maximum overcoating time shall not be less than two (2) days.
31.10
SUBMISSION OF SAMPLES The Contractor shall deliver the following samples for the quotation evaluation:(a) (b) (c) (d) (e)
One number of 250-litre low density polyethylene refuse bins One number of post/wall mounted litter bin completed with mounting brackets One number of six-bin trolley One number of 0.7 cubic metre refuse bulk container model "E"; and One number of metal bulk container frame Model "EF"
Section 32/.....
BLDG12/S31.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 32-1
SECTION 32 RESERVED
SECTION 33 RESERVED
SECTION 34 RESERVED
SECTION 35 RESERVED
Section 36/.....
BLDG12/S3235.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 36-1 SECTION 36 GENERAL REQUIREMENTS FOR SANITARY, WATER, GAS AND OTHER PLUMBING INSTALLATIONS
36.1
WORKS BY REGISTERED PLUMBER AND LICENSED WATER SERVICE PLUMBER It is the intention of the Drawings and Specifications to provide a complete operating system. The omission from the Specifications or Drawings of any details in construction, installation materials, or specialities necessary for a complete operating and safe system shall not relieve the Contractor from furnishing and completing the same in place all at the Contractor's own cost and expense. Should the requirements of the Drawings or Specifications conflict with codes, regulations or standards, the most stringent of the requirements shall govern the Works. All sanitary, water and gas installation Works shall be carried out by a Registered Plumber(LP) registered under the Singapore Plumbing Society(SPS), and Licensed Water Service Plumber (LWSP) and Licensed Gas Service Worker (LGSW) respectively and shall comply with all current Code-of-Practices, Bye-Laws, Requirements and Regulations of the relevant Authorities.
36.2
SANITARY AND WATER SUPPLY Sanitary and water installation, drain lines, inspection chambers, waste sumps and water supply services shall be provided by the Contractor unless specified otherwise. Allow for leaving holes for pipes and traps as shown in the Structural Drawings.
36.2.1
TIMBER MOCK-UPS Within three months after the commencement of the Contract, the Contractor shall erect timber mock-up for toilet, kitchen, air-con ledge and service yard on site for inspection and approval of the SO rep. These timber mock ups shall have the provision of all sanitary pipes and fixtures position, marking of water supply pipes layout, power points and switches locations, electrical water heater socket locations and provision of UPVC entry pipe for water supply using gas water heater. Actual UPVC sanitary pipes, wash basin and pedestal pan; and mock-up of ceiling duct, doors, vanity top (if any) and clothes drying racks shall be installed with respect to the architectural and structural. Markings of beams, columns, wall tiles, floor tiles, window layout shall also be shown. One timber mock up is required for each flat type. All costs and expenses incurred for the erection of the timber mock up and subsequent removal of these mock up shall be deemed to be included in the Contract by the Contractor. The timber mock-ups must be built accurately to facilitate resolution of the following common issues: (a) (b) (c) (d) (e) (f)
36.3
floor waste/trap not obstructed by structural beam; lighting points not obstructed by ceiling-mounted clothes drying rack; use of external clothes drying rack not hindered by air-con ledge; sufficient clearance for access to the air-con ledge for installation and maintenance of the air-con compressors; toilet vent and other fittings do not obstruct future installation of shower screen; and any other practical considerations.
WATER CONNECTION UNDER APRON Allow for the Public Utilities Board's water connection under the concrete apron or the first storey slab within the building to be completed before concreting the apron and the floor slab.
36.4
GAS PIPE THROUGH RC BEAM Provide and install UPVC pipe sleeves through RC beam as shown in the Drawings for the provision of gas pipes. In the event that the gas pipe is not to be installed, the UPVC sleeves shall be capped with UPVC capping all as shown in the Drawings.
BLDG12/S36.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 36-2 36.5
CERTIFICATE FROM WATER RECLAMATION (NETWORK) DEPARTMENT, PUB Apply in writing to Water Reclamation (Network) Department, PUB for final inspection of the sanitary installation and obtain the final approval before the Expiry of the Time for Completion. On completion of the whole of the installation Works, obtain a Certificate from Water Reclamation (Network) Department, PUB certifying that the work has been carried out complying fully with their Regulations and Requirements before the Final Payment can be released. Failure by the Contractor to apply for such inspection on time, shall render him liable for damages or loss suffered by the Employer due to the delay in approving the sanitary installation by PUB, arising out of or in connection with the Contractor's failure to apply for such inspection on time. Notwithstanding the above, the SO Rep shall exercise its rights under Clause 1.6 "Nuisance and Irregularities" to impose a charge against the Contractor.
36.6
INSPECT DRAWINGS AND MAKE ALLOWANCE Examine carefully all Drawings, including the Civil and Structural Drawings and ascertain all probable obstructions such as pile caps, foundations, beams footings, etc. which may necessitate diversions of drain lines, inspection chamber positions and other fittings, from the lines and positions shown in the Drawings. Allow in the Contract Sum for all costs and expenses arising from necessary additional lengths of drain pipes, bends, etc which are required to cater for such adjustments in alignment and running of drain lines, inspection chambers, other fittings, etc. No claims for extras shall be entertained by the SO Rep for non-compliance or misinterpretation of this Clause by the Contractor.
36.7
DIAMETER OF PIPES Unless otherwise stated, the sizes of copper, stainless steel, ductile iron and UPVC pipes shall mean their nominal sizes.
36.8
CONTRACTOR TO GIVE NOTICES AND SUBMIT DRAWINGS FOR APPROVAL Submit all necessary application forms, drawings and give all notices required in connection with the Works. Submit sanitary drawings, water service drawings and gas installation drawings with application forms to the Water Reclamation (Network) Department, Water Supply (Network) Department, PUB; and City Gas respectively for approval not later than 14 days from the date of the Letter of Acceptance. A copy of the application shall be sent to the SO Rep for information.
36.9
EXCAVATE TRENCHES AND REMOVE EXCESS EARTH Excavate all trenches and pits for drain-lines and inspection chambers as shown. The soil condition shall be inspected by the SO Rep. After drain-lines have been tested and approved by the SO Rep, backfill the soil, properly consolidated to original levels and cart away surplus earth promptly and in any case not later than 7 days from the date of instruction by the SO Rep. Where the ground is soft, provide hardcore, bakau piling etc to drain-lines, inspection chambers/waste sumps and unless specified in the Contract, such works shall be treated as a variation under the Contract.
BLDG12/S36.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 36-3 36.10
WORK THROUGH CONCRETE STRUCTURE Every care shall be taken in drilling, coring holes through concrete structure so as not to disrupt the concrete and steel. Care shall also be taken in enlarging holes to the diameters and positions as required without damaging the surrounding area. Seek approval from the SO Rep before carrying out such Works. Where, in the opinion of the SO Rep, concrete structure has been affected or unnecessarily disrupted or damaged, reinstate at the contractor's own and expense the affected parts of structure to the satisfaction of the SO Rep.
36.11
DRILLING OR CORING ON FINISHED AREAS Where drilling or coring of holes are to be carried out on areas where tiles, or other types of finishing had been completed, take all precaution and care to ensure that damage is minimised. In the event of any damage, make good the damage to the satisfaction of the SO Rep all at the Contractor's cost and expense.
36.12
RESERVED
36.13
PATCHING UP Patch up hacked portions and drilled holes of structure with non-shrink cementitious grout of a similar or higher grade than the surrounding concrete, after installation of the services by the contractor or other contractors and with workmanship at least equal to that of the surrounding parts. Where pipes penetrate floor or roof slab, brush away loose particles on concrete and pipe. Brush on one coat neat, thick cement grout immediately before patching. Any leakages through such patching shall be made good by the Contractor. All patching up work shall be carried out to the satisfaction of the SO Rep.
36.14
TESTING OF WATER AND SANITARY INSTALLATION Test the whole sanitary and water installation as specified hereunder.
36.14.1
Water Test As soon as PUB water supply is available, carry out water test to the following items, in accordance with the procedure described below and complete the water test, including making good all Defect, within 10 days from the date PUB water supply is available : (a) (b) (c) (d)
BLDG12/S36.DOC(3) Sal(151211) (DPD)
Water supply pipe; Direct supply pipe; Joints between floor slab and floor trap in bathrooms and kitchens and joints between branching-off for WCs and floor slab; Water pumping Plant.
Bldg Spec Page 36-4 36.14
TESTING OF WATER AND SANITARY INSTALLATION
36.14.2
Procedure Of Water Test
(CONT’D)
36.14.2.1 Water Supply Pipe Test all water supply pipes for leaks. 36.14.2.2 Direct Supply Pipe Where required, apply to PUB and pay all fees for installing meters to the lower floors with direct water supply for the purpose of testing for leaks in the pipe. 36.14.2.3 Floor Traps The gratings to the floor traps in bathrooms and kitchens shall be blocked temporarily with polythene sheets or by other suitable means and the floor flooded with about 10mm depth of water above the gratings. The amount of water shall be maintained for about 2 hours, replenished when necessary, during which the underside of the floor slab shall be checked for signs of leaks. Towards the end of this test, the water shall be allowed to drain off. During this process there shall be no sign of chokage and leakage in the system. The water test shall be carried out 3 days after the laying of floor finishes. 36.14.2.4 Water Pumping Plant Arrange with the SO Rep for test on the whole pumping Plant including transfer pump and booster pump for signs of leak and proper performance of the pumps. Rectify all the Defect found during the inspection immediately so that a re-inspection can be carried out. Arrange for the test to be carried out not later than four weeks before the buildings are handed over to the Employer. Provide electricity for operating the pumps, provide temporary piping, connections, fittings and accessories necessary for the test to be carried out.
36.14.3
Hydrostatic Test Of Underground Mains Arrange for hydrostatic test of all underground ductile iron pipes after PUB bulk meter according to CP 48. After laying, jointing and anchoring of the main and before any backfilling or concreting, charge the piping system slowly and carefully with potable water so that all air is expelled. Test the mains under pressure. Before testing the main, fit all open ends of the main with blank flange and secure them with struts or otherwise to resist the end thrust of the water pressure in the main. Apply a test pressure of 125m head or the maximum working pressure plus 50% whichever is the greater, by means of manually operated test pump or by power-driven test pump. Maintain the test pressure by the pump for 1 hour and check the main for any leakage. General leakage shall not exceed 2 litres per cm of pipe diameter per km of pipe per 100m head per 24 hours. Notwithstanding the above, rectify all visual leaks detected.
36.14.4
Sterilisation Of Underground Water Distribution Mains Sterilisation of underground distribution water mains shall be carried out in accordance with CP 48 "Code of Practice for Water Services" and to the requirements of PUB. The water samples shall be taken for bacteriological and chemical testing by a PSB or SAC accredited laboratory. Two days after taking such samples, flush the underground distribution mains and further water samples shall be taken for testing as described in the foregoing requirements. Provide the water examination and analysis report to the SO Rep and the result of water analysis shall be within the acceptance limits for human consumption. The underground distribution mains shall only be commissioned after two consecutive tests are satisfactory, otherwise the sterilisation procedure shall be repeated until such requirements are met.
BLDG12/S36.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 36-5 36.15
WATER FITTINGS
36.15.1
General Requirements All water fittings shall comply with the standards stipulated by PUB and its use in water service installations shall conform to the Public Utilities (Water Supply) Regulations and SS:CP 48.
36.15.2
Marking Of Information All water fittings shall be legibly marked with the following : (a) (b) (c) (d)
36.15.3
Manufacturer's identification mark, either on the body or plate; Marking of appropriate national standards, eg. BS EN 545:1995; Nominal size and direction of flow; Colour codes for hot and cold water supply.
Non-Metallic Material All non-metallic material in contact with water shall comply with SS 375:2001 and valves with non-metallic seat washers shall also comply with BS 3457:1973.
36.15.4
Metallic Material All metallic material in contact with water shall comply with the test on "Extraction of Metals - App H" of AS/NZS 4020:1999.
36.15.5
Copper Alloy Water Fittings All copper alloy water fittings shall be of gunmetal, or bronze or DZR brass materials only. Gunmetal or bronze water fittings shall comply with BS EN1982:1999. Water fittings of the Dezincification Resistant (DZR) type shall comply with the tests on "Composition" and "Resistance to dezincification" of BS EN 12163:1998 or BS EN 12165:1998 or BS EN 12420:1999. Such fittings shall have the additional marking of "DZR" or "CR".
36.15.6
Water Fittings With Elastomeric Seals All water fittings with elastomeric seals for joints in pipework and pipeline shall comply with SS 270:1996.
36.16
STRUCTURAL CONCRETE All structural concrete shall be as specified in Section 4 "Structural Concrete" including all clauses and subclauses under it.
36.17
RESERVED
BLDG12/S36.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 36-6 36.18
AS-BUILT DRAWINGS FOR CONCEALED WATER PIPES, EXPOSED GAS PIPE INSIDE UNIT AND ALL OTHER MECHANICAL INSTALLATIONS During the progress of the Works, the Contractor shall record and update all water and gas pipe routes, legends and all other related mechanical works (Sanitary/Water/Gas Installations) based on actual site installations for the production of as-built drawings.
36.19
SYSTEMATIC LAYOUT OF ALL SERVICE PIPES AND ELECTRICAL CONDUITS (M&E SERVICES) AT BUILDING ROOFTOP The Contractor shall prepare a coordinated services layout plan showing the overall layout of all the M & E service pipes and electrical conduits at the roof top in consultation with the SO Rep. The layout of the service pipes and electrical conduits at the roof top shall ensure good accessibility and neat arrangement to facilitate the movement of the maintenance workmen, besides meeting all technical and statutory requirements. The Contractor shall submit the coordinated roof top services layout to the SO Rep for approval before installation. Ensure that all the pipes/conduits are arranged in a systematic and orderly manner, and the access to the water tanks, lift motor rooms, pumps, and other services at the rooftop is not obstructed by service pipes and electrical conduits. Work by the various trades at the roof top shall be supervised and coordinated by the Contractor. In areas where pipes are causing obstruction, the contractor is to provide chequered-plate platform and steps over the pipes in accordance with the Drawings. The platform shall be installed at locations furthest away from the building edge and in such a way as not to pose danger to the maintenance workmen.
36.20
AIR-CON PIPE SLEEVE Provide and install UPVC pipe sleeves in RC wall next to air-con ledge. The pipe sleeve shall be complete with end cap on both sides. The drawing on pipe sleeve shall serve as a guide. The actual profile and fastenings of pipe sleeve shall be to manufacturer’s details. Contractor shall submit drawings and sample of pipe sleeve to SO Rep for approval.
Section 37/..... BLDG12/S36.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 37-1 SECTION 37 SANITARY INSTALLATION
37.1
SCHEDULE OF UPVC PIPES FOR FITTINGS FOR SANITARY INSTALLATION Unless specified otherwise, all UPVC pipes and fittings provided for sanitary installations shall be in accordance with the following schedule :
Sanitary Installation (Including Waste/Rain Water Down-Pipe System)
Types Of Pipe/Fitting ( SS : Singapore Standard ) SS 213
SS 141 Class D
Underground Sanitary Drainage System-Main/Branch Drain Lines Above Ground Sanitary Plumbing System (Soil/Waste to I/C) : (a) All except Void Decks
(b) Void decks - Discharge stacks - Discharge pipes & fittings
Remarks
SS 272 *
*
Anti-Mosquitoes Devices, Socket Sleeves and Pipe Skirtings to be used. SS 213/SS 141 Adaptor to be used.
* *
Waste/Rain Water Down-Pipe System (RWDP) : (a) 200 diameter pipes for RWDP system
* (White)
(b) Underground pipes/fittings for 200 diameter pipes (RWDP) (c) Above ground pipes/fittings connected to 200 diameter RWDP system
Roof Outlet to be used. Rectangular Section Fittings to be used.
*
(d) 50, 80, 100 & 150 diameter waste discharge (balcony, lift lobby, etc) pipes/fittings : i. Above ground except void decks and MSCPs ii. Void decks and MSCPs - Down pipes - Discharge pipes/fittings - Underground pipes/fittings
* SS 213/SS141 Adaptor to be used.
* * *
*Denotes the specified pipes/fittings.
37.2
MAIN AND BRANCH DRAIN LINES Unless otherwise stated, all pipes for main and branch lines shall be UPVC conforming to SS 272 and free from breakage, distortions or cracks and of sizes specified in Clause 37.6 "Drain Sizes". All drain-lines shall be laid on grade 30 concrete bed at least 150mm thick, fully haunched with 150mm thick grade 30 concrete all round and reinforced with a layer of BRC A10 or other approved as shown in the Drawings unless otherwise stated.
BLDG12/S37.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 37-2 37.2
MAIN AND BRANCH DRAIN LINES (CONT'D) All drain-lines under roads and carparks shall be cement mortar lined ductile iron pipes complying with BS EN 598 and laid on grade 30 concrete bed at least 150mm thick, fully haunched with 150mm thick grade 30 concrete all round and reinforced with a layer of BRC A10 or other approved as shown in the Drawings unless otherwise stated. Jointing of pipes of different materials in branch drain- lines or in the continuous length of main drain-lines in between two inspection chambers shall not be allowed unless otherwise shown in the Drawings. The section of main drain lines under roads and carparks shall be constructed under the supervision of the SO Rep and the Contractor shall arrange for the inspection by and approval of the SO Rep before covering up. All drain lines in basement carparks shall be of ductile iron pipes complying with BS EN 598 and approved by the SO Rep. Where individual connections of discharge stacks to the inspection chamber are impracticable, a common pipe of adequate size to serve the main discharge stack and a common pipe to serve the secondary discharge stack may be provided to suit the connection to the inspection chamber subject to approval of the relevant authorities. All drain-lines for eating establishments such as eating houses, restaurants, food stalls, etc shall be constructed with cement mortar lined ductile iron pipe to BS EN 598 . The floor traps for the eating establishments shall be of stoneware type or cast iron. The trenches for main and branch drain-lines shall be backfilled with quarry dust and finished as shown in the Drawings.
37.3
GRADIENT FOR DRAIN-LINES Unless otherwise stated or approved by the Water Reclamation (Network) Department, PUB, the gradient of drain-lines shall be as follows : (a)
Branch Drain-Lines Diameter of Branch Drain-Lines
(b)
UPVC
Ductile Iron
Maximum Gradient Upstream at Back Drop Tumbling Bay
110mm
110mm
-
1 in 20 to 1 in 60
160mm
150mm
1 in 70
1 in 30 to 1 in 90
Allowable Gradient in other cases
Main Drain-Lines Diameter of Main Drain-Lines
37.4
Allowable Gradient in other cases
UPVC
Ductile Iron
Maximum Gradient Upstream of Back Drop/Tumbling Bay
160mm
150mm
1 in 70
1 in 30 to 1 in 90
250mm
250mm
1 in 90
1 in 49 to 1 in 150
JOINTS FOR DRAIN-LINE PIPES Only flexible jointed pipes shall be used for drain line pipes.
37.5
JUNCTIONS IN DRAINS All junctions between drains shall be of curved junctions or obtuse angled junctions made at sides of pipes.
37.6
DRAIN SIZES All drain branches from building to inspection chamber shall be 160mm diameter pipes or as shown in Drawings. Main drain-lines shall be 160mm diameter UPVC pipes to SS 272:1983 unless specified otherwise.
BLDG12/S37.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 37-3 37.7
WATER TEST FOR DRAIN-LINES Water test all drainlines before they are surrounded and covered. Drainlines shall be perfectly watertight and it is essential that every length of pipes be tested when completed with water before haunchings and backfilling. For water test, the drainline shall be subjected to a pressure of 1.2 metre head of water and such pressure shall be maintained for half an hour without leakage in excess of 1.0 litre for each length of drainline between the inspection chambers. The fact that the pipes have been tested shall not relieve the Contractor from his responsibility to locate any leak and make good the section, including re-excavation, timbering, backfilling and making good.
37.8
BEDDING AND HAUNCHING TO BRANCH AND MAIN DRAIN-LINE The pipes which have been tested and found satisfactory shall be bedded and haunched with grade 30 concrete to details as shown in Drawings. Provide break joints at pipe joints not greater than 6m intervals and at the first pipe joint next to inspection chamber, all to the requirements of the Water Reclamation (Network) Department, PUB. Carry out all Works in accordance with the requirements of the Water Reclamation (Network) Department, PUB.
37.9
BREAKING UP ROADS AND CARPARKS FOR LAYING OF DRAIN-LINES The Contractor shall provide for breaking up roads and carparks for laying of drain-lines etc. and reinstatement of damages all to the satisfaction of the SO Rep.
37.10
INSPECTION CHAMBERS AND DRAIN LINES
37.10.1
General Requirements The Contractor shall include in the Contract Sum for all Sanitary Works required under the Contract comprising either one or both of the following systems : (a) (b)
37.10.2
suspended from building and / or ; supported on piling
Suspended From The Buildings Where the Inspection Chambers and main drain lines are required to be suspended from the building, it shall be constructed according to the details as shown in the Drawings.
37.10.3
Supported On Piling Where piles are required to support the Inspection Chambers and drain-lines as shown in the Drawings, the Contractor shall ascertain the pile penetration lengths required and allow in the Contract Sum for all costs and expenses incurred on the piling work. The contractor shall plan and incorporate the duration required for the piling work into the Programme for the Works or revised Programme, if any, for the submission to the SO Rep for approval, as required under the contract. In ascertaining the pile penetration lengths, the Contractor may, if he wishes, refer to the Soil Investigation Report available from the Employer. However, the Contractor shall note that the Soil Investigation Report does not form part of the Contract or be taken into consideration in the interpretation or construction thereof or of the Contract. The Contractor shall also take note that all the information in the Soil Investigation Report is only indicative of the likely soil conditions to be encountered at the Site. The Employer shall not be accountable for the accuracy, adequacy or completeness of the information in the Soil Investigation Report. The Contractor shall at his own cost, ascertain the actual soil conditions and shall conduct his own site investigations and allow in the Contract Sum for all costs and expenses whatsoever arising from and/or out of an inaccuracy, inadequacy or incompleteness of the information in the Soil Investigation Report.
BLDG12/S37.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 37-4 37.10.3
Supported On Piling (Cont'd) Notwithstanding the pile penetration lengths ascertained by the Contractor, there shall be no adjustment to the Contract Sum for any difference in pile penetration lengths between those actually provided at the Site and those ascertained by the Contractor. However, if for whatever causes any pile cannot be driven into the ground or is not provided at all, omission by way of variation to the Contract shall be effected. For the purpose of computing the value of such omission, the penetration length of each pile shall be deemed to be 8.0m.
37.10.4
Requirements For Precast Reinforced Concrete Piles To Inspection Chambers And Drain Lines Where precast reinforced concrete piles to inspection chambers and drainlines are included in the Works, the piles provided shall be in accordance with Clause 2.2 "Precast Reinforced Concrete Piling Works".
37.10.5
Inspection Chamber Construct inspection chambers to details and positions as shown in the Drawings. All inspection chambers/manhole covers and frames shall comply with the general requirement of SS 30. Heavy duty cast iron frames and covers (Grade A) shall be used in driveways and carparks and other areas as shown in the Drawings. Form open branch/main channels in inspection chambers with half-round vitrified clay purposed made or cut channels with benching haunched up to the walls of inspection chambers in granolithic concrete 1:1:1 mix and trowel to smooth finish to fall towards the channel. The first inspection chamber of the drainage system shall have a minimum depth of 1070mm from surface level to invert level unless otherwise specified. Construct all walls and slabs of inspection chambers with grade 30 reinforced concrete as shown in the Drawings and to the requirements of the Water Reclamation (Network) Department, PUB. Plaster the internal walls with approximately 13mm thick 1:2 cement mortar and trowel to a smooth finish. Connect the invert of the branch drain-line entering the inspection chamber above the horizontal diameter of the main channels. Grade C Light Duty covers shall be complete with stainless steel handles as shown in the Drawings and approved by the SO Rep.
37.11
CONCEALMENT OF SANITARY STACKS, DISCHARGE PIPES AND FITTINGS All sanitary stacks shall be fully housed within masonry ducts/pre-cast concrete (stack ducts). Leakage tests to all sanitary stacks, discharge pipes and fittings shall be completed before they are fully concealed in the stack ducts and ceiling ducts. All sanitary pipes and fittings at the ceiling shall be fully concealed by ceiling duct of 9mm thick calcium silicate boards, fixed on galvanised steel angle frames as shown in the Drawings. All screws including anchor bolts shall be of AISI grade 304 stainless steel. Board joints shall be taped with paper tape and gypsum compound used to fill screw holes and board joints on the calcium silicate, and this shall be sanded smooth and not visible after painting. The completed boards shall be finished with base coating and 2 layers of emulsion paint. Lighting diffusers shall be 15mm x 15mm x 10mm thick egg crate white plastic type in powder coated aluminium frames. Detailed workshop drawings showing the type of boards and fixing methods, including access panels and lighting diffusers, shall be submitted to the SO Rep for approval prior to their installations The calcium silicate boards shall comply with the following physical properties : Physical Properties Dry density Weight Flexural strength across grain Flexural strength along grain Moisture movement from normal to saturated Nominal moisture content-in situ Thermal conductivity Alkalinity
Requirements 910 kg per m3, ±10% 9.5 kg per m2, ±15% 10 MN per m2 6 MN per m2 0.15% 3 to 5% 0.161 W/mk 7 to 10 pH value
The Contractor shall submit a test report showing compliance with the requirements of the physical properties specified to the SO Rep for evaluation. BLDG12/S37.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 37-5 37.12
UNPLASTICIZED PVC PIPES AND FITTINGS FOR SOIL, WASTE AND VENT APPLICATIONS (ABOVE GROUND)
37.12.1
Material
37.12.1.1
General All unplasticized PVC pipes, fittings and accessories for soil, waste and vent application above ground shall comply with the requirements of SS 213 and its latest amendments. However, UPVC soil and waste stack in the void deck/play area shall be UPVC pipes to the requirements of SS 141 and as shown in the Drawings. The internal and external surfaces of the pipes and fittings shall be clean, smooth, and reasonably free from grooving and other Defect that would impair their performance in service. Provide pipe in standard lengths of 6m + 50mm - 0mm. The pipe shall be provided with ends within ±2 degrees of being normal to the main axis of the pipe, free from chips, rough edges and with sharp edges removed.
37.12.1.2
Dimensions Of Soil, Waste And Vent Pipes To SS 213 Outside Diameter Nominal Size
Wall Thickness Mean Diameter De Minimum
32 40 50 65 80 100 125 150
36.2 42.8 55.7 68.7 82.3 110.0 140.0 160.0
Note :
37.12.1.3
Maximum 36.5 43.1 56.0 69.1 82.7 110.4 140.4 160.5
Incl Ovality D Minimum 36.1 42.7 55.5 68.5 82.1 109.6 139.5 159.5
Maximum
Minimum
Maximum
2.1 2.3 2.4 2.7 3.0 3.2 3.7 4.0
36.6 43.2 56.2 69.3 83.0 110.8 140.4 161.1
(i) De = mean outside diameter (ii) D = any measured diameter
Minimum Socket Dimension To SS 213 The minimum socket dimension for 3m length UPVC pipe shall be as follows :
BLDG12/S37.DOC(5) Sal(151211) (DPD)
Nominal pipe size in mm
Minimum socket dimension in mm
32 40 50 65 80 100 125 150
19 21 23 25 29 34 42 45
2.4 2.6 2.7 3.1 3.5 3.6 4.2 4.5
Bldg Spec Page 37-6 37.12.1
Material (Cont'd)
37.12.1.4
Dimension And Colour Of The Waste And Soil Stack To SS 141 Class D Wall Thickness Nominal Size
Average Outside Diameter
Average Value
Individual Value
Minimum
Maximum
Maximum
Minimum
Maximum
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
80 100 155
88.7 114.1 168.0
89.1 114.5 168.5
5.3 6.8 9.9
4.6 6.0 8.8
5.3 6.9 10.2
All pipes shall be indelibly marked and imprinted longitudinally at interval of not greater than 3m. The markings shall show the following : (a) (b) (c)
Manufacturer's name and/or trade mark. the nominal size. SS 141:1976 Class `D'
The marking of the pipe shall be in accordance with SS 141. 37.12.1.5
Adaptor To Couple The Fitting (To SS 213) And UPVC Pipes (To SS 141) An adaptor shall be used to couple the fitting to SS 213 and its latest amendment (Single junction/single junction with inspection eye) and UPVC pipe to SS 141 to be installed at the void deck. The shape of the adaptor shall comply with the design as shown in the Drawings. The strength, dimensional tolerance and thickness of the adaptor shall comply with the standards and specifications laid down in SS 213 (except that the dimensional tolerance for the socket of the adaptor shall comply with SS 174). Obtain prior approval from the SO Rep before use. Random samples may be chosen for testing at a SAC accredited laboratory.
37.12.1.6
Swept Junction Fitting Use only swept junction fittings (single or double cross junction) with 50mm minimum root radius in all sanitary installation unless otherwise stated.
37.12.2
Installation
37.12.2.1
General All soil, waste and vent pipes used shall be unplasticized PVC pipes complying with SS 213 or SS 141 and all tests as required by Water Reclamation (Network) Department, PUB. All jointing and fixing requirements shall be in strict accordance with the manufacturer's instructions. Provide main discharge stack of 150mm diameter and secondary discharge stack of 100mm diameter as shown in the Drawings. Install double 45 degree bends to SS 272 at the base of the discharge stacks in accordance with the Drawings. Install cross ventilating pipes to the required size between the main and the secondary discharge stack at the specified locations as shown in the Drawings. Unless otherwise indicated in the Drawings or required by PUB, anti-syphonage pipes connecting the appliances to the discharge stack are not necessary.
37.12.2.2
Inspection Openings, Connectors And Fittings All inspection openings shall be screw and washer type with proper adaptors where necessary.
BLDG12/S37.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 37-7 37.12.2
Installation (Cont'd)
37.12.2.3
Floor Traps Unless as required otherwise, fit all floor traps with 150mm square body, circular hinged UPVC gratings with frames having a 30mm deep collar protruding below to fit into the opening of the floor traps. The gratings shall comply with SS 213 and complete with an Anti-Mosquito Device approved by NEA. The gratings for floor traps shall be fixed at 5mm below the graded floor level and as shown in the Drawings.
37.12.2.4
Method Of Fixing The method of fixing UPVC pipes shall be as follows : (a)
All pipes shall be cut square with the edge chamfered 15 degrees using approved pipe cutting tools prior to its installation. The pipe cutting tool shall be able to produce square cut and 15 degree chamfer in one continuous operation. The pipe cutting tools shall be portable and able to cut pipes of all sizes.
(b)
Clean the pipe ends and sockets in pipes or fittings with cleaning fluid or methylated spirit and allow them to dry.
(c)
Mark the pipes and fittings with a marker at a distance to the depth of the socket in the fittings or to the depth of the socket formed in pipes.
(d)
Coat all pipe ends and the internal faces of sockets fully with solvent cement and insert the pipe into the socket immediately. The socket edge of the fittings must touch the marking at the pipes. Remove surplus solvent cement from the socket using a dry cloth.
(e)
After jointing, hold the joint firmly for a period of 30 seconds and do not disturb it for at least 5 minutes.
(f)
All joints shall be jointed with sockets recommended by the pipe manufacturer. In situations where a pipe and socket joint is not possible, a coupling or an adaptor shall be used.
(g)
No socket belling shall be allowed when jointing UPVC pipes.
(h)
The type of solvent used shall be in strict accordance with the manufacturer's instructions and recommendations.
For the jointing of UPVC pipes to other materials, the bonding agent used shall be those recommended by the pipe manufacturer and approved by the SO Rep. Carry out all fixing work in strict accordance with the pipe manufacturer's instructions. 37.12.2.5
Solvent Cement For Jointing UPVC Pipes And Fittings Solvent cement used for jointing UPVC pipes and fittings shall be approved by the SO Rep and comply with BS 4346:Part 3. The solvent cement shall be in light approved colour to enable visual inspection. The Contractor shall submit a test report of the solvent cement to be used on the Site, for approval by the SO Rep before the commencement of the sanitary and water installation Works. The tests shall be carried out by an SAC accredited testing laboratory and shall include : (a)
Shear Strength;
(b)
Film Properties;
(c)
Long-term Hydrostatic Pressure.
BLDG12/S37.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 37-8 37.12.2
Installation (Cont'd)
37.12.2.6
W.C. Joint Place rubber seal over the spigot of the w.c. outlet with the open and facing towards the pan. Lubricate the outer surface of the seal and insert pan spigot complete with seal into connector socket. Snap plastic cover over rim of connector socket. Use pan collar connectors in cases where P-traps are utilised. Apply silicone sealant to groove and recess at pan collar and cover to prevent stagnation of water at groove and recess.
37.12.2.7
Fixing Of Bosses Use bosses for jointing waste and vent pipe into the soil stack. Use bosses for jointing of waste pipe from basin or kitchen sink to the hopper of floor waste or floor trap. Cut the appropriate sized hole in the position required using special hole cutters such as mechanised drill which is attached to a circular hole-saw by a mandrill. Apply solvent weld cement and clean mating surfaces of the boss and pipe. Insert the inner portion of the boss from inside the pipe with the outer portion located. Apply and tighten the toggle clamp and leave it in position for fifteen minutes. When fixing into the stack, ensure that the 92½ degree marks on both parts are upper-most. Ensure that the angles marked on the inner and outer portions of the boss coincide and that the boss is assembled in the correct sequence to give an angle of fall to the stack pipe.
37.12.2.8
Access Doors Access doors may be fitted to pipe or straight portion of branches. Mark positions of holes with template and cut the holes with a fine tooth keyhole saw. Clean the edges of the hole before inserting the access door. The inner portion of the access door shall be set in the hole to locate the unit before it is tightened into position.
37.12.2.9
Weathering Where pipes penetrate through either flat or sloping roofs, the normal type of approved weathering material shall be used. Where necessary, fix an approved weathering apron in accordance with the manufacturer's instructions and as shown in the Drawings.
37.12.2.10
UPVC Vent Cowl Clean the mating surfaces of the pipe fitting before assembling the unit in accordance with normal solvent weld cement procedure.
37.12.2.11
Provision For Thermal Movement In cases where the piping is likely to be subjected to any large variations in temperature and to prevent the slightest movement, use a seal/sleeve ring joint between fixed joints.
37.12.2.12
Support Distances Of UPVC Pipe Lines Horizontal pipes which exceed 1400mm in length shall be supported with PVC coated mild steel hangers. Vertical pipes passing from floor to floor shall be supported with PP collars attached to the pipes as shown in the Drawings. The spacing of the hangers and collars shall not exceed 1400mm for horizontal pipes and 1800mm for vertical pipes.
BLDG12/S37.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 37-9 37.12.2
Installation (Cont'd)
37.12.2.13
Bonding Keys To Concrete Slab Provide bonding keys to concrete floor slab where UPVC pipes go through. Roughen the whole surface of the UPVC pipe which is in contact with the floor slab to form keys. Apply thin coat of solvent cement and sprinkle fine sand to the whole area of the roughened surface before the solvent cement sets. Use solvent welded cement method for all jointing assemblies. Carry out all fixing work in strict accordance with the pipe manufacturer's instructions. Use UPVC pipes to SS 213 where the stacks continue above roof level. Use UPVC pipes to SS 141 where the stacks continue below the ceiling of the open 1st storey.
37.12.3
UPVC Pipes And Fittings For UPVC Sanitary System - Connection and Inspection System The Contractor shall incorporate the easy check double locking system or other connection system to the UPVC sanitary system to ensure that the UPVC pipes and fittings are fully overlapped to minimise leakage at the joints. The Contractor shall arrange for the inspection of all the joints between the UPVC pipes and the fittings after the installation of the completed system to prove that all the joints between the UPVC pipes and the fittings are fully overlapped. The pipe joint system shall include: (a)
The connection of the pipes and fittings in such a way that the soil and waste will flow smoothly from the outlet to the fittings, through the horizontal branches and vertical stacks to the main line. The system shall not allow any possibility of back flow, and stagnation of fluid at the joints due to insufficient overlapping of UPVC pipes and fittings.
(b)
The overlapped portion at the joints between the UPVC pipes and the fittings shall be exposed and can be inspected visually after the installation of the system. The Contractor shall ensure that full overlap between UPVC pipes and fittings is achieved. In the event that the UPVC pipes and fittings are not overlapped sufficiently, the Contractor shall dismantle the affected portion of the system and re-installed to the satisfaction of the SO Rep.
(c)
Big access openings shall be provided (at least 75 mm diameter) to the fittings (including tees, cross tees and elbows) to facilitate the easy clearance of the chokage. The access opening shall be capped with UPVC screw cap with proper rubber seal and PP insert to ensure water and air tightness at all time.
The Contractor shall submit a full set of shop drawings, samples and mini-mock up, including sectional view to demonstrate the above requirements to the satisfaction of the SO Rep prior to the installation of the UPVC sanitary system on the Site. The Contractor shall also ensure that their UPVC fitting manufacturer is licensed to use the patented design. The contractor may propose alternative connection system in lieu of the patented design.
37.13
UPVC DOUBLE 45° BEND Provide and fix 150mm diameter UPVC double 45 degree bends to SS 272 encased in 150mm thick grade 30 concrete and reinforced with a layer of BRC A10 or other approved at the base of each discharge stack below ground level. If the discharge stack is of 100mm diameter, use a 150mm x 100mm UPVC taper piece to SS 213 at above the ground level to connect the 100mm diameter stack to the 150mm single junction fitting with inspection eye to SS 213. Provide single junction fitting with inspection eye to discharge stack at 150mm above the finished ground floor level. Secure screw down cap of the inspection eye of the single junction fitting with 2 no. of brass screws.
BLDG12/S37.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 37-10 37.14
UPVC GULLIES AND UPVC FLOOR WASTES/TRAPS WITH UPVC GRATING TO ALL GROUND FLOOR FACILITIES INCLUDING LINK BUILDING AND MSCP Where the ground floor wastes discharge into floor trap or apron gully at the ground floor as shown in the Drawings, the gullies shall be 100mm diameter UPVC fitting with 150mm square UPVC grating and set on and encased in concrete of minimum 150mm thick and connected to drains discharging into inspection chambers. The gratings for floor wastes/traps and gully traps shall be of approved UPVC 150mm square top body with screw-in round grating cover and to the requirements of the Water Reclamation (Network) Department, PUB; HDB; and complying with SS 213. The grating over floor trap and gully trap shall be complete with an Anti-Mosquito Device approved by the NEA.
37.15
GULLY AND DEEP SEAL TRAP All floor traps to upper floors shall be deep seal traps minimum 100mm diameter with 75mm deep seal all to SS 213 and to the requirements of the Water Reclamation (Network) Department, PUB. No gully or floor traps shall be deeper than 600mm from the top of grating.
37.16
RESERVED
37.17
RESERVED
37.18
RESERVED
37.19
WATER SUPPLY PIPE AND WASTE OUTLETS FOR SINK The Contractor shall fix and terminate the water supply pipe to sink and provide the waste outlets for sink at positions and to details all as shown in the Drawings.
BLDG12/S37.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 37-11 37.20
LOW CAPACITY WC SUITE AND WASH BASIN
37.20.1
Schedule Of Low Capacity WC Suite And Wash Basin Provide and install the following :
Low Capacity WC Suite Accommodation Type
5 Room
3-Room and/or 4Room
Integral Culture Marble Basin & Top
Vitreous China Wash Basin
Colour as chosen by the Architect #
White or other colour basin & pedestal as chosen by the Architect #
Location White or other colour as chosen by the Architect# Common Bathroom/W C Attached Bathroom/W C Common Bathroom/W C Attached Bathroom/W C
*
Rectangular Shaped Vitreous China Wash Basin (+) White or other colour basin as chosen by the Architect #
*
*
*
*
*
*
*
*
*
*
*Denotes the specified type. # The colour shall be decided by the Architect . The Contractor shall provide the colour range specified for selection and approval by the Architect . (+) Alternative choice of rectangular shaped vitreous china wash basin shall be decided by the Architect. The WC suite and wash basin and pedestal shall be of the same brand and approved as a set by the HDB.
37.20.2
Vitreous China Wash Basin And Pedestal (A)
Vitreous China Wash Basin And Pedestal Provide and install wash basin and pedestal as specified in subclause 37.20.1 "Schedule Of Low Capacity WC Suite And Wash Basin". The wash basin and pedestal shall be approved 500mm x 400mm vitreous china (with non-corrosive wall bracket fixings), complying with SS 42, complete with 15mm chrome plated brass mixer tap and handle conforming to requirements in Clause 37.20.5 “Single Lever Basin Mixer and Accessories”, brackets, 1.2mm thick (min.) chrome plated brass pop-up waste assembly and 32mm approved UPVC bottle trap with all necessary washers, seals and nuts. The colour of the wash basin and pedestal (if applicable) shall be decided by the SO Rep as specified in the foregoing subclause. The mixer tap shall be completed with the necessary nut and two rubber washers. Fix and secure the mixer tap firmly on the wash basin. Unless specified otherwise, the waste pipe shall be 40mm diameter UPVC pipe.
BLDG12/S37.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 37-12
37.20.2
Vitreous China Wash Basin And Pedestal (Cont'd)
(B)
Rectangular Shaped Vitreous China Wash Basin (+) Provide and install rectangular shaped wash basin as specified in subclause 37.20.1 "Schedule Of Low Capacity WC Suite And Wash Basin". The wash basin shall be Rigel LH4394 (540mm x 405mm) or Rigel LH/LS8025 (505mm x 460mm) or Saniton Aronia SB114 (560mm x 480mm) or Velin 4016 (590mm x 460mm) or Velin CB1139 (435mm x 365mm) or other approved rectangular shaped vitreous china wash basin (with non-corrosive wall bracket fixings), complying with SS 42, complete with 15mm chrome plated brass mixer tap and handle conforming to requirements in Clause 37.20.5 “Single Lever Basin Mixer and Accessories”, brackets, 1.2mm thick (min.) chrome plated brass pop-up waste assembly and 32mm approved UPVC bottle trap with all necessary washers, seals and nuts. The colour of the wash basin shall be decided by the SO Rep as specified in the foregoing subclause. The mixer tap shall be completed with the necessary nut and two rubber washers. Fix and secure the mixer tap firmly on the wash basin. Unless specified otherwise, the waste pipe shall be 40mm diameter UPVC pipe.
37.20.3
Integral Cultured Marble Basin And Top
(A)
Scope Of Work Provide and install integral cultured marble basin with monolithic top to bathrooms as specified in the subclause 37.20.1 "Schedule Of Low Capacity WC Suite And Wash Basin" and in accordance with the dimensions as shown in the Drawings.
(B)
Material And Product The integral cultured marble basin and top shall be of solid, non-porous, homogeneous polymeric material, either of polyester or acrylic base. It shall be of 19mm thick, complete with 75mm backsplash, 200mm front apron, and with 3 galvanised steel supporting brackets as shown. The integral cultured marble basin and top shall be in gloss finish. Bonding material and sanitary sealants of approved matching colour shall be provided in accordance with the manufacturer's instructions. The integral cultured marble basin and top shall be obtained from manufacturers approved by the SO Rep.
BLDG12/S37.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 37-13 37.20.3
Integral Cultured Marble Basin And Top (Cont'd)
(C)
Physical Properties The integral cultured marble basin and top shall comply with the following requirements : Characteristics 1.
Workmanship and Finish
Shall be free from cracks, crazing, pinholes, porosity, blisters, chipped areas or moulding defects.
2.
Impact Resistance
Shall not show cracks in the gel coat.
3.
Barcol Hardness
40 unit
4.
Oven Test for Cracking and Crazing
After oven test at 74ºC ±2ºC for 10 days, shall not show evidence of cracking or crazing.
5.
Water Absorption
Shall not absorb water in excess of 0.58% in 24 hours.
6.
Gel Coat (if applicable)
Shall not be less than 0.37mm or more than 0.87mm in thickness.
7A. Stain Resistance to : (a) Coffee (b) Tea (c) Detergent (d) Acetone (e) Olive oil (f) Lipstick (g) Fly spray (h) Ink, washable (i) Urea (6%) (j) Alcohol (k) Iodine (1%) (l) Shoe polish (m) Vinegar
(D)
International Association of Plumbing and Mechanical Officials (IAPMO PS 18-66) Requirements
) ) ) ) ) ) ) Shall be such that it will withstand all reagents. ) ) ) ) ) )
7B. Cigarette test
All stain shall be removed without sanding through the gel coat. If sanding is required, not more than 0.37mm of the gel coat shall be removed.
8.
Washability
Shall withstand 40,000 cycles in the scrub test (only slight brush marks are allowable).
9.
Drain fitting connections
Shall withstand the test with no visible damage.
Test Certificate And Compliance Requirements The Contractor shall submit test certificates by PSB or accredited laboratories in relation to the physical properties of the integral cultured marble basin and top. The tests shall be in accordance with the relevant IAPMO PS 18-66 test methods conducted by PSB or accredited laboratories.
BLDG12/S37.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 37-14 37.20.4
Coloured Low Capacity WC Suite (A)
Scope Provide and install close-coupled low capacity WC suite to all the common and attached bathrooms of all flat types as specified in subclause 37.20.1 "Schedule Of Low Capacity WC Suite And Wash Basin" and other locations as shown. The complete system of the close-coupled low capacity WC suite including the WC bowl, cistern, internal parts and fittings forming the complete flushing mechanism, seat and cover, and all the necessary accessories needed for the proper installation and functioning of the WC shall be to the approval of HDB and also to conform with SS 42 "Quality of Vitreous China Sanitary Appliances", Singapore Standards SS 378 - Specification for Vitreous China WC pans for use with low capacity WC flushing cisterns up to 4.5 L max, and SS 379 - Specification for Low Capacity Flushing Cistern up to 4.5 L max. Close-coupled low capacity WC suite shall be operated with a low flushing volume of 3.5 litres to 4.0 litres per single action flush with S-trap or P-trap outlet as shown in the Drawings. The rigid plastic seat and cover with buffers and hinging device shall conform to SS 16:1985 "WC Seats (Plastic)", or its latest amendment. The coloured plastic seat and cover shall match the profile of the WC bowl and approved by the HDB. The whole pedestal WC suite including the internal parts and fittings forming the complete flushing mechanism and all the necessary accessories shall be assembled in the factory as a complete system before delivery to the Site. The WC suite model shall have streamlined lower pan body and fully concealed outlet with no visible WC trap profile. A copy of the user manual/maintenance instruction shall be supplied with the WC and shall be affixed onto the WC using plastic bag and heavy duty adhesive tape.
(B)
Installation Fix the close coupled low capacity WC suite including rigid plastic seat and cover with buffers, hinging devices and with all necessary accessories and associated works in accordance with the manufacturer's written instructions to enable the proper functioning of the system. Fix the WC onto the floor using 4 no. of the original screws provided together with the WC and seal the gap between the base of the WC and the floor with approved silicone sealant. The WC shall not be fixed using cement grout or using other type of screws. Any WC installed using a method not in accordance with the instructions of the manufacturer shall be dismantled and re-installed in accordance with the correct method.
37.20.5
Single Lever Basin Mixer And Accessories All basins shall be complete with 15mm dia (nominal); chrome plated: ceramic disc cartridge operated; a single lever mixer tap, with pop-up waste, aerator and bottle trap. It shall be complete with all necessary seals and nuts, firmly fixed and secured on the basin. The dimension of the tap spout measured from the centre of the outlet orifice to the centre of the inlet shall be 90mm minimum and measured vertically from the lowest part of the outlet orifice to the basin top shall be 25mm minimum. The Hot / Cold indicator shall be clearly visible. The indicator may either be by colour coding and/or with character identification. Hot indicator shall be on the left and cold indicator on the right side. The lever and the body shall be of chrome plated brass. The metallic coating shall comply with BS EN 12540, Service Condition 2 with designation Cu/Ni10b/Crr. For any part of mixer that made of zinc alloy, the electrodeposited coating shall be Zn/Cu20/Ni10b/Crr. The operation of the lever shall be smooth and effortless. The lifting of the lever shall not leave any gap or opening which is likely to trap the finger and/or cause injury. The mixer tap shall comply with BS EN 817 and approved by the SO Rep. The mixer shall pass the PUB stipulated tests in BS EN 817. Bottle trap shall be approved by the SO Rep and connected to a 40mm diameter UPVC waste pipe discharging into a floor trap as shown.
BLDG12/S37.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 37-15 37.20.5
Single Lever Basin Mixer And Accessories (Cont'd) The tap fittings shall be properly cleaned and wrapped immediately after the installation. The protective materials shall be durable and the method of protection shall remain intact till the units are handover.
37.20.6
Sealant Silicone sealant shall be used to seal up all gaps between sanitary wares (including cultured marble basin/top ) and tiled surface. The approved sealant shall be of one-component system, non-sag, class 25 in accordance with ASTM C920-01, and able to be applied without a primer. In addition it shall also meet the following technical requirements: S/N
Characteristics/ Properties
1
Fungal Resistance Test
Test Method ISO 846:1997 (Method B)
Chemical Resistance Test: a)
Household bleach
a)
Concentrated sodium hypochlorite solution - ANSI Z124.3 : 1986 (spot covered)
b)
Urea
b)
Urea, 6.0% (Urine) - ANSI Z124.3 : 1986 (spot covered)
2
3
Tack Free Time (hrs)
ASTM C679-87 (1997)
Requirements No growth ) ) )Surface shall be )unaffected after 16 )hours of spot )covered test ) ) ) 4hrs
The Contractor shall submit the brand/range of silicone sealant and proposed method of application to the SO Rep for approval prior to the commencement of the Works. The Contractor shall also submit samples of the sealant to the SO Rep for selection of colour to match the sanitary Works 37.20.7
Dual-Flush Low Capacity WC Suite (A)
Technical Requirements Unless otherwise stated, all WC suite shall be dual flush low capacity type. The complete system of the close-coupled dual-flush low capacity WC suite including the WC bowl, cistern, internal parts and fittings forming the complete flushing mechanism, seat and cover, and all the necessary accessories needed for the proper installation and functioning of the WC shall be to the approval of HDB and also to conform with SS 42 "Quality of Vitreous China Sanitary Appliances", Singapore Standards SS 378 - Specification for Vitreous China WC cisterns, and SS 379 - Specification for Low Capacity Flushing Pans for use with low capacity WC flushing pans up to 4.5L max. It shall be certified to be rated in the PUB’s “Water Efficiency Labeling Scheme” (WELS). The dual-flush low capacity WC shall enable a full flushing actuation and a reduced flushing actuation. The full flush of the dual-flush low capacity WC suite shall be operated with a low flushing volume of not exceeding 4.5 litres per single action flush. The full flushing performance shall comply fully with the SS 378 and SS 379. The flushing fitting within the cistern shall be set to 4.2 litres. The endurance test for the WC shall be of 100,000 flushing cycles.
BLDG12/S37.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 37-16 37.20.7
DUAL-FLUSH LOW CAPACITY WC SUITE (A)
Technical Requirements
(CONT’D)
(Cont’d)
The reduced flushing actuation shall comply with the following performance requirements:
Performance
Test
Criteria
Volume of water Discharged per reduced flush
SS 378 Appendix I
The cistern shall discharge a volume of water not more than 3 litres.
Endurance of flushing fitting
SS 378 Appendix J
The cistern shall not leak or show signs of defect, damage after 100,000 flushing cycles.
Discharge of colored water
Dilution test with aniline blue solution
No visible traces of colored water remaining in water seal
Loading on operating mechanism
SS 378 Appendix G
Shall not distort, and parts shall not become detached or inoperative.
Paper discharge
4 no of twin-ply toilet papers of 15,000mm² and of 40 g/m²
The toilet papers shall be fully discharged in at least 2 out of 3 tests.
The buttons for the actuation of the full and reduced flushing shall be clearly marked to be easily distinguishable by users. The rigid plastic seat and cover with buffers and hinging device shall conform to SS 16:1985 "WC Seats (Plastic)", or its latest amendment. The colored plastic seat and cover shall match the profile of the WC bowl and approved by the HDB. The whole pedestal WC suite including the internal parts and fittings forming the complete flushing mechanism and all the necessary accessories shall be assembled in the factory as a complete system before delivery to the Site. The WC suite model shall have streamlined lower pan body and fully concealed outlet with no visible WC trap profile. A copy of the user manual/maintenance instruction shall be supplied with the WC and shall be affixed onto the WC using plastic bag and heavy duty adhesive tape. (B)
Installation Fix the close coupled WC suite including rigid plastic seat and cover with buffers, hinging devices and with all necessary accessories and associated works in accordance with the manufacturer's written instructions to enable the proper functioning of the system. Fix the WC onto the floor using the original screws provided together with the WC and seal the gap between the base of the WC and the floor with approved silicone sealant. The WC shall not be fixed using cement grout or using other type of screws. Any WC installed using a method not in accordance with the instructions of the manufacturer shall be dismantled and re-installed in accordance with the correct method.
BLDG12/S37.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 37-17 37.20.8
BATH / SHOWER MIXER AND SHOWER-SET ASSEMBLY The bath / shower mixer shall be 15mm dia (nominal) chrome plated; ceramic disc cartridge operated; single lever mixer tap. It shall be complete with all necessary seals and nuts, firmly fixed and secured. The Hot / Cold indicator shall be clearly visible. The indicator may either be by colour coding and/or with character identification. Hot indicator shall be on the left and cold indicator on the right side. The lever and the body shall be of chrome plated brass. The metallic coating shall comply with BS EN 12540, Service Condition 2 with designation Cu/Ni10b/Crr. For any part of mixer that made of zinc alloy, the electrodeposited coating shall be Zn/Cu20/Ni10b/Crr. The operation of the lever shall be smooth and effortless. The lifting of the lever shall not leave any gap or opening which is likely to trap the finger and/or cause injury. The mixer tap shall comply with BS EN 817 and approved by the SO Rep. The mixer shall pass the PUB stipulated tests in BS EN 817. Shower-set shall be complete with adjustable jet handset type of shower head, flexible hose, and sliding bar, all in chrome finish. Flexible hose shall be of length 1.5m and of stainless steel or chromed brass. An adjustable shower head holder shall be provided on the sliding bar. Shower-sets provided shall also comply with the following requirements:
Characteristic / Properties
Requirements: BS 6340 Part 4-Specification for shower heads and related equipment Clause 9.2-Service condition 2A,
Nickel and Chromium plating on shower head and related equipment
Classification PL/Ni 8b Cr r (8 micron min Full-bright Nickel and 0.3 micron min Regular Chromium)
Spray Trajectories
Clause 13.1
Tensile Load test for Flexible Hose
Clause 14.1
BLDG12/S37.DOC(17) Sal(151211) (DPD)
Bldg Spec Page 37-18 37.21
COLOURED UPVC GRATING OVER FLOOR TRAP/WASTE OUTLET FOR BATH/WC, KITCHEN AND SERVICE YARD All UPVC gratings over 100mm or 50mm diameter floor traps/waste outlets in the Bath/WC, Kitchen and service yard with floor tiles shall be coloured gratings. The colour shall be one of the four basic colours, ie. Blue, Pink, Beige or Grey and shall be approved by the SO Rep. However, the anti-mosquito device need not be in colour.
37.22
BIB TAP AND DRAINAGE OUTLET FOR WASHING MACHINE Provide and fix 15mm diameter chrome plated brass hose union bib tap with cross-head handle at the kitchen. The bib tap shall comply with BS 5412 and approved by the SO Rep. 50mm diameter outlet for washing machine shall be finished with UPVC adaptor and screw-down cap as shown in the Drawings.
37.23
LAY SEWER TO CONNECT TO MINOR SEWER AND SEWER CONNECTION Lay the last length of main drain-line to join the inspection chamber to the minor manhole connection pipe provided by the Employer's civil engineering contractor or Water Reclamation (Network) Department, PUB unless otherwise specified. Allow for the connection to be carried out at a later stage. The connection shall be done under the supervision of the SO Rep or Water Reclamation (Network) Department, PUB. Where in the case pipe joints are not provided, the Contractor shall provide the necessary connections by other methods approved by the Water Reclamation (Network) Department, PUB at the Contractor's own costs and expenses. The last length of the main drain-line from the inspection chamber to such minor manhole shall be of vitrified clay pipe all as shown in the Drawings and to the approval of Water Reclamation (Network) Department, PUB. Backfill with quarry dust and finished as shown. Apply to the Water Reclamation (Network) Department, PUB for the connection and bear all costs and expenses including the necessary fees.
37.24
RAINWATER DOWNPIPE (RWDP) SYSTEM The rainwater downpipe system shall be of UPVC pipes and fittings, all as shown in the Drawings and approved by the SO Rep. Unless specified otherwise, all rainwater downpipes above ground slab level shall be 200mm nominal diameter white UPVC pipes. The rainwater downpipe system shall be complete with downpipes, branch pipes, roof and balcony outlets with gratings, couplings, pipe brackets, swept tee junctions, access pipes, adaptors, rectangular section bends, underground pipes and Y-branch fittings. The 200mm nominal diameter white UPVC pipe shall comply with the requirements of SS 272:83 as shown below : Measurements/Tests a) Dimensions
SS 272:83 Requirements Outside Diameter Mean-minimum 200.0, maximum 200.6; Ovality-minimum 196.3, maximum 204.3; Wall Thickness minimum 4.9, maximum 6.0.
b) Opacity
Not exceeding 0.2 per cent of visible light.
c) Hydrostatic Pressure
No sign of leakage or any Defect at 70 kPa.
The method of jointing pipes and fittings shall be as specified in subclause 37.12.2.4 "Method of Fixing".
BLDG12/S37.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 37-19 37.25
WASTE AND RAINWATER DISCHARGE FROM BALCONIES, SERVICE YARDS, LANDINGS, LIFT LOBBIES AND MSCP DECKS As shown in the Drawings, waste and rainwater discharge from the access balconies, private balconies, service yards, landings, lift lobbies at the second storey and above, and all multi-storey carpark/garage decks shall be connected to the rainwater downpipe system or to waste downpipes discharging into surface drains. All branch pipes and fittings used in the connections shall be of UPVC and comply with SS 213. The discharge outlets shall be square base, screw-in domical grating type as shown in the Drawings. All 80mm, 100mm and 150mm nominal diameter outlets for the private balconies/service yards shall have an adjustable square base of minimum 40mm adjustment. All 50mm nominal diameter outlets for private balconies shall have flat screw-in gratings. The method of jointing pipes and fittings shall be as specified in subclause 37.12.2.4 "Method of Fixing".
37.26
WASTE AND RAINWATER DISCHARGE AT GROUND FLOOR Unless shown otherwise in the Drawings, all ground floor surfaces of void decks, play areas, multi-storey carparks/garages, link buildings, linkways, etc, shall be graded to drain waste water and rainwater into surface drains.
37.27
PAINTING Except for sanitary pipes and water supply pipes, all other ferrous metal surfaces of work installed by the Contractor (eg. mild steel brackets and others) shall be painted with 1 coat of approved primer and 2 coats of gloss enamel paint. All paint used shall be of those quality controlled by PSB and approved by the SO Rep. Allow for numbering to be painted to all sanitary pipes and water supply pipes at void deck.
37.28
MODULAR BRICKS Where clay bricks are shown in the Drawings, the bricks shall be of modular bricks. The common and facing clay bricks shall be 190mm x 90mm x 90mm and 290mm x 90mm x 90mm.
37.29
STAINLESS STEEL PIPE RAIL (FOR HANDICAP) Provide and install stainless steel pipe rail for handicap in public toilets as shown in the Drawings. The stainless steel shall be of AISI Grade 304, and the internal diameter shall be as shown in the Drawings. The end of the pipe shall be split to form fishtail and fixed into the wall and complete with stainless steel capping of the same grade all to the details as shown in the Drawings. The fixing of pipe rail shall be rigid and secured tightly into the walls.
37.30
CONNECTING TUBE TO PILLAR TAPS AND CISTERNS The connecting tube shall be flexible stainless steel tube 15mm diameter and complete with UPVC adaptor coupling where necessary.
37.31
50MM DIAMETER WASTE OUTLET AT ATTACHED BATHROOM Waste discharge outlet for the 50mm diameter pipe at attached bathroom shall be UPVC screw-in flat grating with square base as shown in the Drawings.
Section 38/.....
BLDG12/S37.DOC(19) Sal(151211) (DPD)
Bldg Spec Page 38-1 SECTION 38 WATER INSTALLATION
38.1
GENERAL REQUIREMENT All pipes and pipe fittings shall be approved by Water Supply (Network) Department, PUB unless otherwise specified. The SO Rep reserves the right to carry out test on materials on the Site as and when required. The test shall be conducted at an SAC-SINGLAS accredited laboratories.
38.2
WATER SUPPLY PIPES
38.2.1
Ductile Iron Pipes and Fittings For Water Supply All ductile iron pipes and fittings for water installation shall comply with BS EN 545 and ductile iron flanges type PN16 shall comply with BS EN 545. The pipes and fittings shall be internally cement mortar lined in accordance with the relevant clauses in BS EN 545.
38.2.2
Stainless Steel Water Pipes Provide and fix stainless steel water supply pipes to areas as shown in the Drawings. All stainless steel water pipes, fittings and accessories shall comply with the standards stipulated by PUB and to the requirements of BS EN 10312:02. The internal and external surfaces of the pipes and fittings shall be clean, smooth and free from Defect. Cutting and fixing shall be in strict accordance with the manufacturer's instructions. All stainless steel pipes shall not be bent. Support pipes with stainless steel supporting clips or as shown in the Drawings. Use light gauge stainless steel pipes for water supply unless otherwise specified. The stainless steel pipe fittings shall be of compression fittings of copper alloy or stainless steel press fitting joints. Compression fittings of copper alloy shall conform with BS EN 1254 Part 2:1998 . Stainless steel press fitting joints shall conform with Japanese Waterworks Association (JWWA) G116 "Stainless Steel Pipe Fittings For Water Works". All fittings shall conform with all PUB latest requirements. Fittings of 15mm size and longer shall be legibly marked with the manufacturer's name or trade mark. Support pipes with supporting stainless steel clips and hangers. The maximum spacing for horizontal and vertical support shall be as follows : Nominal Size
Maximum Horizontal Support Spacing
Maximum Vertical Support Spacing
(mm)
(mm)
(mm)
1000 1000 1200 1200
1200 1200 1800 1800
15 20 to 28 35 to 42 54 and above
Notwithstanding this, the Contractor shall ensure that all the pipes shall be secured firmly. If necessary, the compression joint shall be adequately supported with brackets on both sides to avoid any dislocation.
BLDG12/S38.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 38-2 38.3
CONTRACTOR'S WORK COMMENCES FROM PUBLIC UTILITIES BOARD MAIN PUB will provide and lay water main up to the bulk meter for direct and indirect supply or individual meter points for direct supply as shown in the Drawings. The Contractor's Works shall commence from these points.
38.4
BULK METER POSITIONS The exact position of bulk meter, where not fixed by existing mains shall be approved by the SO Rep and Water Supply (Network) Department, PUB before fixing. Otherwise the Contractor shall make good to the proper position determined by the SO Rep.
38.5
WATER METER POSITIONS Provide and install live meter connections to all flats and remove the connections at the time when PUB install the water meters to all flats. The Contractor shall also provide label/tag of unit numbers where one service duct serves more than two dwelling units per floor. The label or tag shall be a permanent feature, with the dwelling unit number clearly indicated and firmly attached to the piping.
38.6
BRASS STOPCOCKS, STOP VALVES, GATE VALVES AND COPPER AND COPPER ALLOY GATE VALVE Provide and fix to every branch service pipe or main supply pipe, one stop valve to SS 75:Pt 2 or gate valve to BS 5163. Provide valve with a detachable crutch head. Where ball stop valves and stopcocks are along public corridors or public access balconies, the upper end of projecting shank of valves shall be tilted to an angle of 15 degrees towards the wall where such pipes are tee off from direct up-riser pipes or indirect down supply pipes. The installation shall comply with PUB regulations. Install copper and copper alloy gate valve to BS 5154 at the down supply pipe on the roof top. When directed by the SO Rep, the Contractor shall remove the detachable levers and deliver them to the Branch Office or Town Council.
38.7
DIRECT SUPPLY TO FLATS Run 100mm diameter underground ductile iron distribution main and 80mm ductile iron sub-main complying with BS EN 545 as shown in the Drawings. From this main, run direct riser of size shown in the following schedule, each serving only 2 units on each floor unless otherwise shown.
BLDG12/S38.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 38-3 38.7
DIRECT SUPPLY TO FLATS (CONT'D) Schedule of Common Direct Riser and Tee Off Pipes For 3, 4 and 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) (a)
Storey No. Served by Common Riser
Block without Void Deck 1
2
3
4
5
6
7
8
Size of Riser
54mm
54mm
54mm
54mm
54mm
54mm
54mm
54mm
No. of Storey
1st
1st
1st to 2nd
1st to 3rd
1st to 3rd
1st to 3rd
1st to 3rd
1st to 3rd
*Tee Off Size
22mm
22mm
22mm
22mm
22mm
22mm
22mm
22mm
No. of Storey
2nd
3rd
4th
4th
4th
4th
4th
*Tee Off Size
28mm
28mm
28mm
28mm
28mm
28mm
28mm
Size of Riser
54mm
54mm
54mm
54mm
No. of Storey
5th
5th
5th to 6th
5th to 7th
*Tee off Size
22mm
22mm
22mm
22mm
No. of Storey
6th
7th
8th
*Tee Off Size
28mm
28mm
28mm
(b) Storey No. Served by Common Riser
Block with Void Deck 2
3
4
5
6
7
8
9
Size of Riser
54mm
54mm
54mm
54mm
54mm
54mm
54mm
54mm
No. of Storey
2nd
2nd
2nd to 3rd
2nd to 4th
2nd to 4th
2nd to 4th
2nd to 4th
2nd to 4th
*Tee Off Size
22mm
22mm
22mm
22mm
22mm
22mm
22mm
22mm
No. of Storey
3rd
4rd
5th
5th
5th
5th
5th
*Tee Off Size
28mm
28mm
28mm
28mm
28mm
28mm
28mm
Size of Riser
54mm
54mm
54mm
54mm
No. of Storey
6th
6th
6th to 7th
6th to 8th
*Tee off Size
22mm
22mm
22mm
22mm
No. of Storey
7th
8th
9th
*Tee Off Size
28mm
28mm
28mm
* The diameter of tee off pipe sizes shall be applied through up to the junction of the last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings.
BLDG12/S38.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 38-4 38.8
HOT AND COLD WATER SUPPLY PIPES AND FITTINGS Hot and cold water supply pipes and fittings shall be provided within the residential units. The Contractor shall submit the proposed work methods for the installation of concealed water pipes including information/details of the suppliers and type of materials used for the approval of SO Rep. All water pipes within the residential units shall be of copper pipes to BS EN 1057-R250, approved by the SO Rep. All pipes shall be chased (embedded) in walls, columns and beams. No pipe shall be exposed within the residential units. Copper brackets shall be used for securing the water pipes. The spacing between copper brackets on the horizontal and vertical pipe run shall not be more than 1m centre-tocentre. In addition, copper brackets shall also be installed immediately before and after each bend. Notwithstanding this, the Contractor shall ensure that all the pipes shall be secured firmly. The nominal size of the water pipes shall be of nominal outside diameter of 22mm with nominal wall thickness of 1.2mm. However, nominal outside diameter of 28mm with nominal wall thickness of 1.2mm shall be used for the topmost 2 storeys. The water pipe shall be reduced to 15mm nominal outside diameter with 1.0mm nominal wall thickness at the tap fittings. For forming of vertical and horizontal recesses in residential units, no hacking is allowed. The contractor shall use modular shaped solid block to form all horizontal and vertical recesses for the water supply pipes. All fittings required for joints (tees, elbows, etc) on the pipes shall be of an approved press-fit coupling system fittings complying with BS EN 1254 Part 2. Bending of copper pipes is not allowed. Joining of fittings to pipes shall be by press-fit coupling system. Before joining, clean the external surface of the copper pipes and the internal surface of the fittings. The press-fit coupling system shall be carried out by means of an approved propriety mechanical clamping jaw to crimp an approved proprietary copper fitting to a standard EN 1057-R250 copper pipe. The press-fit fitting shall consist of an ethylene-propylenediene(EPDM) “O” ring seal. The press-fit fittings/system shall comply with the standards stipulated by PUB and its use in water service installations shall conform to the Public Utilities ( Water Supply ) Regulations and SS : CP 48. The system shall not require proprietary tap fittings/valves and other related accessories. The Contractor shall submit all taps, mixers, and accessories for the approval of the SO Rep. The press-fit system shall be able to withstand a working pressure of 16 bar and a working temperature range of above freezing point to 110 °C. The system shall provide a fail-safe indicator to identify improper assembly. The system shall be suitable for embedment in walls, columns and beams. All pipe works shall be installed and tested to BS EN 1254 Part 2. Taps, mixers and other accessories are not installed during the test. The entire pipe works shall show no sign of defect or leakage for the duration of the test. The test requirements for leak-tightness under hydrostatic pressure test shall be 24 bars at ambient temperature. The pressure shall be applied gradually and maintained for a minimum period of 15 minutes at ambient temperature. This test shall be carried out to every dwelling unit and witnessed by the SO Rep. The pressure gauge used for the testing shall be calibrated by an SAC accredited laboratory. All water pipes including all pipe fittings (tees, elbows, etc) shall be left exposed for inspection for leakage during testing before concealment of the pipes and fittings shall be carried out. A cold water pipe shall be tee-off from the distribution pipe to the designated heater position. Hot water pipes shall be provided from the heater position to all basin and both bath mixers position. A pressure relief drain-off pipe shall also be provided for discharging to the floor trap. The cold water inlets and hot water outlets shall all be terminated with U pipes projected at 80mm away from the wall. The drain-off pipe shall be terminated with compression fitting with capping at 50mm away from the wall. All the 3 termination points shall be fixed with 30mm x 20mm aluminium tags, with engraved markings of "cold water inlet", "hot water outlet" and drain-off" respectively. Light duty coloured masking tapes of 10mm width, shall be fixed on the wall surfaces of all the pipe routing lines concealed behind walls, columns and beams. Red for hot water pipes, blue for cold water pipes and black for drain-off pipe. No wall finish shall be damaged by the removal of the tapes. For each basin, 15mm diameter isolating ball stopvalves shall be fixed below the tap mixer, connecting to the hot and cold water inlet. A 15 mm diameter isolating ball stopvalves shall also be fixed at the provision of cold water inlet for kitchen sink connection where specified (eg. Studio Apartment type of flat).
BLDG12/S38.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 38-5 38.8
HOT AND COLD WATER SUPPLY PIPES AND FITTINGS (CONT'D) A bath mixer complete with adjustable jet shower head, sliding bar, 1.5m flexible hose (all in chrome finish), and a basin mixer, approved by the PUB and the SO Rep, shall be provided within each Bath/WC.
38.9
REFUSE CHUTE FLUSHING SYSTEM
38.9.1
Flushing Pipes From Ground Level Where refuse chute flushing pipes are supplied directly from PUB mains, every refuse chute shall have its own supply teed off from the distribution mains located at apron. Supply pipe of 35mm diameter stainless steel pipe to refuse chute shall have a brass stopcock with detachable brass crutch head located outside at 1.8m above apron. The brass components shall be dezincification resistant complying to BS EN 12163:1998 or BS EN 12165:1998 or BS EN 12420:1999. Such fittings shall have the additional marking of "DZR" or "CR". The flushing pipe shall be 25mm diameter UPVC pipe complying with SS 141 Class E ringing round four sides of the chute and perforated with 5mm ±1mm diameter holes at maximum 50mm centres such that the water flowing out of the holes are directed at 45 degrees towards the refuse chute wall. The flushing pipe shall be supported by non-corrosive clips or hangers to each side of the refuse chute wall.
38.9.2
Flushing Pipes To Refuse Chutes From Distribution Mains At Roof-Top (For Block With Centralised Refuse Chute)
38.9.2.1
Pipe & Fittings For flushing pipes to centralised refuse chutes from distribution mains at roof-top, the 42mm diameter stainless steel supply pipes shall be teed off from the distribution main at the roof top as specified in Clause 38.10 "Indirect Supply From Roof Tanks". One such pipe shall supply only one chute. Provide each supply pipe with a 40mm full bore ball stop valve and a 40mm solenoid valve. The layout and arrangement shall be as shown in the Drawings for flushing chutes. The flushing pipe shall be 25mm diameter UPVC pipe complying with SS 141 Class E ringing round four sides of the chute and perforated with 5mm ±1mm diameter holes at maximum 50mm centres such that the water flowing out of the holes are directed at 45 degrees towards the refuse chute wall. The flushing pipe shall be supported by non-corrosive clips or hangers to each side of the refuse chute wall.
38.9.2.2
Solenoid Valve The approved 40mm solenoid valve shall be electrically operated, two-way, normally closed and capable of operating at zero differential pressure. The supply voltage shall be 230 V ±10% at 50 Hz. The coil shall be epoxy or plastic encapsulated, of at least class F insulation, and capable of 100% continuous duty. The enclosure protection shall be at least IP65 (according to BS 5490) and suitable for conduit connection. The enclosure shall incorporate earthing terminal and terminal block for easy maintenance. The pipe threads shall comply with BS 21. The operating pressure range shall be 0 to 4 bars. The valve body shall be of brass, bronze or other approved metal. Parts in contact with water shall be of stainless steel, brass, bronze or other approved material. All brass components shall be dezincificationresistant complying with BS EN 12163:1998 or BS EN 12165:1998 or BS EN 12420:1999. Such fittings shall have the additional marking of "DZR" or "CR" The Contractor's proposed solenoid valve shall be of the type approved by the SO Rep for the refuse chute flushing systems. Submit technical information of the solenoid valve and other information, as provided in APPENDIX A14, to the SO Rep for approval. Where the pressure of water leading to the solenoid valves exceeds 4 bars, such as in some staggered blocks, provide and install appropriate pressure reducing valves subject to the approval of the SO Rep.
BLDG12/S38.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 38-6 38.9
REFUSE CHUTE FLUSHING SYSTEM
(CONT’D)
38.9.2
Flushing Pipes To Refuse Chutes From Distribution Mains At Roof-Top (For Block With Centralised Refuse Chute) (Cont’d)
38.9.2.3
Control Board The design of control board shall follow the Drawings approved by the SO Rep. The control board shall contain the following : 1 No. 1 No. 1 No. 1 No.
Relay to control the solenoid valve for refuse chute flushing MCB unit for control circuit and solenoid valve 30 minute timer Circuit diagram to be pasted inside the front panel
The front panel shall have : 1 No. 1 No. 1 No. 1 No. 1 No.
Red indicator light to show the flushing is on Green indicator light to show the power supply is on Red emergency stop push button Green push button to start the flushing Key lock to be approved by the SO Rep.
The enclose protection of the box shall be at least IP 54 (according to BS 5490). The box shall be made of 1.5mm thick mild steel sheet, electro-galvanised and coated with one layer of epoxy oven-baked paint. The control board shall be wall mounted inside the refuse chamber next to the consumer unit. The chosen location shall be approved by the SO Rep. 38.9.2.4
Electrical Wiring The power supply to the system shall be from the consumer unit inside the refuse chamber. Cables and electrical wiring shall be PVC insulated to SS 358 and they shall be carried in their own conduits. The cables connecting the solenoid valve to the control switch shall be of 1.5 mm2 nominal cross-sectional area. The metal conduits shall be of heavy gauge, galvanised steel conduit, (Class 4), complying with BS 4568, free from internal roughness and burrs. The conduits shall run inside the building and along the staircase landing. Fixing to walls and other flat surfaces shall be by means of spacer bars saddles at maximum 1m centres for horizontal runs and 1.5m centres for vertical runs. Provide concrete stumps of 50mm diameter and 100mm high to encase the conduits at every floor level. The conduits to the solenoid valves shall run along the piping and be properly supported. All electrical cables and conduits shall be electrically and mechanically continuous throughout. Earth the conduits with copper earthwire of appropriate size. The conduit installation shall be completed before the cables are drawn. The number of cables to be drawn into the conduits shall not exceed those set out in PSB Code of Practice CP 5. Earth all non-current carrying metal parts of electrical equipment. Earth continuity conductors shall have a cross-sectional area of not less than that specified in CP 5.
38.9.3
Inspection During Progress Of Work Provide all necessary facilities such as torch lights etc and access leading to the refuse chute flushing system for inspection by the SO Rep.
38.9.4
Testing Of Installation One month before the completion of the installation, arrange with the SO Rep for testing of the performance and installation of the refuse chute flushing system. All Defect notified during inspection shall be rectified within such time as instructed by the SO Rep. Take all necessary precautions to prevent any collection of water inside the Refuse Handling Plant during any testing which involves the flushing of refuse chute.
BLDG12/S38.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 38-7
38.9
REFUSE CHUTE FLUSHING SYSTEM
38.9.5
Testing For Leakages
(CONT’D)
Carry out leakage test to the following items : (a) (b) (c)
joints between floor slab; joints between branch off pipes; and all the water pipes installed.
Complete the tests, including making good of all Defect within 14 days from the date of Substantial Completion for each building block.
38.10
INDIRECT SUPPLY FROM ROOF TANKS Where supply is from roof storage tanks, run 100mm diameter ductile iron distribution mains complying with BS EN 545 with cement lining internally on roof to beyond the last down supply pipes. From these mains, run down supply pipes of sizes shown in the schedule, "Schedule Of Down Supply Pipes And Tee Off Pipes For 3, 4, 5-Room Flats", each serving only 2 units on each floor unless otherwise shown. Pipe joints, fittings and special tee for ductile iron distribution mains and drawout pipes at roof level shall be of the flanged type. The use of special tee shall be approved by the SO Rep.
BLDG12/S38.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 38-8 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size No. of Storey Below Roof * Tee Off Size
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
1-Storey
2-Storey
3-Storey
4-Storey
5-Storey
6-Storey
7-Storey
8-Storey
9-Storey
42mm 1st 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm 3rd 22mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 3rd to 4th 22mm
42mm 3rd to 5th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 7th 22mm
42mm 3rd to 8th 22mm
42mm 3rd to 5th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 6th to 9th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat units as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 38-9 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof
10-Storey
11-Storey
12-Storey
13-Storey
14-Storey
15-Storey
16-Storey
17-Storey
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 7th to 10th 22mm
42mm 7th to 11th 22mm
42mm 7th to 12th 22mm
42mm 7th to 13th 22mm
42mm 7th to 10th 22mm
42mm 7th to 10th 22mm
42mm 7th to 10th 22mm
42mm 7th to 11th 22mm
42mm 11th to 14th 22mm
42mm 11th to 15th 22mm
42mm 11th to 16th 22mm
42mm 12th to 17th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 38-10 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof
18-Storey
19-Storey
20-Storey
21-Storey
22-Storey
23-Storey
24-Storey
25-Storey
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 7th to 12th 22mm
42mm 7th to 12th 22mm
42mm 7th to 10th 22mm
42mm 7th to 10th 22mm
42mm 7th to 10th 22mm
42mm 7th to 11th 22mm
42mm 7th to 12th 22mm
42mm 7th to 12th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 13th to 18th 22mm
42mm 13th to 19th 22mm
42mm 11th to 15th 22mm
42mm 11th to 15th 22mm
42mm 11th to 16th 22mm
42mm 12th to 17th 22mm
42mm 13th to 18th 22mm
42mm 13th to 18th 22mm
42mm 16th to 20th 22mm
42mm 16th to 21st 22mm
42mm 17th to 22nd 22mm
42mm 18th to 23rd 22mm
42mm 19th to 24th 22mm
42mm 19th to 25th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 38-11 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof
26-Storey
27-Storey
28-Storey
29-Storey
30-Storey
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 12th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 12th to 16th 22mm
42mm 12th to 16th 22mm
42mm 12th to 16th 22mm
42mm 12th to 17th 22mm
42mm 13th to 18th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 17th to 21st 22mm
42mm 17th to 21st 22mm
42mm 17th to 22nd 22mm
42mm 18th to 23rd 22mm
42mm 19th to 24th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 22nd to 26th 22mm
42mm 22nd to 27th 22mm
42mm 23rd to 28th 22mm
42mm 24th to 29th 22mm
42mm 25th to 30th 22mm
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 38-12 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof
31-Storey
32-Storey
33-Storey
34-Storey
35-Storey
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 7th to 12th 22mm
42mm 7th to 12th 22mm
42mm 7th to 12th 22mm
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 13th to 18th 22mm
42mm 13th to 18th 22mm
42mm 13th to 19th 22mm
42mm 12th to 17th 22mm
42mm 12th to 17th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 19th to 24th 22mm
42mm 19th to 25th 22mm
42mm 20th to 26th 22mm
42mm 18th to 23rd 22mm
42mm 18th to 23rd 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 25th to 31st 22mm
42mm 26th to 32th 22mm
42mm 27th to 33th 22mm
42mm 24th to 29th 22mm
42mm 24th to 29th 22mm
42mm 30th to 34th 22mm
42mm 30th to 35th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 38-13 38.10
INDIRECT SUPPLY FROM ROOF TANKS (CONT'D)
Schedule of Down Supply Pipes and Tee Off Pipes for 3, 4, 5-Room Flats (To be of stainless steel complying with BS EN 10312:02) Where Tank Supply No. of Storey Below Roof
36-Storey
37-Storey
38-Storey
39-Storey
40-Storey
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
42mm 1st to 2nd 28mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
42mm 3rd to 6th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 11th 22mm
42mm 7th to 12th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 12th to 17th 22mm
42mm 12th to 17th 22mm
42mm 12th to 17th 22mm
42mm 12th to 18th 22mm
42mm 13th to 19th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 18th to 23rd 22mm
42mm 18th to 23rd 22mm
42mm 18th to 24th 22mm
42mm 19th to 25th 22mm
42mm 20th to 26th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 24th to 29th 22mm
42mm 24th to 30th 22mm
42mm 25th to 31st 22mm
42mm 26th to 32th 22mm
42mm 27th to 33th 22mm
Size of Down Feed Pipe No. of Storey Below Roof * Tee Off Size
42mm 30th to 36th 22mm
42mm 31st to 37th 22mm
42mm 32th to 38th 22mm
42mm 33th to 39th 22mm
42mm 34th to 40th 22mm
* The diameter of tee off pipe sizes shall be applied throughout up to the junction of last fitting within the flat unit as shown in the above schedule. The pipe shall be reduced to 15mm diameter at fitting all as shown in the Drawings. Provide and install 25mm diameter stopcocks before individual sub-meters for top-most 2 storey dwelling units.
BLDG12/S38.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 38-14 38.11
RESERVED
38.12
SILT TRAP AT FOOT OF DOWN SUPPLY PIPES Every down supply pipe shall extend at least 250mm below the last tee-off to form a silt trap fitted with a plug to facilitate cleaning. Provide gate valve with detachable crutch head just before the silt trap.
38.13
PIPEWORKS TO THE STAINLESS STEEL FLANGES AT THE CONCRETE WATER TANKS The fixing of pipes, valves and fittings, including bolts, nuts and gaskets, to the stainless steel flanges of the connecting pipes shall be fixed by the Contractor. Use only stainless steel bolts and nuts. All stainless steel material shall conform to AISI Grade 316 and flanges shall be in accordance with BS 4504. Allow for all pipeworks cost and water for sanitary and water installation leakage test.
38.14
PIPING TO HIGH LEVEL TANKS Provide and install piping to high level water tanks as follows :
38.14.1
Rising Mains Install 100mm ductile iron pipes to BS EN 545 with cement lining internally from bulk meters or low level suction tanks at ground level to high level water tank whichever is applicable. The rising mains shall be connected to a 100mm ball float valve with a 100mm gate valve at inlet. Floats shall be of copper and approved type.
38.14.2
Distribution Outlet Mains Install 100mm diameter ductile iron pipe to BS EN 545 with cement lining internally as shown in the Drawings. Support the pipes on precast concrete block 450mm high and 150mm thick of 1:3:6 mix concrete, embedded onto 150mm high concrete base by mortar at intervals of not exceeding 2700mm all as shown in the Drawings. Provide supports at every fitting or bend. Mains shall extend past the last branching-off of down supply pipe and shall be encased by reinforced concrete end-thrust supports as shown in the Drawings. Provide and fix ductile iron short pipe 450mm in length with 180mm diameter ductile iron collar 20mm thick, welded at middle section of the short pipe. Provide approved flange adaptors along the distribution pipe before each thrust support. All ductile iron pipe joints, flange adaptor, fittings and special tees shall be of the flanged type in compliance with BS EN 545 type PN 16.
38.14.3
Interconnecting Pipe Install 100mm diameter ductile iron pipe to BS EN 545 with cement linings installed between tanks as shown in the Drawings with 100mm gate valve. The invert level of the connecting pipe shall be 400mm above the internal base of the water tank unless shown otherwise in the Drawings. Pipe joints, fittings and special tees shall be of the flanged type ductile iron. Flange type PN 16 shall comply with BS EN 545.
38.14.4
Overflow Pipes 100mm diameter ductile iron overflow pipes to BS EN 545 with cement lining or one size bigger than the diameter of the inlet rising main pipe as shown in the Drawings to each tank compartment shall be connected to washout pipe. Provide an additional 28mm diameter stainless steel overflow warning pipe for each roof storage tank and discharging off roof edge at its nearest point preferably at the kitchen side. The pipe shall project 300mm from eaves of roof as shown in the Drawings. Cover open end of pipes with mosquito screen.
BLDG12/S38.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 38-15 38.14.5
Tank Washout Pipes Install 100mm diameter ductile iron washout pipes complying to BS EN 545 with cement lining before the gate valve from tanks to roof level as shown in the Drawings. The pipes shall discharge direct into roof rain water gutter and properly drained off through rain water downpipes.
38.14.6
Stop Valves, Sluice/Gate Valves, Copper And Copper Alloy Gate Valves Provide and install all necessary stop valves to SS 75:Pt 2, gate valves to BS 5163, Copper and Copper Alloy Gate Valves to BS 5154 and other fittings required to comply with the requirements and regulations of the Water Supply (Network) Department, PUB, regardless of whether such items have been specifically mentioned or not. The wedge of the gate valves (BS 5163) used shall be of rubber bonded gate. Coat the internal surface of valve body with approved material. The spindles of the gate valves shall be of stainless steel or high tensile bronze or other approved type.
38.14.7
Raised Pipes Install raised pipes to raise and support all horizontal pipes above concrete roof as stated in subclause 38.14.2 "Distribution Outlet Mains" to a level of not less than 330mm to clear precast secondary roofing slabs.
38.15
BIB TAP AND STOPCOCK/STOPVALVE Where shown in the Drawings, provide and fix 15mm diameter brass bib taps conforming with BS 5412 and BS 3457; and 15mm and 25mm diameter stopcocks/stopvalves conforming with SS 75:Part 2 and BS 3457. Such bib taps, stopcocks and stopvalves shall be approved by the SO Rep and Water Supply (Network) Department, PUB. Bib taps shall be chrome plated brass body with chrome plated brass operating handles. UPVC tee and cap for fixing bib tap as shown in the Drawings shall conform with SS 174. Fix the cap to the wall by "Ramset ED 655" or other approved.
38.16
TAPS IN PUBLIC AREAS Taps located at the staircase landings, access balconies, refuse hopper areas and wash areas shall be of 15mm diameter chrome plated hose union bib tap with removable handle, as shown in the Drawings. The tap shall be approved by the SO Rep and Water Supply (Network) Department, PUB. The handles shall be handed over to the Employer or the relevant Town Councils as directed by the SO Rep upon handing over of the building blocks.
38.17
WATER SERVICES TO UTILITIES CENTRE Run 25mm diameter UPVC pipe from water meter point to the utilities centre. Water pipes inside the buildings shall be 20mm diameter up to bib taps. Provide and fix 15mm diameter chrome plated brass self-closing delay-action bib tap over lavatory basin and 15mm isolating ball stop valve to W.C. cisterns. Bib tap and ball stop valve shall be of brass high pressure screw down type. Provide similar 15mm bib tap with screw on connecting nozzle for the utilities centre.
38.18
WATER SERVICES TO CENTRALISED REFUSE CHUTE CHAMBER Provide and install stainless steel water pipe and stainless steel down supply pipes to the sizes and locations as shown in the Drawings. The stainless steel pipes shall be approved by the Water Supply (Network) Department, PUB. Provide and fix brass caps to stainless steel water pipes. Provide and fix approved 15mm bib tap with screw on connecting nozzle and approved isolating ball stop valve at positions all as shown in the Drawings.
BLDG12/S38.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 38-16 38.19
FIXING FITTINGS BEFORE HANDING OVER When required, provide and fix taps, stop valves and other removable fittings immediately before all the building blocks are handed over to the Employer.
38.20
BRASS WATER PRESSURE REDUCING VALVE Provide and fix PUB approved bronze or brass water pressure reducing valves (NF E29-170) to down feed pipes where the pressures are more than 35m hydrostatic head, all to be in accordance with the requirements of Water Supply (Network) Department, PUB. The Contractor shall remove the pressure gauge of the pressure reducing valve and install a plug after testing.
38.21
RESERVED
38.22
RESERVED
38.23
TAP FITTINGS REQUIREMENT All taps shall conform to the following standards and technical requirements: Cold Water Tap (a)
Mechanical; water tightness, pressure resistance; hydraulic; and backflow prevention characteristics to- BS 5412;
(b)
Corrosion resistance performance to- BS EN 248;
(c)
All non-metallic material component in contact with water- to SS 375;
(d)
All metallic material in contact with water to- AS/NZS 4020 “Extraction of Metals - Appendix H";
(e)
The metallic coating shall comply with BS EN 12540, Service Condition 2 with designation Cu/Ni10b/Crr. For part that is of zinc alloy, the electrodeposited coating shall be Zn/Cu20/Ni10b/Crr; and
(f)
Certified under PUB’s Water Efficiency Labelling Scheme (WELS)
Mixer (Hot And Cold Water Tap) (a)
Mechanical; leak-tightness; hydraulic; torsion resistance and backflow prevention characteristics toBS EN 817 ;
(b)
Corrosion resistance performance to- BS EN 248;
(c)
All non-metallic material component in contact with water- to SS 375;
(d)
All metallic material in contact with water to- AS/NZS 4020 “Extraction of Metals - Appendix H";
(e)
The metallic coating shall comply with BS EN 12540, Service Condition 2 with designation Cu/Ni10b/Crr. For part that is of zinc alloy, the electrodeposited coating shall be Zn/Cu20/Ni10b/Crr; and
(f)
Certified under PUB’s Water Efficiency Labelling Scheme (WELS)
The Hot / Cold indicator shall be clearly visible. The indicator may either be by colour coding and / or with character identification. Hot indicator shall be on the left and cold indicator on the right side. Section 39/..... BLDG12/S38.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 39-1 SECTION 39 GAS PIPE INSTALLATION
39.1
GENERAL REQUIREMENT The gas pipe installation Works shall refer to the gas pipes after the CityGas Ltd Service Valve (SV) and which includes buried service pipes, horizontal service pipes, risers and internal gas pipes. The gas pipe installation work shall be suitable for City Gas Ltd manufactured gas as specified in CP51 Code of Practice for Manufactured Gas Pipe Installation and shall be carried out by a Consultant’s Licensed Gas Service Worker (hereinafter referred to as the "LGSW" for the purposes of this Section including all clauses and sub-clauses under it) and shall comply with City Gas Ltd requirements.
39.2
CODE OF PRACTICE AND REGULATORY REQUIREMENTS The Contractor shall ensure that the Works are carried out in accordance with the following requirements:
39.3
(i)
Public Utilities Act (Chapter 261)
(ii)
Public Utilities (Gas Supply) Regulations
(iii)
Code of Practice for Manufactured Gas Pipe Installation, ie. CP51 including any amendments,
(iv)
City Gas Ltd Procedures and Requirements for gas supply; and
(v)
Any other relevant rules, regulations and requirements by the relevant authority from time to time.
NOTIFICATION FOR COMMENCEMENT OF WORK Before commencement of the Works, the Contractor shall arrange with the City Gas Ltd project coordinator and the Consultant for a site meeting. After the site meeting, the Contractor shall notify City Gas Ltd before the Works can be carried out.
39.4
SAMPLE UNITS The Contractor shall put up sample unit for each typical installation for inspection and approval by both the City Gas Ltd Engineer and the Consultant. The Consultant shall submit two sets of drawings of the sample unit to City Gas Ltd before inspection. The Contractor shall only proceed with the whole installation only after the sample unit has been inspected and approved by the City Gas Ltd Engineer.
BLDG12/S39.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 39-2 39.5
APPLICATION FOR FINAL PRESSURE TEST OF GAS PIPE INSTALLATION The Contractor shall ensure that the gas pipe installation complies with the approved plan before submitting an application for final pressure test. The Contractor shall carry out preliminary testing of the completed installation and rectify all Defect before arranging with the City Gas Ltd project co-ordinator for the final pressure test. All preparation for the final pressure test shall be made by the Contractor. The final pressure test shall be conducted by the City Gas Ltd Engineer or his authorised representative. The application for final pressure test (City Gas Ltd Form PH-G2 as produced in Appendix A15) must be accompanied by the following : (i)
Four sets of as-built drawings duly endorsed by Consultant.
(ii)
City Gas Ltd Form PH-G1B as produced in Appendix A16 if necessary.
The same endorsed as-built drawings shall be submitted to the Consultant for endorsement. Thereafter the Contractor shall be informed by City Gas Ltd in writing on the approval of the application for the final pressure test of the gas pipe installation through Form PH-GR2 as produced in Appendix A17. A certificate of Final Pressure Test (Form PH-G2A as produced in Appendix A18) shall be prepared by the Contractor and endorsed by City Gas Ltd once the final pressure test is passed. A copy of this certificate shall be submitted to City Gas Ltd by the Contractor. In the event that the installation has failed the final pressure test, the Contractor must resubmit a fresh application for final pressure test. After the gas pipe installation has been tested and passed, the Consultant’s LGSW shall affix all plugs, caps and end-points of the installation with warning labels which read 'Gas Pipe Tested. Do Not Tamper'.
39.6
UNAUTHORISED WORK ON GAS PIPE INSTALLATION After the gas pipe installation has passed its final pressure test, the Contractor shall ensure that no person is allowed to carry out any further work without prior written approval from the City Gas Ltd approving authority. Any further work on the installation, shall render the final pressure test null and void. If any further work has to be carried out, a new application for the work shall be made together with the plans. No person other than an authorised City Gas Ltd employee or authorised City Gas Ltd contractor is permitted to connect any gas pipe installation onto City Gas Ltd gas main.
39.7
APPLICATION FOR CHARGE-IN/TURN-ON OF GAS SUPPLY After the gas pipe installation has passed the final pressure test and approved by the City Gas Ltd Engineer, the Contractor shall apply for charge-in/turn-on of gas supply by submitting City Gas Ltd Form PH-G3 as produced in Appendix A19. The Contractor shall attach a copy of the line drawing of the gas pipe installation indicating the location of the service valves, valves, risers, meters and all installation pipes downstream of the meter. The line drawing shall be subjected to the approval of the Consultant.
BLDG12/S39.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 39-3 39.7
APPLICATION FOR CHARGE-IN/TURN-ON OF GAS SUPPLY (CONT'D) The line drawing(s) of the gas pipe installation shall be displayed inside the 1st storey gas riser service duct(s). The line drawing(s) shall be placed and sealed inside an A4 size clear perspex cover and securely mounted with four stainless steel screws onto the inside of the door(s) of the riser service duct(s). Thereafter the Contractor shall be informed by City Gas Ltd on the approval and charge-in/turn-on of gas supply through Form PH-GR3 & PH-GR4 as produced in Appendix A20 and A21 respectively.
39.8
CHARGE-IN OF GAS The Contractor and/or Consultant must be present during the charge-in of gas. The Contractor shall arrange for a proof test and set up all necessary equipment, fittings and vent points for purging and ensure that all necessary safety precautions are taken. After the installation has been confirmed to be sound with the proof test, the installation is then purged and charged-in with manufactured gas. After the charge-in of the gas supply, the Consultant’s LGSW must affix the labels 'Live Gas. Do Not Tamper' to all plugs, caps and other end points of the gas pipe installation.
39.9
USE OF GAS DETECTOR The Contractor shall use a gas detector which measures the volume of gas in air, when necessary. The Consultant’s LGSW is responsible for the accuracy and the use of this instrument in all the Works that is carried out by him.
39.10
PIPES, FITTINGS AND VALVES All pipes, fittings and valves used in the gas pipe installation shall comply with CP51 and City Gas Ltd requirements. The diameter of all pipes as specified in the Specifications and Drawings shall be their nominal diameter. The diameter of all Polyethylene pipes as specified in the Specifications and Drawings shall be their outer diameter (OD) and based on a Standard Diameter Ratio (SDR) of 11. Unless otherwise specified, copper pipes to BS EN 1057 "Copper and copper alloys - seamless round copper tubes for Water and Gas in sanitary and heating applications" shall be used within the unit for overhead internal gas supply pipe from the meter to the kitchen of individual unit. Fittings shall be of compression fittings of copper alloy and shall comply with BS EN 1254 Part 2: 1998 "Capillary and Compression Tube Fittings for Copper Tubes". The Contractor shall provide a label/tag showing the unit numbers where one service duct serves more than two dwelling units per floor. The label or tag shall be a permanent feature, with the dwelling unit numbers clearly indicated and firmly attached to the piping. Galvanised steel pipes (heavy) complying with SS17 "Steel Tubes suitable for Screwing to BS 21 Pipe Threads" or BS 1387 "Screwed and Socketed Steel Tubes and Tubulars and for Plain End Steel Tubes Suitable for Welding or for Screwing to BS 21 Pipe Threads" shall be used outside the unit for incoming gas supply pipe, gas riser and horizontal supply pipe. The galvanised malleable cast iron pipe fittings shall comply with BS 143 and BS 1256 "Specification For Malleable Cast Iron & Cast Copper Alloy Threaded Pipe Fittings". Ductile iron pipes shall be of the flexible bolted gland joint type complying with BS EN 545-Class K9. The gland ring shall be lead tipped nitrile rubber or epichlorhydrin.
BLDG12/S39.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 39-4 39.10
PIPES, FITTINGS AND VALVES (CONT'D) All galvanised steel pipes and fittings shall first be treated with one coat of polyvinyl butyral etching primer and one coat of lead and chromate free primer. All the exposed galvanised steel pipes and fittings shall be painted with one undercoat and one finishing coat of enamel paint of a colour to match the background as instructed by the SO Rep. All galvanised steel and copper pipes including fittings inside service ducts, inside false ceiling and other enclosures shall be painted with one undercoat and one finishing coat in Canary Yellow to BS 381C Colour No. 309. For buried service pipe at the building footway, Polythene pipe sleeve in Unplasticised Polyvinyl Chloride (uPVC) pipe shall be used. The uPVC pipe shall conform to JIS 6741 Class AW or SS 141 Class E. All Polyethylene pipes and fittings shall be of PE80 Polymer and shall be manufactured in accordance with ISO 4437. The Polyethylene Pipes and Fittings shall be of the City Gas Ltd approved types.
39.11
CATEGORIES OF PIPE The pipes to be installed is categorised and located in the areas as detailed below : (a)
Buried Service Pipe
- Pipe connecting to the vertical service pipe and is laid in concrete channels. The pipe shall extend 600mm beyond the footway drain to receive City Gas Ltd connection. The pipe shall be Polyethylene pipe complying to the standards as specified and shall be sized to OD 63mm. The Polyethylene pipes shall be sleeved in Diameter 80 mm uPVC pipes, and both ends of the sleeve shall be stopped with rubber wall grommet. The pipe-end to receive City Gas Ltd Connection shall be fitted with a temporary 50mm SS141 Class E uPVC end cap with the Internal Diameter pre-enlarged (Hot Water treatment) to 63.5mm for close-fit to the Outer Diameter of the Polyethylene Pipe. The pipe-end to join to the riser shall be fitted with a 50mm GI BSP Adaptor X PE 63mm Electrofusion Transition Elbow complying to Gas Business Engineering specifications GBE/PL3 or equivalent. Alternatively, the above-mentioned Service Pipe configuration can be installed by a factory-fitted Above Ground Entry Elbow. It shall be provided with an assembled 4m Polyethylene tail and a 3.6m uPVC sleeve; the elbow is zinc plated and a grey fusion bonded epoxy coated; and the steel nipple is protected by a Polyethylene sleeve and terminates in a male thread. All buried/concealed pipes shall be left exposed for City Gas Ltd inspection, testing and approval before concealment.
(b)
Horizontal Service Pipe - Horizontal pipe runs normally at the ground floor ceiling level and connecting to all vertical risers. The pipe shall be galvanised steel pipe to SS 17 or BS 1387.
(c)
Riser
- Rising pipe from ground/first floor to the top shall be provided with a branch for a meter connection at each floor (a riser supplies gas to either one or two flats per floor depending on the piping layout). The pipe shall be galvanised steel to SS 17 or BS 1387.
(d)
Internal Pipe
- Pipe installed after the City Gas Ltd meter. The pipes shall be copper pipes which complies to BS EN 1057. Brass compression fittings for copper pipes shall comply to BS 864 Part 2.
BLDG12/S39.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 39-5 39.12
PIPE CHANNEL Where service pipes have to cross the floor footway before entering the building, such pipes shall be accommodated in channels in the footway. The channel shall be cleared of all debris and shall be dry before the gas pipe is laid. The void space between the pipe and the channel shall be filled with cement mortar. Under no circumstances shall the service pipe be located underneath a ground beam.
39.13
PIPE SUPPORTS/BRACKETS The Contractor shall provide galvanised steel pipe brackets on horizontal run and at the ground floor areas at an interval of 3000mm (maximum) or as directed by the SO Rep. The pipe brackets shall be installed before and after every change of direction of the pipe. The pipe brackets shall also be provided at an interval of 3000mm (maximum) for vertical riser pipes. Every riser pipe shall be supported at its base by a duckfoot or similar flange device capable of supporting the total weight of the riser in accordance to CP51. Where the riser passes through a floor, the floor shall be haunched up around the riser or its pipe sleeve. The pipe sleeve shall be at least 50mm above the floor level.
39.14
PIPE SLEEVE ON FLOOR Where the gas riser pipes are not enclosed in service ducts, a PVC sleeve with a minimum of 300mm protruding above the floor level shall be provided to accommodate the gas pipe run through the floor slab. The section of the gas pipe within the sleeve shall be wrapped with petrolatum tape and the gap between the sleeve and the pipe shall be sealed with water-proofed sealant.
39.15
PIPE JOINTING MATERIALS All jointing compounds, jointing pastes, thread sealants and other jointing materials for galvanised steel pipe shall be of the approved type complying with BS 5292. All Polyethylene pipes shall be jointed only by City Gas Ltd approved types of electrofusion fittings. The approved types of Electrofusion Control Units shall operate an output voltage of 39.5 volts. All electrofusion joints shall be carried out by trained workers, certified by the City Gas Ltd Approved Vendors or the Singapore Power Training Institute.
39.16
THREADED JOINTS Galvanised iron pipes of 80mm and below and corresponding fittings shall have taper threads except for connector backnuts to BS 21. Unsintered PTFE (Polytetra fluoro ethylene) tape complying with BS 4375 shall be used on all threaded joints. Prior to jointing, the threads shall be cleaned of all grease and particles. There shall be a 50% overlap when wrapping threads.
39.17
IDENTIFICATION OF GAS PIPES FOR COMMERCIAL AND INDUSTRIAL BUILDINGS All gas pipes shall be painted Canary Yellow to BS 381C Colour No. 309. In addition, a line diagram shall be provided at a suitable location indicating the position of meters, pipework, and isolation valves.
BLDG12/S39.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 39-6 39.18
ENTRY OF GAS PIPE BELOW GROUND LEVEL Direct underground pipe entry into basement shall not be allowed. Gas service pipe shall come up above ground before entering into the building. If entry of underground gas pipes through retaining walls below ground level is necessary, a steel sleeve shall be cast in situ into the retaining wall. The space between the pipe and sleeve shall be sealed at both ends with cement mortar or any other suitable sealing material. The gas pipe shall also be of heavy gauge galvanised iron to BS 1387 or SS17-Class C wrapped up with petrolatum tape with a 50% overlap for buried service pipes 80mm and below. Unsintered PTFE (Polytetra fluoro ethylene) tape complying with BS 4375 shall be used on all threaded joints.
39.19
SOLID SHAFT FOR METER INSTALLATION A solid metal shaft shall be installed at each tee-off of the riser where the gas meter is to be installed as specified in CP51.
39.20
INSTALLATION OF SOLID SPOOL A solid spool shall be installed at the vertical service pipe from the ground in the building during the installation stage. The solid spool of 150mm in length shall be installed 600mm above the ground level. The spool(s) shall be replaced with standard double flanged distant piece(s)/short pipe(s) with Johnson coupling connectors complying to CP 51 or other approved after the gas pipe installation have passed the pressure test and the installation is ready for charge-in.
39.21
BRASS BALL AND PLUG VALVES FOR GAS PIPE INSTALLATION Brass ball stop valves shall be provided to every riser pipe just before the first "Tee-off" pipe and at the riser tee-off point to every dwelling unit. The ball stop valves shall be suitable for use on City Gas Ltd town gas. The ball stop valves shall have the following :
39.22
(a)
Two female end connections having BSP threads, tapered in accordance with BS 21 "Specification For Pipe Threads For Tubes and Fittings Where Pressure-Tight Joints Are Made on the Threads (Metric Dimensions)".
(b)
Ball and plug valves shall be of the full bore type complying with BS 1552.
GAS PIPE WITHIN THE FALSE CEILING SPACE, BASEMENT AND CONCEALED AREAS Where gas pipe is installed within the false ceiling space, basement and concealed areas (these cases to be specially approved by City Gas Ltd), only steel pipe of heavy gauge complying with BS 3601 or complying with the American Petroleum Institute (API) Standard 5L Grade B shall be used and shall comply with the requirements of CP 51. The pipe shall be welded and full circumferential radiography test shall be carried out on all the welds by an accredited laboratory engaged by the Contractor to verify that all these welded joints are sound. The result of radiography tests shall be submitted to the SO Rep. Stainless steel pipe sleeve, one size larger than that of the gas pipe, shall be provided and exposed by 50mm on both ends of the false ceiling. All threaded joints, gas valves, fittings and controls shall be installed outside the false ceiling space of the building. Where gas pipes pass through air-conditioned areas, it shall be adequately lagged with insulating material to prevent excessive condensation.
BLDG12/S39.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 39-7 39.23
MECHANICALLY VENTILATED KITCHEN In a mechanically ventilated kitchen where City Gas Ltd gas is to be used, a solenoid valve shall be installed before the gas meter. This solenoid valve shall automatically shut off the gas supply whenever the ventilation fan is switched off or failed to operate. In the event that the mechanically ventilated kitchen is air-conditioned or linked to an air-conditioned space adjoining the kitchen, a gas detection system, electrically interlock to the solenoid valve and the mechanically ventilated system shall be installed. This is to ensure that if there is a gas leak, the gas supply would be shut off automatically.
39.24
AIR-CONDITIONED AREAS WHERE GAS APPLIANCES ARE INSTALLED In air-conditioned areas where gas appliances are installed, a leak detection system shall be installed to monitor the presence of gas. Leak detector used shall comply with BS EN 50054 and BS EN 50057 or equivalent. The leak detection system shall be connected to a solenoid valve controlling gas supply to the area. The leak detection system may be linked to a monitored alarm system if necessary. All detectors and solenoid valves shall also be explosion proof and shall be certified for use in a hazardous area zone 2 environment as described under SS 254:Part1 or any equivalent standard having a similar classification. The setting for the system to cut-out shall not be more than 20% of the Lower Explosive Limit of manufactured gas (hydrogen).
39.25
PRESSURE TESTING OF PIPES Gas pipes shall be tested in accordance with the following procedures as specified in CP 51 : (a)
Cap or plug off all outlets of the system leaving only one opening which shall be fitted with a Tpiece having a gas cock on one end and a manometer (U-gauge)/or a pressure gauge, in the other;
(b)
Pump air in the system through the gas cock on the T-piece until a pressure of 300mm w.g. is registered on the U-gauge and shut the cock;
(c)
If there is no pressure drop after 10 minutes, the installation may be deemed sound;
(d)
For the Polyethylene service or installation pipe after the service valve, the required test pressure is 70 kPa using a 0-200 kPa pressure gauge, and a test duration of 30 minutes;
(e)
If there is no pressure drop after 30 minutes, repeat Point (b) to (c) to complete the testing;
(f)
If there is a fall in pressure at the end of the test, the leak shall be traced with soap solution, rectified and re-tested.
For chokage test, drop a 15mm diameter ball bearing through each riser from the highest point of the riser and ensure that the ball bearing is able to fall vertically all the way through without any obstructions from inside the riser. After the gas pipe installation had been tested and approved by City Gas Ltd, no further work shall be allowed unless written approval is obtained from City Gas Ltd. The Contractor shall arrange with City Gas Ltd for the charging in of gas before the building blocks are handed over to the Employer.
BLDG12/S39.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 39-8 39.26
PURGING OF PIPES (a)
Purging of gas must be organised by the Designated Representative and conducted in the presence of the City Gas Ltd Project Coordinator.
(b)
A proof test shall be carried out immediately preceding to charging in of all pipes.
(c)
Steps must be taken to ensure that there is no naked flame or any other source of ignition in the vicinity of the purging areas and the areas are well barricaded with relevant warning signs.
(d)
Vent point consisting of standpipes more than 2m long with flame traps and control valves shall be erected at suitable locations and connected to the appropriate points of the pipework via rubber hoses or other suitable hoses.
(e)
Every vent point shall be supervised by the Licensed Gas Service Worker and vent points are to be located such that vent gas cannot drift into buildings.
(f)
A gas detector shall be used to check the mixture content at the end of the standpipe.
(g)
During the purging process, the valve cover shall be left opened.
(h)
Purging is only completed when 100% discharge of gas at the standpipe is achieved.
(i)
On successful completion of the purging process, the standpipe shall be disconnected from the pipe and the pipe properly plugged off and all valve covers replaced.
(j)
The disturbed joints shall be tested for leakage.
Section 40/.....
BLDG12/S39.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 40-1 SECTION 40 EATING ESTABLISHMENT, MARKET FACILITIES, RETAIL AND SERVICES FACILITIES
40.1
EATING ESTABLISHMENT Eating establishment shall include restaurants, eating houses, fast food and family restaurants.
40.1.1
Food Stalls, Kitchen And Wash Area (In Eating House)
40.1.1.1
Sanitary Installation All drain lines connecting floor traps to waste sumps and grease interceptor shall be cement mortar lined ductile iron pipe to BS EN 598:1995 and approved by the Water Reclamation (Network) Department, PUB. Diameter and Type of Drain Line 100mm cement mortar lined ductile iron pipe 150mm cement mortar lined ductile iron pipe 150mm cement mortar lined ductile iron pipe 150mm cement mortar lined ductile iron pipe
From Floor Trap Waste Sump Waste Sump Grease Interceptor
To Waste Sump Waste Sump Grease Interceptor Inspection Chamber
All soil, waste and vent pipes serving food stalls and kitchen shall be cement mortar lined ductile iron pipes or as shown in the Drawings. The grease interceptor shall be constructed in accordance with MEWR drawings and requirements. The floor traps shall be of stoneware or vitrified clay type. 40.1.1.2
Water Installation All internal service/distribution pipes and fittings shall be stainless steel complying with BS EN 10312:02 and fittings complying with BS 864:Part 2 or BS EN 1254 all in accordance with Section 38 "Water Installation" including all clauses and subclauses under it. All concealed pipes shall be copper pipes complying with BS EN 1057.
40.1.1.3
Sinks Provide and install sinks to location as shown in the Drawings. All stainless steel sink shall be of approved type complying with SS:40:1971. Provide and install to each bowl approved 15mm diameter chrome plated brass bib tap to BS 5412 and brass constant flow regulator rated not more than 8 litres per minute all or latest requirements by Water Supply (Network) Department, PUB.
40.1.1.4
(a)
Single bowl stainless steel sink shall be of overall size 432mm x 350mm x 150mm deep.
(b)
Single bowl single drainer (left or right) stainless steel sink shall be of overall size 1500mm x 500mm x 170mm deep.
(c)
Double bowl double drainer stainless steel sink shall be of overall size 1800mm x 500mm x 170mm deep.
Stainless Steel Bowl Trough To Wash Area In Eating House Provide and install stainless steel double bowl trough to locations as shown in the Drawings. The stainless steel double bowl trough shall be of 1.626mm thick and the dimensions shall be 1800mm in length and 600mm in width. The bowl shall be 500mm x 450mm x 300mm deep. The whole trough shall be supported by 42mm diameter tubing with adjustable feet and 25mm diameter cross-rail all as shown in the Drawings.
BLDG12/S40.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 40-2 40.1.2
Staff/Non Public Toilets
40.1.2.1
Sanitary Installation The requirement shall be the same as those specified in Section 37 "Sanitary Installation" including all clauses and subclauses under it. (a)
Pedestal WC Pans Use approved white vitreous china close-coupled washdown pedestal w.c. pan with vitreous china flushing cistern conforming to the standards and regulations stipulated by the PUB. The plastic seat and cover with buffers hinging devices shall comply with SS 16:1985, except that plastic material shall not be used for hinging devices. The minimum thickness shall be 4.7mm for the seat and 6mm for the cover respectively.
(b)
Squatting WC Pans All squatting WC pans shall comply with SS378 and SS379 and other relevant standards set by NEA or PUB. In addition, provide a self closing delayed action tap (the flow rate and timing shall not be more than 8 litres per minute and 3 seconds respectively) in the innermost wall of one of the squatting water closet compartment.
(c)
Urinal Bowls Urinal bowls shall be approved vitreous china with stainless steel pipes, necessary fittings and accessories. High level flushing cisterns shall be vitreous china and shall comply with the standards and regulations stipulated by the PUB. Provide urinal trap to serve a maximum four bowl urinals and fix at least one flushing cistern for four bowl urinals in series.
40.1.2.2
Water Installation All water installation shall be as specified in Section 38 "Water Installation" including all clauses and subclauses under it. All internal services/distribution pipes and fittings shall be stainless steel complying with BS EN 10312:02 and fitting complying with BS 864:Part 2:1983. or BS EN 1254.
40.1.3
Public Toilets
40.1.3.1
Sanitary Installation The requirement shall be the same as those specified in Section 37 "Sanitary Installation" including all clauses and subclauses under it, and shall comply with the "Code of Practice on Sanitary Facilities and Fittings for Public Toilets", standards and regulations stipulated by the PUB. The Contractor shall submit samples for approval before commencement of work. (a)
Pedestal WC Pans Provide and install approved white vitreous china washdown pedestal wc pan with sensor operated flush valve. The rigid (heavy duty) plastic seat and cover with buffers and hinging devices shall comply with SS 16:1985. Plastic material shall not be used for the hinging devices.
BLDG12/S40.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 40-3 40.1.3
Public Toilets (Cont'd)
40.1.3.1
Sanitary Installation (Cont'd) (b)
Squatting WC Pans The squatting wc pans shall be of vitreous china complying with SS 379 with sensor operated flush valves. Provide squatting water closet, pans with raised foot rests. When it is technically not feasible to use flush valves, use white vitreous china flushing cistern with stainless steel pull chain. The flush pipe shall be made of stainless steel. A self closing delayed action tap shall be provided in the inner most wall of at least one of the squatting wc pans compartment.
(c)
Urinal Bowls Urinal bowls shall be approved vitreous china with sensor operated flush valve, stainless steel pipes and fittings and accessories.
(d)
Washhand Basins The single supported approved basin shall be 620mm in length and 445mm in width. The approved vanity basin shall be 548mm in length and 396mm in width. Taps to all public washhand basins shall be of 15mm diameter chrome plated brass self closing delay action water saving spring tap complying with BS 5412 and standards and regulations stipulated by the PUB. The flow rate and the timing shall not be more than 8 litres per minute and 3 seconds respectively.
(e)
Soap Dispenser Provide and install stainless steel AISI Grade 304 soap dispenser to every two washhand basin subject to a minimum of one soap dispenser. The sample shall be approved by the SO Rep before the installation. The capacity of soap dispenser shall be one litre minimum.
(f)
Litter Bin Supply one litter bin to each toilet. The bin shall be 230mm diameter (minimum) and 600mm high approved AISI Grade 304 stainless steel bin.
(g)
Toilet Paper Holder Provide and install semi-recessed 150mm x 150mm approved vitreous china toilet paper holder to each wc. The position shall be determined by the SO Rep.
(h)
Automatic Hand-Dryer Blower Provide and install an approved automatic hand dryer complete with electrical installation to each toilet.
40.1.3.2
Water Installation (a)
Service/Distribution Pipes And Fittings All internal service/distribution pipes shall be stainless steel pipes approved by Water Supply (Network) Department, PUB and to the requirements of BS EN 10312:02. The fittings shall be of capillary or compression fittings of copper alloy and shall comply with BS EN 1254 Part 2:1998 and PUB requirements. All concealed pipes shall be copper pipes complying with BS EN 1057:1996.
BLDG12/S40.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 40-4 40.1.3
Public Toilets (Cont'd)
40.1.3.2
Water Installation (Cont'd) (b)
Flush Valves to Public Toilets Unless otherwise stated, provide and install approved sensor operated flush valves (battery operated) to all water closets and urinals as shown in the Drawings, all in accordance with the "Guidelines on Flush Valves" issued by Water Reclamation (Network) Department, PUB, "Code of Practice on Sanitary Facilities and Fittings for Public Toilets" and "Code of Practice for Water Services". Submit application and obtain approval from the relevant authorities prior to the installation of the flush valves. The flush valve shall be able to operate without sticking, whistling or causing water hammer. For sensor operated flush valves (battery operated), if required by PUB, engage a licensed electrical worker to ensure that the installation of sensor/electronic sensor unit complies with SS CP5 "Wiring of Electrical Equipments of Building" and other relevant regulations or code of practice. Each sensor unit shall only operate one flushing unit for a sanitary appliance. The sensor unit when installed shall not be affected by the operation of adjacent sensor units. The sensor unit's stable sensing area shall be adjusted for an activating distance that is as follows: (a) (b)
600mm for a urinal; and 900mm for a water closet
Flush valves for water closets shall incorporate approved check valves that comply with BS 5154 and approved vacuum breakers that comply with American Society of Sanitary Engineering Standard No. 1001. Every flush valve shall be controlled by an approved stopvalve to SS 75 unless it is provided with an integral shut-off device. All flush valves shall be so adjusted as to give a flush of not less than 2.5 litres and not more than 4.5 litres of water per stall of bowl urinal or not less than 8 litres and not more than 9 litres of water for water closets. Vacuum breaker of the flush valve shall be installed at least 1m above the floor level for squatting wc pan and at least 300mm above the rim of other types of water closet. The water supply pipes shall be sized to give a minimum dynamic pressure of 1.0 bar (or higher depending on the make of flush valve and type of sanitary appliance) at the inlet end of the flush valve. Flush valves shall not be directly connected to the service pipes at a height exceeding 112m reduced level (R.L.). The Licensed Plumber shall check and ensure there is sufficient head and low rate for effective operation of the flush valves. The minimum internal diameter of the flush pipe for water closet shall be 25mm. The concealed (battery operated) sensor-operated flush valves shall be recessed into the wall if the water service pipes are concealed. 40.1.3.3
Stainless Steel Pipe Rail (For Handicap) Provide and install stainless steel pipe rail for handicap in public toilets in accordance with the "Code on Barrier-free Accessibility in Buildings, 1990" and as shown in the Drawings. The grade of the stainless steel shall be AISI Grade 304, and the internal diameter shall be as shown in the Drawings. The end of pipe shall be split to form fishtail and fixed into the wall and complete with the same grade of stainless steel capping all as shown in the Drawings. The fixing of pipe rail shall be rigid and secure tightly into the walls.
BLDG12/S40.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 40-5 40.2
MARKET FACILITIES Market facilities shall include supermarkets, mini-supermarkets, market produce lock-up shops etc. The requirements for Staff Toilets and Public Toilets shall be the same as those specified in Clause 40.1 "Eating Establishment" including all subclauses under it.
40.3
RETAIL AND SERVICES FACILITIES Retail and services facilities shall include shoplets, precinct shops, shops, departmental stores, institutions/schools, Branch Office, Town Council Office and commercial complex. The requirements for Staff/Non-Public Toilets and Public Toilets shall be the same as those specified in Clause 40.1 "Eating Establishment" including all subclauses under it.
40.4
MIRRORS Provide and fix 600mm x 600mm (minimum) x 6mm thick approved coppered back mirror in front of each wash hand basin or as shown. Mirrors shall be fixed on timber ground with chrome plated round head screw with capping.
40.5
WASHING TAPS FOR WASH AREAS/BIN CENTRES 15mm diameter chrome plated brass bib taps and handles to BS 5412 with tread to fit rubber hose for washing shall be provided to locations as shown. Locking device shall be provided as shown in the Drawings.
40.6
BIB TAP TO BATH/WC IN SHOP'S LIVING QUARTERS Provide and fix 15mm diameter chrome plated brass bib tap to BS 5412 with UPVC tee and cap complying with SS 174 all as shown in the Drawings.
40.7
TAP FOR PUBLIC SHOWER Taps to all the public showers shall be self-closing delayed action shower tap. The flow rate and timing shall not be more than 8 litres per minute and 15 seconds respectively.
Section 41/..... BLDG12/S40.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 41-1 SECTION 41 MISCELLANEOUS (SANITARY & WATER INSTALLATION)
41.1
WATER SAVING TAPS FOR PUBLIC WASH HAND BASINS AND SHOWERS
41.1.1
Water Saving Taps For Public Wash Hand Basins Taps to all wash hand basins in staff and public toilets, in swimming complex, sports complex, indoor stadium, training stadium, training hall, bus interchange etc shall be 15mm diameter chrome plated brass self-closing delay-action taps complying with Public Utilities (Water Supply) Regulations, SSCP 48: Code of Practice for Water Services, the requirements and regulations of the Water Supply (Network) Department, PUB and other relevant Statutory requirements. The flow rate and the timing shall not be more than 8 litres per minute and 3 seconds respectively.
41.1.2
Water Saving Tap For Public Showers Taps to all the public showers and showers in swimming complex, sports complex, indoor stadium, training hall etc shall be of self-closing delayed action shower taps complying with the standards and regulations stipulated by the PUB. The flow rate and the timing shall not be more than 8 litres per minutes and 15 seconds respectively.
41.2
FLUSH VALVES Unless otherwise stated, provide and install sensor operated flush valves (battery operated) to all public toilets (water closets and urinals only) as shown in the Drawings, all in accordance with the "Guidelines on Flush Valves" issued by Water Reclamation (Network) Department, PUB, "Code of Practice on Sanitary, Facilities and Fittings for Public Toilet" and "Code of Practice for Water Services". Submit application and obtain approval from the relevant authorities prior to installation of the flush valves.
41.3
SOAP TRAYS Soap trays shall be recessed white vitreous china 150mm x 150mm "Twyfords 3008" or other approved type, one to each shower compartment. Position of soap trays shall be determined by SO Rep.
Section 42/..... BLDG12/S41.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 42-1 SECTION 42 TRANSFER PUMPING SYSTEM AND TELEMONITORING SYSTEM INSTALLATION
42.1
SCOPE OF WORK
42.1.1
Water Transfer Pumping Plants The Works shall include the provision, installation and testing of transfer pumping system, based on the data given, complete with motors, pipework, valves, switch gears, electrical wiring, control panel and connections and all necessary accessories. Details of proposed transfer pumping system shall be submitted to the SO Rep for approval. All Works shall comply with Public Utilities (Water Supply) Regulations, SSCP48: Code of Practice for Water Services, the requirements and regulations of the Water Supply (Network) Department, PUB and other relevant Authorities and Standards.
42.1.2
Telemonitoring System The Works shall include the installation of telemonitoring system as specified in Clause 42.27 "Telemonitoring System For Transfer Pumping System" including all subclauses under it.
42.2
42.3
PUMPROOM - GENERAL (a)
Water supply mains shall be brought into the building at the positions shown.
(b)
A suction (low level) tank shall receive water from the water supply main through an approved 100mm full bore pilot operated float valve. Suction pipes shall then be of individual feed to each pump-set. The pumps shall deliver water through a vertical rising main direct to the storage (high level) tank at the roof of the building.
(c)
The pipework shall incorporate appropriate valves and fittings as specified.
(d)
Floatless level control electrodes in the suction (low level) and storage (high level) tanks shall be arranged to start and stop the pumps on predetermined water levels in the tanks as specified.
(e)
Pumps (duty and standby) shall be operated by electric motors direct-coupled to them and started by suitable starters in the control panel.
(f)
The whole assembly within the pump room shall be laid out to permit ready access to all components: tanks, pipework, valves, pumps, motors, control panel, floatless level control electrodes and wiring for purposes of maintenance and repair. The control panel and pump sets shall be installed near to the entrance of pump room for this purpose.
APPROVAL OF DRAWINGS AND DETAILS OF TRANSFER PUMPING SYSTEM Submit one set of the following to the SO Rep for approval within two months from the date of the Letter of Acceptance : (a)
Detailed proposal shall be submitted in the format as produced in Appendix A22 duly filled and signed by the Contractor.
(b)
Characteristic curves of every pump to indicate the points of performance.
BLDG12/S42.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 42-2 42.3
APPROVAL OF DRAWINGS AND DETAILS OF TRANSFER PUMPING SYSTEM (CONT'D) (c)
Three sets of fully dimensioned scaled drawings of every pump room to indicate : (i) (ii) (iii) (iv) (v) (vi) (vii)
Piping and pumpset layout in pump room Position of control panel and floatless level control electrodes PUB water incoming pipe Rising main Sizes of all fittings Points and details of support for pipes, valves and fittings Mounting of pumpsets
Submit to the SO Rep, fully dimensioned final drawings of the above within two weeks after the installation is commissioned by the SO Rep.
42.4
DEVIATIONS FROM APPROVED DRAWINGS AND DETAILS OF TRANSFER PUMPING SYSTEM Works shall commence only after the approval of the proposal by the SO Rep. Seek fresh approval for any deviation from the approved proposal, failing which the whole installation shall not be accepted by the SO Rep. The written approval of the Drawings shall in no way vary or relieve the Contractor of his responsibility or obligations should the Plant or any of its parts proved inadequate with regard to strength, performance or efficiency.
42.5
BUILDING-IN The Employer reserves the right to build in any steel supporting members or frameworks for the pumping system. Supply all relevant dimensions and information on these pumping system and steel member supports and attend to the work. The Contractor shall be responsible for any error or damages found subsequently.
42.6
PUMPS All pumps shall be of horizontal spindle, single-stage, end suction centrifugal pumps or vertical multi-stage centrifugal pumps with mechanical seals and high performance efficiency of not less than 55%, driven by electric motors through suitably guarded flexible couplings. The whole unit shall be mounted on a common steel base and secured with galvanised steel plain washers, spring washers and double lock nuts. The pumpset foundation shall be properly grouted on complete installation. Galvanised steel bolts and nuts shall be used for mounting the pumpset. The casing of the end suction centrifugal pump shall be of hard, close-grained cast iron or other approved metal. The casing of the vertical multi-stage centrifugal pump shall be of stainless steel, bronze or other approved metal. All internal surfaces of the pump (cast iron type) that come into contact with water shall be coated (fusion bonded) with an approved layer of non-toxic epoxy complying with SS 375:2001.The impeller shall be of bronze or stainless steel and the shaft shall be of stainless steel and able to transmit the required power and to ensure the rigidity of rotating parts. The entire length of the shaft shall be suitably protected against corrosion and be supported by heavy duty bearings in robust housing well clear of the rotating parts. Bearings shall be protected against corrosion and be efficiently lubricated. The pump shall be of the approved type and able to deliver the required capacity of water based on the data given in Appendix A22.
BLDG12/S42.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 42-3 42.7
DUCTILE IRON PIPES, FITTINGS AND SPECIAL CASTINGS All pipes and pipe fittings shall be approved by Water Supply (Network) Department, PUB. All pipes, fittings and special castings in the pump room and to the roof tanks shall be ductile iron complying with BS EN 545. Ductile iron flanges type PN 16 shall comply with BS EN 545. All pipes and fittings shall be internally cement mortar lined in accordance with the relevant clauses in BS EN 545. The mixture shall be tested according to the relevant clauses in BS EN 545. Pipe joints and fittings along any section shall be of the flanged type, the thickness and drilling of which shall comply with BS EN 545 type PN 16. Thickness of sealing compound between the flanged ends shall be at least 2mm. Galvanised steel bolts, washers and nuts shall be used for the installation. Ductile iron pipes, socket and spigot type complying with BS EN 545 is permissible only for vertical riser except that the joint immediately above roof shall be of flanged joint. All vertical risers shall run inside the buildings along the staircase landing where possible. All pipes which pass through walls or floors shall be insulated by cork and sealed on the outer 12mm with approved compound. All pipes which do not pass through the wall or floor but running along the wall shall be supported with built in clips spaced at maximum 2.7m centres. All pipes which pass through walls shall be insulated by neoprene material. All pipes which do not pass through the wall or floor but running along the wall shall be supported with built in clips spaced at maximum 2.7m centres. For blocks with pumps requiring power more than 20kW, the delivery pipe from the transfer pumps which pass through walls or floors shall be insulated by neoprene material of at least 20mm thickness. The pipe in the pump room shall be supported from the floor. Any pipe running outside the pump shall be supported with hangers equipped with neoprene padding. Unless otherwise specified, sizes of pipework shall be as follows : Size of Delivery Piping 100mm
42.8
Size of Suction Piping 80mm
VALVES An approved 100mm full bore pilot operated float valve shall be fitted directly to the incoming connecting pipe at the suction tank. It shall be able to operate on a water pressure in the incoming water supply pipe of not less than 14 bar and shall comply with BS 1212. The dimensions and the flange thickness shall comply with BS 4504. The pilot mechanism of the float operated valve shall be fully covered with acrylic material to prevent mosquito breeding. An approved 100mm globe valve shall be installed before the 100mm full bore float operated valve and at the vertical run of the incoming pipe inside the pump room. Globe valve shall be of the type complying with BS 1010. The valve seat shall be of rubber bonded. The internal surface of the valve body shall be coated with approved material. Gate valves and check valves shall be of the approved type used in high quality water works practice and shall comply with BS 5163 and BS 5153 respectively. The wedge of the gate valves used shall be of rubber bonded gate. The internal surface of valve body shall be coated with approved material. The spindle of the gate valves shall be stainless steel or high tensile brass or aluminium bronze or other approved. Gate valves shall have the directional arrow and the words "open" and "shut" cast on and shall be installed near the inlets and outlets of each suction low level tank and storage high level tank. The suction pipe of each pump shall be fitted with an 80mm gate valve followed by an 80mm rubber expansion joint. The delivery pipe shall be fitted with an 80mm rubber expansion joint, a 80mm spring loaded check valve and an 80mm gate valve. The check valve and gate valve shall be separated by a short pipe of 200mm in length. An 80mm to 100mm enlarger shall be provided between the 80mm pipe and 100mm rising main. An approved 100mm non-slam type check valve shall be fitted along the rising main in the pumproom followed by a 100mm gate valve. This check valve shall also be separated from the gate valve by a short pipe of 300mm in length. All 80mm and 100mm check valves shall be of approved non-slam silent spring loaded type (with stainless steel spring).
BLDG12/S42.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 42-4 42.9
HIGH PRESSURE AND EXPANSION CONNECTION 80mm rubber expansion joint of approved type shall be used to connect the outlet of the pump and the delivery pipe and shall be flanged at both ends and be able to sustain a working pressure of not less than 16 bar. The rubber expansion joint shall be limited from expanding excessively in axial direction. The delivery pipe shall be supported by at least 2 no. of 50mm galvanised mild steel pipe and be properly secured to the floor or wall for this purpose. An 80mm rubber expansion joint shall be used to connect the suction pipe and the discharge pipe of each pump.
42.10
BENDS All bends used in the pipework shall be of 90 degree long bend flanged at both ends and shall be cement mortar lined internally in accordance with BS EN 545.
42.11
RESERVED
42.12
FLOAT OPERATED VALVE Position a 100mm float operated valve as indicated in the Drawings to allow full flow of water from PUB main.
42.13
POWER SUPPLY Power supply available for electric motors shall be 400 volts, 3 phase 50 cycles alternating current.
42.14
MOTORS High efficiency electric motors of approved type shall be squirrel-cage, totally enclosed fan cooled type with minimum Class F insulation except where specified otherwise and be designed for continuous maximum rating. Terminal boxes shall be totally enclosed, of water-tight design and fitted with cable glands.
42.15
MOTOR STARTERS The starters shall be submitted to the SO Rep for approval before its installation. The starters shall provide means of starting or stopping the motors by push-buttons or be automatically activated by the control electrodes in the suction (low level) and storage (high level) tanks. The starters shall be wired in such a way that the duty pumpset shall be activated by normal level floatless control relay unit and the standby pumpset shall be activated by alarm and emergency level floatless control relay unit. The selection of duty or standby pumpsets shall be determined by a manual selector switch. Automatic duty change over relay shall also be provided to alternate standby and duty pumpsets automatically and shall be interconnected to a time setting device to cut off the operation of the pumpset during night time.
BLDG12/S42.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 42-5 42.15
MOTOR STARTERS (CONT'D) (a)
Star-Delta Starter (For building blocks below 25-storey) For building blocks below 25-storey, the starters for motors shall be star-delta starters, capable of limiting current to 2½ times the full load current at (a) standstill (starting up the Plant) and at (b) changeover (when the starter automatically changes the connections from Star to Delta winding). Each starter shall have time relay, overload release, no volt release pilot lamp. The operating voltage of the control coil shall be 230V. The starting apparatus shall be of "frequent duty" rating and be capable of starting under the above conditions intermittently up to 40 times per hour at not less than 20 seconds intervals. It shall be so designed such that under 16 operation hours per day, the Mechanical and Electrical Endurance is not less than 50,000 operations. A manufacture's certificate to this effect shall be produced when required.
(b)
Soft Starters (For building blocks with 25-storey & above) For building blocks 25-storey and above, the soft starters shall be designed to operate at 3-phase 400V 50 Hz and shall be suitable for starting/stopping 3-phase induction motor used for water pumping system. The soft starters shall provide soft acceleration during the starting of motor and soft deceleration during the stopping of motor. It shall be able to reset by itself automatically when power supply is resumed after power failure. Built-in fault indication lights shall also be incorporated in the soft starters to indicate the fault conditions The approved soft starters shall consist of three pairs of thyristors with full wave control and shall be designed for continuous operation above 40°C. The soft starters shall also be sized according to the full load current of the motor and shall comply to IEC 947-4-2 or equivalent as approved.
42.16
TIME SWITCH Connect digital time switch of approved type within the electric circuit, wired to control the pumping hours within the preset time. The time switch shall be able to operate on a 24 hour basis with a minimum of 150 hours reserve to cater for temporary power failure.
42.17
FLOATLESS LEVEL CONTROL RELAY UNITS Floatless level control electrodes mounted on the suction (low level) and storage (high level) tanks in each building shall be connected directly to the relay units mounted on the wall beside the tanks. These floatless level control electrodes shall be positioned near to the manhole of the tank and be easily accessible for maintenance. The floatless level control electrodes shall be installed on the storage tanks operating at Normal Demand Settings. The floatless level control electrodes shall be arranged to start and stop the pumpset at predetermined high and low levels. A floatless level control relay unit mounted on the wall beside the suction tank shall be used to provide over-riding control of the storage tank floatless level control relay units such that at a preset low water level in the suction tank, the storage tank floatless level control relay units will not start the pump. The floatless level control relay units shall be interconnected to the motor starters through the pumps' automatic change over relay. Separate floatless level control relay unit shall be installed for the alarm system and shall be set to activate the alarm device and standby pumpset when the water falls below a predetermined level. The floatless level control relay unit shall also activate the alarm device and deactivate the duty pumpset when the water rises to a predetermined overflow level. The floatless level control relay unit shall be of the plug-in relay unit type for easy maintenance. The unit shall have built-in arrester circuit to protect against surge from power source and lightning surge from the electrodes.
BLDG12/S42.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 42-6 42.17
FLOATLESS LEVEL CONTROL RELAY UNITS (CONT'D) Electrodes shall be stainless steel and be provided with adequate electrode separators. The ceiling roses and flexible cables from the electrode holders shall be legibly marked "NL" and "EA" respectively. Electrode holders mounted on tanks shall be easily accessible and removable for easy maintenance. Run the wiring and conduits from the electrodes to the floatless level control relay units and keep them as short as possible. The wiring to the electrodes shall not run through the same conduit as the power supply wiring. Provide wiring and conduits from the switchboard inside the pump-room to each of these floatless control relay units. All floatless control relay units shall be of the approved type.
42.18
NUMBER OF FLOATLESS LEVEL CONTROL RELAY UNITS Provide a total of three number of floatless level control relay units. Where storage tanks are divided into two or more separate tanks, at least two separate tanks shall be installed with floatless level control electrodes.
42.18.1
Floatless Level Control Relay Unit No. 1 (At Storage Tank Room) Two sets of electrodes for the normal level setting shall be connected so as to activate the starters independently and to activate the alarm and deactivate the duty pumpset when the water rises to a predetermined overflow level. The operating points of both sets of floatless level control electrodes shall be of the same setting.
42.18.2
Floatless Level Control Relay Unit No. 2 (At Storage Tank Room) Provide two sets of alarm and emergency electrodes to activate the alarm and standby pumpsets in case the water level falls below a predetermined level.
42.18.3
Floatless Level Control Relay Unit No. 3 (At Pumproom) Provide one set of electrodes for the suction tank to actuate a warning indicating light and override the operation of pumpsets when the water level in the suction tank (low level tank) falls below a predetermined level. Provide one set of electrodes to activate a warning indicating light and alarm when the level in the suction tank rises to a predetermined overflow level.
42.19
CONTROL PANEL Provide and install an approved control panel required to serve the pumproom as shown in the Drawings. Sufficient wall space shall be selected within the pumproom for the wall mounted control panel and it shall be near to the entrance of the pumproom. Unless otherwise specified, the panel shall be of the front connected type and manufactured from electrogalvanised sheet metal of minimum 1.5mm thickness, using folded section or angle form bracing for rigidity of construction. The panel shall have adequate ventilation and shall be drip proof. The construction shall be such that it allows for ready access to the interior of the cubicles for operation and maintenance purposes.
BLDG12/S42.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 42-7 42.19
CONTROL PANEL (CONT'D) Provide control panel with rubber bushes at knockout holes for the entry of all incoming and outgoing cables. Mount instrument indicating lights, rotary switches, etc. directly on the front panel with locknuts to hold such items firmly in position under all conditions of operation. The control panel shall contain the following : (a)
1 No. ON/OFF control switch.
(b)
1 No. Automatic/off/Manual Selector rotary switch for Auto and Manual operation as described in Clause 42.15 "Motor Starters".
(c)
2 No. Starters as described in Clause 42.15 "Motor Starters".
(d)
2 Sets ON/OFF isolators with 3 phase MCB unit for each starter.
(e)
2 Sets Manual "START"/"STOP" button switch for the starter with pilot lamps indicating "run" and "trip" as described in Clause 42.15 "Motor Starters".
(f)
1 No. Pump selector switch as described in Clause 42.17 "Floatless Level Control Relay Units".
(g)
1 No. Digital Time switch as described in Clause 42.16 "Time Switch".
(h)
1 No. Relay for reset of 'alarm bell' and 'light'.
(i)
1 No. Relay to cut off the warning device and pumpsets during night time.
(j)
1 No. Relay to activate overflow warning device.
(k)
2 No. Relays to activate alarm bell for motor overload trip.
(l)
3 No. Relay to control the pumpsets.
(m)
3 No. Relays for testing of alarm bell and indicating panel lights.
(n)
1 No. Automatic change over relay.
(o)
1 No. Suction tank low level warning indicating panel light.
(p)
3 No. Alarm indicating panel light.
(q)
6 No. MCB (4A) units for control circuits.
(r)
3 No. Phase indicating panel light with MCB (2A) unit.
(s)
1 No. MCB (4A) unit for alarm circuit.
(t)
2 No. Hour-run counters for pumpsets.
(u)
1 No. Ammeter with appropriate scale and current transformer (C/T) if required.
(v)
1 No. Phase Selector Switch for Ammeter.
(w)
1 No. Test push button for alarm bell and indicating panel lights.
The whole of the electrical Works shall comply with SS CP5 and be subject to the approval of the SO Rep.
BLDG12/S42.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 42-8 42.20
ELECTRICAL WIRING Install the cables from the electrical mains isolator in the pumproom. Internal cables and wiring within the pumproom shall be PVC insulated to SS 358 suitable for a 400V 3 Phase 50 cycles 4 wire system and they shall be carried in conduit or cable trunking. The metal conduit shall be of heavy gauge, galvanised steel conduit (Class 4), complying with BS 4568, free from internal roughness and burrs. Fixing to walls and other flat surfaces shall be by means of spacer bar saddles at maximum 1m centres for horizontal runs and 1.5m centres for vertical runs. Conduit termination to loop-on boxes shall consist of a screwed socket and smooth bore bush butt to adaptor boxes, fuse boards and cable trunking, etc. The termination shall consist of a flanged coupling, lead washer and smooth bore bush. Where the conduit is in contact with any structural steel work an efficient and permanent metallic connection shall be made between the conduit and the steelwork. All conduits and trunking shall be electrically and mechanically continuous throughout and shall be efficiently earthed with copper earthwire (in conduits and 100mm x 50mm trunking) and copper tape (in 150mm x 75mm trunking). Copper earth wire or tape shall be of the appropriate sizes. Cable trunking shall comply with SS 249 and shall be fabricated from 1.0mm mild steel sheets, in 1.83m or 2.44m lengths and provided with a 50mm fixing sleeve, spot welded on one end of each length. The trunking shall be treated with approved anti-corrosion paint and finishing paint to a minimum thickness of 45 microns. Jointing of trunking shall be effected by means of round headed bolts and nuts. 4mm x 20mm copper earth tape shall be laid in the trunking run. The copper shall be tinned where it is bolted down. The entire trunking and conduit installation shall be completed before the cables are drawn. The number of cables to be drawn into the conduits shall not exceed those set out in the relevant table in the PSB Code of Practice CP 5. Run conduits for the floatless level control relay unit wiring inside the building and along the staircase landing. Provide an inspection joint for every 10 metres run of conduit. Where exposed to rain, the inspection boxes, elbows and tees shall be sealed. Provide concrete stumps of 50mm diameter and 100mm high to encase the conduits at every floor level. All seals shall be tested not less than 24 hours after completion. This test shall be made with insulation testing equipment of the "Megger" type at 500V and an infinity reading shall be obtained before the conductors are connected to any apparatus. Where wiring are to be in conduit or duct buried in the floor, it shall terminate in approved junction boxes adjacent to the machine or foundation plinth with water-tight flexible conduit enclosing the cables between motors and junction boxes. All non current carrying metal parts of electrical equipment shall be effectively earthed. Earth continuity conductors shall have a cross-sectional area of not less than that specified in CP 5.
42.21
ALARM AND EMERGENCY DEVICE Alarm device shall be turned on by the alarm and emergency level control relay units at the storage (high level) tank and the level control relay unit at the suction (low level) tank. This alarm device shall be in the form of an alarm bell placed beside the control panel in the pumproom and a red bulb placed outside the pumproom and near the entrance. The bell shall be weather-proof and of heavy duty type. The make and model shall be approved by the SO Rep. The alarm bell shall be cut off during night time by the time switch so that only the emergency start warning light on the switchboard panel shall function at night when the water level falls below the 'emergency level'. Provide a re-set button for the alarm and the warning device. The location of the warning device shall be approved by the SO Rep. Provide a shield if the SO Rep deemed necessary all at the Contractor's cost and expense. The design of the shield shall be approved by the SO Rep.
BLDG12/S42.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 42-9 42.22
INSTALLATION OF PUMP SETS The water pumpsets shall be properly installed onto the concrete foundation. The 16 mm high tensile steel foundation bolts shall be cast into the concrete to a minimum depth of : (a) (b)
100 mm for motor up to 7.5 KW 150 mm for motor above 7.5 KW
The Contractor shall be responsible to ensure that the pumpsets are installed according to standard procedure of installation or according to the pump supplier's recommendation subject to approval by the SO Rep. The pumpset nearest to the pump room door shall be legibly marked with permanent lettering and numbering of "P1" and the other "P2", or as directed by the SO Rep. The pumpsets shall be isolated from the foundation by anti-vibration mounting between the base plate and the foundation. Provide mechanical insulators to isolate the pumpset from the floor if the vibration is still substantial. All pumpsets shall be properly aligned and levelled. The pumpsets shall be isolated from the suction and delivery pipes by rubber expansion joints as specified in Clause 42.9 "High Pressure And Expansion Connection". The outlet of the suction pipe shall be set in line with the inlet of the pump and the inlet of the delivery pipes in line with the outlet of the pump. The delivery pipes shall be properly supported and secured by rigid steel supports. Check the location of the switch board. Should this location be not at an optimum position, inform the SO Rep immediately. All bolts, nuts and washers used for mounting the pumpsets shall be of galvanised steel.
42.23
VIBRATION AND NOISE The vibration and noise generated by pumpsets shall not be unduly disturbing to dwellers in the adjacent flats. Provide and fix all necessary noise and vibration abatement devices and equipments to reduce vibration and sound.
42.24
INSPECTION DURING PROGRESS OF WORK Provide all necessary facilities such as torch lights etc and access leading to the tanks for inspections by the SO Rep during progress of the Works.
42.25
STERILISATION OF PIPES, FITTINGS AND PUMPS BEFORE OPERATION Clean and flush all pipes, fittings and pumps internally with sufficient chemical to give the water a dose of 50 parts of chlorine to one million part of water (ie. 50 ppm) before the commencement of the operation of the system, in accordance with PUB requirement.
42.26
TESTING OF TRANSFER PUMPING SYSTEM INSTALLATION One month before the completion of the installation, arrange with the SO Rep for the testing of performance and installation of the transfer pumping system. Furnish the data on transfer pumping system as produced in Appendix A23 and submit 2 copies to the SO Rep one week before the testing of the transfer pumping system. All Defect notified during the inspection shall be rectified before the building blocks are handed over to the Employer, failing which appropriate action shall be taken against the Contractor by the SO Rep.
BLDG12/S42.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 42-10 42.27
TELEMONITORING SYSTEM FOR TRANSFER PUMPING SYSTEM
42.27.1
Scope Of Work The installation of the telemonitoring system shall involve the production and installation of the telemonitoring control panel in the transfer-pump room at the ground level and the laying of electrical cables and conduits to the lift telemonitoring system in the lift room A at the roof-top. Should there be a second transfer-pump room in the apartment block, provide and install a separate telemonitoring control panel in the second pump room and lay separate electrical cables and conduits to the lift telemonitoring system in the lift room B at the roof-top. The Works shall also include the modifications to the control panel(s) of the transfer pumps and the necessary connections between relevant control panels.
42.27.2
Circuit The circuitry shall be as shown in the Drawings. (A)
Inputs The fault signals to be monitored shall be input from the control panel of the transfer pumps. The following inputs are based on negative logic, directly controlling the corresponding source light emitting diodes (hereinafter referred to as "LED" for the purposes of this Clause including all subclauses under it). Terminal Nil 13 14 15 16 17 18 19 20 21 22 23
Function System Power on Battery Control Supply Power Failure Red Phase Power Failure Yellow Phase Power Failure Blue Phase Power Failure Spare Emergency and Alarm Start Pump No. 1 Trip Pump No. 2 Trip Roof Tank Overflow Repair Technician's Key Switch On Spare
The following inputs have their related source LED controlled by the processor. Terminal 24 26 27 28 29 30 31 32
BLDG12/S42.DOC(10) Sal(151211) (DPD)
Function Suction Tank Overflow Suction Tank Low Level Duty Pump Failure Time Switch Control Starter 1 Starter 2 Spare Spare
Bldg Spec Page 42-11 42.27.2
Circuit (Cont'd) (B)
Outputs The various fault conditions are to be grouped into 7 levels as follows : Source 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 -
Condition System Power on Battery Control Supply Power Failure Red Phase Power Failure Yellow Phase Power Failure Blue Phase Power Failure Spare Emergency and Alarm Start Pump No. 1 Trip Pump No. 2 Trip Roof Tank Overflow Repair Technician's Key Switch On Spare Suction Tank Overflow Suction Tank Low Level Duty Pump Failure Spare Total Failure
Level 5 5 5 5 5 0 6 4 4 3 0 0 1 2 4 0 7
The circuit shall generate three signals indicating the fault level from 0 to 7 in the form of a 3-bit binary code; fault level 7 has the highest priority and fault level 0 is the no-fault condition. Fault level indication is based on the source (not memory) fault condition being on. If more than one fault condition is present, the highest fault level shall be indicated. Whenever the fault level changes, fault level 0 (no fault) shall be indicated for 30 secs before the new fault level is indicated. These three signals shall drive three relays, R1, R2, and R3 in the lift motor room as well as three LED in the control panel. When the repair technician's key switch is on, the corresponding LED, which is directly controlled by the processor, should be on. This signal shall drive a separate relay R4 in the lift motor room. The circuit shall function such that when there is no fault all the relays R1, R2, R3 and R4 are energized. Therefore, a by-pass or override switch shall be provided to keep the four relays energized when the telemonitoring system is to be isolated for maintenance.
42.27.3
The Control Panel Based on the circuit described above, the telemonitoring system control panel shall consist of the following : (1) (2) (3) (4)
Battery Compartment and Battery Logic Board Indicator Board Power Supply Section
and are to be laid out in a cabinet as shown in the Drawings. All items shall be properly secured to the cabinet with means that allow ease of detachment if necessary. The cabinet is to be manufactured from electro-galvanised sheet metal of minimum 1.5mm thickness, using folded section or angle form bracing for rigidity of construction. It is to provide IP33 protection, according to BS 5490, whilst allowing for sufficient ventilation. The design and construction must give easy access to all parts of the control panel so as to minimize any hindrance to maintenance work. The indicator board shall be mounted such that there is a clear view of the LED and the labels when the cabinet is closed.
BLDG12/S42.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 42-12 42.27.3
The Control Panel (Cont'd) The entire door arrangement is to be neat and have the following features : (a) (b) (c) (d) (e)
a perspex window for viewing the status of the monitored faults; a key lock to secure the control panel; a key switch to register the arrival time of the repair technician; an indicating light for the supply power on, and an indicating LED for the override switch on.
Sufficient wall space shall be selected within the pumproom for the wall mounted control panel and it shall be near to the transfer pump control panel.
42.27.4
Battery The back-up battery shall be of the sealed lead-acid types and shall provide back-up power supply for at least 12 hours.
42.27.5
Printed Circuit Board The layout for the printed circuit boards (hereinafter referred to as "PCB" for the purpose of this clause including sub-clauses under it) shall be as shown in the Drawings. All items used shall be PCB mounted. All connections made between the boards and power supply shall be of the plugged-in type. (a)
The Logic Board The logic board shall contain the plug-in connections for all incoming lines from the control panel of the transfer pump system and outgoing lines to the lift room. There shall be as much separation as possible between the high and low voltage lines in the PCB. The board shall contain a Motorola MC68705P3 microprocessor or other approved. The pin usage of the microprocessor is as follows : Port A
:
Port A is used as the input/output data bus. All 8 lines are connected to the 3 input buffers (74LS244) and the 3 output latches (74LS373).
Port B
:
Port B is used as the outputs and chip select lines. Pin
Function
0 1 2 3 4
Memory Error (0 = on) Flash Output (square wave of 2 Hz) Chip select for Memory LED 9 to 16 Chip select for Memory LED 1 to 8 Chip select for Fault Level LED, Presence of Repair Technician and Source LED 13 to 16 Chip select for Inputs 1 to 8 Chip select for Inputs 9 to 12 and Timer DIP Switches Chip select for Inputs 13 to 20
5 6 7
*Chip Select for Inputs = 0 (1 = Hi-Z) *Chip Select for Outputs = 1 (0 = latched)
BLDG12/S42.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 42-13 42.27.5
Printed Circuit Board (Cont'd) (a)
The Logic Board (Cont'd) Port C
: Port C is used for miscellaneous function. Pin
Function
0 1 2 3
INPUT : Lamp Test (0 = on) INPUT : Clear Memory (0 = on) OUTPUT : Unused OUTPUT : A square wave of 4 Hz is generated to hold a watchdog timer in a triggered but not time-out state. The timer is used to reset the processor should it ever hang. This square-wave output shall be generated only if the processor is executing the program correctly. Once the processor hangs, this output shall stop, causing the watchdog to reset the processor upon time-out. The resetting process shall not cause any alteration of memory data already present.
In order to prevent corrupted memory data from being taken as correct, a suitable means shall be employed to constantly verify the data in memory and to turn on the "MEMORY ERROR" LED once the data is found to be invalid. A suitable means shall also be employed to ensure that the input data read is valid, thus preventing any spuring data from being used. On the logic board, two push buttons, "CLEAR" and "LAMP TEST", shall be provided. The "LAMP TEST" pushbutton shall cause all processor-controlled LED to turn on when pressed. Normal indication shall resume when the button is released. When the "CLEAR" pushbutton is pressed momentarily, all timers above 5-sec duration are caused to time-out. This is to assist in testing and trouble-shooting. When the "CLEAR" pushbutton is held down for 2 secs, all the "Memory" fault conditions are cleared, including the "MEMORY ERROR" condition. (b)
The Indicator Board There shall be a green LED, indicating "SYSTEM POWER ON" which is to be directly controlled by the 5-V DC power supply, three yellow LED, indicating the binary "FAULT LEVEL CODE", a green LED, indicating the "PRESENCE OF REPAIR TECHNICIAN", and a red LED, indicating "MEMORY ERROR". There shall also be two red LED for each fault. One of them shall be controlled directly or indirectly by the source and the other solely by the processor. Both LED shall be energized on the occurrence of their corresponding fault. However, once the fault has been rectified, the source LED shall be de-energized whilst the processor-controlled LED shall remain energized until the memory is cleared manually. "SUCTION TANK OVERFLOW" indication must be delayed for 2 seconds. This is to prevent false and/or intermittent indication. "SUCTION TANK LOW LEVEL" indication shall be delayed for the number of minutes set by the "TIMER" DIP switches. The range of this 4-bit timer shall be 0 to 15 minutes. "DUTY PUMP FAILURE" indication shall be on only when the logic condition (Duty Pump Failure Input AND Time Switch Control AND NOT Suction Tank Low Level AND NOT Starter 1 AND NOT Starter 2) is positive. The Suction Tank Low Level condition shall be taken after the preset delay. If no other fault condition is present, the "EMERGENCY AND ALARM START" condition shall be reset when the repair technician is present and for 1 hour after his departure regardless of its input status. Should another fault come on the indication shall revert to normal. This forced reset shall be cancelled 1 hour after the technician's departure. Clear labelling of the faults for each LED shall also be provided on the board.
BLDG12/S42.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 42-14 42.27.6
Power Supply Section This shall include all items necessary to provide a safe, uninterrupted power supply to the telemonitoring system and for charging the back-up battery.
42.27.7
Electrical Wiring The power supply to the system shall be from the blue phase of the transfer pump system after the isolator. Cables and electrical wiring carrying 230V shall be of 1.5 mm2 nominal cross-sectional area and PVC insulated to SS 358. There shall be seven cables, with 23 strands of 0.2mm diameter and PVC insulated, connecting the control panel to the four relays (to be provided by the Contractor) in Lift Room A at the roof-top. Should there be two transfer-pump rooms, the Contractor shall run two sets of cables and conduits. The second set of cables and conduits shall run to Lift Room B at the roof-top. The colour for these seven cables shall be red, orange, pink, black, light blue, purple and green. The locations of the termination of the cables and conduits shall be subjected to the location of the lift telemonitoring system and shall be approved by the SO Rep. All cables and electrical wiring shall be carried in their own conduits. The metal conduits shall be of heavy gauge, galvanised steel conduit (Class 4), complying with BS 4568, free from internal roughness and burrs. The conduits which run from the control panel to the lift room shall be 20mm in diameter. The conduits shall run inside the building and along the staircase landing. Fixing to walls and other flat surfaces shall be by means of spacer bar saddles at maximum 1m centres for horizontal runs and 1.5m centres for vertical runs. Concrete stumps of 50mm diameter and 100mm high shall be provided to encase the conduits at every floor level. All electrical cables and conduits shall be electrically and mechanically continuous throughout. The conduits shall be efficiently earthed with copper earthwire of appropriate size. The conduit installation shall be completed before the cables are drawn. Where applicable, the number of cables to be drawn into the conduits shall not exceed those set out in the PSB Code of Practice CP 5. All non-current carrying metal parts of electrical equipment shall be effectively earthed. Earth continuity conductors shall have a cross-sectional area of not less than that specified in CP 5.
42.27.8
Design Work All design Works necessary in producing the control panel shall be based on the requirements aforementioned and is subject to the approval of the SO Rep. All designs, including the PCB artworks, resulting thereof shall be the sole property of the Employer. Two sets of the relevant drawings shall be submitted if requested by the SO Rep all at the Contractor's cost and expense.
42.27.9
Testing Of Installation The Contractor shall arrange with the SO Rep one month before the completion of the installation for the testing of the performance and installation of the telemonitoring system. The Contractor shall provide complete information as produced in Appendix A24 and submit two copies to the SO Rep one week before the testing of the system. All Defect notified shall be rectified within such time as instructed by the SO Rep.
BLDG12/S42.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 42-15 42.28
SERVICING AND MAINTENANCE DURING MAINTENANCE PERIOD (TRANSFER PUMPING SYSTEM) The Contractor shall allow in the Contract Sum for all costs and expenses for providing routine servicing and maintenance to the Transfer Pumping System and for providing an efficient call-back service as specified hereunder for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this Clause including all sub-clauses under it.
42.28.1
Making Good Defects And Leakages During the Defects Liability Period, make good all Defect and leakages found in the system and installation. Replace and/or repair all defective parts or items whenever required if such replacement or repair has been necessitated by the reasons of Defect in the Plant and equipment. The Contractor shall have a supervisor-in-charge of the service, maintenance and repair work to be carried out under this Clause including all sub-clauses under it. The supervisor shall be thoroughly competent in supervising the service, maintenance and repair of transfer pumping system and the workmen shall also be skilled in the service, maintenance and repair of transfer pumping system.
42.28.2
Fortnightly And Monthly Inspection All parts and equipment comprising the complete transfer pumping system shall be maintained and inspected strictly in accordance with the check-list as set out in Appendix A25. The check-list shall be duly completed by the Contractor when performing the fortnightly and monthly inspections. Any Defect detected shall be rectified by the Contractor immediately. Always arrange for a Representative from HDB Branch Office to be present during these inspections. Furnish to the HDB Branch Office a Maintenance Schedule for fortnightly and monthly inspections upon Substantial Completion of the Works or phase or sub-phase of the Works. The Contractor's Supervisor shall also sign on the attendance book/card provided by the Employer in the pump room after completion of each inspection. Items in the check-list for fortnightly inspection shall include : (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) (n)
General condition of the pumprooms Correct setting of time switch Auto/Manual selector switch in "Auto" position Power supply selector switch in "On" position Control panel indicating lights Alarm bell and bulb Suction tank electrode and control module Motor running current 80mm check valve 80mm gate valve Alignment of couplings 100mm check valve 100mm gate valve Ball float valve
Items required to be inspected monthly shall include all items required for the fortnightly inspection specified in the foregoing requirements in addition to the following : (o) (p) (q) (r) (s)
BLDG12/S42.DOC(15) Sal(151211) (DPD)
Motor insulation Pump mechanical seal Pump lubrication oil level (if applicable) Contactors and relays Storage tank electrode and control module
Bldg Spec Page 42-16 42.28.3
Efficient Call-Back Service Provide an efficient 24 hour (whole day) call-back service. All urgent calls or complaints such as no water supply or triggering of the alarm bell of the Transfer Pumping System shall be attended to immediately upon notification by the Representative from the Essential Maintenance Service Unit or Branch Office. The Contractor shall provide a mobile phone for his maintenance supervisor and the mobile phone number shall be given to the respective Branch Office so that immediate notification of any urgent callback service can be met. Provide a set of standby pump to keep the transfer pumping system functioning when the faulty pumps are taken back to the workshop for repairs. In the event that the Contractor fails to : (a) (b) (c)
respond within 30 minutes after being called; or attend to an urgent call or complaint immediately upon notification; or carry out the fortnightly and monthly inspection of the transfer pumping system;
the SO Rep may engage another contractor to carry out the Works and all costs and charges shall be recoverable from the Contractor by the Employer or deducted by the Employer from monies due or becoming due to the Contractor. Notwithstanding the above, the SO Rep may in addition exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. In the event that other contractors are instructed to rectify Defect in the transfer pumping system or to carry out the routine servicing and maintenance of the transfer pumping system due to or arising out of the Contractor's failure to do so when directed by the SO Rep, such actions shall not in any way affect, vary or relieve the Contractor's obligations under the Contract.
42.29
RECTIFICATION OF DEFECTS PRIOR TO ISSUANCE OF MAINTENANCE CERTIFICATE One month before the expiry date of the Defects Liability Period, the Contractor shall arrange with HDB Branch Office and the SO Rep for a final joint inspection. All Defect listed after this joint inspection shall be rectified by the end of the succeeding one month commencing from the expiry date of the Defects Liability Period. Rectify the outstanding Defect and conduct detailed checks on the Works before arranging for inspection by the Representative from HDB Branch Office for the purpose of certifying completion of rectification of Defect. After the second final inspection by the Representative from HDB Branch Office, a list of outstanding Defect shall be issued to the Contractor and the Contractor shall rectify all Defect on the list within fourteen days. If the Contractor fails to rectify and make good the Defect on the second final inspection, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. Notwithstanding the above, the Employer shall in addition have the right to engage his own workmen or other contractors to rectify and make good all Defect and the cost of rectification and charges imposed shall be recovered from the Contractor.
Section 43/..... BLDG12/S42.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 43-1 SECTION 43 BOOSTER PUMPING SYSTEM INSTALLATION
43.1
SCOPE OF WORK The Works shall include the provision, installation and testing of booster pumping system, based on the data given, complete with motors, pipework, valves, flow sensors, switch gears, electrical wiring, control panels and all necessary accessories. Details of the proposed booster pump installation shall be submitted to the SO Rep for approval. All Works shall comply with Public Utilities (Water Supply) Regulations and SSCP 48: Code of Practice for Water Services, the requirements and regulations of the Water Supply (Network) Department, PUB and other relevant Statutory requirements
43.2
APPROVAL OF DRAWINGS AND DETAILS OF BOOSTER PUMPING SYSTEM Submit one set of the following to the SO Rep for approval within two months from the date of the Letter of Acceptance : (a)
Detailed proposal complete with information as produced in Appendix A26 duly filled and signed by the Contractor.
(b)
Characteristic curves of every pump to indicate the point(s) of performance.
The Works shall commence only after the approval of the proposal by the SO Rep. The Contractor shall seek fresh approval for any deviation from the approved proposal, failing which the whole installation shall not be accepted by the SO Rep. The written approval of the Drawings shall in no way affect vary or relieve the Contractor of his responsibility or obligations should the Plant or any of its parts proved inadequate with regard to strength, performance, efficiency or other aspect.
43.3
BUILDING-IN The Employer reserves the right to build in any steel supporting members or frameworks for the pumping system. Supply all relevant dimensions and information on these pumping system and steel member supports and attend to the work all at the Contractor's cost and expense. The Contractor shall be responsible for any error or damages found subsequently.
43.4
BOOSTER PUMPS AND MOTORS All booster pumps of approved type shall be of vertical in-line centrifugal pumps with mechanical seals and high performance efficiency, driven by totally enclosed fan cooled (TEFC) electric motors except otherwise specified in the Specifications. The casing of the pump shall be of stainless steel, bronze or other approved metal. The impeller shall be bronze or stainless steel and the shaft shall be of the stainless steel type and able to transmit the required power and to ensure the rigidity of rotating parts. The entire length of the shaft shall be suitably protected against corrosion and be supported by heavy duty bearings in robust housing well clear of the rotating parts. The shaft seal shall be of the mechanical seal type. Bearings shall be protected against corrosion and be efficiently lubricated. The make of the pumps shall be tested and approved by the SO Rep. The electric motors shall be squirrel-cage, totally enclosed fan cooled type and with at least Class B insulation except where specified otherwise and be designed for continuous maximum rating. Terminal boxes shall be totally enclosed, of water-tight design and fitted with cable glands. The power supply for the electric motors shall be 400 volts, 3 phase 50 cycles alternating current. 230 volts single phase motor shall be used as and when directed and approved by the SO Rep. The power of the motor shall not be more than 1 kW.
BLDG12/S43.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 43-2 43.4
BOOSTER PUMPS AND MOTORS (CONT'D) Unless otherwise specified, the design requirements of the booster pumps shall be as follows : No. of Dwelling Unit served by Booster Pump
Specified Flow Rate (l/s)
Pressure Head (m)
Shut-off Head (m)
20 or below Above 20
3 5
9 9
Not less than 12 Not less than 12
The pumpsets shall be marked with permanent letterings "P1" & "P2" respectively.
43.5
PIPE AND FITTINGS All pipes and pipe fittings shall be approved by Water Supply (Network) Department, PUB. All stainless steel pipes, fittings and accessories shall conform to BS 4127:Part 2. All ductile iron pipes and fittings shall comply with BS EN 545. Ductile iron flange type PN 16 shall comply with BS EN 545. All ductile iron pipes and fittings shall be internally cement lined in accordance with the relevant clauses in BS EN 545. Test the mixture according to the relevant clauses in BS EN 545. Apply two coats of PUB approved epoxy to the portion where cement lining is not possible. Pipe joints, fittings and special tees, for all ductile iron distribution mains and drawout pipes at roof level shall be ductile iron flanged type. Flanges type PN 16 shall comply with BS EN 545. The internal and external surfaces of the stainless steel pipes and fittings shall be clean, smooth and free from Defect. Cutting and fixing shall be in strict accordance with the manufacturer's instructions. Pipes shall be factory marked with manufacturer's name or identification mark and classification of pipes. Any unmarked pipes shall not be accepted. Unless otherwise specified, use light gauge stainless steel pipes for water supply. The stainless steel pipe fittings shall be of capillary or compression fittings of copper alloy and shall comply with BS 864:Part 2 and all PUB latest requirements. All stainless steel pipes shall not be bent. All pipes which pass through walls or floor shall be insulated by neoprene material. All pipes shall avoid running directly above any bedroom of a dwelling unit. Otherwise, noise/vibration abatement device shall be provided. Support pipes with stainless steel supports and clips or concrete supports. All pipes which pass through walls or floor shall be insulated and sealed with approved compound. All pipes which do not pass through the wall or floor but running along the wall shall be supported with built in stainless steel/supports and clips spaced at 1m centres. Unless otherwise specified, sizes of pipework shall be as follows : Size of Suction Piping Size of Discharge Piping Size of By-Pass Piping
-
42mm 42mm 15mm
Connect suction pipe of each pump from the 100mm interconnecting pipe of roof storage tanks and connect the discharge pipe of each pump to the 100mm distribution main which serves the topmost 3 storeys only. No mechanical tee shall be used for connections between suction pipe and interconnecting pipe and between discharge pipe and distribution main. Provide end thrust supports at both ends and bends of 100mm distribution main according to the Drawings. All bolts, nuts and washers used for the ductile iron pipes for installation shall be galvanised steel whilst those for the stainless steel pipes and supports shall be stainless steel of similar grade.
43.6
VALVES Provide suction pipe of each pump with a 40mm full bore ball stop valve. Fit the delivery pipe of each pump with a 40mm full bore spring loaded check valve and 40mm full bore ball stop valve. Provide the bypass pipe with a 15mm stop cock. All valves used shall comply with PUB Water Supply Regulations.
BLDG12/S43.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 43-3 43.7
LABELLING STICKERS Stick aluminium foil stickers of length 75mm and width 40mm bearing the words "DO NOT OPEN" onto the 100mm gate valves at the draw-out pipes from storage tanks to the 100mm distribution main serving the top-most 3 storeys. The base colour of the aluminium foil stickers shall be in white and the wordings shall be in red. The dimensions of the wordings shall be of height 10mm and width 6mm and the line thickness 1mm. Submit a sample of the stickers to the SO Rep for approval.
43.8
POWER SUPPLY Power supply to the booster pumps and control system at the roof storage (high level) tank room shall be connected from the electrical mains isolator in the roof storage tank room.
43.9
MOTOR SOFT-STARTERS Soft-starters for motors shall be of the type as approved by the SO Rep. The soft-starters shall provide means for the soft-start and soft-stop of the motors automatically. The operating voltage of the soft-starter shall be 230V. Both soft-start time and soft-stop time of the soft-starter shall be set at 3 seconds. Each soft-starter shall be designed to operate intermittently during the 24 hours of operation per day. The soft-starters shall be wired in such a way that the duty and standby booster pumps shall be actuated by flow sensors and floatless level switch. Selection of duty or standby booster pumps shall be determined by a selector switch. Provide automatic duty change over relay to alternate standby and duty booster pumps and it shall be interconnected to a flow sensor to start and stop the operation of the booster pumps according to actual water demand.
43.10
FLOW-SENSORS The flow sensor shall be of the type approved by the SO Rep. A flow sensor shall be installed at the central discharge pipe of the booster pumps. Monitoring head of the sensor shall be of stainless steel. The enclosure protection shall be at least IP 67. The voltage of the flow sensor shall be 24V DC. The flow rate range shall be set to 115mm per seconds (adjustable range : 10mm per second to 2m per second).
43.11
FLOATLESS LEVEL CONTROL RELAY UNIT Floatless level control electrodes mounted on each storage (high level) tank shall be connected directly to the relay unit mounted inside the control panel. Position the floatless level control electrodes near to the manhole of the tank for easy maintenance. Arrange the floatless level control electrodes to start and stop the pumpset at pre-determined levels. Interconnect the floatless level switch to the motor soft-starters through the pumps' automatic change over relay. The floatless level control relay unit shall be of the plug-in relay unit type for easy maintenance. The unit shall have built-in arrester circuit to protect against surge from power source and lightning surge from the electrodes. Provide stainless steel electrodes with adequate electrodes separators. The ceiling roses and flexible cables from the electrode holders shall be legibly marked "BP". Electrode holders mounted on tanks shall be easily accessible and removable for maintenance. Run the wiring and conduits from the electrodes to the switch board panel and keep them as short as possible. The wiring to the electrodes shall not run through the same conduit which contains the power supply wiring. All floatless control relay units shall be of the approved type.
BLDG12/S43.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 43-4 43.12
CONTROL PANEL Provide and install approved control panel required to serve the booster pumpsets. Sufficient wall space shall be selected within the roof storage tank room for the wall mounted control panel and shall be near to the booster pumpsets subject to the approval of the SO Rep. Unless otherwise specified, the panel shall be of the front connected type and manufactured from electrogalvanised sheet metal of minimum 1.5mm thickness, using folded section or angle form bracing for rigidity of construction. The panel shall have adequate ventilation and shall be drip proof. The construction shall be such that it allows for ready and easy access to the interior of the cubicles for operation and maintenance purposes. Provide control panel with rubber bushes at knockout holes for the entry of all incoming and outgoing cables. Mount instrument indicating lights, rotary switches, etc directly on front panel with locknuts to hold such items firmly in position under all conditions of operation. The control panel shall contain the following : (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m)
1 No. Rotary selector switch for Auto selection 1 No. Rotary key selector switch with 3 points selection 2 No. Soft-Starters as specified in the Clause 43.9 "Motor Soft-Starters" 2 Sets ON/OFF isolators with 3 phases MCB unit for starters 1 No. Delay Timer with 0 to 6 seconds setting 1 No. Timer with 0 to 30 minutes setting 6 No. Relays to control the pumpsets 1 No. Automatic change over relay 5 No. MCB unit for control circuits 3 No. Phase indicating panel light 2 No. Pump "run" indicating panel light 2 No. Pump "trip" indicating panel light 1 No. Low level warning indicating panel light
The whole of the electrical Works shall comply with SS CP5 and be subject to the approval of the SO Rep.
43.13
ELECTRICAL WIRING Install cables from the electrical mains isolator in roof storage tank room or at other locations. Internal cables and wiring shall be PVC insulated to SS 358 suitable for a 400V 3 phase 50 cycles 4 wire system and they shall be carried in conduit or cable trunking. The metal conduit shall be of heavy gauge, GS conduit (Class 4), complying with BS 4568, free from internal roughness and burrs. Fixing to walls and other flat surfaces shall be by means of spacer bar saddles at maximum 1m centres for horizontal runs and 1.5m centres for vertical runs. Conduit termination to loop-on boxes shall consist of a screwed socket and smooth bore bush butt to adaptors boxes, fuse boards and cable trunking, etc. The termination shall consist of a flanged coupling, lead washer and smooth bore bush. In the event that the conduit comes in contact with any structural steel work, an efficient and permanent metallic connection shall be made between the conduit and the steelwork. All conduits and trunking shall be electrically and mechanically continuous throughout and shall be efficiently earthed with copper earthwire (in conduits and 100mm x 50mm trunking) and copper tape (in 150mm x 75mm trunking). Copper earth wire or tape shall be of the appropriate sizes. Cable trunking shall comply with SS 249 and be fabricated from 1.0mm mild steel sheets, in 1.83m or 2.44m lengths and provided with a 50mm fixing sleeve, spot welded on one end of each length. The trunking shall be treated with approved anticorrosion paint and finishing paint to a minimum thickness of 45 microns. Jointing of trunking shall be effected by means of round headed bolts and nuts. 4mm x 20mm copper earth tape shall be laid in the trunking run. The copper shall be tinned where it is bolted down.
BLDG12/S43.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 43-5 43.13
ELECTRICAL WIRING (CONT'D) The entire trunking and conduit installation shall be completed before the cables are drawn. The number of cables to be drawn shall comply with SS CP 5. Test all seals not less than 24 hours after completion. This test shall be made with insulation testing equipment of the `Megger' type at 500V and an infinity reading shall be obtained before the conductors are connected to any apparatus. Where wiring is to be in conduit or duct buried in the floor, it shall terminate in approved junction boxes adjacent to the machine or foundation plinth with water-tight flexible conduit enclosing the cables between the motors and junction boxes. Earth all non current carrying metal parts of electrical equipment. Earth continuity conductors shall have a cross-sectional area of not less than that specified in CP 5.
43.14
INSTALLATION OF BOOSTER PUMPS Install booster pumpsets on the floor/wall and support and secure them with stainless steel or concrete supports along the pipes closed to suction and discharge side of the booster pumpsets. Install pressure gauge of appropriate scales at the discharge pipe of each booster pump. The pressure gauge shall comply with BS1780 for measuring gauge pressure. The pressure gauge shall be marked with the manufacturer's trademark or brand name. The Contractor shall be responsible to ensure that the booster pumps are installed according to standard procedure of installation or according to the pump supplier's recommendation subject to the approval of the SO Rep. Check the location for the switch board. Inform the SO Rep immediately should this location be not at an optimum position.
43.15
VIBRATION AND NOISE Vibration and noise generated by the pumpsets shall not be unduly disturbing to dwellers immediately below. Provide and fix all necessary noise and vibration abatement devices and equipments to reduce the vibration and sound.
43.16
STERILISATION OF PIPES, FITTINGS AND PUMPS BEFORE OPERATION Clean and flush all pipes, fittings and pumps internally with sufficient chemical to give the water a dose of 50 parts of chlorine to one million parts of water (ie. 50 ppm) before the commencement of the operation of the system, in accordance with PUB requirement.
43.17
INSPECTION DURING PROGRESS OF WORK Provide all necessary facilities such as torch lights etc and access leading to the tanks for inspections by the SO Rep during of progress of the Works.
BLDG12/S43.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 43-6 43.18
TESTING OF BOOSTER PUMPING SYSTEM INSTALLATION One month before the completion of the installation, arrange with the SO Rep for testing the performance and installation of the booster pumping system. Furnish data on booster pumping system as set out in Appendix A27 and submit 2 copies to the SO Rep one week before the testing of the booster pumping system. All Defect notified during the inspection shall be rectified before the building blocks are handed over to the Employer, failing which action shall be taken against the Contractor by the SO Rep.
43.19
SERVICING AND MAINTENANCE DURING MAINTENANCE PERIOD (BOOSTER PUMPING SYSTEM) The Contractor shall allow in the Contract Sum for all costs and expenses for providing routine servicing and maintenance to the booster pumping system and for providing an efficient call-back service as specified hereunder for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this Clause including all sub-clauses under it.
43.19.1
Making Good Defects And Leakages During the Defects Liability Period, make good all Defect and leakages found in the system and installation, replace and/or repair all defective parts or items whenever required if such replacement or repair has been necessitated by reasons of Defect in the Plant and equipment. The Contractor shall have a Supervisor-in-Charge of the service, maintenance and repair work to be carried out under this clause including all sub clauses under it. The Supervisor shall be thoroughly competent in supervising the service, maintenance and repair of the booster pumping system and the workmen shall also be skillful in the service, maintenance and repair of booster pumping system.
43.19.2
Monthly Inspection Maintain and inspect all parts and equipment comprising the complete booster pumping system strictly in accordance with the check-list as set out in Appendix A28. The check-list shall be duly completed by the Contractor when performing the monthly inspection. Any Defect detected shall be rectified by the Contractor immediately. The Contractor shall always arrange for a representative from HDB Branch Office to be present during these visits. Furnish to the HDB Branch Office a maintenance schedule for monthly inspection upon Substantial Completion of the Works or phase or sub-phase of the Works. Items in the Check-list shall include : (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k)
BLDG12/S43.DOC(6) Sal(151211) (DPD)
Flow sensors Soft-starters, relays and control module Power supply selector switch in "On" position Control panel indicating lights Electrodes in storage tanks Motor running current Motor insulation Pump mechanical seal Pressure gauges 40mm check valve and ball stop valves Thrust supports at distribution main
Bldg Spec Page 43-7 43.19.3
Efficient Call-Back Service Provide an efficient 24 hour (whole day) call-back service. Attend to all complaints immediately upon notification by the Representative from the Essential Maintenance Service Unit or Branch Office. The Contractor shall provide a mobile phone for his Maintenance Supervisor and the mobile phone number shall be given to the respective Branch Office so that immediate notification of any call-back service can be met. Provide a set of standby pump to keep the booster pumping system functioning when the faulty pumps are taken back to the workshop for repairs. In the event that the Contractor fails to : (a) (b) (c)
respond within 30 minutes after being called; or attend to complaint immediately upon notification; or carry out the monthly inspection of the booster pumping system;
the Employer may engage another contractor to carry out the Works and all costs and charges shall be recoverable from the Contractor by the Employer or deducted by the Employer from monies due or becoming due to the Contractor. Notwithstanding the above, the SO Rep may in addition exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. In the event that other contractors are instructed to rectify Defect in the booster pumping system or carry out the routine servicing and maintenance of the booster pumping system arising out of the Contractor's failure to do so when directed by the SO Rep, such actions shall not in any way affect, vary or relieve the Contractor's obligations under the Contract.
43.20
RECTIFICATION OF DEFECTS PRIOR TO ISSUANCE OF MAINTENANCE CERTIFICATE One month before the expiry date of the Defects Liability Period, the Contractor shall arrange with HDB Branch Office and the SO Rep for a final joint inspection. All Defect listed after the joint inspection shall be rectified by the end of the succeeding one month commencing from the expiry date of the Defects Liability Period. Rectify all outstanding Defect and conduct detailed checks on work before arranging for inspection by Representative from HDB Branch Office for the purpose of certifying complete rectification of Defect. After the second final inspection by the Representative from HDB Branch Office, a list of outstanding Defect shall be issued to the Contractor and the Contractor shall rectify all Defect in the list within fourteen days. If the Contractor fails to rectify and make good the Defect on the second final inspection, the SO Rep shall exercise his right under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. Notwithstanding the above, the Employer shall in addition have the right to engage his own workmen or other contractors to rectify and make good all Defect and the cost of rectification and charges imposed shall be recovered from the Contractor.
Section 44/.....
BLDG12/S43.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 44-1 SECTION 44 DRY / WET RISING MAIN INSTALLATION
44.1
GENERAL It is the intention of the Drawings and Specifications to provide a complete operating system. The omission from the Specifications or Drawings of any details in construction, installation materials, or specialities necessary for a complete operating and safe system shall not relieve the Contractor from furnishing and completing the same in place all at the Contractor's own cost and expense. Should the requirements of the Drawings or Specifications conflict with codes, regulations or standards, the most stringent of the requirements shall govern the Works. For buildings under construction, dry/wet rising mains shall be provided according to the requirements of the FSSD. The Contractor shall work closely with the SO Rep to ensure that all requirements for the provision of rising mains are complied with during the construction stage. All rising mains (dry and wet) shall be installed progressively as the building gains height and made operational for all storeys (except the uppermost three storeys) as soon as the uppermost completed storey reaches habitable height of 24m. Dry rising mains if used in lieu of wet rising mains in the initial stage shall be converted to wet rising mains when the uppermost completed storey reaches habitable height of 60m. All breeching inlets, landing valves, water tanks and pumps where required shall be provided and made readily operational. The Contractor shall make the necessary arrangements to enable the officers from FSSD, SO Rep, and/or officers from HDB (Technical Department) to carry out any inspection and testing during the construction and completion stages. Charges shall be imposed on the Contractor under the “Nuisance and Irregularities” clause for any non-compliance with the FSSD’s requirements detected during site inspection by FSSD, SO Rep and/or HDB (Technical Department). The Contractor is also subject to action taken by FSSD under the relevant Act/Regulations. The Contractor shall engage a company/firm which is registered under BCA registration head of ME06 (Fire Prevention & Protection System) for the Works. The Contractor shall test and commission the works to the satisfaction of the SO Rep, FSSD and/or the appointed RI. Upon the final completion of the works, the Contractor shall prepare all necessary test reports & certificates to be endorsed by the SO Rep and submitted to HDB (Technical Department). HDB (Technical Department) reserves the right to audit the completed works and the Contractor shall make the necessary arrangements for the inspection when requested.
44.2.1
Scope Of Work (a)
Dry rising main shall be installed in building where any floor is at a height beyond 10m and not exceeding 60m above the ground level. The dry rising main shall be complete with landing valve at every storey, breeching inlet and breeching inlet cabinet (where applicable). The minimum nominal bore of a dry rising main shall be :
(b)
(i)
100mm galvanised steel Class 'C' where the rising main does not exceed 45m in height. The rising main shall be complete with 2 way breeching inlet.
(ii)
150mm galvanised steel Class 'C' where the rising main exceed 45m in height. The rising main shall be complete with 4 way breeching inlet.
For building which is more than 60m, wet rising main shall be provided according to SS CP 29 and the requirements as shown in the Drawings. Fire intercom system shall be provided between the pump rooms of the transfer pumps and the fire pumps. The Contractor shall provide all technical data as shown in Appendix A29.
BLDG12/S44.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 44-2
44.2.2
Rules And Regulations Ensure that the installation of dry/wet rising main system is in accordance with the latest requirements of the following : (a) (b) (c) (d) (e) (f)
Building Control Act and the Regulations made thereunder; Public Utilities Act, and the Regulations made thereunder; Professional Engineers Act; Fire Safety Act; SS CP 29; Any other relevant rules, regulations and by-laws.
In cases of discrepancies between the various standards, the local standards shall prevail. 44.2.3
Material Material, appliances and components shall comply with the requirements of the relevant Singapore Standards, British Standards or their equivalent. Particular items shall comply with the following requirements or their equivalent : (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k)
44.2.4
Ball Valves Boxes for landing valves Breeching inlets Landing valves Pipes Pipe fittings Pipe and valve flanges Pressure gauges Gate valves Starting switches (automatic) Fire safety signs, notices and graphic symbols
BS 1212 : Part 1, 2 or 3 BS 5041 : Part 4, 5 BS 5041 : Part 3 BS 5041 : Part 1, 2 BS 1387, ASTM A120 BS 1740 BS 10 or BS 4504 BS 1780 BS 5163 BS 587 BS 5499 : Part 1
Quality Of Goods And Materials The quality of goods and materials shall comply with the requirement and regulations of the HDB and the relevant Authorities and shall also comply with the relevant Code of Practice as stipulated. All materials used shall be of the approved type unless otherwise specified. Where products are manufactured under the PSB Batch Inspection Scheme, additional testing shall not be necessary unless otherwise specified. The SO Rep shall be consulted when in doubt. Any other relevant requirements issued by the FSSD shall be complied with.
44.2.5
Approval/Submission Of Drawings And Details During the progress of the Works, the Contractor shall record and update all wet and dry riser routes, legends and all other related mechanical works based on actual site installations for the production of asbuilt drawings.
44.2.6
Installation (a)
Seek approval from the SO Rep before any hacking work is to be done.
(b)
For rising main pipe and down-comer (fire fighting) through the floor slabs, provide concrete curb around the rising main pipe. The concrete curb shall be 100mm high and surrounding the pipe. Casting of the concrete curb shall be done together with re-casting of concrete slab as one single operation. The concrete curb and slab shall be water tight.
(c)
The Works shall include hacking, coring, drilling etc, as well as re-casting the concrete slab. The Contractor shall provide and cast water-proof concrete slab of not lesser strength than the original slab.
BLDG12/S44.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 44-3 44.2.7
Damage To Existing Roof Structures And Roofing System For Works to existing building blocks, the Contractor shall liaise with the relevant Branch Office or Town Council for a joint inspection together with the SO Rep to determine the existing roof condition before the commencement of the Works. All defects noted shall be recorded in writing and verified by the parties concerned before the commencement of the Works. Upon the Substantial Completion of the Works, the Contractor shall engage the same roofing specialist contractor, who had provided the warranty for the existing roofing system, to replace any broken or cracked secondary roof slab and carry out all the repairs and reinstatement Works to the damaged waterproofing membrane and roof structure. During the progress of the Works, the Contractor shall, upon verbal or written notification by the SO Rep, engage the same roofing specialist contractor, who had provided the warranty for the existing roofing system, to repair immediately any leakage in the roof caused by the Contractor.
44.3.1
Pipeworks & Fittings (a)
General Pipework for dry/wet rising mains shall be galvanised steel conforming to BS 1387 or ASTM A120 and BS 1740. Tubes/pipes and fittings used shall be suitable for pressures up to 21 bars. Mill certificates shall be produced on request to countercheck with the heat numbers of tubes/pipes at the Site. All fittings shall, as far as practicable, be the same size as the pipes connected. Elbows shall be used, where practicable, in preference to bends; square elbows shall not be permitted. Valves used shall be UL and FM listed according to the pressure rating of SS CP29. Valves used shall be UL and FM listed according to the pressure rating of SS CP29. All fittings/valves used shall be rated at least 1.5 times the system working pressure. All valves shall be kept securely strapped with padlock. All underground pipework shall be of ductile iron cement lined or other approved material. Pipework shall follow the contours of walls and shall be graded to ensure venting and draining. The clearance between pipework and wall and any other fixtures shall be as shown in the construction detail of service duct for dry/wet rising main. Joints shall not be embedded in any wall, floor or ceiling and pipework shall not be embedded in the structure of floors. Where pipework passes through walls, sleeves shall be provided. Sleeves shall be of the same metal as the pipe. The space between pipework and sleeve shall be plugged with an approved sealant. All entry and exit holes to or from a building for pipework shall be sealed and plugged. The sealant shall be mastic compound or silicone rubber. Where the pipework enters the building through a large hole or duct, a mild steel blanking plate not lesser than 6mm thick shall be built into the wall of the hole or duct; the service pipes shall pass through clearance sockets welded to the plate and the space between pipe exterior and socket interior shall be sealed and plugged.
(b)
Pipe Joints All piping shall be installed by means of flanged fittings, mechanical pipe couplings or other approved means. Flanges shall be raised face conforming to BS 4504. Flanged joints shall be made with flat ring gaskets suitable for the pressure and temperature and extending to the inside of the bolt circles. Mechanical pipe couplings shall be self-centring and engage and lock in place the grooved or shouldered pipe and pipe fitting ends in a positive watertight couple. Coupling housing clamps shall consist of two or more metal castings holding in place a composition water sealing gasket so designed that the internal water pressure increases the watertightness of the seal. The coupling assembly shall be securely held together by two or more heat treated carbon steel bolts and nuts. Pipe grooving shall be in accordance with the pipe coupling manufacturer's latest specifications. The entire coupling installation shall be in accordance with the latest manufacturer's recommendations. Pipe joined with grooved fittings shall be joined by a listed combination of fittings, gaskets and grooves.
BLDG12/S44.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 44-4
44.3.1
Pipeworks & Fittings (Cont’d) (b)
Pipe Joints (Cont’d) Couplings and fittings used shall be FM and UL listed according to the pressure rating of SS CP29.
(c)
Pipe Supports Typical pipework hangers for the dry/wet rising main and down-comer (fire fighting) system shall be as shown in the Drawings. Support the pipework on main load bearing members of the structure. The method of support shall be done according to the practice in the industry subject to the approval of the SO Rep. Rising main support shall be located at every storey. Horizontal pipe runs shall be provided with hangers spaced at a maximum distance of 4m.
(d)
Painting Galvanised steel pipes and fittings shall be painted in accordance with the provisions of Section 23. All pipework shall be stencilled with directional arrows of minimum 200 x 30mm in size. A sample showing the pipework painting and welded flange shall be provided to the SO Rep for approval.
44.3.2
Breeching Inlet Provide inlets with instantaneous male couplings for connection to the Singapore Civil Defence Force's 63.5mm diameter standard hose to each rising main with a two-way breeching inlet for a 100mm, or 4 way breeching inlet for a 150mm diameter rising main, at a level of about 760mm above ground level. Each breeching inlet shall conform with the requirements of BS 5041:Part 3. Enclose all inlets in a rust-proof steel inlet box with glass front. Position the inlet box with its lower edge between 400mm and 600mm above ground level. The position of inlets shall be indicated on inlet box using appropriate signs in accordance with BS 5499: Part 1 and using a letter height of at least 50mm. Inlets shall be painted yellow for dry rising mains. The inlet box shall be installed with key lock. Where more than 1 stack are provided for the rising main, the labelling of the rising main shall be subject to the approval of the SO Rep. Provide all pipework of rising main that falls below inlet box level with an additional 25mm drain valve at the lowest point of the pipework, together with either fixed piping or an adequate length of flexible tubing (fitted with a suitable coupling for connection to the valve) to conduct water from the valve to a suitable drain. Where such a low level drain is fitted, provide a permanent notice in 25mm (minimum) block letters of a suitable colour on a contrasting background and place it in a position adjacent to the valve reading 'DRY RISING MAIN - DRAIN VALVE' or 'WET RISING MAIN -DRAIN VALVE'. Provide another permanent notice in the inlet box, similar in size to the indicator plates mentioned in BS 5041: Part 5, reading 'LOW LEVEL DRAIN VALVE IN .........' (state location of the valve). The low level drain valve shall be kept securely strapped and padlock closed except when in use.
44.3.3
Landing Valve Provide landing valve with an instantaneous female coupling for connection to the Singapore Civil Defence Force's 63.5mm diameter standard hose for each rising main as shown in the Drawings. The SO Rep reserves the right to instruct the Contractor to remove items vulnerable to be stolen such as handwheel, blank caps, chain, etc from the landing valves which have already been installed. The Contractor shall deliver these items for storage at a place to be decided by the SO Rep. No claim for such Works shall be allowed as all costs and expenses for such work are deemed to be included in the Contract Sum. The Superintending Officer's decision on which items are considered vulnerable to be stolen shall be final binding on and conclusive against the Contractor. The landing valve shall be kept securely strapped and padlock closed except when in use.
BLDG12/S44.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 44-5
44.3.3
Landing Valve (Cont’d) (a)
Location Provide landing valves at a height with its lowest point between 760mm and 1m above the floor level.
(b)
Recesses And Enclosures For Landing Valves Enclose landing valves for rising mains within a duct as shown in the Drawings. Where a landing valve is in an open recess, duct or alcove, and where a landing valve of a rising main is enclosed in a box, the opening giving access to the landing valve shall not be lesser than 150mm clearance on both sides and not lesser than 230mm below the centre line of the outlet of the landing valve and not lesser than 250mm clearance above the handwheel. The depth of the opening shall not be greater than is necessary, and the front edge of the female coupling of the landing valve shall not be more than 75mm behind the face of the door. Allow adequate space around the valve to permit easy maintenance and testing. Signplate in block letters of height not less than 50mm with the words 'DRY RISING MAIN OUTLET', 'WET RISING MAIN OUTLET' or `DOWN-COMER (FIRE FIGHTING) OUTLET' for the respective rising mains shall be mounted on the door. Landing valves shall be painted yellow for dry rising mains and red for wet rising mains and downcomers (fire fighting).
(c)
Anti-Theft Device Landing valves are to be equipped with means to prevent easy removal of the ear knobs and the plastic covers. Such measures shall be in the form of a 3mm thick brass cap duct cover & a 3mm x 220mm carbon steel chain. The brass cap shall be tightly fit into the ear knob to prevent easy access to the bolt & nut securing the ear knob. The cover shall be secured to the landing valve by the carbon steel chain. The SO Representative reserves the right to request a sample for approval purpose.
44.3.4
Automatic Air Release Valve For Rising Mains A suitable automatic air release valve shall be provided at the highest point in each rising main to permit air in the pipe to discharge to atmosphere when water is pumped in at ground level. The automatic air release valve shall have gunmetal or brass bodies, non-ferrous or stainless steel floats and guides, and non-corrodible valves and seats.
44.3.5
Electrical Earthing Of Rising Mains Rising mains shall be electrically earthed as shown in the Drawings. Joints which do not provide electrical continuity shall be bonded. All the rising mains that are situated in the vicinity of any lightning conductor, shall be bonded to the lightning conductor in accordance with the requirements of the code on lightning protection.
44.3.6
Drain Valves Provide each breeching inlet with a drain valve in the form of a 25mm gate valve complying with the requirements of BS 5154, rating PN 16. For ease of attaching a drain hose, the drain valve outlet shall be positioned so that it faces in the same direction as, and is at a lower level than, the inlet connections to the breeching inlet. The outlet of the drain valve shall have 25mm male threads complying with the requirements of BS 21, and shall be fitted with a female blank cap and chain.
44.3.7
Blank Caps Provide each inlet with a female instantaneous blank cap acceptable to FSSD. Attach every blank cap to the breeching inlet and landing valve by a suitable lug, s-hook and chain.
BLDG12/S44.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 44-6
44.3.8
Signboard The breeching inlets shall be identified by an appropriate sign reading `DRY' or 'WET RISING MAIN'. Where the inlets are not readily visible from the outside, a sign shall be posted in a conspicuous place directing the Singapore Civil Defence Force to the inlets subject to the approval of the SO Rep.
44.4.1
Wet Rising Main System Generally, a water supply capable of providing a minimum of 27 litres per second for a residential building or 38 litres per second for a non-residential or mixed occupancy building at all times shall be required. When more than one wet rising main is required in any zone in a building, the minimum common water supply shall be as stated below : (a)
For a residential building 27 litres per second for the first rising main and 13.5 litres per second for each additional rising main, subject to a total maximum supply rate of 135 litres per second.
(b)
For a non-residential or mixed occupancy building 38 litres per second for the first rising main and 19 litres per second for each additional rising main, subject to a total maximum supply rate of 190 litres per second.
The supply from the breeching inlets shall discharge openly into the tank and at a level of not less than 150mm above the maximum water level in the tank. To reduce the risk of hose bursting, provisions shall be made in accordance with BS 5401 : Part 1 so that when the water is shut off at the nozzle the static pressure in any line of hose connected to a landing valve does not exceed 8 bar. To dispose of excess flows and pressures over and above those required (ie. when only one jet is in use) a pressure control valve shall be incorporated in the body of the landing valve which is then permanently connected into a relief pipe, where applicable. This relief pipe shall run throughout the length of the wet rising main installation and shall terminate either back into the suction tank or to drain. The relief pipe shall be 100mm diameter galvanised steel. All pump control panels shall be of IP 54 enclosures.
44.4.2
Wet Rising Main Water Tank Unless agreeable by the FSSD, tanks supplying water for domestic purposes shall not be used as suction or storage tanks for wet rising mains. The tank shall be compartmented into two separate water-tight sections connected by a valve, normally kept open, to permit tank maintenance without interruption to the water supply. Nevertheless, when more than one water tank is provided in parallel to store the required amount of water, tank compartmentation is not necessary provided the tanks are interconnected with isolating valves which are secured open. Each tank or tank compartment shall be provided with a ductile iron cement lined overflow pipe of at least 100mm in diameter, adequately supported, and extended to discharge into a suitable drain. Ductile iron cement lined drain pipe of at least 100mm diameter and controlled by a gate valve shall be provided for each tank or compartment. Voltex inhibitors shall be installed where applicable to maintain the required water tank storage capacity according to SS CP29. An approved visual level indicator shall be fitted to show the depth of water in each tank or compartment. A permanent aluminium gooseneck ladder with safety guard extending a sufficient distance above the top of the tank shall be provided for each tank. UPVC ladder shall also be provided inside each tank. Reinforced concrete tank shall comply with the requirements specified in Section 9 "Reinforced Concrete Water Tank" including all clauses & subclauses under it. However, notwithstanding the requirements specified therein, sterilisation of water is not required.
BLDG12/S44.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 44-7 44.4.3
Wet Rising Main Pumps The horizontal split case fire pumps for use in wet rising mains and transfer pumps shall be listed by PSB and UL or FM. The fire pumps / motors for use in wet rising mains and transfer pumps / motors shall be tested by approved accredited laboratory and UL (Underwriter Laboratories Inc.), FM (Factory Mutual Approvals). The pumps / motors shall be selected to meet design as well as maximum flow requirements. All pumps and control panels shall be mounted on at least 150mm height plinths. Spring type vibration isolators shall be provided for each pump to ensure minimal vibration transmission to the building structure. The first three pipe supports from the pump discharge shall be the spring mounted type. Pump control panels near/below pipework shall be protected from water leakage / splash. The pumps shall have an independent source of power supply and each shall be capable of providing independently the necessary flow and pressure requirements. The duty pump (or standby pump, in the event of failure of the duty pump) shall start automatically when there is a flow of water or when a fall in pressure occurs in the rising main exceeding 5% of the fire pump churning pressure. The pump shall be fully operational within 30 seconds after starting. Means shall be provided for manual starting by reproducing the pressure reduction. Once started, the pump shall run continuously until stopped manually. Means shall be provided for the 'lagging' pump to operate should the 'leading' pump fail to function upon closing of the starting circuit. (a)
Pressure-sensor switches shall be supplied and fitted on the main supply pipes to initiate automatic starting of the pumps. Pressure-sensor switches shall be of approved type with provisions for independent adjustment of high and low pressure settings. The automatic starting of any pump shall also initiate a visible and audible indication in the main fire alarm panel, if any.
(b)
Floatless level control relay unit complete with electrodes shall be provided for each suction and storage tank to override the control of all the pressure switches in such a way that at a pre-set low water level, the pressure switches shall not cause starting of the jockey and wet rising main pumps. In addition, any pump in operation shall be stopped by the relay unit at that low water level. The relay unit shall also actuate a visible and audible alarm indication when the water level reaches a pre-determined high or low limit.
(c)
The associated jockey pump shall be controlled by pressure-sensor switches so as to maintain a static pressure in the wet rising main about 1 bar (10m) higher than the pressure when the wet rising main pump is churning. The jockey pump shall be automatically de-energised when any of the wet rising main pump operates.
All pumps shall be capable of being started and stopped manually. All pumps shall be primed automatically at all times. This will be effected if the pumps are sited so that at least two thirds of the effective capacity of the suction tank is above the level of the centre of pump suction. Where this is not possible, separate priming tanks maintained automatically and foot valves shall be provided for each pump. Pumps which are automatically controlled shall be provided with a reliable float-operated air release or equivalent valve not less than 12mm in size, to automatically release air from the pump. Means must be provided to allow a continuous flow of water through each pump at a sufficient rate to prevent overheating of the pump when churning. The pump motor capacity shall be such that the maximum motor current in any phase under any condition of pump load and voltage unbalance shall not exceed the motor-rated full-load current multiplied by the service factor. The maximum service factor at which a motor can be used is 1.15. These service factors shall be in accordance with NEMA Standard MG-1. A test valve and direct reading flow meter shall be provided on a pipe connection coupled to the pump delivery branch downstream of the check valve to test the pump. The test piping shall be sized not less than the meter size appropriate to the pump rated capacity. The test piping shall discharge to a suitable drain. A discharge pressure gauge shall be connected to the discharge of each pump. The gauge shall have a valve with arrangement for draining. Its indication dial shall have a range of at least twice the rated working pressure of the pump.
BLDG12/S44.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 44-8 44.4.3
Wet Rising Main Pumps (Cont’d) All electrical wiring, including that for the control and monitoring circuits shall be in accordance with PUB requirements and shall be : (a)
of the fire-resistive type complying with SS 299 or
(b)
enclosed in a 2-hour fire-rated duct throughout the run to the pump room.
A fire-rated duct may house electrical wiring for other emergency services if the running of the wiring does not affect the fire-integrity of the duct. The sharing of a common electrical rising main for the wet rising main and other emergency services is acceptable provided that there is proper protection by fuses or circuit breakers for each and every emergency service. Any switches on the power feed to the motor shall be locked "ON" and clearly labelled "WET RISING MAIN PUMP - NOT TO BE SWITCHED OFF IN THE EVENT OF FIRE". Acoustic treatment shall be provided to reduce the noise generated from the pump to be within the MEWR guideline. The proposal for noise reduction shall be approved by the SO Rep before the actual commencement of the pump room pipework installation.
44.4.4
Wet Rising Main Pumps Control Panels The Contractor shall prepare fully detailed control wiring diagram for the approval of the SO Rep prior to the manufacture of control panels. Provision at the Wet rising main pump Control Panel shall include but not limited to the following : (a)
For each and every pump, indicating lamps shall be provided to show that power supply is available on every phase of each motor. Power failure on any phase of the supply to the wet rising main pumps shall be automatically indicated on the control panel.
(b)
MANUAL/OFF/AUTO rotary selector switches shall be provided for each pump.
(c)
"Start" and "Stop" push-button switches shall be provided for each pump.
(d)
Lead/Lag rotary functions shall be provided for the selection of the duty pumps.
(e)
"Running" and "stop" indicating lamps shall be provided to each pump. Green colour lamps shall be provided to show the pump "Running" status and red colour lamps shall be provided to show the "Stop" status.
(f)
Start push button shall be provided for each pump to close the main contactor for the pump motor mechanically independent of any control circuit.
(g)
Indicator lamps giving indication of the failure of each wet rising main pump to start as monitored by the flow switch at each pump discharge.
(h)
Indicating lamps giving indication of 'Pump on Demand' as controlled by the pump actuation pressure switches. The starting of the pump shall not cancel the indication.
(i)
Remote visible and audible indication panel besides the main control panel, if any for the following conditions : (i) (ii) (iii) (iv) (v)
(j)
BLDG12/S44.DOC(8) Sal(151211) (DPD)
Pump on demand Operation of each wet rising main pump Power failure on any phase of the supply to each wet rising main pump Pump fails to start as monitored by the flow switch at each pump discharge Manual and auto mode selection
Indicating lamps shall be provided to show the high and low water level of the wet rising main storage tanks.
Bldg Spec Page 44-9 44.4.4
Wet Rising Main Pumps Control Panels (Cont’d) (k)
Indicator lamp and buzzer/bell test push button.
(l)
Fault alarm facilities in addition to the indicator lamps shall be provided for the following conditions : (i) (ii) (iii) (iv)
Power failure on any phase of the supply to each pump Pump fail to start High and low level at suction and storage tanks Other faults not mentioned above
The fault alarm facilities shall incorporate a fault alarm buzzer audible from 10m away and a buzzer muting switch. The visual fault alarm indication shall persist unless the fault is rectified. The occurrence of a further different fault while the buzzer is silenced shall cause the buzzer to resume the sound again. The restoration of the silencing switch to its normal position whilst a fault exists shall transfer the fault back to the audible fault warning. In addition, a weatherproof red light bulb with wire guard shall be installed outside the pump room near the entrance to indicate the above fault conditions. (m)
44.4.5
Auxiliary contacts to generator panel to be provided. Volt-free contacts and wiring to relay signals to Fire Indicator Board where applicable.
Jockey Pump Control Panel The jockey pump controllers shall be used for pressure maintenance in the installation to prevent unnecessary cycling of the wet rising main pumps. The jockey pump controller shall either be housed in a separate compartment within the wet rising main pump controller or in a totally separate sheet steel cubicle. The jockey pump controllers shall incorporate incoming MCCB protection, starter with thermal overload relay, contactors, control relays and the following facilities :
44.4.6
(a) (b) (c) (d) (e) (f) (g)
Indicator lamps to show that power supply is available on every phase of the motor Auto/OFF/Manual rotary selector switch 'Run' and 'stop' indicator lamps 'Start' and 'stop' pushbutton Pump 'Overload' indicator lamp Connections to pressure switch Minimum running period timer to prevent frequent automatic starting of the pump. The timer shall be set to keep the motor in operation for at least one minute and interlock with the pressure switch.
(h)
Fault alarm facilities shall be provided to indicate fault conditions of pump overload, pump power supply failure on any phase and pump fail to start.
Wet Rising Main Transfer Pump Control The Contractor shall prepare fully detailed control wiring diagram for the approval of the SO Rep prior to the manufacture of control panels. The transfer pump controllers shall incorporate incoming MCCB protection, starter with thermal overload relay, contactors and control relays. Provision of transfer pump Control Panel shall include but not limited to the following : (a)
Indicator lamps to show that power supply is available on every phase of the motor
(b)
Auto/OFF/Manual rotary selector switch
BLDG12/S44.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 44-10 44.4.6
Wet Rising Main Transfer Pump Control (Cont’d) (c)
'Run' and 'stop' indicator lamps
(d)
'Start' and 'stop' pushbutton
(e)
Pump 'Overload' indicator lamp
(f)
Connections to pressure switch
(g)
Fault alarm facilities shall be provided to indicate fault conditions of pump overload, pump power supply failure on any phase, pump fail to start and high and low water level.
44.5
TEST
44.5.1
Tests On Rising Main System The Contractor shall submit an application to the SO Rep to witness the inspection and commissioning test of the complete installation. The application shall include information on the testing appointment date and statement of completion of the whole Works by the Contractor. The appointed date shall be at least 2 months before the date of Substantial Completion of the building block. For wet rising main system, the Contractor shall provide the complete information as produced in Appendix A30 and submit two copies to the SO Rep one week before the testing of the system.
44.5.2
Static Pressure Test The Contractor shall ensure that the system is in order so that water is allowed to flow through it discharging via the topmost and/or lowest outlet to flush out any debris that may be present. The system shall then be completely charged with water to a hydrostatic pressure according to CP 29 (Clause 8.1) for 2 hours. During this period, an inspection of the system shall be made to check that no leakage of water is taking place at any of the joints or landing valves. The system shall also be charged to the working pressure and at selected landing valve to be tested for operational requirements with matching water hose. Landing valves shall be tested randomly on the proper engagement with matching water hose and hose coupling. Provide diesel driven pump for the tests. Alternatively, electric driven pump may be used but the Contractor shall arrange for its own power supply. The Contractor shall arrange for all the necessary parties such as the FSSD to witness the test as and when required. Provide water and all the necessary instruments such as water hose, hose coupling, pressure gauges for the testing. Water from the domestic water tank shall not be used. The Contractor shall find other means of providing the water subject to the approval of the SO Rep. Instrument for the testing shall be properly calibrated by PSB or PSB accredited laboratory. The Contractor shall ensure that all pipes are securely anchored before carrying out any pressure test.
BLDG12/S44.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 44-11 44.5.3
Flow Test (Wet Rising Mains Only) The following minimum water supply flow-rate shall be maintained in the wet rising system when 3 landing valves within the system are in the fully-open position : (a) (b)
27 litres per second for a residential building. 38 litres per second for a non-residential or mixed occupancy building.
A minimum running pressure of 3.5 bar and a maximum of 5.5 bar shall be maintained at each landing valve when any number, up to three, are fully opened. When water is shut off at the nozzle of the hose connected to a landing valve, the static pressure in that hose line shall not exceed 8 bar. When more than one wet rising main is required in any zone in a building, the minimum water supply flow rate shall be as stated below :
44.5.4
(a)
For a residential building, 27 litres per second for the first rising main and 13.5 litres per second for each additional rising main, subject to a total maximum supply rate of 135 litres per second.
(b)
For a non-residential or mixed occupancy building 38 litres per second for the first rising main and 19 litres per second for each additional rising main, subject to a total maximum supply rate of 190 litres per second.
Performance Test The Contractor shall submit to the SO Rep two copies of the test results using approved HDB Testing Form. Additional FSSD requirements shall also be included. Provide a minimum of seven days notice to the SO Rep to verify the test results on the Site and demonstrate to the SO Rep that the installation fulfils the function for which it has been designed. Adjust, balance and regulate the Works concerned as necessary until the required conditions are attained. Should the SO Rep find discrepancies between the recorded test results and the measurements demonstrated on the Site, the test shall be repeated by the Contractor to the satisfaction of the SO Rep. The test shall be witnessed by the Contractor together with the SO Rep. The testing form shall be endorsed by the QP.
44.5.5
Remedial Action And Re-Testing Remedy all Defect within such time as instructed by the SO Rep and arrange for a re-test of the system.
44.6
SERVICING AND MAINTENANCE PROCEDURES FOR DRY RISING MAIN The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance service and call-back service to the dry rising main system as specified hereafter for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period") for the purposes of this clause including all sub-clauses under it. Whenever, the rising main system or any portion thereof is out of service for any reason, notice shall be given immediately to the Singapore Civil Defence Force and a suitable sign shall be displayed at a prominent position. When the installation is reinstated, the Singapore Civil Defence Force shall again be informed. All parts and equipment comprising the complete system shall be maintained and inspected strictly as specified hereafter and in accordance with the check-list as set out in Appendix A31. The check-list shall be duly completed by the Contractor when performing the routine inspections. Any Defect detected shall be rectified by the Contractor immediately. Always arrange for a Representative from HDB Branch Office to be present during these inspections.
BLDG12/S44.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 44-12 44.6
SERVICING AND MAINTENANCE PROCEDURES FOR DRY RISING MAIN (CONT’D) Furnish to the HDB Branch Office a Maintenance Schedule for the inspections upon Substantial Completion of the Works or phase or sub-phase of the Works. The Contractor's Supervisor shall also sign on the log book in the pump room after completion of each inspection. For inspections at every 6 months, rectify any Defect found after the following inspections : (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x)
Check and verify operation of breeching inlets. Check that breeching inlets and landing valves are not obstructed. Check and verify that landing valves are fully closed and the handwheel are strapped locked. Check that valve caps are secured in position. Check rubber washers of the outlets and replace them if missing. Check handwheel to ensure that they are not jammed, missing or broken. Inspect the earthing connection and tighten it if necessary. Check for damaged and any leakage of pipes, landing valves Check the valve cabinets for damage. Any other inspection as instructed by the SO Rep.
In addition, wet tests shall be carried out annually when the main can be checked for leaks.
44.7
SERVICING AND MAINTENANCE PROCEDURES FOR WET RISING MAIN SYSTEM The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance service and call-back service to the wet rising main system as specified hereafter for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period") for the purposes of this clause including all sub-clauses under it. All parts and equipment comprising the complete system shall be maintained and inspected strictly as specified hereafter and in accordance with the check-list as set out in Appendix A32. The check-list shall be duly completed by the Contractor when performing the routine inspections. Any Defect detected shall be rectified by the Contractor immediately. Always arrange for a Representative from HDB Branch Office to be present during these inspections. Furnish to the HDB Branch Office a Maintenance Schedule for the inspections upon Substantial Completion of the Works or phase or sub-phase of the Works. The Contractor's Supervisor shall also sign on the log book in the pump room after completion of each inspection. Maintenance of wet rising mains shall include the requirements as specified in Clause 44.6 "Servicing And Maintenance Procedures For Dry Rising Main" including all subclauses under it. In addition, the following checks are also required : (a)
Monthly Tests Inspect and service all machinery and equipment comprising the complete Plant and ancillary equipment under this Contract once a month set out in the code of practice, except where otherwise directed by the SO Rep. At each such monthly inspection and service of the complete Plant and ancillary equipment, the minimum items of Works detailed below and in the relevant code of practice shall be performed by the Contractor. Any special maintenance requirements to Plant and equipment not covered by the following list but recommended by the manufacturers shall deemed to be included.
BLDG12/S44.DOC(12) Sal(151211) (DPD)
Bldg Spec Page 44-13 44.7
SERVICING AND MAINTENANCE PROCEDURES FOR WET RISING MAIN SYSTEM (CONT’D) (a)
Monthly Tests (Cont’d) (i)
BLDG12/S44.DOC(13) Sal(151211) (DPD)
Inspect all water pumps, and (1)
Check all seals, glands and pipe lines for leaks, and rectify as necessary.
(2)
Check all pump bearings and lubricate with oil or grease as necessary.
(3)
Check the alignment and condition of all rubber couplings between pumps and drive motors, and rectify as necessary.
(4)
Check all bolts and nuts for tightness, and tighten as necessary.
(5)
Check and verify the automatic starting of each pump by actuating the drain and test valve in a manner to reduce the applied water pressure and the starting device and simulate a fire condition. Record that the pressure is correct. Keep each pump running for a period of at least five minutes and verify the operation of the relief valve.
(6)
Check and verify pump running alarm and phase failure alarm.
(7)
Check pump starting equipment including fuses, circuit breakers and starters.
(8)
Conduct a running pressure test of each pump at full alarm condition by opening the test valve of the pump testing pipe and recirculate water back to the water tanks. Run each pump for a period of not less than 1 minute.
(9)
Simulate failure on one of the pump and verify the operation of the duty-standby changeover mechanism.
(10)
Check and verify no excessive noise and vibration of each pump and motor whilst the unit is running.
(ii)
Inspect and lubricate with grease as necessary all electric motors.
(iii)
Inspect and check the routine operation of all electrical starters, electrical control gears and ancillary electrical apparatus, and
(iv)
Inspect and check the routine operation of all automatic controls, gears and relays, and
(v)
Inspect all water suction and storage tank and drains, clean and flush out the tank as necessary. Check that stop valve and tank inlets interconnecting pipes and pump suction pipes are secured fully open. Verify the operation of the automatic tank filling mechanism. Visually check that tank contains requisite amount of water and verify operation of floatless level control units.
(vi)
Check and inspect breeching inlets.
(vii)
Check and verify operation of water level indicators.
(viii)
At the monthly inspection of control valves, a gauge showing water pressure in the system shall be read to make sure that normal pressure are being maintained - check the gauges with an inspection gauge once a year.
Bldg Spec Page 44-14 44.7
SERVICING AND MAINTENANCE PROCEDURES FOR WET RISING MAIN SYSTEM (CONT’D) (b)
Quarterly Test For quarterly testing, servicing and maintenance, repeat all the testing, servicing and maintenance requirement as specified in Clause 44.6 "Servicing And Maintenance Procedures For Dry Rising Main" including all subclauses under it and subclause 44.7(a) "Monthly Tests" above. In addition, provide the servicing and maintenance as detailed below :
44.8
(i)
Check any relays for correct adjustment and quick effective operation.
(ii)
Thoroughly check the whole system for loose connections, terminals, frayed wires, etc.
(iii)
Replace any broken or faulty equipment as may be required.
(iv)
Enter test results and details of any faulty components, repairs and replacements in the log book.
(v)
Every pump tank shall be completely flushed out and thoroughly cleaned annually. Other maintenance as recommended by the tank supplier shall be carried out. The stays, cleats, bolts and nuts, surface of the plates and other accessories of the tank shall be examined for rust, corrosion, crack, etc.
(vi)
The water in the whole pipework system shall be completely drained out and filled with fresh water again.
(vii)
Meggar test the motor winding cables and wiring to check the insulation resistance between phase to phase and phase to earth.
SERVICING AND MAINTENANCE SCHEDULE For routine tests and inspection during the Defects Liability Period, all parts, Plant and equipment comprising the complete rising main system shall be maintained and inspected strictly in accordance with the specifications and check-list as set out in Appendix A31 and A32. The check-list shall be duly completed by the Contractor when performing the routine inspection. Any Defect detected shall be rectified by the Contractor immediately. Always arrange for a Representative from the HDB Branch Office to be present during the inspection. Furnish to the HDB Branch Office a Maintenance Schedule for the routine inspection upon Substantial Completion of the Works or phase or sub-phase of the Works.
44.9
CALL-BACK SERVICE During the Defects Liability Period, provide an efficient 24 hour (whole day) call-back service. All urgent calls or complaints shall be attended to immediately upon notification by the Representative from the Essential Maintenance Service Unit or Branch Office. The Contractor shall provide a mobile phone for his maintenance supervisor and the mobile phone number shall be given to the respective Branch Office so that immediate notification of any urgent callback service can be met. In the event that the Contractor fails to : (a) (b) (c)
respond within 30 minutes after being called; or attend to an urgent call or complaint immediately upon notification; or carry out the routine inspection of the rising main system;
the SO Rep may engage another contractor to carry out the Works and all costs and charges shall be recoverable from the Contractor by the Employer or deducted by the Employer from monies due or becoming due to the Contractor. Notwithstanding the above, the SO Rep may in addition exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. In the event that other contractors are instructed to rectify Defect in the rising main system or to carry out the routine servicing and maintenance of the rising main system due to or arising out of the Contractor's failure to do so when directed by the SO Rep, such actions shall not in any way affect, vary or relieve the Contractor's obligations under the Contract. BLDG12/S44.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 44-15 44.10
MAKING GOOD DEFECTS AND LEAKAGES During the Defects Liability Period, make good all Defect and leakages found in the system and installation. Replace and/or repair all defective parts or items as produced in Appendix A29 whenever required if such replacement or repair has been necessitated by the reasons of Defect of the system and equipment. The Contractor shall have a supervisor-in-charge of the service, maintenance and repair work to be carried out. The supervisor shall be thoroughly competent in supervising the service, maintenance and repair of rising main systems and the workmen shall also be skilled in the service, maintenance and repair of rising main systems.
44.11
RECTIFICATION OF DEFECTS PRIOR TO ISSUANCE OF MAINTENANCE CERTIFICATE One month before the expiry date of the Defects Liability Period, the Contractor shall arrange with HDB Branch Office and the SO Rep for a final joint inspection. All Defect listed after this joint inspection shall be rectified by the end of the succeeding one month commencing from the expiry date of the Defects Liability Period. Rectify the outstanding Defect and conduct detailed checks on the Works before arranging for inspection by the Representative from HDB Branch Office for the purpose of certifying completion of rectification of Defect. After the second final inspection by the Representative from HDB Branch Office, a list of outstanding Defect shall be issued to the Contractor and the Contractor shall rectify all Defect on the list within fourteen days. If the Contractor fails to rectify and make good the Defect on the second final inspection, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. Notwithstanding the above, the Employer shall in addition have the right to engage his own workmen or other contractors to rectify and make good all Defect and the cost of rectification and charges imposed shall be recovered from the Contractor.
44.12
LOG BOOK Keep a log book at the pump room in which details of all alarms (genuine, practice test or false), faults, tests, routine maintenance and repairs carried out shall be recorded. The type of log book and the record format shall be subject to the approval of the SO Rep.
44.13
CONSUMABLE MATERIALS Provide the following consumable materials as and when required during the Maintenance Period : (a)
All oils and grease required for lubrication of pump bearings, motor bearings, pivots and other moving parts.
(b)
All carbon brushes required to replace worn brushes in electric motors.
(c)
All electric contact points required to replace those points in switch gears, motor starter gears, electric control gears and electric relays.
(d)
All indicating lamps required to replace blown lamps.
(e)
All cotton waster, soap detergent and other cleaning materials required for cleaning purposes.
BLDG12/S44.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 44-16
44.14
FIRE PUMPS/MOTORS FOR USE IN WET RISING MAINS AND TRANSFER PUMPS/MOTORS The fire pumps/motors for use in wet rising mains and transfer pumps/motors shall be tested by approved accredited laboratory and UL(Underwriter Laboratories Inc.), FM (Factory Mutual Approvals). The pumps/motors shall be selected to meet design as well as maximum flow requirements. All pumps and control panels shall be mounted on at least 150mm height plinths. Spring type vibration isolators shall be provided for each pump to ensure minimal vibration transmission to the building structure. The first three pipe supports from the pump discharge shall be the spring mounted type. Pump control panels near/below pipework shall be protected from water leakage/splash.
Section 45/.....
BLDG12/S44.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 45-1 SECTION 45 FIRE PROTECTION INSTALLATION
45.1
DEFINITIONS "Electrical Worker" shall mean a qualified competent person to perform electrical work under the Electricity Act (Cap. 89A).
45.2
SCOPE OF WORK
45.2.1
General The fire protection installation Works shall include the provision, installation, testing, commissioning and maintenance of the Fire Fighting and Protection Installation. Unless otherwise specified, the Works shall include : (a)
Fire hose reel system (complete with hose reel, suction tanks, pressure tanks and pumpset)
(b)
Portable fire extinguishers (where applicable)
(c)
Fire hydrants
Pipes shall be made of steel in accordance with BS 1387. However, the pipework for hose reels with direct water supply from PUB mains shall be copper or stainless steel, notwithstanding other provisions specified in this Section including all clauses and subclauses under it. For hose reels with direct water supply from the PUB mains, pumpset and its associated Works including suction tanks and pressure tanks shall not be part of the scope of fire protection installation Works for the purposes of this Section including all clauses and subclauses under it. The Drawings shall in part be diagrammatic and when read in conjunction with the Specifications shall be intended to convey the scope of the Works, indicate the general arrangement of Plant, piping, and the like, and show approximate sizes of Plant and outlets. The Contractor shall follow the Drawings as closely as practicable in laying out the Works and in so doing shall co-ordinate all systems to secure the best possible installation in the available space. Where Works is specified but the exact location of Plant or control is not specifically shown, obtain the approval of the SO Rep prior to the installation. It is the intent of the Drawings and Specifications to provide a complete operating system, unless specified otherwise. The omission from the Specifications or Drawings of any details in construction, installation, materials, or specialities necessary for a complete operating and safe system shall not relieve the Contractor from the provision of a complete operating and safe system. The Contractor shall provide all technical data as produced in Appendix A33.
45.2.2
Regulations And Codes Of Practice Provide and install the fire hose reel system in accordance with BS 5306 : Part I, EN 671-1, SS CP 29 and the requirements of local governing authorities such as BCA, FSSB and PUB. The Contractor shall engage a company/firm which is registered with the BCA under the registration head of ME06 (Fire Prevention & Protection System) and shall be responsible for all applications to and arrangements with the local authorities such as PUB and FSSD representatives for the necessary completion, testing and commissioning of the installation for each building under the Works and all costs in connection therewith shall be deemed to have been included in the Contract Sum. Should the requirements of the Drawings or Specifications conflict with codes, regulations or standards, of the relevant authorities, the most stringent of the requirements shall govern the Works.
BLDG12/S45.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 45-2 45.2.3
Weatherproof And Flameproof Designs Where any apparatus forming part of the installation is situated outdoor or subjected to damp condition, such apparatus shall be of weatherproof design. Where any apparatus forming part of the installation is sited in an area where flammable vapour of explosive gas is liable to occur, such apparatus shall be of flameproof construction.
45.2.4
Provision Of Openings For Electrical Wirings Provide structural openings through walls, floor and roof for the installation of pipework and electrical wiring. Make good such openings with non-combustible and waterproof material to the satisfaction of the SO Rep.
45.2.5
Painting Galvanised steel pipes and fittings shall first be treated with one coat of polyvinyl butyral etching primer and one coat of lead and chromate free primer and then painted with two coats of approved enamel paint.
45.2.6
As-built Drawings And Details Of Pumping Plant During the progress of the Works, the Contractor shall record and update all Fire Protection System Installation, pipe routes, plants, legends and all other related works based on actual site installations for the production of as-built drawings. The Works shall only commence upon approval by the Consultant but additional approval shall be sought before any deviations from the approved proposal can be carried out, failing which the whole installation may not be accepted by the Consultant. The approval of the proposal shall in no way relieve the Contractor of his responsibility should the Plant or any of its parts proved inadequate in any aspect.
45.2.7
Quality Of Goods And Materials The quality of goods and materials shall comply with the requirement and regulations of the HDB and the relevant Authorities and shall also comply with the relevant Codes of Practices as stipulated. All materials used shall be of the approved type unless otherwise specified. Where products are manufactured under the PSB Batch Inspection Scheme, additional testing shall not be necessary unless otherwise specified. The Consultant shall be consulted when in doubt. Prior to the installation of hose reels at the Site, where corrosion test is not conducted under the PSB Batch Inspection Scheme, the Contractor shall arrange to submit a sample under the same batch to PSB for the test. The test report shall be submitted to the Consultant. Any other relevant requirements issued by the FSSD shall be complied with.
BLDG12/S45.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 45-3 45.3
FIRE HOSE REEL SYSTEM
45.3.1
General (a)
Installation Fix the hose reels so that the centre is between 0.75 metre and 1.4 metre above floor level. Mount the hose reels on a swivel bracket suitable for mounting in a 1.6mm thick sheet steel hose reel cabinet or recesses clearly marked with "FIRE HOSE REEL" in white letters of at least 50mm high. Hose reel cabinet or recesses shall be painted red. Any doors provided for hose reel cabinet or recess shall be so hinged that they open approximately 180 degrees and they shall not obstruct the running out of the hose in either direction. The door shall have a 4mm glass front with spring locked to open from within. The Contractor shall provide five sets of master keys to the Employer. Where the hose reel is within a service duct, a signplate with the words "FIRE HOSE REEL" in white letters of at least 50mm height shall be displayed on the door.
(b)
Rubber Hose The rubber hose shall be of 25mm internal diameter and shall have a minimum working pressure of 7 bars and shall be of the non-kinking type. The rubber hose shall be manufactured with an inner tube or lining, a reinforcement braided with textile material and an abrasion resistant rubber cover. The reinforcement shall consist of a single rayon braid or double braid of cotton. The length of rubber hose on the reel shall be 30 metres. There shall be no joints in the length of the hose. Samples and certification shall be provided to verify that the hose supplied is manufactured according to the requirements of BS 3169/EN 694.
(c)
Stop-Valve Provide and fix 25mm stop-valve for the connection of the hose reel to water supply. An indication of the open and shut position shall be fixed or permanently marked on the wheel of the valve, and the body of the valve except for gate valves which shall be marked with a directional arrow indicating the direction of flow through the valve.
(d)
Shut-Off Nozzle Provide a shut-off nozzle assembly in accordance with the following requirements :
BLDG12/S45.DOC(3) Sal(151211) (DPD)
(i)
The assembly shall be constructed of a corrosion resistant metallic material or other materials approved under EN 671-1.
(ii)
In the absence of a hose reel cabinet, means shall be provided for the secure attachment of the assembly in a locked enclosure in such a manner that it cannot be disengaged until the enclosure has been opened.
(iii)
The assembly shall be permanently marked to indicate the open and shut position of the valve.
(iv)
The internal surface of the nozzle shall be finished to provide a smooth surface.
(v)
The internal diameter of the nozzle shall be 6.35mm.
Bldg Spec Page 45-4 45.3.2
Hose Reel
45.3.2.1
General The hose reel shall extend not more than 350mm from the mounting surface and shall have an overall diameter not greater than 760mm. The side plates of the hose reel shall have a continuous outer rim and shall be rigid in construction. The side of the reel shall be painted red. The diameter of the inner core on which the hose is wound shall be not less than 200mm. When the full length of the hose is coiled on the hose reel without the use of abnormal tension, the rim of the side plates of the hose reel shall project at least 10mm beyond the external diameter of the coiled hose at any point. The fittings to which the hose are attached on the hose reel shall be arranged in such a manner that the hose is not restricted or flattened by the application of additional layers. The water connection through the rubber hose shall permit the full flow of water to the hose without external leakage during any rotation of the hose reel. The hose reel waterways connecting the water supply to the hose, including the inlet pipe after the stop valve, shall be constructed of non-ferrous material and/or stainless steel and/or galvanised steel. Where hose reels are within service ducts, they shall be mounted such that their operations are not hindered. The mounting position shall be approved by the SO Rep. The clips used to attach the hose to the nozzle and the drum shall be galvanised ear clips.
45.3.2.2
Markings Mark every hose reel with the following information : (i)
The manufacturer's name, trade name or mark.
(ii)
Instructions for operation and use which shall include the following : (1) Turn on stop valve (2) Run out hose (3) Turn on water at nozzle (4) The hose shall be fully charged before winding it onto the reel (5) The year of manufacture (6) The test pressure in Bar
All notices and instructions shall be weather and corrosion resistant and shall be set out in letters easily readable. In addition, the operating instructions "For Emergency Only : Break glass to open the door from inside" and "TO TURN ON THE INLET VALVE BEFORE RUNNING OUT THE HOSE" shall be of 12mm height and printed in white on the hose reel cabinet. Where there is no cabinet, the same notice shall be provided on a 2mm thick aluminium plate affixed to the wall adjacent to the reel. 45.3.2.3
Tests The hose reel shall be factory tested against water leakage after assembly at a test pressure of 13.8 bars (200 psi). The Contractor shall furnish documentary evidence of such factory test to the SO Rep before delivery of the hose reels to the Site on request by the SO Rep.
45.3.3
Pumpset (a)
Hose Reel Pumpset The hose reel pumpset shall consist of two sets of fire pumpsets, one duty and one standby to the approval of the SO Rep. Pumpsets shall be of centrifugal multistage vertical pumps. Notwithstanding the above requirements, single stage centrifugal end suction pumps shall be used where applicable. The pumps shall have stainless steel shafts and mechanical seals and shall be driven through flexible couplings by electric motors with speed of not more than 3000 rpm. Each pump shall be capable of providing a flow of water of at least 0.8 litres per second in the rising main.
BLDG12/S45.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 45-5 45.3.3
Pumpset (Cont'd) (a)
Hose Reel Pumpset (Cont'd) Multistage vertical pumps shall have stainless steel outer sleeve and the suction/discharge casing shall be of cast iron. The pump impeller shall be of either stainless steel or bronze. Each pump shall also be capable of being started or stopped manually. The standby pump shall be so arranged that it will operate automatically on failure of the duty pump. The pumpsets shall be able to withstand 20 times start/stop per hour. Provide each pump with a ball valve and flexible connection at both the suction and discharge ends, a spring loaded check valve at the discharge end and a strainer at the suction end. The suction and discharge connections shall be flanged. Screwed suction and discharge connections shall have flange adaptors. Provide pressure gauges at the main discharge pipe. The gauge shall have a range of at least twice the rated working pressure of the pump. All pumps shall be automatically primed at all times. This shall be activated if the pumps are sited so that at least two thirds of the effective capacity of the suction tank is above the level of the centre of pump suction. Where this is not possible, provide separate priming tanks with foot valves for each pump. Submit to the SO Rep for approval the characteristic performance curves of the pumps offered. The efficiency of the pumpset shall not be less than 50% at the operating conditions. Mark each pump conspicuously and permanently with letter "P1" or "P2" to the satisfaction of the SO Rep. Provide and install all the pipework and accessories connecting the pumpsets to the suction tank and hose reel riser. Provide spring type vibration isolation mounting for each pump to ensure minimal vibration transmission to the building structure.
(b)
Hose Reel Pumps Controls Provide, install, connect and test all necessary starting and control equipment. Enclose all such equipment in a front connected wall mounted and manufactured from electrogalvanised sheet metal of minimum 1.5mm thickness IP54 cubicle with full locking hinged door. The cubicle shall be painted in accordance with sub-clause 45.3.6(h)(iv) "Painting". The sequence of operation of the hose reel pumps shall be as follows : (i)
The duty pumpset shall automatically come into operation when a pressure switch located in the branch out pipe feeding the two pressure tanks detects a fall of normal static pressure in the pipe below a predetermined value.
(ii)
If the duty pump fails to start or the demand for water exceeds the nominal output of the duty pump (ie. when three or more hose reels operate simultaneously), this drop in pressure shall be sensed by another pressure switch located adjacent to the first pressure switch, which shall then start the standby pump. The exact cut-in pressure of the standby pump shall be varied according to the normal system pressure and the performance curve of the pump.
(iii)
As the requirements for water reduces, the pressure in the system increases. When there is no demand to the system and the normal static pressure has been established, this preset pressure shall be sensed by both pressure switches and the duty and standby pump shall be switched off respectively. After each start/stop pumping cycle, the duty pump shall be alternated automatically by the use of an auto changeover relay to avoid one pump remaining stationary for long period. Provide a manual selector switch to select the duty or standby pump.
BLDG12/S45.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 45-6 45.3.3
Pumpset (Cont'd) (b)
Hose Reel Pumps Controls (Cont'd) Provide a 7-Day Dial, 2-Hour Dial time switch to start the pumps running for a pre-set duration of time weekly. At a pre-set time of each week, the time switch shall energise the coil of a solenoid valve for a pre-set period of time. The solenoid valve shall be located in a by-pass pipe connecting the main discharge line with both the suction tanks. As the solenoid valve is opened, water shall be forced to flow back to the water tanks by the system pressure which will then reduce progressively. This drop in system pressure shall be sensed by the pressure switch which shall then start the duty pump and the standby pump. Each pump shall be activated after the other when the solenoid valve is opened at two different pre-set times on the time switch. Provide a globe valve to throttle excessive pressure upstream of the solenoid valve. Install a ball stop valve to enable manual test run of the pumpsets and a pressure relief valve to avoid excessive build-up of system pressure in parallel with the solenoid valve. Use the third pressure switch installed next to the above two pressure switches to initiate an audible and visual alarm in the event that the normal pressure in the pipe falls to 1 bar. The controller shall be fully wired and mounted within the cubicle requiring only incoming supply, necessary control and alarm connections. The following starting and control equipment shall be incorporated in the cubicle : (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) (xii) (xiii) (xiv) (xv) (xvi) (xvii) (xviii) (xix)
1 no. ON/OFF isolating switch for incoming. 1 no. MCB unit for incoming. 2 sets ON/OFF isolators, each completed with MCB unit for starters. 2 no. direct on line starters. 2 no. thermal overload relays with ambient temperature compensation. 1 no. rotary selector switch for AUTO/MANUAL selection. 1 no. pump selector switch. 2 sets START/STOP button switch for the starters. 8 no. MCB units for control circuits. 1 no. automatic change over relay (100% continuous rating). 2 no. relays to activate alarm bell for motor overload trip. 1 set of cancel alarm pushbutton and cancel alarm relay. Relays to control the pumpsets. 1 no. water tank low level warning light. 1 no. power supply on light. 2 no. pump "RUN" indicating lights. 2 no. pump "TRIP" indicating lights. 1 no. low pressure warning light. 1 no. 7-Day Dial, 2-Hour Dial Time Switch to control the weekly running of the pumpsets. (xx) Voltage-free contacts to relay signal to remote fire indicator board and initiate a fire alarm when flow switch is actuated. (xxi) 2 no. relay for lamp and bell test. (xxii) 1 no. pushbutton for lamp and bell test. (xxiii) 1 no. 230V/24V AC transformer. (xxiv) Terminal block for connection to remote equipment. Submit the control circuit diagram for approval before the installation. Provide the pressure switch settings on a 240mm x 150mm perspex sheet mounted by self-adhesive tape. The details and locations shall be approved by the SO Rep.
BLDG12/S45.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 45-7 45.3.4
Pipes & Fittings (a)
Scope This subclause sets out the requirements, standards of workmanship and materials in general for the piping system for the hose reel system.
(b)
General Before delivery to the Site, clean all pipes thoroughly so that they are free from scale and rust. Reject old and damaged pipes and use only new pipes. On the Site, all pipes shall be checked again and thoroughly wire brushed and prime coated prior to the installation. Install all pipework so that clearance of approximately 80mm is left between the outside of the pipe and the nearest wall, ceiling or equipment surface, whenever possible. Pipe joints or fittings shall not be permitted within the thickness of walls, floors, any partitions or below a beam.
(c)
Materials Provide and install all pipework as indicated in the Drawings. The internal and external surfaces of the pipes and fittings shall be clean, smooth and free from Defect that would impair their performance. Cutting, bending and fixing shall be in strict accordance with the manufacturer's instructions. Pipes shall be factory marked with the manufacturer's name or identification mark and classification of pipes. Any unmarked pipes shall not be accepted. Lay pipes outside buildings underground, and the depth of cover measured from the top of the pipe to the finished surface of the ground level shall not be less than 750mm. Stainless steel pipes shall comply with BS 4127:Part 2. Stainless steel pipe fittings shall be of capillary fittings and compression fittings in accordance with BS 864:Part 2. Fittings of 15mm and longer shall be legibly marked with the maker's name or trade mark. All stainless steel water pipes, fittings and accessories shall be approved by Water Supply (Network) Department, PUB. Ductile iron cement lined pipes shall comply with BS EN 545 and medium galvanised steel pipes shall comply with SS17. Joints and connections to galvanised steel pipework of up to and including 65mm diameter shall be made by means of screwed connections. Join pipes of 80mm diameter and above by means of flanged connections. Unless otherwise specified, use galvanised steel bolts and nuts for all supports and flanged connections. Flanges shall be raised face conforming to BS 4504. All flanges shall be flushed and aligned, and shall be made with corrugated jointing rings, coated on both sides with the recommended jointing compound. Use ductile iron cement lined pipes where pipes are concealed such as those within concrete slabs or below ground.
(d)
Valves All valves shall either be of bronze, brass or cast steel construction and conforming to the relevant British Standard and be suitable for the working pressure encountered. Where valves are located above 2m from the floor level or in an inaccessible location they shall be operated by chain mechanism. Valves used for working pressure above 19 bar shall be of the flanged type. All valves shall be located in accessible positions. Isolation valves of 50mm diameter and below installed along pipework inside the pump room shall be of ball stop valves approved by Water Supply (Network) Department, PUB. Valves up to and including 65mm diameter where connected to steel pipe shall be of brass/bronze with female screwed connections.
BLDG12/S45.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 45-8 45.3.4
Pipes & Fittings (Cont'd) (d)
Valves (Cont'd) Valves of 80mm diameter and above where fitted to steel pipes shall be of the flanged cast iron or ductile iron type. Check valves shall be of the spring loaded non-slamming type. The Contractor shall select these valves in relation to the velocity of the water in the pipe. In all cases the valve shall operate silently on reversal of water flow. Solenoid valve shall be of the normally closed, magnetically operated pilot type. Valve body shall be of brass or bronze and the solenoid coil shall be replaceable on Site without removing the valve body from pipe fitting. Install "Y-type" strainer upstream of the solenoid valve to trap any dirt and debris. The power supply of the solenoid valve shall be 24V AC 50Hz.
(e)
Strainers Install "Y-type" strainers upstream of all pumpsets. Provide all strainers with isolating valves so that the strainers can be cleaned without draining away the water of the system. Where a system cannot be shut-down for strainer cleaning, install by-pass in parallel to the strainer.
(f)
Pressure Gauges, Pressure Switches And Flow Switches Pressure gauges shall be of the 100mm diameter brass cased type. They shall be designed for pipe mounting and be provided with suitable gauge cocks and snubbers to prevent vibration of the needles. Pressure gauges shall conform to BS 1780 Part 2. Pressure gauges shall be of the Bourdon tube type and be calibrated in m-bar. Select suitable gauges for mid-range indications at normal working pressure and the maximum measurable pressure shall be twice the maximum working pressure. Pressure gauges shall have scales with divisions not exceeding 0.2 bar for a maximum scale value of 10 bars, not exceeding 0.5 bar for a maximum scale value of 16 bars, and not exceeding 1.0 bar for a maximum scale values in excess of 16 bars. Pressure switches shall comply with BS 6134 and shall be of automatic reset type. Install pressure gauge and pressure switches near to the pressure tanks. The enclosures of the pressure switches shall be of water tight IP 65 construction. Pressure switches shall be suitable for conduit construction and with terminal block for wire connection. Power supply for the pressure switches shall be 24V AC 50 Hz. Failure of pressurized components of the pressure switches shall not result in a build up of pressure within the enclosure. The parts in contact with water for the pressure switches and pressure gauges shall be of brass, stainless steel or other approved corrosion resistant materials. The pressure switch shall have adjustable and independent high and low pressure settings.
(g)
Pressure Tanks Two rechargeable pressure tanks of replaceable membrane type and pre-charged according to operating conditions shall be installed at the discharge of the pumps to keep the hose reel riser pressurized at any time. The pressure tank shall be of carbon steel, designed and fabricated to British Standard or Standard of American Society of Mechanical Engineers for Pressure Vessels. The Contractor shall furnish the design and detailed calculations for the proposed pressure tanks. The design and construction of the pressure tanks shall be subjected to the approval of the SO Rep. The pressure tanks shall be of the vertical type and the impermeable diaphragm shall be of heavy duty vinyl or butyl material.
BLDG12/S45.DOC(8) Sal(151211) (DPD)
Bldg Spec Page 45-9 45.3.4
Pipes & Fittings (Cont'd) (g)
Pressure Tanks (Cont'd) The system shall consist of two numbers of interconnected pressure tanks. The capacity of each tank shall not be less than 50 litres. The pump shall be started automatically by a pressure switch to recharge the pressure tanks in response to a drop of storage pressure below a pre-set value according to operating conditions. The pump shall be stopped automatically when the required storage pressure has been reached in the pressure tanks. Provide each pressure tank with safety relief valve. Technical details including the manufacturer, specification and pressure setting shall be labelled on metal or plastic plate attached to each of the tank.
(h)
Vibration Isolation Connectors All pipe connections to pumpsets and any equipment subjected to vibration shall be carried out by means of flexible neoprene connectors. Unless specifically permitted by the SO Rep, rigid connections between pipelines and equipment shall be rejected. Use neoprene or spring hangers from approved manufacturer for supporting pump delivery and return mains.
(i)
Pipe Supports And Fittings Support all pipework by pipe hangers and supports. Unless otherwise stated, all pipe hangers and supports shall be of mild steel adjustable for height. Vertical pipe risers penetrating through floor slab shall be supported to each floor by clamp or collars. All vertical pipe risers shall have foot elbows or concrete block supports at their lowest point. The spacing of fixings of pipe supports shall not exceed the following :
Material of Pipe
Diameter of Pipe (mm)
Maximum Spacing Horizontal (m)
Vertical (m)
Galvanized Steel Pipe
10 to 15 20 to 25 32 40 to 50 65 to 80
1.75 2.5 2.75 3.0 3.5
2.5 3.0 3.0 3.5 4.5
Ductile Iron Pipe
75 to 100
2.75
2.75
Stainless Steel Pipe
10 to 15 20 to 25 32 40 to 50 65 to 80
1.75 2.5 2.75 3.0 3.5
2.5 3.0 3.0 3.5 4.5
Fixing shall wherever possible be built into the building structure. Alternatively, they shall be secured to the building structure by means of expansion or power driven bolts.
BLDG12/S45.DOC(9) Sal(151211) (DPD)
Bldg Spec Page 45-10 45.3.4
Pipes & Fittings (Cont'd) (j)
Pipework, Testing And Cleaning All pipework shall be flushed with clean water before final topping up and putting into service. All pipework shall be hydrostatically tested to 10 bars or two times the working pressure whichever is the greater before lagging or putting into service. The test pressure shall be maintained for a minimum duration of 24 hours.
45.3.5
Suction Tanks (a)
General Tank supplying water for domestic purposes shall not be used as suction for hose reel installation. Lay a separate line from the PUB bulk meter position to supply water to the suction tanks or the fire hose reels directly in case boosting of the PUB water pressure is not required. The line shall serve the fire hose reel system only. To prevent contamination, provide approved double check valves assembly complete with drain cocks in accordance with the Drawings. The effective water capacity of two suction tanks with automatic inflow shall not be less than 1100 litres. Effective water capacity shall be labelled on the tanks as directed by the SO Rep. The tanks shall be constructed of reinforced concrete and flanged stainless steel (AISI Grade 316) pipe connections. The interconnecting pipes for the tanks shall be correspondingly aligned. Nominal pipe thickness for stainless steel pipe shall be 4mm complying with JIS G3459 Schedule 20S. Provide and install piping to each suction tank of nominal diameter as follows : (i) (ii) (iii) (iv) (v) (vi) (vii)
1 no. 54mm diameter stainless steel incoming pipe from PUB bulk meter; 1 no. 50mm diameter galvanised steel outlet pipe to fire hose reel booster pump; 1 no. 32mm diameter galvanised steel by-pass pipe; 1 no. 100mm diameter ductile iron washout pipe; 1 no. 100mm diameter ductile iron over-flow pipe. The over-flow pipe shall be connected to the washout pipe if suction tanks are situated at the 2nd storey and above. 1 no. 28mm diameter stainless steel over-flow warning pipe if suction tanks are located at 2nd storey and above; and 1 no. 100mm diameter cement mortar lined cast iron or ductile iron interconnecting pipe.
Provide a 100mm diameter UPVC air vent to each tank. All air vents shall be fitted with elbow end and covered by mosquito netting. Provide a 100mm diameter UPVC pipe to each tank for the mounting of level control electrodes. (b)
Level Control (i)
Ball Float Valve Approved 50mm equilibrium ball float valve shall be fitted in the suction tank and bolted directly to the incoming water supply pipe. It shall be able to operate on a water pressure in the incoming water supply pipe of not less than 700 KN per m2 and shall be approved by the PUB. The fulcrum and lever shall be of bronze with copper ball float. The internal valve shall be of bronze with leather trim and the packing plate shall be of gun metal with winged guide and links. The body shall be of cast iron with bronze lines and gun metal seal ring and the flange shall be at right angle and drilled to BS 4504 or BS 10 with approved rating.
BLDG12/S45.DOC(10) Sal(151211) (DPD)
Bldg Spec Page 45-11 45.3.5
Suction Tanks (Cont'd) (b)
Level Control (Cont'd) (ii)
Floatless Level Control Relay Units Connect floatless level control electrodes mounted on each suction tank directly to the relay units mounted on the wall beside the tank. Arrange floatless level control electrodes to stop the pumpset at pre-determined low level. Use a floatless level control relay unit mounted on the wall beside the suction tank to provide over-riding control of pressure switches such that at a pre-set low water level in the suction tank, the pressure switches shall not start the pump. At that low water level, even a pump in operation shall be stopped by the relay unit. The floatless level control electrodes shall also actuate a warning indicating light and an alarm bell when the water level in the suction tank falls to a predetermined level. The floatless level control relay unit shall be of plug-in relay unit type. Electrodes shall be stainless steel and provided with electrode separators. Electrode holders mounted on tanks shall be easily accessible and removable to facilitate maintenance and shall be installed to the satisfaction of the SO Rep. Run the wiring in conduits from the electrodes to the floatless level control relay units and keep it as short as possible. The wiring to the electrodes shall not run through the same conduit as the power supply wiring.
(c)
Alarm And Emergency Device Install alarm device to be turned-on by the floatless level control relay unit which shall be activated when low water level in the suction tanks and/or low pressure relay and/or thermal overload relays for the pump motors are encountered. This alarm device shall be in the form of an alarm bell placed beside the control panel in the pumproom and a red bulb placed outside the pumproom and near the entrance or other location as directed by the SO Rep. The bell shall be weatherproof and of heavy duty type. The alarm bell shall give a distinctive sound different from that of any fire alarm sounder and the audible fault alarm at the fire indicator board. Provide a pushbutton to cancel the alarm bell. The make and model shall be approved by the SO Rep.
45.3.6
Power Supply (a)
General The power supply available for electric motors is 415 volts, three phase, 50 cycles alternating current.
(b)
Motors The electric motors shall be squirrel-cage totally enclosed fan cooled type with minimum Class F insulation unless specified otherwise and shall be designed for continuous maximum rating. Motor type and model shall be approved by the SO Rep before the installation. Terminal boxes shall be totally enclosed, of water-tight design and fitted with cable glands. The motor efficiency and power factors of the motors shall be more than 90% and 0.85 respectively at full load and shall comply with the current PUB Regulations.
BLDG12/S45.DOC(11) Sal(151211) (DPD)
Bldg Spec Page 45-12 45.3.6
Power Supply (Cont'd) (c)
Motor Starters The starters for the motors shall be direct on-line type. The starter shall provide means of starting or stopping the motors by push-button or be automatically actuated by the pressure switches in the main riser pipe. Each starter shall have time relay, undervoltage release, no volt release, adjustable and ambient compensated (-5ºC to 50ºC) thermal overload protection with manual reset and pilot lamp. The starter shall be submitted to the SO Rep for approval before the installation. The operating voltage of the control coil shall be 230V. The starting apparatus shall be of "frequent duty" rating and be capable of starting under the above conditions intermittently up to 40 times per hour at not less than 20 seconds intervals. The mechanical and electrical endurance of the starter shall be not less than 50,000 operations. Provide the manufacturer's certificate to this effect when requested by the SO Rep. The starters shall be wired in such a way that the floatless level control relay unit shall be able to override other pump controls and actuate the pumps according to different pre-set conditions.
(d)
7-Day Dial, 2-Hour Dial Time Switch Use an approved type of time switch. Connect the time switch to control the coil of the solenoid valve. Time switch shall be able to operate on a 7-day basis with a minimum 24 hours reserve to cater for temporary power failure. The time switch shall be capable of providing at least two on-off operations per week. Time switches shall incorporate a 7-day dial and a 2-hour dial with a shortest switch period of not more than 3 minutes for the 2-hour dial. Provide ON/OF lever transfer switch for each time switch to facilitate manual ON/OFF to override control without disturbing the preset schedule. The power supply for the timer shall be 230V AC 50 Hz. Provide time switch with a clear plastic front cover.
(e)
Auxiliary Relays Auxiliary relays shall be suitable for AC operation and shall have silver contacts with an inherent self cleaning action. Auxiliary relays shall close satisfactorily at 80% nominal volts and hold in satisfactorily at 65% nominal volts. Auxiliary relays with functions common to a number of circuits and which are fitted to a common panel as referred to previously shall be of the plug-in type. Auxiliary relays fitted to demountable units shall be of the plug-in type where possible. Fixed relays are acceptable if they are a design feature of the units. Auxiliary relays shall have a minimum of 6 contacts rated at 5 Amps minimum for an inductive load. Contacts shall be capable of carrying and breaking without damage, the inrush and operating currents of contactor or starter coils they are switching. The contact arrangement shall be easily alterable.
(f)
Pushbuttons Pushbuttons shall be of the oil tight pattern heavy duty unless otherwise specified and rated at a minimum of 5 Amps inductive. Pushbuttons shall consist of an actuating button assembly coupled to an interchangeable contact assembly of sufficient poles to suit the application. Pushbutton bezels shall be black. Employ the following colour codes : Green Red Black
BLDG12/S45.DOC(12) Sal(151211) (DPD)
-
"START" or "ON" "STOP" or "OFF" Reset
Bldg Spec Page 45-13 45.3.6
Power Supply (Cont'd) (g)
Indicator Lamps Indicator lamps shall be 24V rating. Each lamp shall be clearly labelled to indicate the designation of service, circuit and locations. Indicating lamps shall be of the domed glass or plastic lens type rated at 6 watts. The indication shall be clearly visible from the sides or front. Indicating lamps shall have black bezels. The bodies of indicator lamps shall be ventilated to ensure efficient heat dissipation. Connection to lamps shall be by screws or clamp terminals; soldered terminations shall be rejected. Employ the following colour codes : Green Amber Red
(h)
-
"ON" status "OFF" status "FAULT", "FAILURE", "ALARM" status
Hose Reel Pump Control Panel (i)
Construction Provide and install approved switchboard required to serve the booster pumpsets. The wall mounted switchboard cabinet shall be installed in the pumproom and it shall be near to the entrance of the pumproom. The location shall be subject to the approval of the SO Rep. The cabinet shall be of front connected type and unless otherwise specified, manufactured from minimum 2mm gauge sheet steel using folded section or angle form bracing for rigid construction. The cabinet shall have adequate ventilation and shall be drip proof. The construction shall be such that it permits ready access to the interior of the cubicles for operation and maintenance purposes. The opening of a panel door shall allow access to that compartment only. Provide continuous mild steel to complete separate adjacent cubicle. Provide switchboard cabinet with rubber bushes at knockout holes for the entry of all incoming and outgoing cables. Schematic wiring and field connection diagrams shall be permanently secured to the inside of the enclosure door. Instrument indicating lights, rotary switches, selector switches, push buttons, isolating switches, etc shall be mounted directly on the front panel with locknuts to hold such items firmly in position under all conditions of operation. Indicating lights shall be of the transformer type. Isolating switch shall be mechanically interlocked so that the enclosure door cannot be opened with the handle in the `ON' position. Carry out the whole of the electrical Works in compliance with the SS CP5 and subject to the approval of the SO Rep.
(ii)
Internal Wiring The control panel shall all be internally wired, including all wirings between individual units and between units and terminal strips located near the room entrance. Number all terminals on the strips and these numbers shall correspond with the numbers on the wiring and field connection diagrams permanently secured to the inside of the enclosure door. Wiring shall be multi-strand of not less than 1.5 mm2 copper conductors, PVC insulated, colour coded and numbered for identification.
BLDG12/S45.DOC(13) Sal(151211) (DPD)
Bldg Spec Page 45-14 45.3.6
Power Supply (Cont'd) (h)
Hose Reel Pump Control Panel (Cont'd) (ii)
Internal Wiring (Cont'd) Identification shall be by means of moulded ferrules or sleeves at both ends of the cables. The ferrules or sleeves shall be of insulating materials with white glossy finish and black lettering. The ferrules or sleeves shall be unaffected by oil or damp. The numbering shall be approved by the SO Rep. No PVC tapes shall be used for colour coding of cables. Each wire shall be separately terminated with tinned (but not soldered) crimped lugs of approved type. Conductor terminations need not be provided where insertion or tunnel type terminals are employed. Unless otherwise approved by the SO Rep, connect only one wire to each terminal of insertion or tunnel type block. Terminals shall be identified using an approved marking and numbering system. Run all control circuit wirings separately from power circuit wiring and protect them by using MCB units or fuses.
(iii)
Labelling Provide each supervisory control panel with a main label mounted in a prominent position. Labels shall be easily replaceable and shall be secured with brass screws or rust proofed steel screws or in other approved manners. Unless otherwise specified, all labels shall be black lettering engraved on white traffolyte. The size of lettering and the wording of the labels shall be approved by the SO Rep. Submit schedule to the SO Rep for approval prior to manufacture. Labels shall designate circuit number and equipment function. Label terminal strips to identify the circuit number, phase connection, terminal number and function - eg. control, indication, protection, etc. Label clearly all control relays, timers, fuses and other items of switchgear located on common panels to identify circuit number, function and rating.
(iv)
Painting After degreasing, apply one coat of etch primer, follow by one undercoat and two top coats of synthetic enamel. All coats shall be stoved baked to paint manufacturer's requirements. The finished colour of internal and external surfaces shall be red. Make good all damages occurred during transit or installation to a standard equal to that manufactured originally.
(v)
Wiring The wiring shall comply with SS CP 5. Label clearly isolation switches and circuit breakers on the power feed to the pumps : "Fire Hose Reel Pump Supply - Do Not Switch Off In Case Of Fire". Install the cables from the pumproom electrical mains isolator to the pump's starting and control switchboard. Trunking cables and wiring within the pumproom shall be PVC insulated to SS 358 suitable for a 230V single phase 50 cycles system and they shall be carried in conduit or cable trunking.
BLDG12/S45.DOC(14) Sal(151211) (DPD)
Bldg Spec Page 45-15 45.3.6
Power Supply (Cont'd) (h)
Hose Reel Pump Control Panel (Cont'd) (v)
Wiring (Cont'd) The metal conduit shall be of heavy gauge, G.I. conduit (Class B), complying with BS 4568, free from internal roughness and burrs. Fixing to walls and other flat surfaces shall be by means of spacer bar saddles at maximum 1m centres for horizontal runs and 1.5m centres for vertical runs. Conduit termination to loop-on boxes shall consist of screwed socket and smooth bore butt to adaptor boxes, fuse boards and cable trunking, etc. The termination shall consist of a flanged coupling, lead washer and smooth bore bush. Where the conduit is in contact with any structural steel work, make permanent metallic connection between the conduit and steel work. All conduits and trunking shall be electrically and mechanically continuous throughout and shall be earthed with matching standing copper link. Cable trunking shall comply with SS 249 and shall be fabricated from 1.0mm mild steel sheet, in 1.83m or 2.44m lengths and provided with a 50mm fixing sleeve, spot welded on one end at each length. Treat the trunking with anti-corrosion paint and finishing paint to a minimum thickness of 45 microns. Jointing of trunking shall be by means of round headed bolts and nuts. Lay 4mm x 20mm copper earth tape in the trunking run. The copper shall be tinned where it is bolted down. Complete the entire trunking and conduit installation before the cables are drawn. The number of cables to be drawn into the conduits shall comply with SS CP 5. Test all seals not less than 24 hours after completion. This test shall be made with insulation testing equipment of the "Megger" type at 500V or other approved and obtain an infinity reading before the conductors are connected to any apparatus. Terminate wiring in conduit and duct in the floor in approved junction boxes adjacent to the machine or foundation plinth with water-tight flexible tubing enclosing the cables between motors and junction boxes. Earth all non current carrying metal parts of electrical equipment. Earth continuity conductor shall have cross-sectional area of not less than that specified in Table D1 of CP 5.
45.4
PORTABLE FIRE EXTINGUISHER Provide and install portable fire extinguishers in locations as shown in the Drawings. Extinguishers for use in all Pump Rooms, Ejector Pump rooms, Generator Rooms shall be appropriate for dealing with class B and C fires for eg. CO2 Fire Extinguishers. Those for use in Utilities Centre, Centralised Refuse Chambers, Consumer Switch Rooms, Lift Machine Rooms and similar nature services rooms shall be appropriate for dealing with class A, B & C fires for eg. Type ABC Dry Chemical Fire Extinguishers in accordance to CP 55. Provide and install each fire extinguisher complete with horn, wall bracket and visual indicator (indicating whether the extinguisher has been used). Extinguishers equipped with nonmetallic horns, such as plastic or PVC horns, shall be used in location with energised electrical equipment such as switch rooms. Metal horns shall not be used in location with energised electrical equipment. All fire extinguishers’ location, quantity, rating, type and weight shall comply with SS 232, CP 55 and other current codes and regulations and shall be approved for use by all relevant local authorities. Good practice as recommended in BS 5306:Pt 3 shall be observed and implemented where applicable. Install fire extinguisher at a height of 1m above the floor level on the hangers/brackets supplied together with the fire extinguisher. They shall be placed in a manner such that their operating instructions face outward. The operating instructions shall be simple and shown clearly in pictorial form. Fire extinguisher shall be embossed with 2 number of HDB logo not smaller than 30mm x 30mm on the external face of every extinguisher. The logo shall be red and white. No stick-on logo shall be acceptable as a substitute.
BLDG12/S45.DOC(15) Sal(151211) (DPD)
Bldg Spec Page 45-16 45.4
PORTABLE FIRE EXTINGUISHER (CONT’D) House each fire extinguisher in a 1.6mm thick sheet steel case complete with front hinged door, 3mm thick glass panel and handle master lock. The case shall be coated with 2 coats of red paint. Lettering such as "FIRE" or "FIRE EXTINGUISHER" shall be eminently and permanently marked on the case and shall be of approved sizes and colour. Provide 5 sets of master keys for the door lock. Provide each case with a master key placed inside a recess covered by a front break glass and the recess shall be mounted on the front hinged door.
45.5
TESTING AND COMMISSIONING
45.5.1
General The Contractor shall submit an application to the SO Rep to witness the inspection and commissioning test of the completed installation. The application shall include information on the testing appointment date and statement of completion of the whole Works by the Contractor. The appointed date shall be at least 2 months before the Substantial Completion of the building block. The Contractor shall provide complete information as produced in Appendix A34 and submit two copies to the SO Rep one week before the testing of the system. Provide a complete set of testing equipment. The minimum requirements of which shall be set out below : (a) (b) (c)
Tachometer with accessories for measurement of pumps and motor shaft speeds. Meter-Recorder for measuring flow rate through orifice plate. All necessary electrical testing equipment such as insulation resistance tester.
The whole of the instruments and equipment and labour required for conducting these tests and demonstrations shall be provided by the Contractor and the cost thereof shall be included in the Contract Sum. The test instruments and equipment shall remain the property of the Contractor.
45.5.2
Test Records The records shall include : (a) (b) (c) (d) (e) (f)
45.5.3
date and time for inspection or test person carrying out the test test results noted any external factors significantly affecting the results follow-up actions required work carried out as a result of (e) above with date and result of re-test
Pipework All water pipework and other fittings shall be hydrostatically tested to 10 bar or 2 times the working pressure whichever shall be the greater, and this test pressure shall be maintained for 24 hours. Allowable pressure drop during the 24 hour testing shall be decided by the SO Rep but generally shall not exceed 3% of test pressure. During tests, all welded joints shall be hammered.
45.5.4
Control Equipment Set and calibrate all limit switches, pressure switches, time switches, etc. as required to ensure that operating directions are correct. Test and verify the time and control sequence.
45.5.5
Pumps Check all pumps for alignment, flow rates, pressure and speed and their balance to comply with the required flow and head.
BLDG12/S45.DOC(16) Sal(151211) (DPD)
Bldg Spec Page 45-17 45.5
TESTING AND COMMISSIONING (CONT’D)
45.5.6
Performance Test On Substantial Completion of the Works, the Contractor shall submit to the SO Rep two copies of the test results using approved HDB Testing Form. Provide a minimum of seven days notice to the SO Rep to verify the test results on the Site and demonstrate to the SO Rep that the installation if adjusted and regulated correctly fulfils the function for which it has been designed. Adjust, balance and regulate the Works concerned as necessary until the required conditions are attained. Should the SO Rep find discrepancies between the recorded test results and the measurements demonstrated to him on the Site, the test shall be repeated by the Contractor to the satisfaction of the SO Rep.
45.5.7
Electrical Commissioning Tests Test the complete installation, both before and after the connection, to the requirements of the SO Rep. The Contractor shall be responsible for all electrical tests at the Site in the presence of the SO Rep during the whole of the period required for the tests. All materials and equipment provided or installed which fail the tests shall be replaced or rectified at once by the Contractor and the tests shall be repeated. Conduct all tests to the satisfaction of the SO Rep. Provide all necessary instruments, apparatus, connections, skilled and unskilled labour required for the tests to the satisfaction of the SO Rep. Make accurate records of all tests and furnish test certificates and a schedule of the results in an approved form. Two copies of such schedules and of each test certificate shall be required. Make good any circuit or section of the installation which fails to comply with the required standard for acceptance. The site tests to be carried out on each completed section of the electrical installation where applicable, shall be as follows : (a)
Insulation resistance tests to earth and between conductors of cables and wires
(b)
Continuity tests.
(c)
Tests to prove correct operation of interlocks, tripping and closing circuits, indications, etc.
(d)
Test operation of alarm devices.
(e)
Rotational tests on all motors.
(f)
Insulation resistance test on any electrical apparatus supplied and/or installed before and after connecting such apparatus to the supply.
BLDG12/S45.DOC(17) Sal(151211) (DPD)
Bldg Spec Page 45-18 45.5
TESTING AND COMMISSIONING (CONT’D)
45.5.8
Hose Reel Tests (a)
Flushing Out Before any water is introduced into the hose reel, it shall be thoroughly flushed out to ensure that no harmful matter is passed into the reel. After flushing out, the tubing shall be run out and the water turned on to establish that the assembly is fully operational.
(b)
Procedure For Direct PUB Mains Supplies The most hydraulically remote reel shall provided a jet of at least 10m in length at a flow rate of at least 0.4 litres per second.
(c)
Procedure For Boosted Supplies The most hydraulically remote reel shall provided a jet of at least 10m in length at a flow rate of at least 0.4 litres per second. Check and verify pump running alarm. Repeat the test with simulated mechanical or electrical failure of the duty pump. Check and test the ability of the standby pump to come into service automatically and to maintain the required outputs. Check and verify pump failure warning indicated on local control panel and remote fire indicator board. Test the various control features of the hose reel booster pump to verify that they function correctly.
(d)
Putting Into Operational Readiness When the tests have been satisfactorily completed, restore the system to its normal operating state. Reels shall never be left under pressure and, where practicable, drain the hose prior to returning it to the drum. Restore the hose on the drum, pay particular attention to automatic hose reels to ensure that the automatic valve is fully closed when the hose has been restored. Where an isolation valve has been incorporated, close the isolation valve on completion of storage, and complete the nozzle interlock, where fitted.
45.5.9
Final Drawings and Operating Manuals During the progress of the Works, the Contractor shall record and update all Fire Protection System Installation, pipe routes, legends and all other related works based on actual site installations for the production of as-built drawings. On completion of the installation, provide three sets of operation and maintenance manuals and the testing record/results of each installation.
.
BLDG12/S45.DOC(18) Sal(151211) (DPD)
Bldg Spec Page 45-19 45.6
SERVICE AND MAINTENANCE (FIRE PROTECTION SYSTEM) The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance service and call-back service to the Fire Protection System as specified hereunder, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this clause including all sub-clauses under it).
45.6.1
General During the Maintenance Period, provide all consumables/materials and make good all Defect and leakages found in the system/Plant/equipment. Replace and/or repair all defective parts or items as produced in Appendix A33 whenever required if such repair or replacement has been necessitated by reasons of Defect in the system/Plant/equipment.
45.6.2
Workmanship And Materials The service and maintenance Works shall be performed by workmen skilled in the service, maintenance and repair of pumping Plant and fire protection systems of all types. All materials to be provided in connection with such service and maintenance Works shall be new and unused, and shall generally be of the best quality as regards manufacture and performance.
45.6.3
Supervision Provide a foreman to take charge of the service, maintenance and repair Works. This foreman shall be thoroughly competent in supervising the service, maintenance and repair of pumping Plant and fire protection system, and shall be in the direct employment of the Contractor, and acceptable to the SO Rep. The Contractor shall have in his direct employment, workmen who shall be skilled in the service, maintenance and repair of pumping Plant and fire protection system.
45.6.4
Servicing And Maintenance Schedule For monthly tests and inspection, all parts, Plant and equipment comprising the complete hose reel pumping system shall be maintained and inspected strictly in accordance with the Specifications and check-list as set out in Appendix A35. The check-list shall be duly completed by the Contractor when performing the monthly inspection. Any Defect detected shall be rectified by the Contractor immediately. Always arrange for a Representative from the HDB Branch Office to be present during the inspection. Furnish to the HDB Branch Office a Maintenance Schedule for monthly inspection upon Substantial Completion of the Works or phase or sub-phase of the Works.
BLDG12/S45.DOC(19) Sal(151211) (DPD)
Bldg Spec Page 45-20 45.6
SERVICE AND MAINTENANCE (FIRE PROTECTION SYSTEM) (CONT’D)
45.6.4
Servicing And Maintenance Schedule (Cont’d) The Contractor's foreman shall also sign on the attendance book/card provided by the Employer in the pump room after completion of each inspection. Items in the check-list for the monthly inspection shall include : (i) General condition of the pumprooms (ii) Correct setting of the time switch (iii) Auto/Manual selector switch in "Auto" position (iv) Power supply selector switch in "On" position (v) Control panel indicating lights (vi) Alarm bell and bulb (vii) Suction tank electrode and control module (viii) Motor running current (ix) Check valves (x) Gate valves (xi) Alignment couplings (xii) Ball float valves (xiii) Motor insulation (xiv) Pump mechanical seal (xv) Pump lubrication oil level (if applicable) (xvi) Contactors and relays (xvii) Hose reel (xviii) Pressure and flow switches
45.6.5
Call-Back Service Provide an efficient 24 hour (whole day) call-back service. All urgent calls or complaints shall be attended to immediately upon notification by the Representative from the Essential Maintenance Service Unit or Branch Office. The Contractor shall provide a mobile phone for his maintenance supervisor and the mobile phone number shall be given to the respective Branch Office so that immediate notification of any urgent callback service can be met. In the event that the Contractor fails to : (a) respond within 30 minutes after being called; or (b) attend to an urgent call or complaint immediately upon notification; or (c) carry out the routine inspection of the rising main system; The SO Rep may engage another contractor to carry out the Works and all costs and charges shall be recoverable from the Contractor by the Employer or deducted by the Employer from monies due or becoming due to the Contractor. Notwithstanding the above, the SO Rep may in addition exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor. In the event that other contractors are instructed to rectify Defect in the Fire Protection System or to carry out the routine servicing and maintenance of the Fire Protection System due to or arising out of the Contractor's failure to do so when directed by the SO Rep, such actions shall not in any way affect, vary or relieve the Contractor's obligations under the Contract.
BLDG12/S45.DOC(20) Sal(151211) (DPD)
Bldg Spec Page 45-21 45.6.6
Rectification Of Defects Prior To Issuance Of Final Completion Certificate One month before the expiry date of the Defects Liability Period, the Contractor shall arrange with HDB Branch Office and the SO Rep for a final joint inspection. All Defect listed after this joint inspection shall be rectified by the end of the succeeding one month commencing from the expiry date of the Defects Liability Period. Rectify the outstanding Defect and conduct detailed checks on the Works before arranging for inspection by the Representative from HDB Branch Office for the purpose of certifying completion of rectification of Defect. After the second final inspection by the Representative from HDB Branch Office, a list of outstanding Defect shall be issued to the Contractor and the Contractor shall rectify all Defect on the list within fourteen days. If the Contractor fails to rectify and make good the Defect on the second final inspection, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor. Notwithstanding the above, the Employer shall in addition have the right to engage his own workmen or other contractors to rectify and make good all Defect and the cost of rectification and charges imposed shall be recovered from the Contractor.
45.6.7
Log Book Keep a log book at the pump room in which details of all alarms (genuine, practice test or false), faults, tests, routine maintenance and repairs carried out shall be recorded. The type of log book and the record format shall be subject to the approval of the SO Rep.
45.6.8
Consumable Materials Provide the following consumable materials as and when required during the Maintenance Period :
45.7
(a)
All oils and grease required for lubrication of pump bearings, motor bearings, pivots and other moving parts.
(b)
All carbon brushes required to replace worn brushes in electric motors.
(c)
All electric contact points required to replace those points in switch gears, motor starter gears, electric control gears and electric relays.
(d)
All indicating lamps required to replace blown lamps.
(e)
All cotton waster, soap detergent and other cleaning materials required for cleaning purposes.
FIRE HYDRANTS Private Fire Hydrants where so required by The Fire Authority shall be provided within the perimeter of the building lot all to the requirements of the Fire Authority. The fire hydrant shall be positioned to be within 50 m from an entry to the building and not more than 50 m apart. In the case of a building where rising mains are installed, the 50 m distance shall be measured up to the breeching inlets of the rising mains. The siting and type of fire hydrants shall comply fully with the requirements stated in SS CP 29: Code of Practice for Fire Hydrant Systems and Hose Reels. Fire hydrants shall be of suitably corrosion protected and sufficiently robust material. Their works parts shall be of gunmetal to BS 1400 or other suitable material. The fire hydrant shall be installed on concrete plinths with size of 750 mm x 750 mm x 150 mm thickness. A control valve shall be installed to each hydrant. The control valve shall be able to open and closed from the surface of the ground.
BLDG12/S45.DOC(21) Sal(151211) (DPD)
Bldg Spec Page 45-22 45.7
FIRE HYDRANTS (CONT’D) Fire hydrant mains shall be of heavy duty ductile iron with cement lining type conforming to BS EN 545. The hydrant mains routes and locations shown on the Drawings are approximate and intended to indicate the general runs and locations only. The exact routes and locations of the mains shall be determined at the Site all at the Contractor’s cost and expense. Any mains that are routed in basement of building shall be in protective enclosure. The protective enclosure to the mains shall have the same fire resistance as the elements of structure of the building where the mains are located. The protective enclosure to the hydrant mains shall be labelled with the word " HYDRANT MAIN " of minimum 50 mm height at suitable intervals. The Contractor shall be deemed to have allowed in the Contract Sum for all costs and expenses for such protective enclosures. The fire hydrants shall be painted on the stem with a 100 mm yellow band, the lower edge of which is 300 mm from the ground. The outlets shall be provided with protective standard caps of cast iron or other suitable material and attached to the standpipe by stainless steel chains. The topmost part of the valve shall not exceed a depth of 1000 mm from the ground level. The water supply for the fire hydrant shall comply with the requirements stated in latest Code of Practice for Fire Precautions in Buildings. Valve pits shall be of adequate size, and readily accessible for inspection, operation, testing and maintenance and removal of equipment contained therein. They shall be so constructed and arranged as to properly protect the installed equipment from ground movement and accumulation of water as specified in SS CP 29. For fire hydrants sited in roadways, care shall be taken that the pits and covers are capable of bearing the heaviest vehicle that may use the road.
Section 46/..... BLDG12/S45.DOC(22) Sal(151211) (DPD)
Bldg Spec Page 46-1
SECTION 46 RESERVED
SECTION 47 RESERVED
SECTION 48 RESERVED
Section 49/..... BLDG12/S4648.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 49-1 SECTION 49 GENERAL REQUIREMENTS FOR ELECTRICAL WORKS
49.1
REGULATIONS The electrical works include electrical installation, lighting installation, lightning protection works, telephone/data cabling, fire alarm system and other miscellaneous electrical works. The electrical installation works shall comply with all statutory rules, regulations and requirements of the EMA, SP Services Ltd and PowerGrid, current at the date of submission of the Tender and to the complete satisfaction of the SO Rep. In particular, the electrical installation works shall comply with the following: (i) (ii) (iii) (iv)
49.2
Electricity (Electrical Installations) Regulations made under The Electricity Act (CAP. 89A) including any subsequent updates and amendments of the Regulations. Singapore Standard CP 5; Any additional regulations issued by EMA, SPSL and PowerGrid. All other electrical works shall comply with their respective Codes of Practice.
INTERPRETATION OF DRAWINGS It is the intention of the Drawings and/or Specifications to provide a complete and safe operating system. The omission from the Drawings and Specifications of any details in construction, installation, materials or specialities necessary for a complete, operating and safe system shall not relieve the Contractor from furnishing and completing the same in place all at the Contractor's own cost and expense. Before submitting the Tender, and also prior to the execution of the Works, the Contractor shall study the Drawings and inspect the Site to satisfy themselves that the Works could be carried out as specified. Should it be deemed necessary to make modifications to the Drawings, method of installation or site adjustments to suit the structural and site constraints and to ensure compliance with the Statutory Rules and Regulations, the Contractor shall inform the SO Rep of his recommendations within two weeks from the commencement of the Contract and to obtain the concurrence of the SO Rep before proceeding with the modifications. The Contractor shall be deemed to have allowed for all costs and expenses in the Contract Sum for complying with the requirements of this clause. The Drawings and/or Specifications indicate the minimum requirements of the Employer only. Should the requirements of the Drawings and/or Specifications conflict with the requirements of the Statutory Rules and/or Regulations, the most stringent of the requirements shall govern the Works.
49.3
AMBIENT CONDITIONS All Plant and equipment or materials specified in the Specifications and any other Plant and equipment or materials provided under the Contract shall be fully tropicalised and suitable for use in Singapore. The local climate is tropical with a mean shade temperature of 27.8°C. The normal maximum shade temperature is 31°C and the minimum shade temperature is 23.9°C. The mean relative humidity is 80%, the maximum and minimum being 100% and 65.1% respectively.
49.4
ITEMS OF ANY ONE CLASSIFICATION Any items, fittings or accessories which are used in quantity, shall in each case be the product of one manufacturer and shall be used only for the service recommended by the manufacturer.
BLDG12/S49.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 49-2 49.5
INCOMING SERVICE CABLES The incoming service cables will be provided by PowerGrid up to and terminated at the incoming service panel provided by the Contractor. For service entries where there are no switch rooms, the Contractor shall provide weatherproof enclosures to house the incoming service terminations. The enclosures shall have hinged doors and facilities for locking. Where necessary, the Contractor shall provide concrete pedestal bases to the requirements of SPSL/PowerGrid for mounting the weatherproof enclosures. The Contractor shall provide jumper or consumer terminal service (CTS) cables connecting the Employer's installation to the weatherproof enclosure. For service entries terminated directly at the main switch board, inside a switch room, the Contractor shall provide suitable cable end boxes for the termination. For Bulk Intake Consumer Switchroom, the Contractor shall supply, deliver, install/lay, terminate, test and commission the incoming service cable, on cable tray/cable ladder/trunking, from the Bulk Intake Consumer Switch Room to all Sub-Switchboards in Consumer Switch Room of the residential block, basement carpark and commercial block as indicated in the drawing. The termination shall be with suitable terminated accessories in accordance to PowerGrid's requirement. The Contractor is to maintain the service cable for a period of one year.
49.6
FIXING SCREWS All screws used for fixing meter boards, moulded or steel boxes, switches, socket outlets, consumer control units etc shall be in brass.
49.7
SWITCH ROOMS Unless otherwise specified in the Drawings, all switch rooms shall be provided with at least a lighting point controlled by a switch, a 13 Amp switch socket-outlet, a consumer control unit, a fluorescent batten luminaire complete with tube and emergency battery/inverter pack (2 hours), a glass framed single line diagram of the electrical installation in at least A3 size (the wordings of the diagram shall be legible), first aid chart and a 900mm wide rubber mat complying with the latest edition of SS 298. The rubber mat shall be placed all around the floor standing switch board and indoor service electrical distribution box if any. All switches, socket-outlets and consumer control units shall be metal clad. All final sub-circuit wirings to lighting and power points in the switch rooms/meter rooms shall be run in metal conduit. Wirings for public lighting circuits shall be grouped and taped together according to their circuits. The circuits shall be bunched and secured on the cable tray by means of plastic fixing ties. All other cables shall run on metal cable trays. The cables shall be neatly secured on the trays by plastic fixing ties or PVC coated metal saddles at regular intervals not exceeding 300mm. No over lapping of cables shall be allowed except for crossing of different circuits which shall be kept to a minimum.
49.8
POWER SUPPLY POINTS OUTSIDE SWITCH ROOMS AND AT STAIRCASE LANDINGS A 15 Amp metal-clad switch socket-outlet housed in a metal enclosure shall be installed outside each switchroom and at staircase landings or as indicated in the Drawings. These power supply points shall be connected to a separate way of the consumer control unit in the switchroom. The wiring to the power supply point shall be installed concealed unless shown otherwise in the Drawings. The metal enclosure shall be fabricated from electro-galvanised sheet steel of 1.2mm thickness. It shall be treated with a coat of finishing paint giving an overall paint thickness of not less than 45 microns. A sample of the metal enclosure shall be submitted to the SO Rep for approval before installation. The enclosure shall be semi-recessed such that use by external electrical plug is convenient and easy. The Contractor can propose alternative solution to the metal enclosure so long as there is locking provision/facility for these public power supply points. The alternative solution shall be subjected to approval by the SO Rep.
BLDG12/S49.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 49-3 49.9
TESTING OF INSTALLATION
49.9.1
General The following work of the electrical installation shall be inspected and tested on Site after completion : (a) Main Switchboard and Mains Cables (b) Earthing System (c) Unit's Wiring & Final Circuit Wiring (d) Lightning Protection System (e) Telephone System (f) CATV System All electrical tests including continuity, insulation resistance, polarity, earth fault loop impedances, phasing and earth electrode resistance shall be made in a manner prescribed in Singapore Standard CP 5 or other relevant standard specifications and Codes of Practice. Where no Standard/Code/Regulation is applicable, the tests shall be conducted in a manner approved by the SO Rep. For new wiring installations, the value of insulation resistance shall be as follows : (a) (b) (c)
Main Switchboard and Mains Cables shall be more than 10 Megaohms New underground cables shall be more than 5 Megaohms Unit's Wiring & Final Circuit Wiring shall be more than 1 Megaohms
The Contractor shall check and test the installation to ensure that it is complete and complies with the requirements of the Specifications, the EMA and SPSL. All tests shall be witnessed, endorsed and verified by the Consultant’s LEW. Employer reserve the right to conduct any audit testing if required. lnspection or approval of tests by the SO Rep of any Plant and equipment, work or installation shall not relieve the Contractor from his obligation to supply the complete Plant and equipment, and complete the Works and installation in accordance with the Specifications. The Contractor shall supply all necessary instruments, apparatus, consumable stores, connections, skilled and unskilled labour and services with proper, reasonable and safe facilities required for the tests and any audit testing. If site electricity supply is not available for testing or setting protection relays, the Contractor shall provide a portable diesel generator set for the purpose. Any costs which may be involved in the tests shall be deemed to be included in the Contract Sum by the Contractor. 49.9.2
Application For HDB Testing HDB reserve the right to conduct audit testings if necessary on main switchboards, risers, distribution boards, telephone and CATV system etc including the earthing system. The Contractor shall test the installation works and submit all the tests reports to SO Rep/or Consultant for verification/endorsement before submission to HDB Technical Management (M&E) Unit for audit testings. If any of the test reports and relevant documents are not submitted to HDB Technical Management (M&E) Unit for audit testings, HDB reserve the right not to take over the block upon completion until the outstanding test reports and documents are submitted to HDB and HDB is satisfied with the testings. The onus will be on the Contractor to submit all test reports and relevant documents to HDB Technical Management (M&E) Unit at least 14 days prior to any scheduled handing over date of the block.
49.9.2.1
The electrical installation to individual residential unit shall be tested by HDB Technical Management (M&E) Unit. The Contractor shall apply to the HDB Technical Management (M&E) Unit at least 7 working days in advance together with the respective test reports and supporting documents duly endorsed and verified by the Consultant’s LEW. The following shall be submitted at the time of application for testing: (a) (b) (c) (d) (e) (f) (g) (h)
BLDG12/S49.DOC(3) Sal(151211) (DPD)
One Certificate Of Fitness For Turn-On For Residential Units in each building block. A schedule of electrical installation for each residential building block (Form E) A block layout plan showing the types of residential units on each floor and unit layout plans with relevant single line diagrams. A photocopy of Certificate of Compliance (COC) of the electrical installation for each block A photocopy of licence to use or operate electrical installation for each block A soft copy (in CD Rom) of the as-built Single Line Drawings (in dwg format) of the electrical installations of the main switchboard and sub-switch board for each block. Quality Acceptance Report for the telephone wiring installation Telecom installer testing report for each block One copy of as-built MATV schematic installation drawing and other supporting drawings in A3 size paper.
Bldg Spec Page 49-4 49.9.3
Re-Testing And Charges Any omissions or Defect or faults or failure to meet test requirements detected during the testing shall be rectified by the Contractor within three (3) working days and verified by the Consultant . For re-testing of residential unit, the Contractor shall arrange for re-testing with HDB Technical Management (M&E) Unit within three (3) working days. If the Contractor fails the first testing/re-tests due to omissions or Defect or faults or failure to meet test requirements the Employer shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.
49.10
SCHEDULE FOR ELECTRICITY SUPPLY TARGET DATES For building blocks with lifts, Main Distribution Frame (MDF) room, Telecommunication Equipment Room (TER) and Consumer Switch Room (CSR), the main switchboards including the lift electricity cables and the supply cables for the MDF room, TER and CSR shall be energised at least 9 weeks before the date of Substantial Completion of building blocks not more than 30 storeys and 10 weeks before the date of Substantial Completion of building blocks more than 30 storeys. This is to allow time for the testing and commissioning of the lifts and telephone systems by others to meet the date of Substantial Completion of the building blocks. All electrical tests shall be completed and electricity supply to all other parts of the electrical installation shall be energised at least 2 weeks before the date of Substantial Completion of the building blocks.
49.11
WIRING/TRUNKING ROUTES AND POSITION OF ELECTRICAL PLANT AND EQUIPMENT/ACCESSORIES AND FITTINGS The wiring/trunking routes where indicated in the Drawings and the positions of electrical Plant and equipment/accessories and fittings where indicated in the Drawings are meant to serve as a guide only. The actual routes or positions shall be determined on the Site subject to the approval of the SO Rep. There shall be no variations to the Contract or adjustments to the Contract Sum arising from the selection of a more suitable route or position which might differ from those indicated in the Drawings. The Contractor shall be deemed to have allowed for all costs and expenses for complying with these provisions specified herein. The Contractor shall ensure a minimum clearance distance of 100mm between the electrical trunking/fitting and the ventilation opening at the Gas and Water (G&W) duct so as not to block such ventilation opening.
49.12
MAINS CABLE INSTALLATION AT GROUND FLOOR AND RISER DUCT Mains cable installation at the ground floor and riser ducts shall be encased in metal trunking of standard widths of 375mm, 300mm, 200mm, 150mm and 75mm and standard height of 75mm. CATV cables shall be installed in separate 75mm x 75mm metal trunking throughout. Along the ground floor ceiling where the CATV trunkings and electrical trunkings are installed adjacent to each other, the CATV trunking shall be installed on the side nearer the service duct. For CATV cables to cross inside the metal trunking of electrical mains, 20mm diameter metal conduits for the crossing shall be installed as close to the trunking base as possible. The ends of the metal conduits shall be secured to the trunking sides using locknuts and female brass bushes. Only one metal conduit is allowed for each CATV cable.
49.13
SEGREGATION OF METERED SUPPLY CABLES Metered supply cables after the electricity kWH meters shall be installed in their own separate trunkings/conduits or if installed in a common trunking with other unmetered supply cables, then they shall be installed in the manner hereinafter specified. The metered supply cables shall be grouped and secured together by plastic fixing ties. These shall be tagged and identified as metered supply cables within each removable sections of the trunkings.
BLDG12/S49.DOC(4) Sal(151211) (DPD)
Bldg Spec Page 49-5 49.14
AS-BUILT DRAWINGS FOR ELECTRICAL WORKS During the progress of the Works, the Contractor shall record and update all wiring routes, circuiting, circuitry, electrical points, legends, lightning protection system and all other electrical works based on actual site installations for the production of as-built drawings. The Contractor shall provide two batches of as-built drawings. The first batch of the as-built drawings is for the electrical installation of each individual dwelling unit. These shall be provided inside each dwelling unit before completion of the works for each building block. The size of the as-built drawings shall be A3 size. The as-built drawings for the dwelling unit shall show : (a)
block number and house number of the unit;
(b)
the single-line drawing ( SLD ) of the electrical installation inside the unit;
(c)
the concealed conduit routes in the ceiling slab for the electrical, telephone/data and television services ( scale between 1:50 and 1:100 );
(d)
the concealed conduit routes in the floor slab for the electrical, telephone/data and television services ( scale between 1:50 and 1:100 );
(e)
legend used.
Each as-built drawing shall be duly checked, certified and endorsed by the Contractor. The as-built drawings shall be kept inside a specially - designed and durable envelope and fix adjacent to the unit's consumer unit. For detail arrangement, the Contractor shall liaise with the SO Rep. The second batch of as-built drawings is for the complete electrical works and shall be submitted in the following: i. Two CDROMs containing the as-built drawings in "pdf" format. Every "pdf" drawing must show the "As-Built" stamp. ii. One set of as-built tracings. Every tracing must be stamped "As-Built". iii. Three sets of as-built prints. Every print must be stamped "As-Built". These as-built drawings shall be submitted to the SO Rep. on a block-to-block basis not later than two weeks upon the handing over of each building block. The Contractor shall submit a listing of the as-built drawings submitted and a letter certifying that the submitted drawings is a true record of the works asbuilt. Without this certification letter, these as-built drawings will not be accepted. The thickness of these as-built tracings shall be such that its weight is approximately 110 gram per m2. The ink in the as-built tracings shall be permanent and not of the powered-type. The details in the tracings shall be legible and shall not have double or faded images. These as-built tracings will be rejected if found to be of poor quality. 49.15
SAMPLE WORK The Contractor shall put up sample work for the approval of the SO Rep and SPSL before proceeding with the entire installation. The actual positions of all electrical fittings and accessories shall be determined at site by the SO Rep. The Contractor shall inform and obtain approval from the SO Rep when installing lighting and accessories. The Contractor shall notify the SO Rep at least two days in advance between putting up the following sample work so that specific instructions may be given : (a) (b) (c) (d) (e) (f) (g)
Sample unit wiring to all different types of flats Mains trunking Rising mains and horizontal mains Wiring for public lighting Lightning protection system Driving of earth electrodes Other wiring or installation as instructed by the SO Rep
Failure to inform and obtain approval from the SO Rep may result in the rejection of the installation work and no claim for compensation shall be entertained by the Employer. BLDG12/S49.DOC(5) Sal(151211) (DPD)
Bldg Spec Page 49-6 49.16
TEMPORARY STORES The Contractor shall provide suitable temporary store/s at the Site for the safe-keeping of fittings and materials and for their protection against damage or loss by weather or other causes. The location and type of store/s shall be approved by the SO Rep who will have the discretion to exclude in his payment certificates, payment for any fitting or material which is not stored to his satisfaction.
49.17
SUBMISSION OF DETAILS The Contractor's Tender where applicable shall be accompanied by details of the proposed system including details on the technical and performance aspects of the Plant and equipment (antenna, preamplifier, mixer, amplifier, splitter, etc). Single line diagrams of the distribution system with the signal strengths in dbV, for all the distribution points and the proposed underground cable route (if underground system is involved) shall be submitted together with the Tender or when requested by the SO Rep. The approval, with or without amendments, by the SO Rep of the Contractor's System shall not in any way affect vary or relieve the Contractor's liabilities or obligations to ensure compliance of the System with the specified technical performance standards.
49.18
NEW MATERIALS, PLANT AND EQUIPMENT If the Contractor intends to use Plant and equipment and materials which have not been approved previously by the HDB, he shall arrange with the manufacturer or supplier to submit the items for approval prior to the acceptance of the tender. Each article which is submitted for approval shall be accompanied by a full description and technical specification with supporting performance and test data from the manufacturer. In addition, a report of type tests conducted on the article in accordance with the relevant standards shall be submitted. Each article shall be suitably marked for identification and will be retained by the SO Rep for record purposes. When the article is required to be returned, the Contractor shall submit a photograph or illustration suitable for identification and record.
49.19
PLANT, EQUIPMENT/PARTS (a)
The Contractor shall confirm the brands and models of the Plant and equipment and accessories to be used for the Contract within one week from the date of the Letter of Acceptance. At the same time, the Contractor is also required to place order for the Plant and equipment early.
(b)
At the time of tendering, the Contractor shall only offer in his main offer items which have already been approved by the HDB. If the Contractor offers items in his main offer which have not been approved, the tender may be treated as non-compliance with the Specifications and the Employer reserves the right to reject the tender.
(c)
If the Contractor proposed to use a product other than those specified in the Specifications and/or indicated in the Drawings, the Contractor shall submit a sample of the proposed product to the SO Rep for approval not later than one week after the date of the Letter of Acceptance. The provision of subclause 1.2.5 shall be applied accordingly.
BLDG12/S49.DOC(6) Sal(151211) (DPD)
Bldg Spec Page 49-7 49.20
TYPE TEST Type test reports issued by the following third-party certified laboratories are acceptable : Laboratories with SAC-SINGLAS accreditation; Laboratories with SAC-MRA partners accreditation; Laboratories participating in IECEE CB scheme. [SAC also signs bilateral Mutual Recognition Arrangement (MRA) with other national accreditation bodies. It is also a signatory to the International Laboratory Accreditation Cooperation (ILAC) Arrangement and regional cooperation bodies such as Asia Pacific Laboratory Accreditation Cooperation (APLAC). IECEE stands for IEC System for Conformity Testing and Certification of Electrical Equipment. The IECEE operates the CB (Certification Body) Scheme which is a multilateral certification system based on standards prepared by the International Electrotechnical Commission.]
49.21
SYSTEMATIC LAYOUT OF ALL SERVICE PIPES AND ELECTRICAL CONDUITS (M&E SERVICES) AT BUILDING ROOFTOP The Contractor shall prepare a coordinated services layout plan showing the overall layout of all the M & E service pipes and electrical conduits at the roof top in consultation with the SO Rep. The layout of the service pipes and electrical conduits at the roof top shall ensure good accessibility and neat arrangement to facilitate the movement of the maintenance workmen, besides meeting all technical and statutory requirements. The Contractor shall submit the coordinated roof top services layout to the SO Rep for approval before installation. Ensure that all the pipes/conduits are arranged in a systematic and orderly manner, and the access to the water tanks, lift motor rooms, pumps, and other services at the rooftop is not obstructed by service pipes and electrical conduits. Work by the various trades at the roof top shall be supervised and coordinated by the Contractor. In areas where pipes are causing obstruction, the contractor is to provide chequered-plate platform and steps over the pipes in accordance with the Drawings. The platform shall be installed at locations furthest away from the building edge and in such a way as not to pose danger to the maintenance workmen.
49.22
INSTALLATION OF TRUNKING FROM THE MAIN ROOF TO THE LIFT MACHINE ROOM The Contractor shall ensure that the electrical riser trunking is not exposed to any ingress of water when it is run from the main roof to the lift machine room (LMR). The trunking shall run vertically from the main roof to the soffit of the LMR’s floor. It shall then run on the underside/soffit of the LMR’s floor such that the beams prevent the rain from entering the trunking. Puncture the floor and enter the LMR at the most appropriate location. Provide a 500mm wide x 100mm thick brickwall for the vertical run from the main roof to the soffit of the LMR’s floor so as to mount the trunking and to protect the trunking from any ingress of water/rain. Provide a 100mm high x 50mm thick concrete kerb all round the base of the trunking to prevent water from seeping into the base of the trunking. Additional protection shall be provided, if required, to suit the site conditions and where the trunking is still very exposed to weather. The opening through the main roof must be properly sealed to prevent water from seeping through it. Obtain the concurrence of the SO Rep before installing the brickwall.
Section 50/.....
BLDG12/S49.DOC(7) Sal(151211) (DPD)
Bldg Spec Page 50-1 SECTION 50 SWITCHBOARDS, DISTRIBUTION BOARDS AND SWITCHGEARS
50.1
SWITCHBOARDS
50.1.1
General The switchboards shall be suitable for use on a 400/230V 3 phase 4 wire 50 Hz supply system and shall comply with the requirements of IEC 61439. The switchboards shall incorporate all the items as set out in the Drawings. All costs relating to testing, testing fees and miscellaneous charges necessary for the completion and commissioning of the switchboards ready for continuous operation at its designated Site positions shall be included in the Contract Sum.
50.1.2
Drawings Detailed construction drawings and circuit and wiring diagrams of all switchboards shall be submitted to the SO Rep for approval before construction. These drawings and diagrams shall indicate clearly the following (where applicable) : (i)
Plant and equipment
(ii)
Current ratings including short circuit capacities
(iii)
Colour of indicating lamps
(iv)
Position of switches
(v)
Internal connections of all apparatus with all terminal markings
(vi)
All Plant and equipment to be shown in the open or de-energised position
(vii)
All secondary or primary plugged contacts
(viii)
Wire ferrule numbers
(ix)
Size, type and colour of wire
(x)
Current transformer terminal markings and outputs
(xi)
Ammeter and voltmeter scaling
(xii)
Relay settings
(xiii)
The main physical dimensions showing all necessary clearances required for removing covers, opening doors and withdrawing compartments.
(xiv)
Position of all Plant and equipment on panel faces indicating whether flush or projecting
(xv)
Identification of all Plant and equipment with the appropriate label engraving describing function and coding
The quantities, sizes and ratings of Plant and equipment incorporated within the switchboards shall be as indicated in the Drawings.
50.1.3
Construction The switchboards shall be of enclosed assembly design, suitable for indoor use in the form of free standing or wall mounting, self-contained, flush fronted cubicles sectionalised as necessary to facilitate easy transportation and erection. The assembly shall be Type Tested in accordance with IEC 61439. The main incoming unit, functional units of metered and unmetered supply, the metered and unmetered busbar sections shall be separately housed in their own cubicles.
BLDG12/S50.DOC(1) Sal(151211) (DPD)
Bldg Spec Page 50-2 50.1.3
Construction (Cont'd) Wall mounting switchboards shall be suitable for front access only and the maximum height shall be 2.0m. Floor mounting switchboards shall be suitable for front and back access. The cubicle sections shall be constructed of electro-galvanised sheet steel frames of minimum thickness of 2.0mm and the panels shall be constructed from electro-galvanised sheet steel of minimum thickness of 1.6mm. It shall be able to withstand a fault level of 36 KA for 1 second unless specified otherwise in the single-line-diagrams. The enclosures for the switchboards shall provide a degree of protection IP 4X. Each cubicle unit shall be incorporated with a removable cover with hidden hinges. The front cover shall have apertures for the protrusion of operating handles of circuit breakers. The covers shall be constructed of folded electro-galvanised sheet steel of minimum thickness of 1.6mm. The various units comprising a complete switchboard shall be grouped in a multi-tier arrangement including cabling and wiring chamber of ample dimensions to accommodate terminal boards, cable boxes and gland plates. All external panels of the switchboard shall be treated with a coat of finishing paint giving a total paint thickness of not less than 50 microns. All coats of paint shall be oven baked and dried.
50.1.4
Busbars Four pole air insulated busbars of uniform cross-sectional area throughout their length with a continuous rating or dimensions not less than that indicated in the Drawings shall be arranged neatly. The busbars and busbar connections between the busbars and various items of the switchgear shall be manufactured from copper. All busbars shall be tinned, and continuous lengths without connections shall be insulated with heat shrinking sleeves. Busbars shall be mounted on non-hygroscopic, anti-tracking insulators strong enough to endure, without damage, forces set up by any thermal expansion within the bars under normal operating conditions and forces created by prospective fault currents. Busbars shall be housed in separate compartments and these compartments shall not contain any wiring or apparatus other than that required for coupling to the busbars. Access to busbars and busbar connections shall be gained only by the removal of a cover secured by bolts. Behind the covers, an insulating sheet with warning labels bearing the word "DANGER" in bold letters and the lightning symbol shall be provided so that final access can be gained only through removing this sheet secured by round head screws. In addition, for the chambers housing the main busbars, the insulating sheet shall be of transparent material with the word "Danger" in bold letters and the lightning symbol. The material for the transparent sheet shall be of minimum 3mm thick clear polycarbonate with the following properties : (a)
greater than 86% light transmittance
(b)
special treatment for high abrasive resistance
(c)
high self ignition temperature.
The busbars shall, where necessary, have built-in facilities near the load side of the incomer to enable PowerGrid to fit their metering transformers and sealing of this compartment.
BLDG12/S50.DOC(2) Sal(151211) (DPD)
Bldg Spec Page 50-3 50.1.5
Circuits And Connections All connections between busbars and the switchgears shall be copper busbars or PVC insulated copper cables of minimum cross-sectional area of not less than the rating of outgoing cables connected to the switchgear. All cable connections shall be terminated with proper cable lugs and shrouded with heat shrunk PVC sleeves of the appropriate phase identifying colour. Small wiring shall be neatly bunched and cleated in harness form, or shall be enclosed in plastic purpose made small wiring trunking or trough. Supplies for control circuits shall be taken from within the compartment of the related item of the switchgear. A HRC fuse shall be fixed within the respective compartment to protect the control circuit. Where control circuits pass through auxiliary contacts the fuse shall also be used to isolate the terminals of these contacts. Where auxiliary contacts are used for interlocking purposes and supplies are derived from other sources, isolating facilities shall be provided to render the auxiliary switches safe. This isolation shall be in the form of auxiliary switches mounted on the respective compartment isolating device or a separate isolator mounted within the respective compartment. All small wiring shall be of multi-stranded copper not less than 1.5mm2 (7/0.50mm) with PVC insulation. All control wiring shall be identified with numbered ferrules. These numbers shall be shown on the schematic wiring diagram. All fuses shall be of the HRC type complete with bridges, terminal shrouds and carriers. Small wiring associated with external control circuits shall be connected to terminal strips which shall be conveniently arranged to facilitate the termination of incoming multi-core cables. Each connection shall have separate incoming and outgoing terminals and no more than two wires shall be connected to any outgoing. Each terminal block for external wiring shall have a minimum of 10% spare capacity. All wiring diagrams shall show the terminal blocks in terminal sequence.
50.1.6
Earth Bar A solid, tinned copper earth bar shall be provided at the base of the switchboard. The minimum crosssectional dimensions of the earth bar shall be 25mm x 3mm. It shall run the length of the switchboard and shall be easily accessible by removing the bottom front panels of the switchboard. All earth continuity conductors of the mains cables shall be terminated by means of appropriate cable lugs at the earth bar. The earth terminal of any cubicle of the switchboard shall also be connected to the earth bar by an adequately-sized earth continuity conductor. The earth bar shall be connected by a PVC insulated 70mm copper earth cable to the main earth bar in the switch room.
50.1.7
Metering, Instruments And Accessories Facilities shall be provided on the switchboards for PowerGrid to carry out their metering. The cubicle for housing PowerGrid meters, fuses, cut-outs and neutral links shall comply with the requirements of PowerGrid/SPSL. Where required, the Contractor shall collect and install the meters for PowerGrid all at the Contractor's cost and expense. Where indicated, voltmeters and ammeters shall be provided. Indicating instruments shall comply with IEC 60051, accuracy class 1.5. Instruments shall be of the moving iron type, with external zero adjustment. They shall be flush-mounted and housed in a pressed steel or plastic case with shield plate. Instrument terminals shall be shrouded.
BLDG12/S50.DOC(3) Sal(151211) (DPD)
Bldg Spec Page 50-4 50.1.7
Metering, Instruments And Accessories (Cont'd) Voltmeters shall be incorporated with selector switches for phase to phase and phase to neutral indication. Ammeters shall be of the current transformer operated type and shall be incorporated with selector switches for indication of all phase currents. Switches shall be of the rotary wafer type. Where maximum demand ammeters are specified, they shall be of the bimetallic type with thermal delay to suppress the short-term current and indicate the average effective value. The response time of the maximum demand ammeter shall be 8 minutes. The maximum pointer shifted by the bimetallic mechanism shall be reset manually by means of an external knob. Maximum demand ammeter shall be provided for each phase. Phase indicator lamps shall be of the light emitting diodes (LED) types, operating on direct 230 volts or on step-down voltage provided by a step-down transformer.
50.1.8
Current Transformers Current transformers shall be of the straight through type with suitable ratio, output and class of accuracy for their function and shall comply with IEC 60044. Measuring current transformers shall have accuracy of Class 1 and protective transformers shall have an accuracy of 5P10. Groups of current transformers used on three phase systems shall have their secondary connections starred and earthed. When measuring line current values using a common meter with a selector switch, they shall be connected so that the current transformers shall be shorted out when not being used for indication. This shall be carried out in the selector switch by "make before break" contacts.
50.1.9
Earth Fault Digital Protection Relay The digital protection relays offered shall be in compliance with the following : Parameters Operating temperature Humidity Vibration Shock and Bump Seismic Insulation
Relevant Standard IEC 60068 IEC 60068 IEC 60255 IEC 60255 IEC 60255 IEC 60255
Transient Overvoltage
IEC 60255
High frequency Disturbance
IEC 60255
Electrostatic Discharge Radio Frequency Disturbance Fast Transient Enclosure Protection EMC Compliance
IEC 60255 IEC 60255
Dielectric withstand
IEC 60255 SS IEC 529 EN50081-1,2 EN50082-1,2 89/336/EEC IEC60255
Impulse voltage
IEC60255
BLDG12/S50.DOC(4) Sal(151211) (DPD)
Requirements -10C to +55C 56 days at 40C and 95% RH class I class I class I 2kVrms for 1 min between all terminals and earth 2kVrms for 1 min between independent circuits 1kVrms for 1 min across NO contacts class III, 5kV 1.2/50s between all terminals and earth without damage or flashover. 2.5kV common mode
