Emissivity Measurements of Common Construction Materials

Emissivity Measurements of Common Construction Materials Edward L. Fronapfel, M.S., P.E. Bradley J. Stolz, B.S., EI Professional Investigative Engineers, Inc.

ABSTRACT This paper will review and discuss the determination of the emissivity of common c onstruction materials to aid the investigator during infrared inspections/surveys inspections/surveys of building envelope systems. Specifically, this paper will discuss the results of product testing of constructed wall assemblies. The wall assemblies are constructed to mimic the common materials encountered in building envelope surveys. They include materials such as hardboard lap sidi ng, stone veneers (faux and natural), stucco, exterior insulation and finish systems (EIFS), trim accessories, vinyl frames, painted flashings, self-adhering flexible flashing membranes, oriented strand board (OSB), ethylene-propylene-diene monomer (EPDM roofing material), wood framing, and concrete. In order to provide a better analysis and determination of results with thermography measurements it is important to understand the relationships of the products emissivity on multi-surface, multi-material multi-material constructed assemblies. As well, the thermographer thermographer should understand the effects of the angle of inclination utilized when when conducting thermographic surveys. This paper will deal with the determination of the values of emissivity of such common materials and the effect of the angle of view used at the time of the the thermographic imaging. Additionally, it will discuss the effects of visible light on the heating of objects and, therefore, its implications when performing emissivity calculations in the presence of visible light such as sunlight. Multiple full-scale mock-ups of building wall assemblies assemblies will be constructed and a determination of parameters parameters will be made from these these full-scale assemblies. The results will be tabularized and provided for this paper. INTRODUCTION The use of infrared measurements during building skin applications involves the process of reviewing single images with multiple emissivities. This paper is being prepared to provide the the users with a means of evaluating the differences in emissivities of many common exterior building cladding materials. Mock-up assemblies were constructed of various materials used to commonly clad, cover or protect the building envelope. These mock ups included (as photographed photographed below), stucco, stone, siding, flashing, decking, concrete, coatings, trim, and window frames (vinyl and aluminum). A common laboratory temperature of 70 degrees Fahrenheit was maintained for the testing environment, with with low humidity (