RCI Foundation Supports Research on Thermal Bridging via Roof Fasteners

By Rick Gardner

The RCI Foundation has approved funding for a study, titled “Laboratory Testing of Roof Assemblies for Comparison with Simulated Models: Thermal Performance Assessment of Thermal Bridges due to Roof Fasteners” at Virginia Tech. The team, consisting of Dr. Elizabeth Grant and Dr. Georg Reichard, along with their students, as well as industry sponsors Simpson Gumpertz & Heger (SGH) and GAF, will conduct selected laboratory tests to compare the thermal performance of physical models of simple roof assemblies under different controlled laboratory environmental conditions with computational models of these assemblies.

The overall goal of the project is to provide a better understanding to the industry of simulated versus tested thermal conductance in 3-D configurations, in support of relative comparison of quantitative thermal effects of fasteners in different roof assemblies.

The expectation is that the study will contribute to a better overall understanding of thermal performance of roof systems, enable both our members and the industry to understand the thermal penalty incurred by the use of roof fasteners in their designs, and ultimately provide validated simulations of approaches geared toward justification of any performance impact.

The expected completion date is June 30, 2020. Following conclusion of the study, the research team hopes to share results through presentations at IIBEC conferences and meetings, as well as through scientific papers.

Funding for this research is made possible through gifts to the RCI Foundation’s General Fund for Research and Education and, specifically, through GAF, as well as through in-kind donations from SGH. “GAF and SGH are both very excited to support this research and the information it will provide for the entire building industry,” said Helene Hardy-Pierce, Secretary of the Foundation and GAF’s Technical Director.

“After running computer models for an SGH-sponsored paper published by ASTM in 2015, it became apparent that roofing insulation fasteners will cause significant thermal bridging,” said Eric Olson of SGH, the lead author of a 2015 paper considering thermal bridging of roofing details. “These effects are not considered by many in the roofing industry, and there exists no clear guidance on how to deal with them. Validation of the computer models with physical laboratory analysis—the aim of the current study—is the next logical step to building practical methods for considering their effects.”

If you have questions or would like more information about the Foundation, please contact Development Officer Rick Gardner at rgardner@iibec.org or call 919-859-0742.