Roofing Researchers to Develop New Test Protocol for Quantifying Air Leakage Through Low-Slope Assemblies
 

Increasing demand for and the rising cost of energy have intensified interest in the issue of air leakage through the building envelope. However, until recently, the roof – in contrast to walls and windows – has not received much attention regarding its air-leakage performance. 

Being able to control air intrusion is critical in roofing design, as this has several effects on the performance of the roof – on wind uplift, energy consumption and moisture migration. Now, advances in roofing technology are providing greater opportunities to control air intrusion. But at present, there are no code requirements, standard specifications or test methods for the design or quantification of air-barrier performance in roofing assemblies. 

NRC-IRC researchers are working to address these deficiencies. They have laid the groundwork by conducting a feasibility study, which included the creation of a small-scale test facility, and attempted to quantify the air-leakage rate of the roofing assembly both with and without an air barrier. 

The preliminary results clearly demonstrated the significance of the barrier in providing air-leakage resistance. But because these observations were based on small-scale experiments, which were devoid of any joints, junctures or penetrations, it is clear that there is a need to build a full-scale air-leakage facility that replicates a real roof so that further research can be conducted.

 

NRC-IRC is seeking collaborators from both private and public sectors for this study to develop:

• A laboratory test protocol to quantify air leakage in roofs that could be used in the development of codes, standards and guidelines;
• Design tools for air barrier systems in roofs;
• A field test protocol that provides comparable results to those of the laboratory test protocol;
• An analytical tool to predict changes in energy demand due to variations in the air-leakage characteristics of roof assemblies.

 

Specific questions can be directed to Dr. Sudhakar Molleti at (613) 993-9373, Fax: (613) 998-6802, or e-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .