Energy Rating of Roofing Assemblies: Research Partners Sought

While SIGDERS research has advanced understanding of the wind uplift performance of membrane roofs, NRC-IRC is seeking new partners to quantify air movement into this type of roof construction and to determine its impact on the overall energy performance of the roof.

Owing to the flexible and elastic nature of mechanically attached membrane roofs, wind can cause the membrane to balloon or flutter. This change in shape leads to volume change, creating negative or bubble pressure under the billowed membrane and thereby drawing conditioned interior air into the roof assembly. This is called air intrusion, which differs from air leakage (air movement from one environment to the other) that is common to wall assemblies. Damage from condensation and energy wastage are only some of the problems caused by air intrusion.

The research will focus on:
  •  Developing a test tool for analysing air intrusion characteristics for a variety of details, junctions and penetrations. As a first step toward the development of a test standard, the results of a pilot study have been submitted to ASTM.
  •  Generating air intrusion limits that may be used in the development of design guides, codes and standards.
  •  Identifying techniques to counter the impact of air intrusion on wind uplift performance and moisture transport.
  •  Studying the continuity of the roof/wall barrier and quantifying air movement.
  •  Relating air intrusion to energy performance and developing an analytical tool to predict changes in energy demand due to variations in the air intrusion characteristics of roof assemblies.

This research will benefit from the collaboration of researchers, regulatory authorities, manufacturers, roofing associations and organizations, and building professionals. NRC-IRC is seeking partners for the project. To learn move about the project and to explore becoming a partner, contact: Dr. Sudhakar Molleti (Suda) at (613) 993-9673, Fax: (613) 998-6802 or e-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .