At an American Society for Testing and Materials (ASTM) meeting last year, the issue of heat aging of TPO single-ply roofing membranes was raised and a tougher test standard proposed.

At an American Society for Testing and Materials (ASTM) meeting last year, the issue of heat aging of TPO single-ply roofing membranes was raised and a tougher test standard proposed.

Keep in mind, this occurred long before the Midwest Roofing Contractors Association (MRCA) Technical and Research (T & R) Committee distributed its advisory on TPO roofing systems. This advisory recommends that MRCA members take special precautions to limit TPO accelerated weathering due to excessive solar or thermal loading.

Last month, in a letter to Tom Drake, executive director of MRCA, SPRI Technical Director Mike Ennis said SPRI agrees that special care must be taken in areas of a roof that may be subjected to temperatures beyond the in-service limits recommended by materials manufacturers. However, Ennis added that MRCA did not include data to support its conclusions, and the advisory unfairly singles out TPO membranes.

While it seems like another controversy is brewing in the low-slope roofing industry, the end result should benefit roofing contractors, architects and building owners.

While we cannot predict the future, it seems probable that the industry’s three top TPO producers will agree to raise the bar on TPO heat aging performance. The change will most likely come within ASTM D 6878 Standard Specification for Thermoplastic Polyolefin Based Sheet Roofing. It is also likely that other TPO producers besides the “big three” will have to step into line and adhere to the new requirements.

SPRI and MRCA may rightfully agree to disagree on certain points of the latter’s advisory bulletin. But, in general, it appears the roofing industry is working together to improve the performance of TPO roofing membranes. Should that scenario take place, then everyone will win.

We can also look forward to the introduction of some significantly enhanced TPO roofing membranes in the coming months.

There will always been differences of opinion in the roofing industry, but in this case, ASTM, MRCA, SPRI and certain TPO manufacturers all deserve a round of applause should things pan out as expected.