More on PVC Roofing

More on PVC Roofing

We read your article entitled “Low Slope Roofing: Prospects Looking Up” (EBN

Vol. 7, No. 10 – November 1998) with interest. We would like to bring some items to your attention.

•Fire resistant EPDM (needed to obtain Factory Mutual and U.L. fire ratings for adhered and mechanically fastened systems) contains bromine. EPDM also requires solvents for cleaning of seams and solvent-based adhesives for seaming.

•We find the debate on fire performance of PVC very interesting. Sarnafil’s PVC membranes have been specifically asked for to protect some of the most important buildings in the world—in part because of their ability to resist combustion and spread of flame. Sarnafil’s roof system was selected for the National Fire Protection Agency Headquarters located in Quincy, Massachusetts. A video is available from Sarnafil that compares fire performance of Sarnafil to fire-retardant EPDM and fire-retardant polyolefin (both containing bromine as the fire retardant).

•Firefighters we have spoken to have expressed concern with contents of buildings and have said that the type of roof has little impact on smoke developed within the building.

•It is interesting to us that low-sloped metal may prove to be “one of the most environmentally friendly roofs.” Creating metal requires a tremendous amount of heat and energy. Processing oils are typically needed during the manufacturing process, and hazardous fumes can be created. Why is it that metal is okay, but products containing halogens such as chlorine are not?

•On page 18 there are two references that polyolefin membranes may replace PVC membranes. The fact is that PVC roof membrane usage continues to grow. EPDM membranes are losing market share to TPO [polyolefin] and PVC membranes.

We at Sarnafil support the ongoing discussion of designing sustainable building products. We disagree, however, with the wholesale statement that PVC is bad. We feel that Sarnafil defines “sustainable building products for roofing.” Sarnafil is far different from a “used-once” disposable product, such as many PVC medical products.

Brian J. Whelan

Sarnafil, Inc.

Canton, Massachusetts

Response: Thank you for your comments. Evaluating such complex products is not simple, and our article, while pointing out many of the key issues, is clearly not the last word. A rigorous, unbiased life-cycle assessment examining these different materials would go a long way towards answering some of these questions. It would be particularly important to examine the issues surrounding the use of bromine fire retardants. Bromine is a significant ozone depleter, and there is evidence that brominated fire retardants may bioaccumulate in the food chain—as do many chlorinated compounds.

– The Editors