Letters

Manufacturer offers clarification

I am writing to you in response to "Thermoplastics 101," June issue. Specifically, I would like to address the incorrect information about PVC membranes that was published.

PVC membranes are known for their flexibility and heat-welding properties. Although available in a wide variety of colors, white membranes most commonly are used because of their superior reflectivity. PVC and TPO membranes typically are reinforced with polyester scrim or fiberglass mats and can be mechanically attached, adhered or induction-welded to roof decks. The process of heat welding only is meant for seaming two membrane sheets together—not to attach it to the building as the article implies.

PVC and TPO membranes commonly are used in low-slope applications and range in thickness from 40-80 mils. Comparing these materials as an alternative option to asphalt shingles, typically used in steep-slope roofing projects, is inaccurate and misleading as is the mention of the need to use primer and coatings during maintenance. Although coatings are an option for protecting and prolonging the life cycle of thermoplastic membranes, they are not a required maintenance expense as the article indicates.

And though there are similarities between the two materials, it is important to note key differences when selecting the right product and manufacturer for low-slope projects. TPO and PVC membranes can be ENERGY STAR^®-rated and recyclable; however, Duro-Last and Sika^® Sarnafil are the only two single-ply roofing manufacturers to earn the NSF/ANSI 347 Platinum certification for the sustainability of their products.

Additionally, the article correctly states thicker membranes offer extra protection, but it's important to understand where the thickness comes from on the membrane. The top "performance" layer of a single-ply membrane is most critical because it is the layer that is exposed to the harsh elements every day. Coupled with the use of walkway pads in high-traffic areas, a PVC membrane will offer superior performance for years to come.

All of us at Duro-Last are proud to offer high-quality solutions for contractors and building owners and work hard to promote learning and growth within the roofing industry. And though we are honored to be an active member of an organization that offers much needed leadership and guidance to the industry, we sincerely hope more care will be given to the authenticity of articles and information that is published in the future.

Keith Gere
Duro-Last Inc.
Saginaw, Mich.

Professional Roofing responds: Thank you for your letter and for clarifying the points the article made.