Vinyl ranks high as roofing material

A four-year durability study ranks vinyl, typically used for siding, as a more climate-compatible roofing material than other single-ply options, according to the Chemical Fabrics and Film Association.

Researchers rated material performance based on thermal expansion, load-strain properties, water absorption, puncture resistance and glass transition temperature using test sites in Phoenix, Key West, Fla., and Champaign, Ill. The two vinyl membranes studied ranked first and third in Phoenix and Key West, with scores higher than 77 on a 100-point scale. They ranked second and fifth in Champaign, with 71.1 and 78.7.

The following materials were tested:
· membranes made of vinyl;
· asphalt-glass fiber felt;
· thermoplastic polyolefin;
· atactic-polypropylene polymer modified asphalt;
· styrene-butadiene-styrene polymer modified asphalt;
· ethylene-propylene-diene rubber; and
· PVC alloy.

Jay Thomas, director of marketing at Sarnafil, a high-tech plastic polymer manufacturer, said the material is widely used on commercial industrial roofs such as retail stores, hospitals and manufacturing facilities. It’s been on the market for nearly 40 years.

“Vinyl is a single-ply material used for low-slope commercial projects, so it’s not necessarily competitive with shingles,” he said, “but it is very competitive with other single-ply materials.”

The study, which is the third in a series, was conducted by engineering firm Simpson Gumpertz & Heger in Waltham, Mass., the U.S. Army Corps of Engineers Construction Engineering Research Lab in Champaign, Ill., and the National Research Council of Canada in Ottawa, Ontario. The first study documented the results of exposure to various artificial aging procedures, and the second documented the results of two years of field exposure. By the time the study series is complete, it will have drawn from six years of research.

Results from the most recent tests were presented at the International Conference on Durability of Building Materials and Components in Lyon, France.

According to the Single Ply Roofing Industry, single-ply membranes are stronger, more flexible and last longer than built-up roofing materials like asphalt and felt.