A recently completed multi-year study, conducted by the Vinyl Roofing Division of the Cleveland, OH-based Chemical Fabrics and Film Association, reveals the excellent ability of thermoplastic vinyl roofing material to withstand the elements. The study compared the relative durability of 12 roofing materials in three climate zones (the hot and dry climate in Phoenix; the hot and humid conditions in Key West, FL; and the moderate, mid-continent climate in Champaign, IL) after 4 years.
The purpose of the study was to determine the parameters that can be considered predictive of the long-term performance of roofing membranes in service. Physical properties of each material have been carefully measured at each of the three sites by researchers. The two vinyl membranes studied in Phoenix and Key West ranked first and third; in Champaign, they ranked second and fifth. Test compared membranes made from the following materials:
- Asphalt-glass fiber built-up.
- Thermoplastic polyolefin (TPO).
- Atactic polypropylene polymer modified asphalt.
- Styrene-butadiene-styrene (SBS) polymer modified asphalt.
- Ethylene-propylene-diene (EPDM) rubber.
- PVC alloy.
Data has been collected by researchers on thermal expansion, load-strain properties, water absorption, puncture resistance, and glass transition temperature under identical conditions, ensuring an apples-to-apples comparison. Measurements will continue to be taken over the next 2 years and, once completed, a total of 6 years of data will have been collected. The Waltham, MA-based engineering firm Simpson Gumpertz & Heger Inc. is conducting the study along with the Champaign, IL-based U.S. Army Corps of Engineers Construction Research Lab, and the National Research Council of Canada, Ottawa, ON.
For more information or to review the complete study results, visit (www.vinylroofs.org) and click on “Predictive Service Life Tests for Roofing Membranes.”