RICOWI Study Finds EPDM Offers Superior Protection Against Hail

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For the past decade, ERA has disseminated science-based information about the superior protection that EPDM membranes offer against hail damage.

In 2007, ERA commissioned independent laboratory testing comparing many types of roofing materials and their resistance to hail up to three inches in diameter. The results of the study showed that EPDM roofing membranes did not suffer membrane damage and avoided leaking problems endemic to other roofing surfaces in similar circumstances. Based on field observation, and this test data, it was clear that EPDM roof membranes outperform other roof systems in terms of hail protection.

Our findings have been reinforced empirically since our study was conducted ten years ago. Now RICOWI, the prestigious Roofing Industry Committee on Weather Issues, has released an exhaustive study on the damage caused by a history-making hailstorm in North Texas on April 11, 2016. Once again, EPDM delivered superior protection against one of the fiercest opponents that Mother Nature can unleash. As stated in the RICOWI report, the goal of the study was “to create a greater industry understanding of how roofs perform in severe hail events.” The organization hopes this
understanding “will lead to overall improvements in roof system durability; reduction of waste from reroofing activities; and a reduction in insurance losses, which can lead to lower overall costs for the public.”

The April storm that triggered the RICOWI study was declared an insurance catastrophe by Property Claim Service (an insurance services company) and left a path of destruction nearly 200 miles in length and had hail reported up to 4”diameter. Five RICOWI teams were assigned to inspect low-slope sites; sites were offered for inspection by one large retailer and some governmental agencies in the area. Roof membranes that were solidly supported or protected with gravel or aggregate ballast performed well. Approximately 2.5 million square feet of low-slope roofing was inspected, and at least 1 million square feet of the roofing was scheduled for replacement. Of the low-slope roofs, 27 were single-ply roofs and seven of those were severely damaged. Four of the severely damaged roofs were exposed to hail 2.5 inches and greater. Two thermoplastic membranes (without ballast) sustained significant damage from hail less than two inches in diameter. Three inspections were made on EPDM membranes with hail sizes between 1.0 and 3.0 inches in diameter, and no punctures or fractures were documented.

The RICOWI study adds to the body of evidence that EPDM affords excellent protection against severe hail and outperforms other single-ply membranes extreme conditions.

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