The truth about Hail and EPDM

True or False: Hailstorms, while damaging and potentially dangerous, are relatively isolated events confined to one portion of the United States.

False! Seventy-five percent of American cities experience at least one hailstorm a year, and the risk extends throughout the country in areas east of the Rockies.

So how did we learn this surprising fact about hailstorms, and why is it so important to us?

ERA leadership visited the Insurance Institute for Business and Home Safety (IBHS) Research Center earlier this month. The center, located in Richburg, South Carolina, is a state-of-the-art facility dedicated to conducting “objective, scientific research to identify and promote effective actions that strengthen homes, businesses and communities against natural disasters and other causes of loss.” The visit was part of ERA’s concerted effort to get first-hand knowledge of what creates a resilient building. (see

ERA members have long known about the damage that hailstorms can inflict, and have designed their EPDM products to protect against these natural events. But the visit to IBHS took our understanding of hail, and the damage it causes, to a whole new level. For instance, average annual hail losses in the United States approach one billion dollars. And severe hailstorms, delivering a pounding with stones one inch in diameter or larger, appear most commonly in thunderstorms or even in super cell storms that can also deliver tornadoes.

Our visit to IBHS increased our understanding of resilience. It was also an important reminder of the value that EPDM can provide in a resilient system. For instance, in 2007, ERA commissioned an independent laboratory test 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.

And, more recently, RICOWI (the Roofing Industry Committee on Weather Issues) released a report on the damage caused by the April, 2016 hailstorm in Texas
which left a path of destruction nearly 200 miles long and reported hail up to 4”diameter. The report noted twenty-seven inspections were made on low-slope roofs and seven of these roofs were severely damaged. 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. (see

ERA continues to gather more science-based evidence about the threat of hail, and the strength of our product as it withstands potentially damaging storms. And we will continue to pass these important findings along to our customers. It’s all part of our commitment to let you know about the strength of EPDM products, and how they contribute to the resilience of roofing systems.