TAMPA, FLA. — The Institute for Business & Home Safety (IBHS) has released its latest research study, “Surviving Nature’s Fury: Performance of Asphalt Shingle Roofs in the Real World,” which investigated damage from Hurricanes Gustav and Ike in 2008.
Roof cover damage continues to be the most frequent source of hurricane-related insurance claims not related to storm surge. The multi-variant IBHS findings offer compelling evidence of how well asphalt shingle roofs would perform during a hurricane.
“Our research took a much broader approach than what has been done in prior post-hurricane disaster investigations,” said Dr. Timothy Reinhold, IBHS senior vice president of research and chief engineer. “IBHS’ analysis examined damage levels at relatively low wind speeds as a function of the age of the roof, the adoption and enforcement of modern building codes, and investigated the validity of questions concerning whether the current approach to the design of shingles that reduces uplift loads is adequate.”
“Surviving Nature’s Fury: Performance of Asphalt Shingle Roofs in the Real World” uncovered a number of findings, among them:
•A significant number of roofs installed after 1998 experienced damage. Many of the roof coverings experienced damage to less than 1 percent of the total roof covering. The damaged roof area of homes built between 1996 and 2001 averaged 4 to 5 percent. Roof damage dropped dramatically for homes built after 2002. It is too early to tell whether the better performance was due to the newness of the roof covers or to building code changes in 2002, which added a check for roof cover wind rating.
•Newer shingle roofs installed after the Texas Department of Insurance adopted the 2000 International Building Code in February 2003 exhibited much less wind damage from the wind speeds produced by Hurricane Ike than older roofs in the same area. This could be attributed to a combination of age and code/product changes. The Institute noted that more study is needed to further explore these issues.
•Damage occurred even in fairly light winds — peak gust wind speeds in the areas where houses were studied were less than 90 mph. This demonstrates that it does not take a major hurricane with high wind speeds to substantially damage a roof.
To reduce future losses, Reinhold stressed that there must be a better understanding of damage risks for current roofing products, and for improving products and producing wind ratings that more accurately predict performance in hurricanes and other severe wind events.
“This study just begins to address the issues associated with shingle performance in high winds,” said Reinhold. “More research is needed both in terms of field investigations for events, where new wind-rated products are exposed to higher wind speeds, and in a controlled environment such as the new IBHS Research Center, where effects of aging and wind speed can be investigated on demand for a variety of products.”
Reinhold presented the preliminary findings of the study at the recent National Hurricane Conference in Orlando. The full version of the study is available in the summer issue of IBHS Disaster Safety Review.