Abstract
On May 24, 2011, a series of thunderstorms that produced significant hail moved through the Dallas-Fort Worth metroplex and caused an estimated $876.8 million in insured damages to property and automobiles according to the Texas Department of Insurance. The Roofing Industry Committee on Weather Issues (RICOWI), of which the Insurance Institute for Business & Home Safety (IBHS) is a sponsoring member, organized a week-long damage survey project to evaluate the performance of roofing materials and systems, particularly impact resistant roofing. IBHS engineers participated in this study. In addition to the RICOWI study, this storm provided an opportunity to investigate hail-related losses from damage to roofs and other building components in an area where impact resistant roofing has been promoted. This was accomplished by evaluating property claim and policy-in-force data for more than 67,000 residential properties located in 20 ZIP Codes.
For this study, IBHS utilized these data to evaluate the importance of roofing material type and age with regards to roofing resiliency to hailstone impacts. In addition, the study also focused on evaluating the relative damage costs associated with roofing systems versus wall systems and provided a comparison of radar-estimated hail sizes to damage levels seen in the claims data. While there was a desire to evaluate the relative performance of impact resistant roofing and non-impact resistant roofing products of similar age, there were not sufficient data to do so. Recommendations for improved data collection and quality of data are provided in this report, and guidance for the conduct of future studies is summarized.
