Performance of Asphalt Shingles in Extreme Severe Convective Storm Winds

The derecho windstorm of August 10–11, 2020 was the most prolific single severe convective storm event of 2020.

Its impact resulted in substantial insured losses, reaching billions of dollars. Over a span of 12 hours, a cluster of thunderstorms accompanied by extreme outflow winds traveled more than 750 miles, affecting several states from Nebraska to Indiana. Among the areas significantly affected by the storm’s long-lasting and powerful straight-line winds, Cedar Rapids, Iowa experienced the most widespread and severe property damage.

The performance of asphalt shingle roofs in high winds is a dominant driver of loss in any windstorm. However, most research into wind performance of asphalt shingles has centered on their performance in hurricanes. The 2020 derecho event offered an opportunity to explore asphalt shingle performance and how it evolves with roof age from a damaging straight-line severe convective storm wind event.