Roof Hail damage to roofs and buildings. In many parts of the US, hailstorms are a way of life. For many homeowners, it’s not a question of whether a hailstorm will hit. But when damaging, hail will hit. Areas in the U.S. receive hail six or more times a year, rain, and many homes are damaged yearly. By definition, hail damage is any damage resulting from hailstones and hailstorms. Hailstones that are 0.75 inches or greater are large enough to cause substantial damage to homes. Automobiles & property. For comparison. 075 inches is the diameter of a penny, which can be checked by roof hail damage by professional engineers.