Hail Storm?

When hail storms come thundering along, they mean trouble of a particular kind for your roof. No roofing system is hail-proof. But there are roofing materials with hail-resistance ratings. These are provided by the American Society of Testing and Materials (ASTM).

You can choose a material rated one through four (four being most resistant.) They achieve this rating by dropping a steel ball from a predetermined height onto the roofing material and determining the damage.

Many roofs carry this rating. For steep slope, these roofs include some metal roofs, some tile and some composition shingles. For flat roofs, these are some gravel-surfaced built-up, and some spray foam (with the right coating system), and just a few others.

Installing a Class IV hail resistant roof may qualify you for lower insurance premiums, depending on where you live. Call your agent for verification. Keep this in mind, too: not many agents and adjusters will know the specifics about hail resistant roofs. Consult either a good roofing contractor or your local roofing supply warehouse.

Since World War II scientists have tried many techniques to lessen the damage from hail storms. The most well-known technique involved "seeding" large thunderstorms with silver iodide. The theory was that the resulting small hail would probably melt and therefore not cause any damage. Unfortunately other experiments using this technique were not successful, and hail suppression remains elusive.

Another novel technique to supress hail was recently installed in a company parking lot by an auto manufacturer trying to protect its inventory of newly painted cars. Under certain thunderstorm conditions detected by the company's own radars, a cannon-like device will send sonic waves up to 50,000 feet in the air to keep hailstones from forming. Now they must wait for a hailstorm to pass over the parking lot to test the device!