After a tornado blew through in the spring of 1998, Minnesota home improvement contractor Dean Williams began to get questions from prospects about the wind and impact resistance of the siding products he installs.

"[Homeowners are] all worried about whether or not the panel is going to damage as a result of impact," says Williams, owner of Quality Home Improvement of Le Seuer. "They've seen pictures of vinyl with holes in it."

As stories of hurricanes, tornados, hailstorms, and other untoward weather phenomena multiply, consumer demand for stronger, tighter vinyl siding increases. In 1994, Williams switched to a heavy-gauge vinyl with an installation system that is what he calls "goof proof," meaning it has built-in safeguards that guarantee proper installation. Since he made the switch, "other than a hockey puck and some mid-winter snow shovels thrown against the house, we've had no calls" for service work regarding impact resistance. Williams tells prospects that if hail punctures the siding he installs, it will also puncture steel siding. In either case, a call to the insurance agent is in order.

Last year, for the first time, Williams also installed five foam-backed siding jobs. He notes that the considerable rigidity of foam-backed siding lends weight to manufacturers' claims that the product is 10 times as impact-resistant as new-construction vinyl. And, he adds, "I'm sure it's less apt to be sucked off the wall" in a windstorm. It's also more expensive, not only for the cost of materials but because labor hour costs for installation are typically 15% to 20% greater than for heavy-gauge vinyl.

New Jersey contractor Joe Iuvara, who's owned and operated Iuvara Siding amp; Windows in Haddon Heights for 38 years, says he's skeptical about foam-backed siding but plans to attend a supplier-sponsored presentation on the product. Five years ago, Iuvara began installing a product with a double-rolled, .088-inch-thick nail hem, which multiplies wind resistance to 180 mph and is perfectly suited for installations at the New Jersey shore. The product also features a stud-finder installation system, which combines nail slot locations with graphics to ensure that every nail hits a stud.

That's impressive to customers, who are becoming more knowledgeable about home improvement issues. Not long ago, Iuvara explained to a prospect that his siding would hold in winds of up to 200 mph. Iuvara says the prospect reminded him that "if it's not installed properly, it'll blow off in 30 mph winds."