As populations grow denser throughout the “tornado alley” that stretches from North Texas through South Dakota, many experts say communities should consider designing buildings to withstand twisters just as coastal communities build to survive hurricanes.
“Tornado-resilient designs of houses, or of any structure, is a thing within our grasp,” said University of Florida engineering professor David Prevatt, who surveyed the damage in North Texas. “It’s something we can do, and we ought to do it.”
A few weeks after the storm in North Texas, Prevatt walked the streets of Rowlett with a team of his students. They were joined by employees of Simpson Strong-Tie, a California-based company that makes products for wind-resistant building. He pointed to older homes vulnerable to damage because of weak construction.
Building codes have improved as engineers and researchers analyze what worked and what didn’t after disasters. In the 1980s, codes in North Texas and in most places required design against only 70 mph winds. That threshold rose to 90 mph about 15 years ago, in accordance with standards set by the International Code Council.
Cities typically adopt the ICC’s codes, sometimes adding their own small amendments. But builders tend to spend money on things that buyers can see. Bricks and stone make nice-looking façades, but add little strength. The two-by-four studs behind the bricks are what make a structure sturdy, and homebuyers should consider asking for — and be prepared to pay more for — structural features that meet or exceed the code.
Adding a skin of plywood or wood particle board to the studs of a wall structure strengthens it a lot, experts say. The costs that you’re looking at are generally less than the cost of the granite countertop that the homeowner wants in the kitchen.
Excerpts from this article were taken from the Dallas Morning News and insurancejournal.com
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