Keeping Your Home Safe From Tornadoes
WHY YOU SHOULD CARE
In late April, 15 people died in storms in Arkansas; more than 150 were injured. Could better protection for their homes have helped?
By Anne Miller
The sky blackens. The Klaxons blare. The tornado comes. You pull the shutters, tuck into an interior bathtub and … pray the garage holds?
If only Dorothy knew.
One move could save your house, a new study finds: a properly braced garage door.
Garages might seem like afterthought when it comes to securing a wind-tossed house. Sure, there are cars and bikes and those boxes of crap you’ve forgotten about since you moved in, but do they really matter in comparison to, say, your main abode and all the dither of keeping yourself and your family physically safe?
But it’s not just about saving the kids’ bikes. Twisting metal garage doors can wreck a whole house.
Now’s the time to get on it: We’re in the middle of tornado-season hell. Typically, April and May see half the year’s twisters, and the most deadly. The majority of people who have died from such storms in the U.S. perished in the early spring.
Last May, a ferocious F5 tornado barreled through Moore, Oklahoma, with wind speeds between 261 and 318 miles per hour — the strongest possible, according to the Fujita scale that measures such things. Two dozen people died.
Professor Andrew Graettinger of the University of Alabama’s engineering department and a team of scientists with government funding tracked, mapped and analyzed the storm’s damage. They mapped damage through tweets. They cross-checked storm-ravaged homes with Google Maps photos for before-and-after comparisons. They visited sites.
On wooden houses, they found significant damage to garages, roofs, and walls that was triggered in part by thin metal garage doors.
Here’s how it works:
During a tornado, you want your house as enclosed as possible. It’s bad enough that winds rage at the pace and strength they do outside. Breaches in the house can lead to pressurization during a tornado — building pressure inside the house so it’s more likely to blow off the roof, or cause other damage.
The researchers found that garage doors, especially on attached garages extending out from the main house, breached more readily than solid house walls. The breach pressurized the garage, the roof collapsed, the walls collapsed, and that left the main house more vulnerable to damage.
The weakness of garage doors has come up before. In the wake of Hurrcane Andrew, some Florida communities must have reinforced garage doors. Those winds maxed out at around 175 mph — half of the wind speed of the Moore tornado.
And just a few weeks before Greattinger and his cohorts publicly released their report, Moore enacted new building codes, some of the strictest in the nation, requiring reinforced garage doors on new construction.
But there’s a lot of iffy doors already in place, and your house might have one of them. So add “reinforced garage door” to your list of must-have stormproofing items.
Dorothy, be warned: As go the garage doors, so goes the rest of the house.