Feb 12 2008
The devastating tornadoes that recently stunned five states are a reminder of nature's power and unpredictability. But according to the Institute for Business & Home Safety (IBHS), houses in inland areas of the United States would have a greater chance of surviving violent windstorms if they were better-connected.
About 1,300 tornadoes are reported in the U.S. each year with activity increasing between March and June. While only a few specialty buildings are designed to withstand the direct impact of a severe tornado, good construction choices can give added protection and increase the likelihood that at least part of a home will remain standing to provide some shelter. Strengthened homes near the storm's edge would have a good chance of surviving intact or with minor cosmetic damage.
However, according to IBHS, homes in inland areas of the United States are typically held together only with nails, instead of straps connecting the roof, walls and foundation, which is commonplace in hurricane-prone areas and should be considered by anyone who wants to increase their property's protection from other severe windstorms.
IBHS offers these tips for increasing structural wind resistance for new wood frame houses:
- Have the builder install metal straps to connect the roof structure to the walls. This should only cost a few hundred dollars for a typical 1,500 to 2,000 square foot house.
- Have the builder use straps and wood structural sheathing to tie the structure together and anchor it to the foundation. High wind guides such as those from the American Forest & Paper association (AF&PA) provide helpful graphics of these elements.
- Consider installing a safe room. FEMA offers construction guidelines or you can contact the National Storm Shelter Association (NSSA) for more information.
"A home has to be well-connected in order to distribute the forces caused by wind pressure, which reduces the chance it will come apart or collapse," said IBHS Vice President and Director of Engineering Tim Reinhold. "The good news is these connections are relatively inexpensive when used during construction, maybe adding three to four percent to the price of a home."
Information about disaster-resistant construction and increased protection from tornadoes is available free from IBHS. To help protect homes or businesses from disasters or more common causes of loss, visit the IBHS web site http://www.DisasterSafety.org.