Small Changes Can Prevent Damage

A new study of tornado destruction in Tuscaloosa, Ala., found that minor changes in construction could have prevented much of the damage to houses on the fringes of the twister.

Researchers said nothing could have saved structures that were in the direct path of the EF-4 tornado, which skirted the University of Alabama campus with winds up to 190 mph on its way through the city. Forecasters said it was one of the strongest twisters to hit the state during the severe weather outbreak that killed more than 240 people statewide on April 27.

“The vast majority of the area (experienced) lower wind speeds that you can engineer for,” said researcher Andy Graettinger of the University of Alabama. “You need to have the roof tied to the walls and the walls tied to the foundation.”

Homeowners on the fringes of the tornado would have been spared at least some damage with different construction methods or improvements to existing homes, Graettinger said. In some cases, he said, homes could have been saved from catastrophic damage by metal clips or straps that cost about $1 each.

A research team funded by the National Science Foundation assessed more than 150 homes along the path of the Tuscaloosa tornado, looking at everything from homes that were leveled to those that weren’t damaged at all. The most serious damage was at the center of the path of destruction, but homes on the twister’s fringes had far less damage because the storm was weaker on its edges.

Focusing on how to reduce damage in that zone, researchers found that basic changes like using wind-rated shingles; additional anchors at the bottom of porch columns; metal straps to link roofs with walls; and higher-quality vinyl siding could have made a huge difference in how well some homes survived the storm.