How homes devastated by tornadoes could have been saved by $1 straps

Two lethal twisters which killed 206 people have shown how minor changes can help tornado-proof homes, a study has found.

Simple additions such as $1 straps, stronger shingles, more anchors and thicker vinyl siding could have prevented much of the damage to houses on the fringes of the Tuscaloosa and Joplin tornadoes, researchers said.

Nothing could have saved structures that were in the direct paths of the EF-4 or EF-5 twisters, but properties in areas with lower wind speeds could have benefited, a team from the National Science Foundation found.

Devastation: Residents of Joplin help a woman who survived the tornado in her basement

Devastation: Residents of Joplin help a woman who survived the tornado in her basement

According to forecasters, the Tuscaloosa tornado, which had winds of up to 190mph on its way through the city, was one of the worst to hit Alabama during the severe weather outbreak that killed more than 240 people on April 27.

Missouri’s Joplin tornado, which was rated the strongest possible and the deadliest single twister in the U.S. since 1947, destroyed 8,000 houses and apartment buildings on May 22.

'The winds are so high that a wood-frame structure is not going to withstand them,' said researcher Dr Andy Graettinger of the Tuscaloosa tornado. 'In those cases, you need a safe room.

Roof clip: This is the kind of low-cost strap which could have prevented huge damage to homes on fringes of tornadoes
Tornado strap: Made from galvanized steel, the low-cost straps can come in a variety of shapes and sizes. Fixed when the roof system is complete, each truss or rafter needs one for the front and one for the back

Tornado strap: Made from galvanized steel, the low-cost straps can come in a variety of shapes and sizes. Fixed when the roof system is complete, each truss or rafter needs one for the front and one for the back

'But the vast majority of the area (experienced) lower wind speeds that you can engineer for. You need to have the roof tied to the walls and the walls tied to the foundation to prevent major damage.'

Homeowners on the fringes of the tornado would have been spared at least some damage with different construction methods or improvements to existing homes, said Dr Graettinger, an engineering professor at the University of Alabama.

In some cases, he said, homes could have been saved from catastrophic damage by metal clips or straps that cost about $1 each.


The twister which hit Tuscaloosa in April claimed the lives of 46 people. It skirted around the University of Alabama and had wind speeds of 190mph.

In May, Joplin witnessed the deadliest tornado in the U.S. since 1947 when 200-mph-winds wiped some houses clean off their foundations and left behind random walls, staircases and porches.

'You’re looking at a few thousand dollars for these clips that hold everything together,' Dr Graettinger said. 'It's a very small amount compared to the cost of the house.'

A research team funded by the National Science Foundation assessed more than 150 homes along the nearly six-mile path of the tornado in Tuscaloosa, looking at everything from homes that were levelled to those that weren't damaged at all. Their report was released on Monday.

The most serious damage was at the centre of the path of destruction, where the swirling winds were strongest and the most debris flew through the air.

Homes on the edges of the storm received far less damage because the storm was weaker on its edges, and the team focused 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.

Ominous: The Tuscaloosa tornado moves through the city

Ominous: The Tuscaloosa tornado moves through the city

'We would have saved a lot of rebuilding cost if that had been done,' said Dr Graettinger.

Researchers didn't determine how much the needed changes would add to the cost of a new home, or the cost of retrofitting existing homes to make them stronger.

But they hope the findings will lead to better construction techniques in tornado-prone areas, much as coastal areas have adapted building codes and methods to help structures withstand hurricanes.

In Joplin, the research team used 3D image scans of homes and a destroyed hospital to gather data for researching better building techniques.

Dr Graettinger said he had also been to see buildings destroyed by Hurricane Katrina in 2005.

Mess: A Joplin resident surveys the rubble his home has become
Mess: Joplin residents survey the rubble their homes have become

Mess: Joplin residents begin picking through the rubble their homes have become after the EF-5 twister struck

David Prevatt, a University of Florida assistant engineering professor who was on the Tuscaloosa team, said that Florida's experience with hurricanes might help tornado-vulnerable communities build better structures.

He told NBC News: 'The more difficult part — and this affects particularly not just tornadoes, hurricanes, anything in the country — is what do you do about the existing structures?

'Do we place a saferoom in all these structures? Do we reinforce or refit those structures or do we sort of break down and start again?

'It's an economic question, it's a social question. But we have the engineering knowledge now to add to that question.

'We want to be at the table when a city or town like Joplin is discussing what they want to look like in the next 50 years in terms of their residential structures.'

It was reported last week that after crews in Joplin had taken more than 2.4million cubic yards of debris to nearby landfills, officials gave the go-ahead for rebuilding to begin.

The comments below have not been moderated.

The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.

We are no longer accepting comments on this article.

Who is this week's top commenter? Find out now