Jul 8, 2008 11:16 pm US/Central
Protection From Disasters: Building A Safe Room
(WCCO)
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DuPont Storm Rooms are made of plywood, foam and Kevlar -- the same material used in bullet proof vests and armored vehicles. They've also passed strict FEMA safety tests.
CBS
When tornado warnings are issued we're told to seek shelter in the basement. They are the safest place to seek shelter from a storm. However, when you look at the remnants of the tornado that hit Hugo, it's easy to question that concept.
Many of the once three-story homes have been leveled with the contents scattered on the basement floor.
"I've seen houses like caved in like this in all the major disasters in the last 20 years that I've looked at," said Tim Marshall, an engineer and storm failure consultant.
Marshall travels the country studying storm damage for the federal government. WCCO asked him to look at how the homes in Hugo held up. His biggest concern was the basements, particularly those made of concrete block instead of poured cement.
"This is a typical mode of failure when wind, tornado, hurricane hits a house on a concrete masonry unit foundation," he said pointing to a home with concrete blocks scattered around the foundation. "I know we're always told to go to our basement when there's a tornado warning issued, but that could actually be a deadly decision if you have one of these weak foundations. The house will literally crush you in your basement."
Marshall said there is one way to protect your family if you have a basement like that.
"Build a safe room or have some safer area in the basement to go under," he said. Marshall suggests hiding under a staircase or choosing a bathtub in a basement bathroom without a window.
Stenerson Lumber in Moorhead just began selling and installing DuPont Storm Rooms.
Those storm rooms are made of plywood, foam and Kevlar -- the same material used in bullet proof vests and armored vehicles. They've also passed strict FEMA safety tests.
According to company information, " Kevlar is five times stronger than steel and provides a powerful and highly resistant barrier against wind borne debris. And the rooms will resist winds up to 250 miles an hour." "It's built so that the Kevlar acts like a net to catch any debris, any airborne missiles from the storm," said manager Les Stenerson.
"This can withstand 70,000 pounds of crush so it could take a fully loaded tractor trailer weight on top of this room. So if the house does come down it would be better to be in this than under the stairs in the basement," said Stenerson.
The door is meant to look like any other door in your home with an important hidden safety feature.
"If you take a closer look at the door it's got six, one inch stainless steel bolts that slam into a steel frame," said Stenerson.
The other difference between this storm room and the ones we've traditionally seen that are made of steel or concrete, is the Kevlar makes them light enough to fit into any existing home. They need to be bolted to the cement so they are typically placed in the basement or a garage. The Kevlar also means you can still get radio reception, even cell phone reception while you're inside.
The standard room is a 4 foot by 6 foot model and costs $7,400. DuPont, the company that manufacturers the rooms, said these storm rooms can be much bigger (12 foot by 12 foot). You can even custom build them to incorporate a bathroom, a closet or pretty much anything as long as it doesn't have a window.
It may seem like an extreme measure but Marshall said it's worth considering in a walkout basement especially if it's built of concrete blocks. Marshall said the fact that cement blocks are hollow is what makes them so weak.
"I've seen plenty of houses that have shifted off their foundation and they carry with them the top block and leave the rest of the foundation there," he said. "So that's why I don't like concrete masonry unit foundations."
Years of experience and thousands of disasters have taught Marshall sometimes the extra price is worth the peace of mind.
"I think that just depends on your level of risk," Marshall said. "There are a lot of people who say well it's not going to happen to me, tornadoes are rare, but I bet if you go to Hugo and you talk to people, a lot of them would say, 'We never thought we were going to be hit by a tornado'."
(© MMIX, CBS Broadcasting Inc. All Rights Reserved.)
Home Construction Lessons From Hugo Tornado
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