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Tornado Storm Shelters

When a deadly tornado hits, moving into an interior room or closet of your home – as many guidelines recommend – might not offer enough protection. That's why some homeowners choose to build or buy a family storm shelter.

What kinds of storm shelters are there?

Three main types of shelters are designed to help protect you from severe weather. While each is intended to keep you and your family safe, each has its pros and cons.
Underground: A modern version of the old "storm cellars," these shelters are usually safe from flying debris and high winds. If you have to go outdoors (however briefly) to get inside, it can be difficult to access them if conditions outside are hazardous. Installation can be a problem, depending on the type of rock and the water table in your area.
In-residence: These act more like fortified closets, so they are more accessible when a tornado is imminent. They are usually built into a new house using reinforced concrete, reinforced masonry or wood/steel combinations. Building one into an existing house can be difficult and costly. Alternatives include pre-built metal shelters that are not only easier to install, but can be placed almost anywhere in the house.
Community: If a family shelter isn't an option, community shelters can hold multiple families (from as few as a dozen people to several hundred). Commonly used in manufactured housing areas, these shelters are usually above ground – which exposes them to flying debris – but many more lives can be saved.

What's the best storm shelter?

There's no one authority to tell you what the best storm shelter is, nor can the federal government endorse a specific type of storm shelter as being "the best." However, safety standards for storm shelters and shelter components have been established by the Federal Emergency Management Agency to ensure that you will be protected in most tornadoes, while the National Storm Shelter Association has also established a shelter standard.
The Wind Science and Engineering Research Center at Texas Tech University performs tests on shelters and various shelter components to see if they meet both sets of guidelines. Researchers use high-powered air cannon to shoot wooden two-by-fours at shelter walls and doors to simulate flying debris, while another test uses a wind tunnel to simulate the high winds and stress that walls would encounter. These tests and guidelines can help you choose the shelter that can best protect your family when a real tornado hits.

FEMA guidelines

The following rules are only a few of the federal guidelines established by FEMA. More information, including building plans, materials and more is available either by calling 1-888-565-3896 and requesting publication FEMA 320 ("Taking Shelter from the Storm: Building a Safe Room Inside Your House").
High winds: Tested with a 3-second gust of 250 mph.

• Walls, doors and ceilings must be able to withstand the peak wind velocity without buckling or separating.
• The shelter cannot overturn or slide.

Debris: Tested with a 15 lb. two-by-four wooden board propelled at 100 mph (250 mph wind equivalent)

• The walls and ceiling of a shelter must resist penetration by a test object.

Other requirements:

• Shelters must have a protected ventilation system.
• Shelters should have at least one fire extinguisher, flashlights, a first-aid kit, 8 hours' supply of drinking water, and a NOAA weather radio.

Additional requirements for underground shelters:

• Shelters must be watertight and resist flotation due to saturated soil.
• Shelters must contain a transmitter of some sort to signal the location of the shelter to emergency personnel, should debris trap shelter occupants.

Where can I find more information?

The National Storm Shelter Industry standard is available at: http://www.nssa.cc
Texas Tech's Wind Science and Engineering Research Center explains the testing process and has a number of links: http://www.wind.ttu.edu

Source: National Weather Service, Huntsville, Ala.www.ProvidenceSafeRooms.com