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Shelter Tornadoes

Above Ground Tornado Shelters: Everything You Need To Know

You live in Tornado Alley. While spring brings warmer weather, March through June brings the threat of storm systems that can spawn deadly tornadoes.

The 2021 tornado season was one of the worst ever, with the season extending through December for an unusual late-autumn outbreak across the south and Midwest.

So far, you and your family have been spared those violent touchdowns of EF3 tornadoes with their 140-150 MPH debris hurled devastation. While not attributing any tornado to the effects of climate change and warmer weather, says the NOAA, “We can say that warmer weather temperatures… make tornadoes more likely.”

Tornadoes Defined

Tornadoes are nature’s most violent storms. Their whirling winds can reach as much as 300 miles an hour. The funnel clouds are spawned in severe thunderstorms that begin with high winds and produce golf-ball- to softball-sized hail.  According to NOAA’s National Severe Storms Laboratory, about 1200 touch down in the U.S. every year.  

What about personal shelters?

Twister Pod 4 ft. x 6 ft. Tornado Storm Shelter

When you bought your home, it didn’t come with a safe room or a tornado shelter (your bathroom is the closest). You notice a few homes in your subdivision have been retrofitted with storm shelters. You’re interested in learning more so that you can confidently shop and begin to talk to contractors.  

So, as a starting point, we have gathered the information below for you to make informed decisions.

Before the tornado arrives

Now that you have decided to build or install your tornado shelter/safe room, here’s a list of things you need to know:

Definition of a Safe Room

The FEMA definition of a Safe Room is “a hardened structure specifically designed to meet the Federal Emergency Management Agency (FEMA) criteria and provide near-absolute protection in extreme wind events, including tornadoes and hurricanes.”

The term “near-absolute protection” is based on the current knowledge of tornadoes where the occupants have a very high probability of being protected from injury or death. The safe room, however, must be built in accordance with FEMA guidance to fulfill that requirement as well as make the structure eligible for FEMA Hazard Mitigation Assistance (HMA) funding.

Above-ground Tornado Shelters

The first thing you should know about above ground tornado shelters

According to FEMA P-320, Taking Shelter from the Storm, provided the shelter meets FEMA P-361 requirements, “an above-ground safe room is just as safe as a below-ground or in-ground safe room (emphasis added).”

Also, FEMA emphasizes that above-ground shelters

“are a great option if you are not able to install a safe room in your basement or in-ground because of issues such as flood hazards…” or other physical limitations of elderly occupants, for example.

In some cases, above ground storm shelters can be a better option than an in-ground or basement storm shelter.

Below-ground shelters used to be considered the best sanctuaries against high winds and airborne debris, but they come with risks of flash flooding or trapping the occupants underground because of debris blockage around the doors, or access and escape obstacles to the elderly or infirm.

So, conventional wisdom for seeking shelter from a tornado was once that the only safe place to seek shelter was below ground. However, 15 years of research at Texas Tech University’s National Wind Institute found that above-ground storm shelters can keep occupants safe even from 2×4 wood beams propelled at 100 mph.

More Things You Should Know About Above Ground Tornado Shelters

ShelterCube 6x4 Panelized Steel Indoor Tornado Shelter (Door on 6-Ft Side) - FEMA Compliant - from Survive-a-Storm Shelters

Structural design criteria for storm shelters

FEMA P-361 (2021) has updated and refined the criteria for construction of safe rooms. This comprehensive publication shows how to design and construct a safe room for “near-absolute protection from wind and wind-borne flying debris for its occupants.”

Everything you need to know is outlined in this two-part, multi-chapter guide for use by designers, owners, and emergency management officials.

The second part is eight additional chapters that match the FEMA Funding Criteria corresponding to ICC 500-2020, Standard for the Design and Construction of Storm Shelters.

Where to locate your above-ground storm shelter

Regardless of where you decide to install a safe room, above ground storm shelters be able to withstand the same wind pressures and flying debris as a stand-alone exterior safe room that has been laboratory tested. The surrounding home structure could be completely blown away.

Your home has a number of good locations for the inside construction of a tornado shelter—your garage or carport, for example (especially in states with rare basements). The shelter can also be located outside the house as either a detached structure away from the home or adjacent to it.

An interior above-ground safe room can offer more convenient access to the home’s occupants, but unless included during the home’s construction, it could require extensive and expensive retrofitting. For that reason, a separate, detached safe room located outside the residence is likely to be more affordable.

Of course, your family will need to quickly and safely exit your home to get to the exterior safe room. The prescribed safe room access opening, according to FEMA, must not exceed 150 feet from the nearest entrance of the shelter to the residence.

Before a Tornado, You Need a Plan

If a tornado funnel cloud is coming your way and you have not installed a tornado shelter or safe room, you need a plan.

Sheltering in place could be your only option. Listed below are emergency tornado sheltering steps you can take in an emergency:

Designate a safe room inside the home.

Your home may be well-built, but no home can withstand the winds and destruction of an EF-3 tornado packing 140-150 MPH. Before your roof begins peeling away and your internal walls begin collapsing, you should read the American Red Cross suggestions on tornado safety.

If you have no safe room, basement or storm cellar, shelter in the center of an interior room on the lowest accessible level of your home. You need to have a room ready and easily accessible and in one of the following locations:

  • A first-floor interior room or closet
  • A below-ground safe room that will give you and your family the greatest protection provided:
    • the walls, ceiling and doors are clear of wind pressure and away from penetration by falling debris and flying objects; and
    • the room is located so that damage to your home will not cause damage to the sanctuary room.

When riding out the storm, remain clear of corners, windows, doors and outside walls. Take shelter under a sturdy table and cover your head and neck with your hands and arms. Do not open any windows.

Gather emergency supplies and tools.

Assemble a tornado survival kit consisting of the following items (similar to a bug out bag or survival shelter):

  • a complete first aid kit
  • a fire extinguisher
  • flashlights and extra batteries
  • a charged cellphone
  • a portable emergency radio
  • adjustable wrenches to turn off the water or gas in case of supply pipe ruptures
  • bottled water, energy bar snacks
  • cash—When you dig out, ATM’s may not be working and stores credit card systems could be off line.

If you are caught in the open

If you are outside in a vehicle, trailer, or mobile home, leave the vehicle immediately. Go to the nearest building or storm shelter. If outside with no shelter, find a ditch or depression and lie flat. Cover your head with your hands and arms.

Avoid the temptation to seek refuge under a highway overpass. Overpasses have concrete overheads, but tornado winds under overpasses speed up to create a tunnel of high winds.

Finally, remember that you cannot outrun a tornado, especially in a congested urban area with traffic. Leave your vehicle and seek safety. Be aware of flying debris, which can cause serious injury or death.

If you end up trapped, do not move around. Tap on a pipe or wall to help rescuers locate you. Don’t panic. Rescuers are motivated and highly trained in finding and rescuing trapped victims.

Let’s Recap

Climate change and higher temperatures could result in more tornados. If you live in Tornado Alley, your home may be well constructed, but may not include a safe room or tornado shelter.

When deciding to install a safe room above ground, remember that the above-ground safe room is just as safe as the traditional below-ground version. In some circumstances, it can be a better option.

Read all about FEMA’s structural design criteria in its publication FEMA-361 (2021). Your home has a number of ideal locations for your shelter, including a structure a short distance from your home where you and your family can quickly get to before the storm arrives.

A tornado with its destructive funnel clouds can cause winds in excess of 100 miles per hour. Even if you don’t have a safe room, you can take precautions and prepare a room in the interior of your home on its lowest floor to ride out the storm.

You should have an emergency kit of water and tools ready in your safe room. Also, know what to do if you are caught outdoors when a tornado touches down. You can’t outrun the storm and you should not seek shelter in a highway underpass.