How do I build a hurricane shelter?

When a hurricane barrels your way, you have a decision to make: Do I stay or do I go? If you live in a low-lying area, or near a lake, river or the sea, your choice is clear. If you're in an area that has any chance of flooding, you need to evacuate as soon as possible [source: Skinner].

However, if flooding poses no risk (check with your local emergency management office to make sure), and if you haven't been ordered to evacuate, you may choose to stay home, hunker down and ride out the storm. If you do stay, you'll have a better chance of survival if you're protected from wind-borne debris and projectiles like trees, branches, parts of houses, and even cars. You can get that protection in a stand-alone shelter outside your home or a fortified space inside your house, known as a safe room or in-residence shelter.

Stand-alone hurricane shelters are typically made of steel panels welded together into a box-shaped structure with a steel door and bolted to a concrete pad. Unless you have metalworking skills and tools, this is not a DIY project. You can expect to pay $5,000 and up for a shelter built to standards set by the Federal Emergency Management Agency (FEMA).

A stand-alone shelter strong enough to protect against a hurricane's fury could also be made of concrete fortified with reinforcing iron bars (known as rebar), fortified masonry blocks, or insulating concrete forms (foam molds into which concrete is poured, known as ICFs). To be built properly, a storm shelter can be designed by an engineer and built on-site by a contractor, or you can have a pre-fabricated unit delivered to your chosen site and assembled there. Companies that sell storm shelters include Armor Vault of Oklahoma City, Okla., and Steel Storm Shelters, based in Jackson, Tenn. These shelters are made for "extreme wind events" like tornadoes and hurricanes.

Now that we've convinced you to build some sort of hurricane shelter, how large should it be? It depends on the number of people in your household; FEMA suggests that your home hurricane shelter building have at least 10 square feet (.93 square meters) of space per person, so a shelter made to house a family of five would need to be at least 50 square feet (4.65 square meters). You'll need even more space than that if you have sick or shut-in relations, as each bedridden person needs 30 square feet (2.8 square meters). For an idea of what you're up against, consider that a typical two-car garage measures 400 square feet (37.2 square meters).

If you'd rather build a safe room inside your house, read on to the next page for some ideas.

Hurricane Safe Rooms

A safe room is a windowless box inside your house where you and your family can escape the danger of wind-borne projectiles during hurricanes or tornadoes. Safe rooms have several advantages over outside shelters. For example, safe rooms are usually less expensive: A simple lean-to shelter in a basement will cost around $2,000, while a fortified safe room in a new house will add an extra $3,000 to $6,000 to your construction costs. If timing is critical, you also don't need to venture outside to access the safe room, since you can reach it from inside the house.

The secret to building an effective safe room is to fortify existing walls with plywood (the most economical choice), steel or concrete, and to make sure the whole room is properly fastened together. According to the Texas Tech University Wind Science and Engineering Research Center, adequate fasteners are important to the shelter's structural performance. The shelter's roof must be securely anchored to its walls, the walls to each other, and the walls to the shelter's foundation. In addition, proper ventilation is a must if you're using your safe room to protect you and yours from hurricanes.

At its Baton Rouge campus, Louisiana State University has included a safe room inside its Louisiana House (LaHouse), a showcase home was constructed to demonstrate storm-resistant building techniques and materials. Although the LaHouse has been officially used as LSU's Home & Landscape Resource Center and offered educational outreach since Hurricane Katrina hit the Gulf Coast in 2005, the home itself has only been fully functional since July 2008. The LaHouse's safe room is off the master bedroom and can be used as a walk-in closet. This safe room includes these upgrades:

Ceiling and walls fortified with thicker sheathing (plywood or oriented strand board)
More anchors, straps and fasteners (nails and screws) to hold the walls, floor and ceiling together
A hidden sliding steel door for more protection during storms
A ceiling structurally independent from the second story of the house built so that if the second story blows away, the safe room on the ground floor remains intact

A shelter or safe room may be empty, or it may be stocked with items like bottled water, non-perishable food, blankets, battery-operated lights, a radio and a first-aid kit. Unlike tornadoes, which blow through an area quickly, hurricanes can take hours to pass through. You'll want your family to be warm and comfortable as the storm passes.

For more information on hurricane shelters, please see the links on the following page.

Lots More Information

Sources:

Federal Emergency Management Agency (FEMA). "Are You Ready?"http://www.fema.gov/areyouready/index.shtm
Federal Emergency Management Agency (FEMA). "National Hurricane Program."http://www.fema.gov/plan/prevent/nhp/
Hanna, Jason. "Their house survived Ike, but it's the only one left." CNN. Sept. 18, 2008.http://www.cnn.com/2008/US/09/18/ike.last.house.standing/index.html
Huus, Kara. "Quarreling through Katrina: A saga of survival" MSNBC. Aug. 19, 2006.http://www.msnbc.msn.com/id/14468069
Louisiana State University Ag Center. "'Safe Room' Provides Protection From Storms, High Winds." Press release. May 2005. http://www.lsuagcenter.com/news_archive/2005/may/headline+news/safe+room++provides+protection+from+storms+high+winds.htm
"Wind Safe Room." Red Cross. http://www.redcross.org/images/pdfs/code/Wind_Safe_Room.pdf

How do I build a hurricane shelter?

Hurricane Safe Rooms

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