Concrete homes aren't suitable for all homeowners who live in tornado- or hurricane-prone regions, but concrete promoters still can profit from selling above-grade concrete residential walls. Instead of going for the whole home, in some cases promoters can increase the market share of concrete by capturing one room in a residence. A complete concrete home will reduce damage costs and save lives, but a less expensive safe room serves the more basic of the two needs, and it offers the room the supplemental benefits of fireproofing, soundproofing, and insulation found in a full concrete home.
The major concept behind the in-home safe room is the fact that residents who need to escape flying debris, referred to as missiles (the primary cause of death and injury in windstorms), never have to leave the home. In regions where basements are not common, safe rooms are a relatively minor alteration to stick-frame home plans and appear no different from any other room. Key considerations are a footing of sufficient strength to support the weight of a concrete room, adequate fasteners for roof-to-wall, wall-to-wall, and wall-to-floor connections, a central location for accessibility from any location in the home, a missile-resistant door, and wall and roof material strong enough to resist missile penetration. Reinforced concrete has performed well in missile impact testing.
However, in-home safe rooms are impractical for existing homes because the rooms must be constructed as close to the center of the home as possible. A freestanding safe room in the backyard provides easier storage and slightly better flood protection than a below-ground shelter, although the homeowner loses the benefit of not having to leave the home during a windstorm.
The article includes a list of online resources with information about safe rooms.
In addition, the article includes information about missile impact tests on walls of various materials at the Texas Tech University Wind Engineering Research Center.