With the increased frequency of extreme winds impacting structures across the U.S., homeowners and small business owners are looking for ways to stay safe in a disaster. One way to assure safety is to build a safe room; the most common construction technique is concrete walls, whether formed and cast walls and roof, concrete masonry units, insulating concrete forms, or precast. There’s a big potential market for construction of safe rooms and concrete contractors should learn a little about this before turning away (or bidding on) potential business. As communities, owners, and zoning officials increasingly recognize the need for resilient structures, the number of safe rooms will increase.
The key aspects of a properly-designed and -built safe room are:
Foundation: Typically concrete slabs on ground either below or at grade. When necessary, though, safe rooms can be built on piers and elevated, such as in areas prone to flood or storm-surge.
Walls: Must be able to withstand wind forces and also to resist falling debris and wind-borne “missiles,” such as framing lumber.
Roof: A concrete roof deck must cap the safe room; both walls and deck need to be steel-reinforced.
Door (and hardware): Must also be able to withstand wind forces and missiles.
Adding a safe room when a home is first built is relatively easy and cheap, while adding one to an existing building is often more difficult. An 8-foot square safe room, which would comfortably hold six people, costs about $8000 in new construction. FEMA estimates the cost to be 20% higher in existing structures. One option is freestanding safe rooms, although that reduces the usefulness in a sudden storm event like a tornado.
The best reference for safe room design and construction is “Taking Shelter from the Storm: Building a Safe Room for Your Home or Small Business,” FEMA P-320, available for free at www.fema.gov. In 2015, FEMA will publish the fourth edition of this important document, which has become the guide to how contractors should build these structures.
WOC Safe Room Learning Opportunities
Two events at the 2015 World of Concrete will give contractors a chance to learn about safe rooms.
Luncheon: Expand Your Business with High Wind Safe Room Construction, Wednesday, Feb. 4
Speakers from PCA and FEMA will describe:
- The potential size of the resilient construction market.
- The status of legislative, marketing, and promotion efforts.
- Common concrete and masonry construction designs.
Showcase (Gold Lot): Tornado Safe Room Showcase
Sponsored by FEMA, PCA, and FLASH (Federal Alliance for Safe Housing), experts in this live, interactive work zone will demonstrate how to construct safe rooms using various construction techniques: insulating concrete forms, concrete masonry units, cast-in-place concrete, precast concrete, and prefab steel on poured concrete footings.