Concrete blocks are another quick, relatively simple method for building a saferoom. Water repellant can now be mixed into the block at the plant, and additional sealer and flashing applied on-site. Foam insulation is used as a moisture repellant, while lightweight metal brackets allow space for wiring and plumbing.
Concrete masonry can be used in new construction, on existing homes, and in stand-alone saferooms.
The Federal Emergency Management Agency's (FEMA) guide for safe room construction included plans for conventionally cast concrete safe rooms and reinforced concrete masonry safe rooms. The new plans include details for 4- and 6-inch flat ICF walls and 6-inch waffle grid ICF walls.
The FEMA publication Taking Shelter From the Storm: Building A Safe Room Inside Your House, includes construction plans, materials, and construction cost estimates. It's available from FEMA at no charge by calling toll free (800) 480-2520.