Identifying appropriate construction materials and understanding their characteristics may help you reduce flood and water damage to your home’s contents and structure. See Selecting Materials to Resist Moisture for specific types of materials.
Water will, in some manner at some time, get into wall, floor, and other structural systems. Floods, high winds, and water leaks can cause water damage to materials. Some materials used in houses are more resistant to moisture, water, flooding, and mold than other materials. Selecting materials that are more suited for contact with floodwaters or water for three days or more without significant damage is important in areas where flooding occurs and hurricanes are possible.
More research and testing of multiple materials together in components or wall and floor systems is needed to determine how materials perform and how they impact each other in the draining and drying process.
Construction or remodeling methods should allow for the structure, including wall and floor cavities or systems, to drain and dry. Rain, floodwater, and wind-blown water will move through very small cracks to enter cavities or systems. Water and vapors must be able to escape in at least one direction so the structure can dry. Construction material that allows water to escape and can dry in two directions is preferable.
Homes with flood-prone lower levels that also have the potential for high humidity or water leaks should not contain valuable materials, antiques, important papers, photographs, and other important keepsakes, furnishings, and products.
How To Select Materials
Try to select materials that do the following:
Why To Select the Suggested Materials
Flood cleanup may be easier if water-resistant materials and drainable and dryable structures are in place. Materials should be easy to clean and able to withstand disinfectants. Materials that contain cellulose such as paper, wallboard, and natural fiber fabrics (cotton, linen, jute) are more likely to develop mold than synthetic materials such as nylon and olefin. Some materials are subject to warping or delamination. Hard surfaces such as metal will be easier to clean than porous surfaces such as ceiling tile, wallboard, and upholstered furnishings. How these materials are combined into a wall or floor system will affect drying time.
Construct Structural Systems to Drain and Dry
• Walls, floors and other structural systems should be able to dry.
• Structural systems should be able to dry in at least one direction.
Moisture trapped inside the structure and in wall and floor systems must have a way to get out so the structure can dry. As you select material to be used in and on floors and walls at lower levels, consider the material's resistance to water and flood damage, its location, and its function. Some materials have the ability to dry without damage and to allow other wall and floor components to dry.
Prior to selecting and installing materials, check with local or area building officials and a floodplain manager about building requirements. Consider National Flood Insurance Program regulations as well as local and state requirements.
The National Flood Insurance Program requires materials to be resistant to flood damage in areas that are below the Base Flood Elevation in new construction and when substantial improvements are made. The Federal Emergency Management Agency (FEMA) indicates a building material is flood-resistant if it is able to “withstand direct contact with floodwater for at least 72 hours without being significantly damaged.” Check with local code officials and housing professionals about the best building practices and flood-resistant materials for your area. The home’s structure, design, and natural environment, including climate affect the types of construction and insulation methods.
Check local codes before you buy materials. Local and state building codes may not allow some materials to be used inside the home. Some materials should be used in outdoor applications only. Read the labels on all adhesives, sealants, treated lumber, paints and materials. Some materials, adhesives, and sealants may not be safe for interior use, may be toxic, and may outgas creating indoor air quality problems.
Select materials that resist water damage, are easy to clean, and allow wall and floor systems to drain and dry or are easy to remove to allow drying. Look for materials that resist mold growth, do not transport water or moisture to adjacent materials, are dimensionally stable when exposed to water, and maintain their strength and stiffness after exposure to water.
Livengood, S. & Aglan, Heshmat. (2003, Jan/Feb.) After the Flood. Home Energy. pp. 12-16.
National Disaster Education Coalition (1999). Talking About Disaster: Guide for Standard Messages.Repairing Your Flooded Home.
Reichel, C. (2006). Midconstruction LaHouse Meets Katrina and Rita. Hurricane Season. Home Energy. pp 8-10.
U.S. Department of Homeland Security, Federal Emergency Management Agency. (2005, June). Home Builder’s Guide to Coastal Construction Technical Fact Sheet Series (FEMA 499). Technical Fact Sheet No. 8.
U.S. Department of Homeland Security, Federal Emergency Management Agency. Build with Flood-Resistant Materials.
Wendt, R. and Alan, H. (2006). Rebuilding Your Flood-Damaged Home. Home Energy. pp. 20-26.
York, B. (2006). Safety Measures for Stormy Windows. Hurricane Season. Home Energy. pp. 37.