Everyone lives in a flood zone. In fact, floods are one of the most common hazards in the U.S. Flooding typically causes more than $2 billion in property damages annually. Changing weather patterns and an ever-increasing number of impervious surfaces, such as roads and sidewalks, are putting more homeowners at risk. Homeowner's insurance rarely covers flood losses, and federal disaster assistance is available only if the President formally declares a disaster. Even when disaster assistance is provided, it's usually a loan that has to be repaid with interest.
There are a number of actions that can be taken to protect a home from flooding. The Federal Emergency Management Agency (FEMA) offers the following 7 steps to provide flood protection.
Build with flood-resistant materials, which can withstand direct contact with flood waters for at least 72 hours and will require only low-cost, cosmetic repair. These materials should be used for walls, floors, and other parts of a home that are below the flood level. Commonly available flood-resistant materials include concrete, closed-cell and foam insulation, pressure-treated and marine grade plywood, and ceramic tile.
Make adjustments when constructing walls. One way to protect a home from shallow flooding is to add a waterproof veneer to the exterior walls. For instance, the veneer can consist of a layer of brick backed up by a waterproof membrane. For interior walls, replace batt insulation with washable closed-cell foam insulation in areas below flood level. Any wood blocking added inside the wall cavity should be made of exterior grade lumber.
Raise electrical system components, such as service panels, meters, switches, and outlets. These materials are easily damaged by flood water, and will probably have to be replaced. Another serious problem is the potential for fires caused by short circuits. All components of the electrical system, including the wiring, should be raised at least 1' above the 100-year flood level.
Anchor fuel tanks. Unanchored fuel tanks can easily be moved by flood waters and pose a serious threat. An unanchored tank outside a home can be driven into the walls by flood waters or swept downstream, where it can damage other property. If it’s in a basement, the supply line can tear free and contaminate the basement with oil. One way to anchor a tank is to attach it to a large concrete slab that has a weight great enough to resist the force of the flood waters. This method can be used for all tanks, both inside and outside a home. An outside tank can also be anchored by running straps over it and attaching them to ground anchors.
Raise or flood proof HVAC equipment. HVAC equipment, such as a furnace or hot water heater, can be damaged extensively if inundated by flood waters. The amount of damage will depend partly on the depth of the flooding and the amount of time the equipment remains underwater. In flood-prone homes, a good way to protect HVAC equipment is to move it from the basement or lower level of the home to an upper level or even to the attic. A less desirable method is to leave the equipment where it is and build a concrete or masonry block floodwall around it.
Install sewer backflow valves to block drain pipes temporarily and prevent sewage back up into the home. This precaution will prevent damage that's difficult and costly to repair and protect your homeowners from dangerous health issues.
Protect wells from contamination by extending the well casing at least 2' above the highest known flood elevation and storing potential contaminants at least 100 feet away. Flood water that enters a well can contaminate the groundwater and make the well water unsafe to drink or use – exposing homeowners to hazardous and toxic materials, including raw sewage, animal wastes, oil, gasoline, solvents, and chemicals. The effects may last long after the flood waters have receded.
If flooding isn’t your only concern, read our related article, “Riding out the Storm: Protecting homes from hurricane damage,” or sign your team up for BuildIQ University’s new Water Management Suite of online courses.