Floodproofing Your Home
If your home has plumbing fixtures or floor drains that are below street level, your basement can flood.
Water can enter your house in a number of ways:
1) Flooding or rainstorms
2) Sewer backup
3) Groundwater seepage or spring melting
Sometimes there may be no visible water in your basement, but it still might be damp. This page gives tips for preventing moisture from forming, as well as preventing water from entering your basement. For information on protection from major floods, see Flood Safety.
Flood Proofing Maintenance
These steps will help to prevent water from entering your basement and to keep moisture forming
- Make sure that internal moisture sources such as clothes dryers and bathrooms are properly vented.
- Use humidifiers and dehumidifiers carefully. Don't place humidifiers in the basement; in a moist environment, a humidifier may actually draw moisture into the basement.
- If your basement is moist, don't open the basement windows in the summer.
- Make sure basement drains are clear of roots, grease, etc. Have your sanitary service pipe (also called a lateral) cleaned out at least every other year. Your sanitary service carries discharged water from toilets, sinks, showers and disposals from the house to the sanitary sewer in the street. A slow drain might indicate that more frequent cleanings are needed.
- Keep gutters and downspouts clean; they should extend at least four feet from the outside wall of the house.
- Check for cracks in the foundation, chimney, and fireplace.
Preventive and Corrective Measures
Start with simpler and less expensive measures
- Build up the ground around your foundation so that it slopes away from the building.
- Put appliances, furniture and other items in your basement up on blocks.
- Place 1/2 inch of coarse gravel in window wells, sloping away from the house. The sides of the window should extend above ground level. Cover window wells.
- If the heating ducts are under the basement floor, make sure they are insulated and watertight.
- If only 3 or 4 inches of water are present, install a float plug in the drain. A float plug is inexpensive and easy to install, and does not require a permit. If the floor drain backs up, the float rises and plugs the drain. However, the plug must be removed to drain any water from the basement and it can cause problems if there is more than 4 inches of water in the basement.
- Have a licensed plumber install a backflow valve to keep water from backing up into your basement through the drain.
- Install a vapor barrier or retarder on the basement walls. A building permit may be required.
- Install a false floor over the basement floor, allowing the water to flow to a drain or sump pump.
- Install an interior or exterior drainage system, including a sump pump. An exterior drainage system is the most effective, but may be the most expensive. This must drain to the surface on the property (a permit is required).
For more information about protection from flooding, see these sites:
- North Dakota Extension Services offers information about Coping with Floods.
- FEMA provides information about protecting your property from flooding here: Install Sewer Backflow Valves.
Disclaimer: The items listed on this page are merely summaries of the possible measures that can be used for floodproofing your home. For more information and specific how-to steps, consult with experts and check the websites listed.
Last updated Jan 25, 2017