Prevent basement flooding
If your basement floods every time it rains hard, chances are your house is located in an area with an elevated water table. There are measures that will help prevent your home from flooding.
Sub-surface water accumulates in pore spaces and cracks deep below the ground. The upper surface of this underground aquifer is referred to as the “water table.” During heavy rainstorms, successive strata of soil and gravel become saturated with rain runoff, and the water table rises. Conversely, during extended dry spells, the water table falls.
Other factors contribute to the elevation of the water table besides rainfall. Excess water can drain down into your area from higher elevations, or the soil around your house may not absorb excess water particularly well.
Houses that are built in areas with high water tables often require some structural and landscaping alterations in order to keep foundations dry and your basement flood free. In particularly flood-prone neighborhoods, homeowners may need to invest in a sump basket and a pump.
Tips For a Flood Free Basement
1. Gutters are key.
Make sure your gutters are in good shape, free from leaves and other detritus, and that their downspouts face away from the house and its foundations.
Gutters are engineered to catch rainwater, and to funnel it away from the house. Downspouts need to have at least a 4- to 6-foot horizontal extension to direct water away from the foundations.
How can you tell if your gutter extensions are long enough? Water should not be flowing out the sides of your gutters in a rainstorm. The next time it’s raining heavily, go outside and see if your gutters are performing their job adequately. If water is pouring from the sides of the gutters, add additional downspouts or a wider downspout to increase your water-carrying capacity.
2. Shunt water away from your foundations.
You may need to regrade the yard around your house in order to keep rain from flowing into your basement. Optimally, there should be a four-foot slope around your house. You may need to re-landscape the area around your foundations, and haul in additional soil or gravel. If your house is built on a flat piece of property, you may need to build a reservoir sub-addition.
3. Waterproof your basement walls.
Plug all holes and cracks in your basement walls. Water can seep through those fissures. Patching them with hydraulic cement won’t prevent flooding when other problems are present, but it will help. Additionally, painting a waterproof sealant on your basement walls will help prevent water vapor from seeping in from the outside.
4. Install a basement drainage system.
Installing a drainage system into an existing home can be expensive and challenging, but it is the most effective remedy for chronically leaky basements. To install drainage tubing connected to a sump basket and pump beneath an existing basement floor, you will have to dig up the existing concrete floor, bury the tubing and then re-lay the floor.