Keep Water Away From the Foundation
If your basement leaks after heavy rains or after snow melts, making sure water is diverted away from your foundation may solve the problem. It's common for the soil alongside your house to settle over time, creating a moat that collects runoff and directs it down your foundation wall and into the basement. Lawn edging and gravel along the foundation can make things worse. Solve the problem by creating a 6-ft.-wide slope that drops about 4 in. away from the foundation. For extra insurance, cover the sloping soil with a layer of 6-mil poly. Then hide the poly with mulch, gravel or a layer of soil covered with grass. This will keep water from soaking in near the foundation.
Add Gutters and Extend Downspouts
If your basement leaks after it rains and you don't have gutters, consider adding them. Gutters catch the rain and channel it to the downspouts, which direct it away from the house. Whether you're installing new gutters or already have them, be sure the downspouts have 4- to 6-ft. horizontal extensions to move the water away from the house.
Plug Holes and Cracks in the Foundation
Holes and cracks in your foundation can let moisture and water seep into your basement. Plugging them probably won't solve basement leaks, but it'll help. Hydraulic cement works great for patching holes in a foundation because it can set up even under water, and it expands as it sets to seal the hole and lock the plug in place. Use a cold chisel or an angle grinder fitted with a masonry-cutting disc or diamond blade to enlarge the hole or crack into an inverted “V,” with the narrow part of the “V” on the surface of the wall. Then follow the package instructions for mixing and using the hydraulic cement.