Stopping Basement Leaks

By Mark J. Donovan

Stopping basement leaks begins with the inspection of the outside of your home. Take a look at the soil grade around the basement foundation. The soil grade should be such that water will be directed away from the foundation and not to it. If this is not the case, you should modify the grade around the foundation so that water run off is directed away from the home.

Also check your gutters. Make sure they are clean and that the downspouts are directing roof run off water away from the home.

When the basement is dry identify the cracks in the basement foundation walls to be repaired. Using a hammer and chisel “key” out the cracks. Keying a crack is the process of opening the crack with a hammer and chisel such that the inside of the crack is slightly larger than the outside surface of the crack. “Keying” helps to create a better seal when the hydraulic cement is applied.

Once you have completed the chiseling process, clean out the crack with a wire brush. With the completion of the chiseling and cleaning process, you are now ready to add hydraulic cement to the crack.

Note: Make sure you wear safety glasses during the chiseling and cleaning process as cement pieces have a tendency to fly everywhere.

Once the cracks have been cleaned out, apply hydraulic cement to them in a two step process. Note that it is best to lightly dampen the crack areas with water just before applying the hydraulic cement to them.

For the first step, fill each crack with hydraulic cement to just about ¼ - ½” from the surface edge of the crack. For the second step, let the hydraulic cement harden overnight and then apply additional hydraulic cement to each crack to complete the filling of them. Use a trowel to smooth the hydraulic cement into the cracks and around the crack edges.

Once the hydraulic cement has dried apply a water proofing sealer over each crack area. You may also want to consider applying a coat of water proof sealer over the entire basement wall area for aesthetic reasons.

With these simple steps your basement should now stay dry.