HOW TO SEAL CRACKS IN A FOUNDATION WALL

To repair a stable crack, chisel cut a keyhole cut that’s wider at the base then at the
surface, and no more than 1/2" deep. Clean out the crack with a wire brush.

To help seal against moisture, fill the crack with expanding insulating foam,
working from bottom to top.

Mix hydraulic cement according to the manufacturer’s instructions, then trowel it
into the crack, working from the bottom to top. Apply cement in layers no more than
1/4" thick, until the patch is slightly higher than the surrounding area. Feather cement
with the trowel until it’s even with the surface. Allow to dry thoroughly.