How To Seal The Joints Between The Basement Wall And Floor

Step 1

Remove any dirt or debris from the joint between the floor and the wall, using a wire brush, and then sweep along the base of the wall with a stiff-bristle broom to remove any remaining loose dirt and debris. Clean the joint and about a foot of adjacent wall and floor space with a concrete degreaser, using a scrub brush to remove oil deposits. Rinse thoroughly with water, then vacuum up any moisture with a wet vacuum. Allow the concrete to dry overnight.

Step 2

Measure the length and width of the joint, using a measuring tape. Cut a piece of foam backer rod slightly larger in diameter than the width of the joint to the measured length, using a utility knife. Stuff the backer rod into the joint, packing it firmly while leaving a space of about ¼ inch along the top of the rod to the surface of the floor.

Step 3

Step 4

Place strips of masking tape along the edges of the joint to prevent the sealer from overflowing onto the floor or wall.

Step 5

Pour the self-leveling polyurethane sealant into the joint above the backer rod, filling it to the top. Start at the end of the joint and pour along the entire length, moving in a single direction. The sealant will level itself out at the top of the joint. Wait two hours for the sealer to begin to cure.

Step 6

Remove the masking tape to create a clean line in the sealer at the joint edges. Allow the sealer to cure completely for seven days.

Step 7