How to Seal Leaking Basement Walls

Basement leaks are caused by cracks in the concrete wall. Left unrepaired, the water that seeps through the cracks can result in mold, an unpleasant smell and, more seriously, damage to the foundation of the structure. Sealing the cracks is fairly straightforward and inexpensive, but the method to be used depends on the size of the crack. Small cracks, meaning cracks that are less than 1/4 of an inch wide and 1 inch deep, can be filled with caulking, while larger cracks typically require a latex bonding agent and a concrete patch product.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Masonry chisel
• Wire brush
• Hand vacuum
• Gray-tinted masonry caulk
• Caulking gun
• Putty knife
• Latex bonding agent
• Concrete patch product

Filling Small Cracks

1. Remove any loose concrete from the damaged area with a masonry chisel and a wire brush.

2. Clean the dust and debris from the surface with a hand vacuum.

3. Apply a bead of gray-tinted masonry caulk to the crack with a caulking gun. The crack should be slightly overfilled with the caulk, as the caulk will be smoothed down with a putty knife.

4. Smooth down the caulk with a putty knife to fill the crack. Start the stroke with the putty knife at one end of the crack, then pull the putty knife across the caulk to the opposite end of the crack while applying even pressure to complete the repair.

Filling Larger Cracks

5. Remove any loose concrete from the damaged area with a masonry chisel and a wire brush.

6. Clean the dust and debris from the surface with a hand vacuum.

7. Apply latex bonding agent to the edges of the crack with a putty knife.

8. Mix the concrete patch material from the concrete patch product with water, then mix in the product's bonding liquid. The quantity of patch material, water and bonding liquid varies depending on the manufacturer, so be sure to consult the manufacturer's mixing instructions.

9. Apply the patch material to the crack with a putty knife, then use the knife to fill the crack with the material and to smooth the surface of the material.

References

• "Home Improvement 1-2-3;" Benjamin Allen; 2003
• "Home Repair and Improvement; Creative Homeowner;" 2006