How to Repair Cement Block Walls

Home builders generally use cement blocks as your home's foundation. Cement blocks can last for up to 100 years, however, cracks can form long before your wall begins crumbling. Most cracks do not threaten the wall's structural support, but, they do allow water to seep into your basement. Use an expanding concrete epoxy to permanently repair the cement block's cracks. Since the epoxy expands, it locks itself into the concrete block if you prepared the crack correctly.

Chisel
Hammer
Vacuum
Expanding cement epoxy
Putty knife

Instructions

- 1
  Hold a small chisel in the crack. Position the chisel so it angles out from the crack's edge, not toward the crack's center. Hit the chisel lightly with a hammer to slightly widen the crack's base but keep the crack's surface narrow.
- 2
  Move the chisel other side of the crack and angle the chisel so it points away from the crack's center. A properly shaped crack appears in a "V," with the point being the crack's surface and the "V" widening in the cement block.
- 3
  Vacuum out as much of the dust and cement chips as possible. Mix an expanding cement epoxy according to the manufacturer's directions.
- 4
  Use a putty knife to apply the epoxy in and over the cement block's crack. Use the putty knife to push the epoxy all the way into the crack. Smooth the surface by angling the putty knife at a 45-degree angle and dragging it over the crack. Allow the epoxy to dry according to the manufacturer's directions.

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