How to Repair a Cracked Old Cement Slab

Unsightly cracks in cement slabs are easy to repair.

Concrete is a popular flooring material because it is both durable and inexpensive. Concrete that has been poured for a slab or foundation can often crack due to shifts at the ground level. While not serious enough to ruin the integrity of the slab, these cracks are not pleasant to look at. To repair the cracks, however, all you need is a simple hydraulic cement mix to fill the cracks and restore the looks of the floor.

Things You'll Need

• Hammer
• Chisel (1/2 inch wide)
• Wire brush
• Shop vacuum
• Water
• Plastic bucket
• Putty knife
• Broom

Instructions

1. Insert a 1/2-inch-wide chisel into the crack and gently hammer to widen the crack along its length.

2. Sweep away all of the concrete chips and dust with a wire brush. Suck up fine particles with a shop vacuum.

3. Apply a small amount of water to the length of the crack so that is is slightly moist.

4. Mix the hydraulic cement mix with water in a plastic bucket. Follow the specific instructions on the package for the proper ratio of the mix to the water.

5. Scoop the hydraulic cement into the crack and smooth over with a putty knife.

6. Draw a moist broom over the wet surface to add texture to the cement. Allow the repair to dry for 24 hours before using the surface.

7. Repeat the crack repair for all cracks in the slab.

References

• This Old House: Concrete Floor Aid