Repairing Cracks in Concrete

Left unchecked, cracks in concrete surfaces—including sidewalks, driveways, and patios—can allow water to penetrate and cause further deterioration as well as potentially undermining the slab.

Using a cold chisel to widen the crack and cutting caulking tube nozzle at a 45° angle.
Widen crack with chisel (left). Cut caulk tube nozzle at a 45° angle (right).

To repair cracks in concrete:

Widen Crack: Use a cold chisel to widen the crack, if needed, to allow the caulk to adhere.

Clean Crack: Clean out the crack of any dirt or concrete dust.

Cut Caulk Tip: Cut the tip off a tube of concrete sealant or sanded, acrylic concrete caulk at a 45° angle with the opening wide enough to fill the crack.

Apply Caulk: Use a caulking gun to apply the caulk into the crack.

Smooth Caulk: Smooth the caulk so it fills the crack evenly.

Allow Caulk to Cure: Allow the caulk to set before walking on it.

Applying concrete caulk to crack in patio.
Applying concrete caulk to crack in patio.

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Further Information

Cracks in your concrete are not just unsightly; if left unrepaired, they can lead to further deterioration. Flexible sealants are the best option for repairing cracks since they allow the concrete to shift without affecting the repair.

These sealants are also easy to apply using a standard caulk gun. Just cut the tip of the tube on an angle to match the size of the crack, and slowly draw the gun down the crack forcing the sealant in.

You can also choose a sanded, acrylic caulk designed to match the color and texture of the existing surface.

These tips are brought to you by Quikrete – What America’s Made Of.