How to Repair a Cracked Garage Floor

Clean out the crack thoroughly, apply concrete crack filler or hydraulic cement, and smooth the surface level with the surrounding floor.

1. Strip the Crack Bare. Remove all loose concrete, dirt, oil, and debris from the crack using a wire brush, chisel, or pressure washer. For oil stains, scrub with degreaser and let dry completely. The crack needs to be completely clean for the repair material to bond properly.
2. Pick Your Weapon. For hairline cracks less than 1/8 inch wide, use concrete crack filler or caulk. For wider cracks up to 1/2 inch, use hydraulic cement or concrete crack repair compound. For cracks wider than 1/2 inch, use concrete mix with bonding agent.
3. Press It Deep. Follow the manufacturer's mixing instructions exactly. For narrow cracks, squeeze the filler directly into the crack from the tube. For wider cracks, mix the compound and press it firmly into the crack with a putty knife, slightly overfilling to account for settling.
4. Flush It Flush. Use a putty knife or trowel to smooth the repair material level with the surrounding concrete. Remove excess material immediately. For textured floors, drag a brush across the wet repair to match the existing texture.
5. Wait—Really Wait. Keep the repair damp for the first 24 hours by misting with water or covering with damp cloth. Most repairs cure enough for foot traffic in 24 hours but need 3-7 days before driving on them. Check the product label for exact timing.