How to Repair Concrete Driveway Cracks

Cracks in concrete driveways aren't just cosmetic problems—they're invitations for water to get underneath and freeze, which makes them expand and spread. A crack that's a quarter-inch wide today becomes a six-inch break in two winters if you ignore it. The good news is that filling cracks is straightforward work that stops the damage before it becomes expensive. The key is choosing the right material for your crack's width and sealing it so water can't return.

  1. Blast Away All Debris. Use a pressure washer set to 3000 PSI or higher to blast out dirt, debris, and loose concrete. Work the nozzle into the crack at an angle, moving along its length several times. If you don't have a pressure washer, use a wire brush or compressed air to remove everything loose. The crack must be bone dry before filling—wait at least 24 hours after washing if rain is possible.
  2. Widen Hairlines for Grip. If your crack is thinner than 1/8 inch, use a concrete saw or carbide-tipped crack chaser to widen it to about 1/4 inch wide and 1/4 inch deep. This gives the filler something to grip. For wider cracks, skip this step. Work slowly and let the tool do the work—pushing hard just dulls the blade faster.
  3. Match Material to Crack Width. For cracks under 1/4 inch, use flexible concrete caulk. For cracks 1/4 to 1/2 inch, use polyurethane concrete sealant or concrete crack filler. For cracks wider than 1/2 inch, use concrete patching compound or a concrete repair kit. Read the temperature requirements on the package—most products won't cure properly below 50°F or above 85°F.
  4. Fill in One Smooth Pass. For caulk, cut the nozzle at a 45-degree angle and apply in one smooth pass, keeping the bead slightly mounded above the surface. For concrete filler, pour it into a caulk gun if it comes in a tube, or use a putty knife to press it firmly into the crack, overfilling slightly. Work from one end to the other without stopping and starting.
  5. Wait for Full Cure Time. Read your product's cure time—most concrete fillers need 24 to 48 hours before foot traffic and 72 hours before vehicles. Don't rush this. Apply it in the evening or early morning so it cures undisturbed. If rain is forecast during the cure window, cover the repair with a plastic sheet weighted down at the edges.
  6. Seal the Whole Surface. After the filler cures, apply a concrete sealer to the whole driveway to protect your repair and prevent future cracks. Use a roller or squeegee to apply sealer evenly, following the product's coverage rate. Most driveway sealers dry to the touch in 2-4 hours but need 24-48 hours before driving on them.
  7. Track Long-Term Performance. Check the repair every few weeks for the first season. If the filler shrinks or pulls away from the edges, apply a second coat. If the crack reopens, the driveway may be settling or the original repair wasn't deep enough—in that case, remove the old filler, widen the crack deeper, and refill.