Chips in a Concrete Driveway

Preparing the Area

• All damage to a concrete driveway except for very thin hairline cracks must be sufficiently widened and often deepened for sound repair. Use a chisel and hammer to enlarge the area so that the bottom is larger than the top and at least an inch deep or more depending on the load that the repaired portion of the driveway must support. The area must be thoroughly cleaned for the adhesive or concrete to hold well. Remove all loose material from the site, brush it with a wire brush and use a garden hose or air compressor to wash or blow away all debris and dust.

Performing the Patch

• A concrete adhesive will help to hold the patch in place but is not necessary. Either brush the adhesive into the area and allow it to dry until it is tacky, or prepare the surrounding old concrete by soaking it to prevent it from absorbing moisture from the patch. Prepare the concrete mix. For driveways, utilize gravel rather than sand mix. Tamp the mix tightly into the chipped area, and smooth the top with a wooden float or metal trowel. Cover the patched area with sheeting or boards, and do not drive on it for at least five days, but wet the repair daily during this period.

Edges and Steps

• Chipped concrete edges or steps require a braced board or form to ensure an even, well-formed edge. For corners screw two short pieces of wood together, and hold it in place with duct tape or stakes. For edges make a wall board, and hold it in place using wooden stakes. Coat the interior of the form with cooking oil so that the concrete will not stick to the wood. Press the concrete into the form, and let it dry for a day before removing the form. An edger may be used before the concrete sets to improve the repair's appearance and make it match the existing edge.

Large Repairs

• Larger chips or holes may warrant replacement concrete. The replacement concrete method is suitable when the broken area is greater than 1 square foot and has a depth greater than 6 inches if the hole reaches through the entire section or when the break extends beyond the metal reinforcement. Replacement concrete involves bonding the new concrete directly onto the existing concrete without a bonding agent. To perform large repairs, remove concrete so that 1 inch of clearance is provided around each reinforcement. Verify that the perimeter of the hole is cut to at least 1 inch deep, cut the bottom and sides of the hole to be square and clean the hole thoroughly before filling it with replacement concrete.