How to Repair Concrete Treads on Stairs

Clean any cracks or chips in the concrete tread using a wire brush. Remove all of the loose concrete and debris to give the new concrete a clean surface to bond to.

Use a paintbrush to apply bonding compound to the chips and cracks. Apply an even coat of the compound, making sure to get all the way into the cracks. The compound helps the new concrete bond to the old, making it essential for you to get it on all of the surfaces that you will be applying concrete to.

Build a wood form around the tread if the edges or corners are chipped. The form provides a support for the new concrete and makes it easier to create clean edges around the step. Cut sections of board to create the form. Nail the sections of board together at right angles to create the corners of the tread. Make sure the top of the form is level with the surface of the stair tread, and then secure it in place by running other boards to the ground and nailing them to the form. It doesn’t need to hold any weight, but you don’t want the form moving while the concrete cures.

Mix a small amount of concrete and water together in a bucket. The concrete should have a consistency similar to thin peanut butter. As you gain experience and move faster, you can mix larger batches. Until then, start small so the concrete doesn’t harden and become unworkable while you’re still patching the stairs.

Apply the concrete to the cracks and chips with a flat trowel. Work the concrete into the cracks with a back and forth motion to make sure it compacts into the cracks. Fill the cracks until the concrete is slightly above the surface of the tread, and then smooth the concrete with the trowel.

Fill the spaces between the tread and the form with concrete. Work the concrete all the way into the void to create a smooth surface against the boards. Slightly overfill the void and smooth the concrete along the board to create a clean, sharp edge on the step. Do this all the way around the step if the edges and corners are chipped.

Allow the concrete to cure according to the manufacturer’s instructions. Remove the form from the tread and finish it with a sealer, if desired.