Steps require more maintenance and repair than other concrete structures around the house because heavy use makes them more susceptible to damage. Horizontal surfaces on steps can be treated using the same products and techniques used on other masonry surfaces. For vertical surfaces, use quick-setting cement, and shape it to fit.
How to Replace a Step Corner
Retrieve the broken corner, then clean it and the mating surface with a wire brush. Apply latex bonding agent to both surfaces. If you do not have the broken piece, you can rebuild the corner with patching compound.
Spread a heavy layer of fortified patching compound on the surfaces to be joined, then press the broken piece into position. Lean a heavy brick or block against the repair until the patching compound sets (about 30 minutes) Cover the repair with plastic and protect it from traffic for at least one week.
How to Patch a Step Corner
Clean chipped concrete with a wire brush. Brush the patch area with latex bonding agent.
Mix patching compound with latex bonding agent, as directed by the manufacturer. Apply the mixture to the patch area, then smooth the surfaces and round the edges, as necessary, using a flexible knife or trowel.
Tape scrap lumber pieces around the patch as a form. Coat the insides with vegetable oil or commercial release agent so the patch won’t adhere to the wood. Remove the wood when the patch is firm. Cover with plastic and protect from traffic for at least one week.How to Patch Step Treads
Make a cut in the stair tread just outside the damaged area, using a circular saw with a masonry-cutting blade. Make the cut so it angles toward the back of the step. Make a horizontal cut on the riser below the damaged area, then chisel out the area in between the two cuts.
Cut a form board the same height as the step riser. Coat one side of the board with vegetable oil or commercial release agent to prevent it from bonding with the repair, then press it against the riser of the damaged step, and brace it in position with heavy blocks. Make sure the top of the form is flush with the top of the step tread.
Apply latex bonding agent to the repair area with a clean paint brush, wait until the bonding agent is tacky (no more than 30 minutes), then press a stiff mixture of quick-setting cement into the damaged area with a trowel.
Smooth the concrete with a float, and let it set for a few minutes. Round over the front edge of the nose with an edger. Use a trowel to slice off the sides of the patch, so it is flush with the side of the steps. Cover the repair with plastic and wait a week before allowing traffic on the repaired section.
