Broken concrete step edges can be a safety hazard, so quickly repair concrete steps that have developed crumbling edges. Follow the steps outlined below to repair broken concrete step edges.
Step 1 - When to Repair Broken Concrete Steps
Schedule this repair when you can follow up with the curing process and when the steps can be blocked from use for 48 hours. Do all concrete repairs in cool temperatures, below 70 degrees F (21 C).
Step 2 - Clean Up the Step Edges for Repair
Use the cold chisel and hammer to break off crumbling concrete bits. Make wedges in the step edge to get down to solid concrete material. Wear safety goggles while chipping the step edges. Sweep the wedges out with a small hand broom and blast off any remaining crumbs with high pressure from your water hose.
Step 3 - Build Recasting Forms for Each Step
Cut 2 by 4 planks to the width and depth of the stairway to go along its vertical edge. Cut riser planks and push the plank against the riser with bricks. Have the top edge of the stairway planks level with the top of the step to be repaired. Brace the recasting forms in place with 2 by 4 planks wedged under the bottom of the forms.
Step 4 - Prepare Ready Mix Concrete for Use
In your wheelbarrow, mix the ready mix concrete and water according to the directions on the bag. Stir the mixture with the paddle on the power drill at medium speed.
Step 5 - Apply Liquid Concrete Epoxy to the Step
Dampen the step with the mist setting of the water hose and apply liquid concrete epoxy to the cracked edge with the stiff paintbrush. Spread it deeply into the wedges you created, covering the inside of each wedge completely. Rinse off the paintbrush at once with water.
Step 6 - Add the Concrete
Fill the recasting form with the ready-mix concrete, using your putty trowel. Remove air spaces by slicing through the concrete mix with the point of the trowel. Level the surface with the trowel where the new and old concrete meet.
Step 7 - Smooth Out the Concrete
Use the wood float to flatten and smooth the poured concrete. Hold the float as level as you can at the junction where the old top meets the new edge. Allow 45 minutes for the new edge to become firm, and then smooth over again with the wood float. To make a smoother finish on the new step surface, let the concrete absorb the water film and shape the edge of the step with the edge of a clean trowel.
Step 8 - Cure the Concrete
Cover the recast step with a plastic dropcloth weighted with bricks on the steps above and below the repaired step. Dampen the recast step 4 times a day with water, every day for a week and cover them again with the plastic sheet. Leave the wood forms in place during the curing period.