As concrete expands and contracts over the years, sometimes the joints between the slabs separate and require repair. These joints are in place to prevent cracking and breaking in poured concrete, and you should repair them as soon as you detect any damage to prevent it from spreading. If the joint between the front steps and your home widens, or if cracks begin to appear in the steps radiating from the joint, it requires repair. Repairing the joint is an easy project requiring materials found at any home repair store.
Remove any dirt and debris in the joint between the step and the adjoining building. If an expansion joint strip is present, pull it out using a screwdriver. Remove any caulking or joint sealer compound from the joint using a putty knife to lift the caulking from the edge.
Clean the step using a power washer to remove the dirt. Allow the step to dry completely before repairing.
Repair any cracks that have formed on the step. Fill the cracks using a mortar and patch repair kit. Scrape the top of the repair material to even the patch with the surrounding step then allow it to dry overnight.
Cut a panel of tar-impregnated fiberboard to the depth of the expansion joint between the step and the building less 1/4 inch. Use a plywood saw to cut the panel. Place the fiberboard into the expansion joint, tapping it in place with a hammer and screwdriver.
Cut a strip of closed cell pipe insulation to the same length of the step using a utility knife. Place the insulation into the joint between the step and the wall on top of the tar-impregnated fiberboard to fill the space between. The insulation prevents water from flowing into the joint.
Place masking tape onto the side of the step against the edge of the joint and the building. Fill the joint on top of the insulation with joint sealer compound, overlapping the concrete with the compound spread over the masking tape. Place a bead of the compound down each side of the steps against the adjoining building, covering the entire joint between the step and the building.
Wait for the compound to dry completely following the manufacturer's label directions. Remove the masking tape to create a clean line on the edge of the sealant.