How to Fix Broken & Cracked Grout on Stairs

Clean the tiles and grout with a mixture of equal parts white vinegar and water to remove any built-up cleaning products.

Cut away all damaged grout with a hand-held grout saw or multi-purpose tool with a grout saw attachment. Remove all of the loose debris with a shop vacuum.

Dampen the joints with water from a spray bottle. Wipe up any puddles of excess water.

Place the grout mixture you selected in a mixing container. Add water following the package directions.

Push the grout into the joints with a grout float. Wipe the float over the surfaces of the stair treads and risers diagonally to avoid pulling the grout back out of the joints. Wipe any excess grout off the tiles with a clean, damp sponge. Clean the sponge frequently.

Create joints similar to the appearance of the existing joints. Use a jointing tool or the rounded end of a craft stick. Allow the grout time to dry, following package recommendations. The temperature and humidity may affect drying time. Avoid using the stairs if possible until the grout dries to avoid damaging it again.

Apply a joint sealer to all of the grout following package directions after the grout dries completely. This helps protect the porous grout from dirt and debris that can cause the grout to eventually crack again. Allow the sealer to dry completely, following the manufacturer’s recommendations.