Remove cracked or crumbling grout. If there are cracks in the grout, water can seep in and start damaging the subflooring, loosen tiles design, and even promote mold growth. Minimizing these cracks and repairing cracks that are there are critical steps to take to minimize tile cracking. Scrape out the damaged grout and clean the seam. Remove pieces of the old grout and other bits of material and dirt.
Mix new grout. Mix a small amount of new grout according to the manufacturer’s instructions. The grout should be a pudding-like consistency. Too much or too little water in the mix will prevent the grout from functioning effectively, leading to loose element tiles and opportunities for water leakage. If you need to add water, squeeze in a little at a time from a sponge.
There are different kinds of grout for different applications. There are grouts with urethane and epoxy mixed in, but most homes will use cement grout. If the joints between common marble tiles are less than 1⁄8 in (0.32 cm), use grout without sand. Joints that are larger than this can use sanded grout.
Pack grout around the tiles. Use a rubber float held at a 45-degree angle to the floor to push the grout into the spaces between the ceramic tiles. Make sure there are no small holes or cracks along the edge of the tile. Use your finger to scrape off excess grout and make the new grout level with the grout surrounding it. Work from the edges of the room toward the center so you don’t accidently box yourself in.
Clean up excess grout with a sponge and warm, soapy water. Wait 20-30 minutes for the grout to start setting. It should be firm to the touch. Then wipe away grout left on the tile with a wet sponge, taking care not to pull grout out from between the glazed rustic tiles. You’ll probably have to clean up dried grout on the tiles after the grout has set. Use a dry towel to clean the kitchen tiles, as a wet cloth will only continue to spread around particles of grout.
Apply a coating of grout sealer after the grout is dry. Grout sealer comes in a small can and can be applied with a small foam brush. Pour some of the sealer into a cup and use the brush to trace the grout with sealer. Clean up any sealer that gets on the wood tiles within a few minutes.