How to Fix Cracked Grout: A Guide to Repairing Damage and Protecting Your Tile

First, put on your safety glasses, dust mask, gloves, and hearing protection. If the damaged grout is on the floor, start by sweeping and vacuuming the area. Then, you can clean the grout with warm water and a grout brush. 

Alternatively, if your grout is sealed, you can mix warm water and white vinegar in a spray bottle (using a 1-to-1 ratio) and apply it to the grout. After five minutes, scrub it with a grout brush.

To remove damaged grout, start by using your hands to pull out any cracked, chipped, or crumbling grout that’s loose and easy to remove. 

Next, use a grout saw to break up the rest of the damaged grout that you couldn't remove by hand. Work slowly and carefully so you don’t chip the tiles. When the grout is loose enough, pull it out with your hands.

If you’re only replacing some of your grout, it’s important to find a grout color that matches the shade of your current grout. Otherwise, the new grout won’t blend in with the old stuff.

To do this, take a piece of your old grout to a home improvement store and ask an employee to help you find a similar shade.

Use a shop vac to get rid of any dust and debris from the places where you removed grout. Wipe the area down with a clean damp cloth and let it dry.

When you’re done, check to see if there’s any remaining damaged grout. If so, remove it using the process outlined in steps one and two.

If you purchased premixed grout, you can skip this step. But if you bought a mixable version, measure out the right amount of water according to the manufacturer’s instructions. Add it into a bucket, mix in the grout powder, and stir it with a trowel.

Scoop grout onto your rubber grout float. Hold the float at a 45-degree angle and move it over the joints, using sweeping motions to apply the grout evenly. Work in small sections and avoid applying too much grout at once.

Move the float diagonally over the tiles to remove excess grout. This helps create a smooth layer, which is especially important if you’re regrouting floor tile. Otherwise, the uneven grout could create a tripping hazard.

Let the grout sit for 15 to 30 minutes, then wipe the surface of the tiles with a damp grout sponge to remove excess grout. Try not to pull any grout out of the joints, and rinse the sponge often to keep it clean.

Let the grout dry completely. Depending on the type you’re using, it can take between 24 and 72 hours for grout to dry.

When the grout is dry, you might notice a slight haze on the tiles. To remove grout haze, wipe the tiles with a damp cloth and then polish them with a dry cloth.

Sealing grout can help prevent future cracks and protect your grout against water damage, mold, and grime. To seal your grout, start by combining 1/4 cup of vinegar and 8 ounces of water in a spray bottle. Then, apply it to the grout, wipe it down with a cloth, and let it dry completely.

Use a paintbrush or sponge to apply a thin coat of sealer to the new grout. Let it dry for about an hour before applying a second coat.