How to Fix Cracked Grout in 7 Easy Steps

Select the Right Tools for Your Task

Each cracked grout repair job is different, so you'll want to carefully select the tools you use to grind down and remove damaged sections.

For example, grout blades are angled and curved differently. Look for a multi-tool that you can adjust or find a one-off tool that works for the job at hand.

Grind Down the Crumbling Grout

Using your dremel or grout blade, grind down the cracks or crumbling grout so that you can easily replace it. Start with the sections where the grout grooves are deepest and work your way back.

Aim for uniformity throughout; no uneven edges or rough patches. This step will set you up for success later when you place new grout in the area.

Remove the Damaged Grout

Next, you’ll need to remove what’s left of your cracked grout. For grout that’s already loose and easy to remove, you can do it by hand. The more difficult-to-access pieces should be jarred loose during the grinding-down process.

You should always remove as much of the old grout as you can before adding a new layer. Otherwise, newly applied ground won't bond correctly to the surrounding surfaces, creating an even bigger headache later on.

Color-Match the New Grout

Unless you’re replacing all the grout in your space, you’ll need to find a replacement that’s as close to the original color as possible. Otherwise, it’ll be very obvious where you regrout.

You can get help by taking a piece of your old grout to a home improvement store. An employee might be able to color-match the sample to one of their products.

Apply Your New Grout

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If you purchased a mixable grout, start by mixing grout powder with water per the instructions. Read the instructions and product labels carefully to get the ratio correct.

Pour a quarter to a half-gallon of grout over the tiles that you’re regrouting. You can also use a putty knife if it's a smaller section. Using a rubber grout float, spread the material evenly over the edges. Move the grout float in sweeping circles to help move it evenly across the tiles and into the crevices.

Avoid putting too much grout on the tiles at one time. It's better to start with small layers and add more later. You'll need to wipe any excess grout off the surrounding tile before it dries to prevent it from adhering to surface tiles.

Let It Dry

Whether you’re fixing the grout on your floor or your walls, you’ll need to let it dry completely before walking on the surface or allowing water to come into contact with it. Drying times vary by product, but normally grout requires 48 hours to fully cure.

Seal the Surface

An easy way to keep your grout looking its best—and prevent future cracks—is by sealing it. This step is an investment in keeping your grout looking its best for a long time, and it ensures that it will last as long as possible. You'll reduce the likelihood of future cracks and holes—as well as mold—by using a grout sealant.

Once the grout is dry, use a ¼ cup of vinegar mixed with eight ounces of water in a spray bottle to wipe down the area. This step removes impurities and also helps disinfect the area. Be sure to wait the appropriate amount of dry time per instructions.

Apply a thin coat of the appropriate sealant with a sponge, quickly wiping any excess off before it has the chance to dry. Apply between two to three coats, being sure to allow an hour of drying time between each layer.

The type of sealant you use varies depending on the type of surface. For instance, your bathroom will probably see more moisture than your living room floor, so you’d want to make sure any sealant you use in that area has a waterproof component.