How to Repair Kitchen Backsplash Grout

Repairing cracked or damaged grout in your kitchen backsplash is an important maintenance task that will help keep your backsplash looking its best. With some basic tools and materials, repairing grout is an easy DIY project that most homeowners can tackle. Here is a step-by-step guide to repairing kitchen backsplash grout.

Assessing the Damage

The first step is to thoroughly inspect the grout lines in your backsplash and identify any problem areas. Look for cracks, missing grout, discoloration, or signs of mold/mildew growth. Pay special attention to grout around the edges and corners of your backsplash as these areas tend to fail first. Grab a flashlight to illuminate all the nooks and crannies. Determine how much of the grout needs repair – you may only need to spot repair small sections rather than re-grouting the entire backsplash.

Gathering Supplies

Once you’ve identified areas needing repair, gather the necessary supplies:

  • Grout removal tool: A carbide-tipped grout saw, rotary tool, or oscillating multi-tool with grout blade to remove old grout
  • Grout float: For applying new grout into joints
  • Grout: Use sanded grout for wider joints, unsanded for smaller joints
  • Grout sealing product (optional): For protecting repaired areas
  • Cloth, bucket, and sponge: For cleaning work area
  • Painter’s tape: For protecting edges around grout repairs
  • Safety gear: Goggles, dust mask, gloves

Make sure to get grout that matches the existing color as closely as possible. Having all supplies readily on hand will make the repair job much smoother.

Removing Old Grout

Start by using your grout removal tool to rake out the cracked or crumbling grout around the repair areas. Work at an angle to avoid damaging the edges of the tile. Sweep or vacuum away all the debris as you go.

If you are repairing just a few small cracks or pits, you can skip the removal step and apply new grout directly over the old – just make sure the old grout is still firmly bonded. Wider areas with failing grout will need complete removal and replacement.

Prepping the Surface

Once all the old grout is removed, wash the entire backsplash surface with a diluted vinegar/water solution to remove any dirt, grease, or soap scum. This will help the new grout adhere properly. Rinse well and let the surface dry completely before moving to the next step.

Use painter’s tape to mask off the edges of the tile around any repaired areas – this will make clean up much easier. Make sure there are no gaps for grout to seep under the tape edges.

Mixing and Applying New Grout

Prepare the grout mix according to the manufacturer’s instructions. Only mix up as much as can be applied within 30 minutes. Using the grout float, spread the grout thoroughly over the raked-out joints, packing it deeply into the crevices. Remove any excess grout from the tile surface with the edge of the float.

Allow the grout to firm up for about 10-15 minutes. Then go over the joints again to smooth and shape into a concave profile. Clean excess grout from the tile surface as you work. Mist the grout with water and allow to dry another 10 minutes before moving to final cleaning.

Final Clean Up

Once the grout has firmed up, use a lightly damp sponge to clean any remaining grout haze from the tile surface. Work in circular motions, rinsing the sponge frequently. Avoid smearing grout onto the tiles. Remove the painter’s tape before the grout dries.

Allow the grout to cure 24-48 hours before using the backsplash. Avoid moisture on the repaired grout during this time. Wipe down the tiles with a dry cloth to remove any remaining dust or residue.

Sealing Grout (Optional)

Sealing your repaired grout is an optional extra step but can help protect grout from future staining or moisture damage. Use a penetrating grout sealer and carefully follow the product directions. Make sure the grout has fully cured first. Re-apply sealer yearly or as needed to maintain protection.

And that’s it! With some simple DIY techniques, you can successfully repair kitchen backsplash grout, keeping your backsplash looking fresh and neat. Properly repaired and maintained grout will help ensure your backsplash provides years of beauty in your kitchen.

Frequently Asked Questions About Repairing Kitchen Backsplash Grout

What causes grout to crack or crumble?

There are a few common reasons grout can become damaged:

  • Normal wear and tear over time
  • Moisture damage from spills or leaks
  • Improper initial installation/curing
  • Movement in the wall or tiles causing stress on grout
  • Harsh cleaning agents eroding grout

What’s the best way to match new grout color to old grout?

Take a sample of the old grout to the hardware store and compare colors in person rather than relying on a photo. Natural light is best. Let the grout sample dry first for the most accurate color. Purchase a few close options and do a test in an inconspicuous spot.

Should I use sanded or unsanded grout for my kitchen backsplash?

In general, use sanded grout for joints wider than 1/8 inch and unsanded for anything narrower. The sand in sanded grout helps reinforce wider grout lines. Check your existing grout type if unsure.

Is it OK to grout over existing grout?

In some cases, yes. If the old grout is still firmly bonded and you are just repairing hairline cracks or small chips, applying new grout directly over old is fine. But if the old grout is crumbling or missing in wider areas, full removal is best.

How soon can I use my backsplash after regrouting?

It’s best to wait 24-48 hours for new grout to fully cure before regular use of the backsplash. Avoid getting the area wet during that time. After 48 hours, the grout should be ready for exposure to moisture and daily use.

How often should grout be sealed?

For high-traffic kitchen backsplashes, it’s ideal to seal grout every 1-2 years. Use a penetrating sealer and apply according to product directions. Check for wear and reapply yearly or as needed. Harsh cleaners may require more frequent sealing.


Repairing failing or damaged grout in a kitchen backsplash is an essential maintenance job for any homeowner. With the right tools and materials, as well as proper prep and application techniques, you can successfully DIY grout repairs and restore your backsplash to its former glory. Paying attention to grout condition and promptly fixing any problem areas will go a long way in keeping your kitchen looking its very best.