How to Repair Grout in Kitchen Backsplash

Repairing grout in a kitchen backsplash is a common task for many homeowners. With repeated exposure to moisture and daily use, grout can become stained, crack, or fall out completely. Thankfully, with the right tools and techniques, repairing grout is an achievable DIY project.

Assessing the Damage

The first step is to assess the scope of damage to determine what kind of repairs are needed:

Cracks or Gaps in Existing Grout

If the grout has developed hairline cracks or small gaps, this is likely due to normal wear and tear. Thankfully, these can often be filled in with new grout.

Stained or Discolored Grout

Grout can become stained over time from cooking splatters, grease, and mold. Discoloration can usually be remedied with a good grout cleaning prior to sealing.

Missing or Crumbling Grout

In high-traffic areas, grout can start crumbling away leaving holes along the grout lines. These exposed areas will need the old grout scraped out and replaced with new grout.

Gather Supplies

Once you’ve determined the repairs needed, gather the necessary supplies:

  • Grout removal tool – This handy tool has a curved blade to scrape out old grout.
  • Grout float – For smoothing and shaping grout once applied.
  • Grout – Use sanded grout for wider grout lines, unsanded for narrow. Match color to existing.
  • Grout sealant – Essential for protecting newly applied grout.
  • Grout sponge – For wiping excess grout off tiles.
  • Bucket for mixing grout
  • Old rags, painter’s tape

Prep the Area

Proper prep work is key to achieve the best results:

  • Clear the area of appliances, rugs, and removable items. Cover remaining surfaces with drop cloths.
  • Apply painter’s tape vertically along edges of backslash to protect tiles.
  • Dampen the area to prevent grout from drying too quickly.
  • Use the grout saw to scrape out any loose or crumbling grout.
  • Vacuum up all loose debris and dust.

Mix and Apply New Grout

Follow all instructions when mixing the grout, then work it thoroughly into the grout lines:

  • Use a grout float to force grout into any cracks and gaps. Hold the float at a 45° angle applying even pressure.
  • Remove any excess grout from the tile surface with edge of float. Wipe diagonally across tiles.
  • After 10-15 minutes, use a damp grout sponge in a circular motion to further smooth and shape grout.
  • Wipe any remaining haze with a dry cloth once grout becomes firm.
  • Allow 24 hours for grout to fully cure before sealing or using kitchen.

Seal the Grout

Sealing is imperative to protect grout from future staining and damage:

  • Once fully cured, apply grout sealant using sealant’s applicator or a small paintbrush.
  • Work sealant thoroughly into grout lines, wiping any excess off tiles.
  • Allow sealant to cure fully per manufacturer instructions, usually 30 minutes to 1 hour.
  • Apply a second coat of sealant for maximum protection.

With the proper tools and techniques, repairing grout in a kitchen backsplash is an achievable weekend project. Taking time to properly assess damage, prep the area, and apply new grout and sealant will allow you to restore your backsplash to its former glory. Be sure to allow full cure times before use, and re-seal grout every 1-2 years. Your backsplash will look amazing for years to come!

Frequently Asked Questions About Repairing Grout in Kitchen Backsplash

What is the best way to clean grout before regrouting?

The best way to clean grout before regrouting is to use a combination of baking soda, vinegar, and warm water. Make a paste with baking soda and vinegar, apply to stained or dirty grout, let sit for 5 minutes, then scrub with a grout brush or old toothbrush. Rinse thoroughly with warm water.

How long does new grout need to cure before sealing?

New grout should cure for a full 24 hours before applying a sealant. This allows the grout to fully hydrate and harden. Sealing too early can cause issues with the sealant adhering properly.

What color grout should I use when regrouting?

It’s best to match the new grout color as closely as possible to the original grout. Have a grout sample or tile on hand when purchasing new grout for an accurate color match. If the original color is no longer available, choose a neutral shade like bone or linen white.

Can I use unsanded grout for kitchen backsplash repair?

For kitchen backsplashes with grout lines 1/8″ or smaller, unsanded grout is the best choice. It will fill hairline cracks easier. Use sanded grout for any grout lines wider than 1/8″. The sand helps fill in larger gaps.

How soon can I use my kitchen after regrouting the backsplash?

It’s best to avoid use of the kitchen for a full 24 hours after applying new grout. This allows proper curing time. After 24 hours, you can use the kitchen gently, avoiding standing water on countertops or vigorous cleaning of the backsplash for about 3-4 more days.

How often should grout sealer be reapplied?

For high-traffic areas like kitchens, grout sealer should be reapplied every 1-2 years. Look for signs of wear like staining or hazing and reseal promptly. Applying a second coat of sealer after the initial application helps prolong the protection.


Repairing damaged or deteriorating grout in a kitchen backsplash is a project any DIYer can take on. With some simple tools, fresh grout, sealant, and a lot of elbow grease, you can breathe new life into your backsplash. Pay special attention to properly preparing the area, methodically applying new grout, and adequately sealing. In just a weekend, you can avoid the cost and hassle of a full tile replacement by restoring your existing backsplash yourself. With routine sealing, your revitalized backsplash will look fantastic for many years before needing repairs again.