How to Apply Grout to a Backsplash

Applying grout to a backsplash is an important step in finishing your kitchen or bathroom tiling project. Properly grouting the joints between tiles seals the surface, prevents moisture damage, and gives your backsplash a polished, finished look. With some basic tools and materials, grouting a backsplash is a straightforward DIY project for most homeowners. Follow these steps for smooth, even grout lines and a durable, quality backsplash.

Choosing Your Grout

When grouting a backsplash, you’ll need to select the right type of grout for the job. Here are some of the most common options:

Unsanded Grout

  • Best for joints 1/8 inch or smaller
  • Smooth consistency is easy to spread
  • Common in bathrooms and kitchens
  • Available in different colors

Sanded Grout

  • Contains fine sand for joints 1/8 inch or wider
  • Sturdier and less prone to cracking
  • Useful for floors or countertops
  • Limited color options

Epoxy Grout

  • Made from epoxy resins for chemical resistance
  • Withstands stains and moisture well
  • Great for kitchen backsplashes
  • More difficult to work with

Polymer-Modified Grout

  • Contains polymers for flexibility
  • Resists shrinking and cracking
  • Water-resistant for wet areas
  • More expensive but very durable

For a kitchen backsplash, an unsanded or polymer-modified grout works well. Avoid epoxy grout in the kitchen unless chemical resistance is needed. Match the grout color to your tile color for a seamless look.

For a bathroom backsplash, use an unsanded, polymer-modified, or epoxy grout. Water-resistance is important in this wet environment. Contrasting grout colors can enhance the tile design.

Always check the manufacturer’s recommendations and use a grout suitable for your type of tile and joints.

What You’ll Need

Gather these supplies before starting your project:

  • Grout mix or pre-mixed grout
  • Grout float for spreading grout
  • Grout sponge and bucket of water for cleaning
  • Old towels or rags
  • Grout sealer (recommended)
  • Tiling spacers for consistent joints
  • Safety gear like gloves and goggles

Optional handy tools:

  • Grout bag for grouting corners
  • Grout rake for removing excess grout
  • Grout haze remover if needed after grouting
  • Carpenter’s level for checking flatness

Tip: Have extra sponges and water available for grout clean-up. Change the water frequently to avoid leaving a film.

Preparing for Grout Application

Proper prep work ensures the grout adheres well and creates clean results:

  • Allow mortar to cure: Let tile mortar dry completely, usually 24-48 hours. Appplying grout too soon can displace tiles.
  • Clean tiles: Wipe down the tile surface with a damp sponge to remove dust and debris. Grout won’t bind well to dirty tiles.
  • Moisten tiles slightly: Use a sponge to apply a light coat of water to the tiles and joints. This helps the grout penetrate and stick. Take care not to over-saturate.
  • Check for flatness: Use a level across tiles to identify any uneven spots. Adjust tiles if needed to keep joints consistent.
  • Apply spacers: Place tile spacers in joints to maintain even grout lines as you work. Remove spacers once grout is applied.
  • Plan your approach: Work in manageable sections so grout doesn’t dry too quickly. Start from the top and work downwards.

Mixing and Applying Grout

Follow these steps for hassle-free grout application:

Mix Grout

For bagged grout, mix powdered grout according to package directions in a bucket. Use cool, clean water and mix to a thick, toothpaste-like consistency. Don’t mix too thin or using hot water.

For pre-mixed grout, no mixing is needed. Just open the container and use.

Only mix what you can use in 30-45 minutes. Grout will start to harden and become unusable.

Tip: If using colored grout, mix batches consistently for color uniformity across the project.

Apply Grout

1. Use a grout float. Hold at a 45° angle and firmly press grout diagonally across the joints to fill completely. Apply in sections working top to bottom.

2. Pack joints. Use the edge of the float to pack the grout tightly into the crevices between tiles. Remove excess grout on the tile surface.

3. Clean excess grout. Once section is packed, use a damp grout sponge in a circular motion to gently clean off residue and smooth joints. Rinse sponge frequently.

4. Shape and refine joints. For a neater finish, use a damp finger to shape and define grout lines after sponging. Remove any haze.

5. Check for unfilled spots. Look for any voids and re-apply grout as needed before moving to the next section.

Repeat across the entire installation for full grout coverage. Take care not to accidentally displace tiles while grouting.

Cleaning and Curing Grout

Follow these tips for proper grout clean-up and curing:

  • Allow grout to firm up slightly before cleaning, usually 10-15 minutes. Don’t wait too long or it will be hard to clean.
  • Gently clean tiles and joints using a damp sponge in a circular motion. Rinse sponge frequently to avoid grout haze.
  • Buff tiles with a soft cloth once majority of grout is cleaned off for a polished finish. Take care not to disturb joints.
  • Check for haze and use grout haze remover if needed per product directions.
  • Allow grout to cure fully for 24-48 hours. Avoid heavy cleaning during this time.
  • Seal grout with a penetrating sealer for added protection (recommended).
  • Avoid walking on tiles for at least 24 hours. Install carpets or boards temporarily if needed.

Proper grout clean-up and curing prevents issues like cracking, discoloration, and tile displacement down the road.

Grout Maintenance and Repair

With proper installation and care, grout can last for years. Follow these tips for longevity:

  • Seal grout annually or as needed to protect from stains and moisture.
  • Clean grout regularly as part of routine tile maintenance. Use gentle cleaners and avoid abrasives.
  • Address cracks or damage promptly to prevent further deterioration. Re-grouting may be needed.
  • Check for missing or weak grout. Loose grout can lead to damage. Re-apply if spots are hollowing or empty.
  • Spot treat stains carefully using a specialized grout cleaner. Avoid harsh chemicals that can degrade grout.
  • Consider re-coloring discolored or stained grout periodically with dye kits rather than replacing.

With proper installation and care, you can enjoy a beautiful, long-lasting backsplash. We hope these tips give you confidence to tackle your own grouting project. Let us know if you have any other questions!

Frequently Asked Questions About Applying Grout to a Backsplash

Here are answers to some common questions about grouting backsplash projects:

What’s the easiest way to apply grout?

Using a grout float is the quickest and most effective technique. Hold at a 45° angle to completely fill joints. Follow with gentle sponge cleaning to smooth and shape joints.

Should I grout bottom row first or top?

It’s best practice to start grouting at the top and work your way down. This prevents dripping grout from landing on clean tiles below.

How long should I wait before cleaning excess grout off tiles?

Wait 10-15 minutes for grout to firm up slightly. This makes grout easier to shape cleanly. Don’t wait longer than 30 minutes or cleaning becomes difficult.

What causes grout haze?

Grout haze occurs when a film is left behind on tiles after grouting. It’s often caused by not letting grout cure partly before cleaning or using too much water during sponging.

Can I use sanded grout for vertical joints?

Sanded grout is not ideal for vertical surfaces like backsplashes. The sand particles can settle, leaving the upper parts of joints weaker. Use unsanded or polymer-modified grout instead.

How soon can I expose grout to water after application?

Avoid significant moisture for the first 72 hours while grout cures. Limit cleaning during this time or you may compromise grout integrity.

Why is my grout cracking in spots?

Cracking often occurs from improper joints, inadequate curing conditions, tile movement, or general wear over time. Carefully re-grouting is the solution.

How often should grout be sealed?

Sealing frequency depends on use, but annually is recommended for kitchen backsplashes. Seal more often for heavy use areas or if grout seems to be absorbing liquids.

Can I change the color of my existing grout?

Yes, grout color can be changed using a dye or whitener. This is a good option if your grout has become stained or discolored over time.


Grouting may seem intimidating, but don’t be afraid to give your backsplash project a professional finish. With the right tools, materials, and techniques, you can achieve beautiful results. Pay special attention to preparation, mixing, clean-up, and curing for grout that withstands daily use.

Remember to work in small, manageable sections. Let the grout firm up slightly before cleaning for smoother joints. And be patient during curing to avoid issues like cracking or weak spots.

With some practice and patience, you can become a pro at grouting backsplashes. We hope these tips give you the confidence and knowledge needed to properly apply grout. Let us know if you have any other backsplash grouting questions!