How to Apply Grout to Subway Tile Backsplash


Installing a subway tile backsplash can be an easy and affordable way to add style and personality to your kitchen or bathroom. Subway tiles are classic rectangular tiles that are typically 3 by 6 inches, though you can find many variations on size and color. The grout lines in between the tiles are part of what gives subway tile its signature look. Applying grout properly ensures your backsplash will be sturdy, water-resistant, and look professionally installed.

Grouting may seem intimidating if you’ve never done it before, but it’s actually a straightforward process if you follow some key tips. With the right tools, materials, and techniques, you can achieve flawless grout lines and a long-lasting backsplash. We’ll walk you through all the steps and considerations for how to apply grout to subway tile backsplash successfully.

What You Need to Grout Subway Tile

Before starting the grouting process, you’ll need to gather the right supplies. Having these materials on hand will make the job much smoother:


  • Sanded grout is best for subway tile with grout lines 1/8 inch or wider. It contains sand for durability.
  • Unsanded grout works for grout lines less than 1/8 inch. It has a smoother texture.
  • Choose a grout color that complements or matches your tiles. Grey and white are popular choices.

Grout Float

  • A grout float, or rubber grout float, is used to spread grout evenly and work it into joints. Get one with a soft, flexible edge.

Grout Sealer

  • Applying a grout sealer after installation will protect porous grout from stains. Use a water-based sealer for the best results.

Sponge and Bucket

  • Have several clean sponges and buckets of water to wipe away excess grout. Damp, not overly wet, sponges work best.

Grout Remover Tool

  • A handy tool for removing grout from the tile surface before it dries. A simple plastic scraper will also work.

Painter’s Tape

  • Mask off edges with painter’s tape for easier clean up and to avoid staining tiles like natural stone. Remove tape before grout dries.

Tiling Tools

  • Have any tools used in the original tile installation on hand for fixing uneven tiles or adjusting as needed.

Preparing to Grout Subway Tile

Taking a few steps to prepare the tile surface will mean you can grout subway tile quickly and efficiently with no hassles:

Allow Tile to Cure

It’s crucial to allow tile thinset adhesive to fully cure before grouting. Check the thinset manufacturer instructions, but you’ll typically need to wait at least 24 hours. Rushing this step can lead to cracks or loose tiles later on.

Clean Tile Surface

Use a damp sponge to wipe off any thinset, spacers, dirt or debris on the tile and in joints. Grout won’t bond effectively to dirty tile. Ensure the surface is clean and dry before grouting.

Apply Painter’s Tape

Use painter’s tape to cover walls, countertops, or any surfaces you want to protect from grout during the installation process. Avoid natural stone, which could absorb color underneath the tape.

Fill Wide Joints

If joint spacing between tiles exceeds 1/8 inch, fill the extra space with sanded grout before normal grouting. This prevents cracking as the grout dries.

Cut Caulking Tubes

If using caulk for transitions or edges, cut the tubes and put them in a caulking gun beforehand for easy access later.

Mixing and Applying Grout

With your prep work done, it’s time to start grouting. Follow these steps for hassle-free application:

Mix the Grout

Mix grout per the package directions in a bucket. Use cool, clean water and mix to a smooth, toothpaste-like consistency. Only mix as much as you can use in 30 minutes.

Apply Grout to the Tile

Use the grout float to spread grout diagonally across a small section of the tile. Push the grout firmly into the joints until fully packed.

Work in Small Sections

Grout 3-4 square feet at a time so it stays workable. Come back to any missed spots to ensure joints are completely full.

Let Grout Sit

Allow grout to firm up on the tile for about 10-15 minutes. This helps ensure it stays in the joints when wiping. Don’t let it sit for too long.

Wipe Grout Off Tile

Use a lightly damp sponge in a circular motion to wipe any grout haze or film off the tile surface. Rinse sponges frequently.

Smooth and Shape Joints

Once grout haze is removed, use the rounded edge of the grout float to shape and compress grout lines. Smooth any uneven sections for a consistent finish.

Remove Painter’s Tape

Carefully pull off any painter’s tape from edges once grout is semi-dry. Wipe away any residue or bleeding under tape edges with a damp sponge.

Allow Grout to Cure

Let grout dry 24-72 hours for proper curing. Avoid getting the area wet during this time. Check for any missed spots and lightly sponge again while still workable.

Grout Care and Maintenance

Grout plays an integral role in protecting the underlying tile. Follow these tips to keep your subway tile backsplash looking fresh:

Seal Grout

Applying a penetrating sealer to grout lines will prevent stains and make cleaning easier. Reapply yearly or as needed.

Clean Grout Routinely

Use a mild pH balanced cleaner and soft cloth for regular grout cleaning. Avoid harsh chemicals which can degrade grout.

Check for Cracks

Inspect grout closely for any hairline cracks forming, which could allow water underneath. Re-grout if needed.

Re-Grout When Necessary

Over time, grout can become brittle and crack. Carefully remove and replace old grout to protect tiles from damage.

Installing the grout for your subway tile backsplash takes precision and patience but is very manageable for any DIYer. Just be sure to properly prepare the tile surface, use quality grouting materials, work in small sections, and wipe tiles thoroughly. With the right approach, you can achieve flawless, professional-looking grouted subway tile that will last for years to come. Don’t be afraid to get your hands dirty!

Frequently Asked Questions About Grouting Subway Tile

How long should I wait to grout subway tile?

It’s crucial to allow tile thinset adhesive to cure fully, which usually takes at least 24 hours. Grout applied too soon could compromise adhesion and cause tiles to crack or come loose over time.

What color grout is best for white subway tile?

White and light grey grout are popular choices for white subway tile. They provide contrast without overwhelming the white tiles. Dark grout can also create a bold look. Go with a grout shade that matches your overall design vision.

Should I seal subway tile before or after grouting?

Sealing is only needed for porous tiles like natural stone. In that case, seal tiles before grouting. Otherwise excess sealer could get trapped in grout joints or discolor grout. Wait at least 72 hours after grouting to seal finished grout lines.

How do I get hard grout off new tile?

If grout residue has already hardened on tiles, carefully scrape it off with a plastic scraper or the edge of a credit card. Avoid metal scrapers, which could scratch tiles. Use a damp sponge in a circular motion for any remaining haze.

Should I grout subway tile in the shower?

Yes, it’s important to fully grout subway tile even in wet areas like a shower. Using waterproof grout and a grout sealer will prevent water damage and create a water-tight seal. Leave a small gap caulked at corners or changes in plane.


Grouting subway tile backsplashes provides a polished finish and helps lock the tiles firmly in place. Follow the recommendations here for how to apply grout to subway tile backsplash and you can expect a successful project that looks professionally installed. Take your time to thoroughly pack joints and wipe away excess grout. Your beautiful finished backsplash will be an enduring focal point providing classic style.