How to Grout Subway Tile Kitchen Backsplash

Grout is an integral component of any tiled surface. For kitchen backsplashes, grout plays the crucial role of filling the joints between subway tiles, sealing the installation and giving a finished look. Properly grouting subway tile backsplash ensures water resistance, durability and an aesthetically pleasing finish. This article provides a step-by-step guide to grouting subway tile kitchen backsplash.

What You Need to Grout Subway Tile Kitchen Backsplash

Before starting the grouting process, ensure that you have all the necessary materials and tools:

  • Grout – Choose an appropriate grout type like sanded grout or unsanded grout depending on tile spacing.
  • Grout float – For forcing grout into joints.
  • Grout bucket – For mixing grout.
  • Grout sponge – For wiping off excess grout.
  • Old towels – For wiping and cleaning.
  • Utility knife – For scraping off hardened grout.
  • Grout sealer – For sealing grout pores after installation.
  • Caulk gun – For sealing corners and edges with silicone caulk.
  • Tape – For covering gaps you don’t want filled with grout.
  • Mixing paddle – For mixing grout thoroughly.
  • Rubber gloves and eye protection – For safety.

Step-by-Step Guide to Grout Subway Tile Backsplash

Follow these steps for a flawless grouted backsplash:

Step 1: Prepare the Tile Surface

  • Ensure tiles are firmly set and adhesive has cured completely as per manufacturer’s instructions.
  • Remove all tile spacers.
  • With a damp sponge, wipe down the tile surface to remove any dirt, dust or debris.

Step 2: Mix the Grout

  • Take the amount of grout required and put in a bucket.
  • Add water according to manufacturer’s instructions and mix to achieve a smooth, lump-free consistency.
  • Let the grout slake for 10 minutes then remix before applying.

Step 3: Apply Grout

  • Use the grout float to scoop and apply grout diagonally across the tiles to fill all joints completely.
  • Hold the float at a 45° angle and force grout deeply into gaps between tiles.
  • Apply in sections of 4-5 sq. ft. at a time to avoid premature drying.

Step 4: Let Grout Sit for a Few Minutes

  • Allow grout to sit for 5-10 minutes so it can settle properly in tile joints. This helps complete the filling.
  • Use the grout float edge to scrape off any excess grout sitting on the top of tile surfaces.

Step 5: Wipe Excess Grout

  • After 10 minutes, use a damp grout sponge in a circular motion to wipe any remaining grout off the tile surface.
  • Rinse sponge in bucket of water to remove excess grout after every wipe.
  • Wipe diagonally to edges for a smooth finish. Avoid smearing grout from joints.

Step 6: Let Grout Dry

  • Allow grout to dry naturally for about 2-3 hours without disturbing it.
  • Once dry, use a soft, dry cloth to polish the tiles and finish wiping any remaining haze.

Step 7: Seal the Grout

  • After 24 hours of grout drying, seal grout lines with a penetrating sealer.
  • Apply sealer with a paintbrush and wipe off excess with a clean cloth.
  • This seals pores and prevents staining or discoloration due to moisture.

Step 8: Caulk Corners and Edges

  • Use a silicone caulk to seal grout joints in corner joints and along countertop, sink or exposed tile edges.
  • Apply caulk with a caulk gun, smooth with finger and let dry completely.
  • Caulking prevents water seepage and cracking at vulnerable joints.

Tips for Successful Grout Application

  • Grout small sections of up to 4-5 sq. ft. at a time to prevent premature drying.
  • Hold grout float at a consistent 45° angle to force grout into gaps efficiently.
  • Ensure all joints are packed fully with grout to prevent cracks or holes later.
  • Let grout sit for 5-10 minutes before wiping to allow proper settling into joints.
  • Wipe diagonally across tiles and rinse sponge frequently for smooth, haze-free finish.
  • Don’t overwater grout when mixing to avoid color variations and weak grout.
  • Grout width should not exceed 1/8” for optimal fill and strength. Wider areas need caulk.
  • Allow 24 hours of curing before sealing or getting grout wet to achieve full hardness.

Common Grout Issues and Solutions

Cracking – Can be caused by poor grout packing, uneven tile surfaces or normal movement. Regrout affected areas.

Efflorescence – Whitish grout haze from moisture is common on new installations. Can be cleaned off once substrate is dry.

Discoloration – Dirt, grime and moisture can stain grout over time. Can be cleaned with grout whitener or colored sealant.

Grout Haze – A residue left on tiles after grouting. Remove with vinegar or grout haze remover within 24 hours before drying.

Holes or Pits – Indicates improper grout installation. Should be raked out and regrouted for a consistent finish.

Crumbling Grout – Usually from cheap grout quality or inadequate mixing. Needs raking and replacement with better grout.

Frequently Asked Questions

What is the best grout color for a subway tile backsplash?

For a classic look, white grout pairs well with subway tiles. Gray is also popular for a modern vibe. Choose a color that matches your tiles.

How soon can I get the grout wet after installation?

Wait at least 24 hours before exposing grout to moisture. This allows complete curing and hardness.

Should spacers be removed before grouting?

Yes. Leaving spacers in can affect proper filling of joints and lead to holes once they’re removed later.

What is the typical grout joint size for subway tiles?

1/8” is the commonly recommended grout line thickness for subway tiles. Wider joints may require caulk instead of grout.

How do I apply grout on uneven tile surfaces?

Hold the grout float firmly at an angle and apply pressure to force grout into wider joints for proper fill.


Grouting may seem intimidating for first-timers. But following the right techniques and using quality materials ensures flawless results. Preparation, proper application, and curing are key steps for maximum grout integrity. With some care and patience, you can achieve the stylish and water-resistant backsplash you desire with subway tile grouting.