How to Put Subway Tile Backsplash

Installing a subway tile backsplash can transform the look of a kitchen or bathroom by adding an elegant, timeless finish. Subway tiles are rectangular ceramic tiles that get their name from their resemblance to tiles used in New York City subway stations. With the right planning and supplies, you can easily install subway tile yourself as a weekend DIY project. This guide will walk you through all the steps needed for a successful subway tile backsplash installation.

Choosing Your Subway Tile

The first step is to choose the right subway tile for your space. Here are some things to consider:

Tile Material

  • Ceramic: Classic and affordable option available in glossy or matte finish. Durable and water-resistant.
  • Porcelain: More durable and water-resistant than ceramic. Low porosity makes it stain and moisture resistant.
  • Glass: Adds shiny, sleek look. Softer than ceramic or porcelain so can chip or scratch.
  • Natural Stone: Materials like marble, travertine, slate. Add organic, natural look. Require sealing.

Tile Size

  • Standard subway tiles are 3 x 6 inches, but larger formats like 4 x 8 or 4 x 12 inches are available. Larger tiles mean fewer grout lines.
  • Mini formats like 2 x 4 inches have more grout but create intricate patterns.
  • Be sure to account for 1/8 inch grout lines when calculating how many tiles you need.

Tile Finish

  • Matte finish has an understated, classic look. Helps hide grout haze and fingerprints.
  • Glossy finish has a shiny, sleek appearance. Reflects light to create depth. Shows more signs of wear.
  • Glazed vs. unglazed – glazed has a protective coating for easy cleaning. Unglazed has porous, natural texture.

Tile Color

  • White or light gray for a clean, timeless look.
  • Bold colors or patterns for dramatic impact.
  • Neutral earth tones like beige for a subtle effect.
  • Contrasting grout color to make tiles stand out.
  • Match grout to tile for seamless look.

Gathering Supplies

Once you’ve selected your subway tile, gather the necessary supplies before starting your installation:

Tile and Grout

  • Subway tile sheets – calculate 10-15% extra for cuts and waste.
  • Grout – sanded grout for joints 1/8 inch or larger, unsanded for smaller.
  • Grout sealer to protect grout color and help prevent staining.


  • Tile cutter for straight cuts
  • Nippers and snips for irregular cuts
  • Trowels for spreading adhesive
  • Grout float for applying grout
  • Sponges and buckets for cleaning
  • Tile spacers for consistent grout lines


  • Thinset mortar adhesive designed for walls
  • Non-sanded caulk for corner joints and edges
  • Backerboard like cement, fiberglass mesh, or greenboard
  • Sealant if installing near wet areas

Preparing the Surface

Make sure your installation surface is properly prepped before applying tile:

  • Clean surface thoroughly – no debris, grease, etc. that could prevent adhesion.
  • Apply waterproofing membrane if installing near water sources.
  • Install appropriate backerboard if surface is drywall. Follow manufacturer instructions.
  • Make any repairs to surface defects – fill holes, smooth bumps.
  • Mark your starting point and snap chalk lines as guides for first row.

Applying the Tile Adhesive

Proper application of your thinset mortar is key to a long-lasting tile installation:

  • Use a notched trowel to spread adhesive on small sections at a time.
  • Apply even layer covering entire area, using right trowel size and notching.
  • Use flat side of trowel to flatten ridges and create uniform texture.
  • Only cover sections you can tile before adhesive skins over (15-20 minutes).
  • Use tile spacers for consistent grout line width if desired.
  • Press tiles firmly into adhesive with twisting motion. Check for full coverage on back.
  • Periodically remove tile to check adhesive thickness and coverage.
  • Scrape out improperly embedded tiles and re-apply before adhesive dries.

Cutting the Tiles

Follow these tips for perfectly cut subway tiles:

  • Always cut tiles face up to prevent chipping. Mark line with pencil or marker.
  • For straight cuts, use a snap tile cutter aligned on cutting marks.
  • For L-cuts and notches, use nippers and then a file to smooth the edges.
  • For intricate or irregular cuts, use a wet saw or angle grinder with diamond blade.
  • Test cuts on spare tiles first to ensure proper size and fit.
  • Blend cut edges strategically within pattern to make them less noticeable.
  • Mullion cuts to fit outlet covers, faucets, etc can be made with carbid rasp.

Grouting the Tile

Grout fills the joints between tiles. Follow these best practices:

  • Allow thinset to fully cure before grouting, generally 24-48 hours.
  • Apply grout by working it into joints with a rubber grout float.
  • Hold float at 45° angle and use diagonal sweeping motion across tiles.
  • Ensure joints are fully packed, spreading excess grout over entire area.
  • Let grout sit for 5-10 minutes until slightly hardened.
  • Use sponge and buckets of clean water to wipe diagonally across tiles.
  • Rinse sponge frequently and change water often for best results.
  • Avoid wiping grout out of joints – focus on cleaning tile surface.
  • Allow to dry 24 hours, then apply grout sealer as needed.

Finishing and Sealing

The final steps complete your backsplash installation:

  • Allow grout and thinset to fully cure, generally 24-72 hours.
  • Use caulk along countertop seam and corners – do not grout these joints.
  • If necessary, use tile sealant to provide water protection near sinks, etc.
  • Clean any remaining grout haze with damp microfiber cloth once cured.
  • Examine final installation closely for any missed areas needing touch up.
  • Enjoy your stylish, durable subway tile backsplash!

Subway Tile Backsplash FAQ

Get answers to common questions about installing a subway tile backsplash:

What type of thinset should I use?

For walls, use an adhesive mortar formulated for wall applications. It will provide the flexibility needed for normal structural movements. White thinset can help prevent shadowing through translucent glass tile.

How do I cut holes for outlets and fixtures?

Use a carbide-tipped hole saw and drill to cut neatly around any outlets, switches, or plumbing fixtures. Or make traced outline cuts with a rotary tool before carefully knocking out the piece with hammer and chisel.

Can I install tile directly over painted drywall?

No, tile should only be applied over cement board, greenboard, or other suitable backer material. The exceptions are mastic adhesives on walls.

What spacing do I need between tiles?

Standard subway tiles should have 1/16 to 1/8 inch spacing. Natural stone tiles can use wider grout lines of 1/8 inch or more. Use tile spacers for consistent spacing.

How soon can I grout after setting tiles?

Wait at least 24 hours after applying tile for thinset mortar to fully cure before applying grout. Check manufacturer guidelines as thinner layers may cure faster.

How do I cut subway tiles around electrical outlets?

Carefully measure and mark the areas to cut around outlet boxes. Use a carbide hole saw for round cuts. For square cuts make a series of holes inside box outline with rotary tool and then chisel out remainder.

Can I use dark grout with white subway tile?

Yes, contrasting white tiles with a dark charcoal or gray grout highlights the grout lines for a dramatic effect. Be sure to seal grout well so color does not get absorbed into the tile.

How do I finish the edge near a countertop?

Use a matching color caulk between the tile and countertop instead of grout. This flexible material allows for expansion and contraction without cracking grout.

What kind of saw should I use to cut tile?

The best tool for most tile cutting is a wet saw, which keeps the blade cooled and tile dust minimized. A snap tile cutter works for straight cuts under 1 inch thick. Use an angle grinder for specialty cuts.


Installing a subway tile backsplash is an approachable DIY project for any homeowner with basic tiling experience. Careful planning and preparation are needed to ensure proper execution. Key steps include selecting your tiles, gathering supplies, prepping the surface, applying thinset mortar, cutting any specialty tiles, expertly grouting, and finishing with caulk and sealant as needed. Paying close attention to details like using quality setting materials, allowing proper cure times, and cleaning thoroughly will result in a backsplash you can enjoy for years to come. With the right know-how, you can transform your kitchen or bath with the classic beauty of subway tile.