How to Install 3×12 Subway Tile Backsplash

Installing a 3×12 subway tile backsplash can add a classic, timeless look to your kitchen or bathroom. With some planning and preparation, even novice DIYers can achieve professional-looking results. Here is a step-by-step guide on how to install 3×12 subway tile for your backsplash.


Subway tiles are rectangular ceramic tiles that get their name from their resemblance to tiles used in New York City subway stations. The 3×12 size refers to tiles that are 3 inches high by 12 inches long.

Subway tiles are a popular backsplash choice because they are:

  • Affordable
  • Easy to install
  • Available in glossy, matte, or textured finishes
  • Offered in a range of solid colors and patterns
  • Classic and timeless aesthetic

Installing a 3×12 subway tile backsplash is a relatively easy DIY project that can completely transform the look of your kitchen or bathroom. With proper planning and preparation, even first-time tilers can achieve stunning results.

Planning Your Backsplash

Before purchasing tiles and supplies, take some time to plan your backsplash installation:

  • Measure the area to be tiled. Be sure to measure both height and width. Having these measurements will allow you to purchase the correct amount of tile and supplies.
  • Make a layout. Map out the tile layout on paper, including cut tiles. This will help minimize wasted tiles.
  • Purchase 10-15% extra tiles. It’s always smart to buy extra tiles to account for broken or damaged tiles during installation.
  • Select grout color. Choose a grout color that complements or contrasts with your tile. White and gray grout are popular with subway tiles.
  • Gather tools and materials. Make sure you have all the necessary tools like a tile cutter, spacers, grout float, etc. before starting.

Proper planning is crucial for a successful subway tile backsplash installation.

What You Need


  • Tile cutter
  • Mixing bucket
  • Notched trowel
  • Grout float
  • Sponge
  • Tile spacers
  • Level


  • 3×12 subway tiles
  • Thinset mortar
  • Grout
  • Sealer
  • Caulk

Other supplies:

  • Drop cloths
  • Rags
  • Tape
  • Painter’s tape

Make sure you have all the necessary tools and materials on hand before beginning the installation. This will prevent delays or having to stop mid-project.

Preparing the Surface

Installing tile over an existing backsplash surface? You’ll first need to remove the old backsplash completely.

Once the old backsplash is removed, follow these steps to prepare the surface:

  • Clean thoroughly. Use a degreaser to remove any oil, dirt, or residue from the area. Ensure the surface is clean and dry.
  • Make any repairs. Fix any damaged areas in the wall surface and allow repairs to dry completely.
  • Apply primer. Prime the surface with a latex primer to improve adhesion.

With the area prepped, you can move on to installing the tile backsplash.

Installing the Subway Tile

Follow these steps for proper installation:

Step 1: Apply Thinset Mortar

  • Use a notched trowel to spread a layer of thinset mortar on the installation surface. Apply enough to cover an area that can be tiled in 30 minutes.
  • Use the flat side of the trowel to knock down any high spots.

Step 2: Place the Tiles

  • Place the first tile in the corner. Use spacers to leave an even 1/8 inch gap between tiles.
  • Press tiles firmly into the thinset mortar. Use a level to ensure the tiles are even.
  • Continue laying full tiles, using spacers to maintain even spacing.
  • For cut tiles, measure and mark the tiles to the proper size. Use the tile cutter to score and snap tiles.

Step 3: Let Tiles Set

  • Allow tiles to set for 24 hours without disturbing them. This allows the thinset to fully cure.
  • Keep the tiles protected while curing so they don’t get damaged or dirty.

Step 4: Grout the Tiles

  • Mix up grout according to package directions. Apply grout over the tiles using a rubber grout float.
  • Push grout into gaps between tiles. Ensure gaps are fully packed with grout.
  • Use a damp sponge to clean excess grout off the tiles before it dries. Rinse sponge frequently.
  • Allow grout to dry completely, about 24 hours.

Step 5: Seal and Finish

  • Apply a penetrating sealer to the grout lines using a small foam brush. This prevents stains and damage.
  • Caulk between the countertop and backsplash, along the edges, leaving a neat finished edge.

Follow these tips for a successful subway tile backsplash installation. With some patience and care, you can achieve stunning results!

Tips and Tricks

  • Stagger tiles so the grout lines don’t all align. This creates a more interesting look.
  • Mix tiles from several different boxes. This prevents color variations from being noticeable.
  • Use painter’s tape along the edges of the backsplash area while tiling. This creates clean finished edges.
  • Wipe away excess grout as you work to make final cleanup easier. Don’t let it dry completely on the tiles.
  • Consider using a light-colored sanded grout. This offers an attractive contrast with darker subway tiles.

Frequently Asked Questions

What thinset mortar should I use?

Use a polymer-modified thinset mortar which offers better adhesion and strength. Make sure it is formulated for wall applications.

How do I cut the subway tiles?

Use a wet saw or snap tile cutter. Score the tile and snap it for straight cuts. For L-cuts, use a wet saw.

Should my tiles go all the way to the ceiling?

Not necessarily. Standard height is 4-6 inches above the countertop. Going all the way up is optional for a full subway tile effect.

What are the best grout colors?

Popular choices are white and gray, which offer nice contrast. But any grout color that complements your tiles can work.

How soon can I expose the backsplash to water?

Wait a full 72 hours after grouting to allow the grout to fully cure before regular exposure to moisture.


Installing a 3×12 subway tile backsplash is an easy, affordable way to make a big impact in your kitchen or bathroom. With proper planning and preparation, even inexperienced DIYers can achieve professional-looking results. The classic subway tile style pairs beautifully with any decor. Just follow the steps for installing the tiles, grouting, and sealing, while utilizing the tips provided. In no time, you’ll have a stunning new backsplash to enjoy for years to come.