How to Mortar Backsplash

Mortaring a backsplash is a great way to add visual interest and protection to your kitchen or bathroom walls. With the right materials and techniques, you can achieve a beautiful, long-lasting mortar finish. In this comprehensive guide, we’ll walk you through everything you need to know to properly mortar a backsplash in your home.

What You’ll Need

Mortaring a backsplash requires some specialized materials and tools:


The tile itself comes in endless options – ceramic, porcelain, glass, stone, and more. Choose a material and style that fits your design aesthetic. Smaller tiles like mosaics create more grout lines for a textured look. Larger tiles have fewer grout lines for a smoother finish.


Premixed mortar is ideal for most backsplash projects. It already contains the correct proportions of cement, sand, and chemicals needed to create a strong bond and cure.

Notched trowel

This tool is used to spread mortar evenly on the wall and tile. The notches determine the thickness of the mortar layer.


Grout fills the joints between tiles with color and texture. Sanded grout works best for joints wider than 1/8 inch. Unsanded is best for narrow joints. Match grout color to your tile.

Grout sealer

Sealing the grout helps prevent staining and erosion. Use a water-based sealer for a natural look.


These small plastic crosses ensure consistent spacing between tiles for straight, even grout lines.

Tile cutter

Essential for custom cutting partial or edge tiles to fit.

Mixing bucket

For blending mortar as needed to prevent it from hardening too quickly.

Grout float

A tool used to spread grout evenly across the tile joints.

Grout sponge

Important for smoothing grout lines and removing excess grout from tiles.

Safety gear

Like gloves, goggles, mask, and knee pads to protect yourself while working.

How to Prepare the Wall

Proper prep work is crucial for good adhesion and preventing cracks or tiles popping off later. Here’s how to get your backsplash wall ready for tiling:

  • Clean thoroughly – Use TSP cleaner to remove grease, soap residue, or any other grime on the wall. Rinse well. Let the wall dry completely.
  • Repair any damage – Fill holes, smooth bumps or uneven areas so you have a flat surface for tiling. Use drywall joint compound as needed.
  • Prime – After repairs, apply a coat of masonry primer to help the mortar adhere properly.
  • Mark the layout – Determine the tile layout pattern. Use a level to mark straight horizontal and vertical guide lines on the wall to align the first row.
  • Install backerboard – For moisture-prone areas like behind a sink, use cement backerboard as an underlayment before tiling.

Now your backsplash wall is prepped and ready for mortar and tile!

How to Mix the Mortar

Mixing the mortar to the right consistency is key for proper application and adhesion:

  • Pour mortar powder into a bucket according to the manufacturer’s instructions.
  • Add the recommended amount of clean water.
  • Mix it together thoroughly with a paddle mixer on low speed.
  • Adjust water amounts if needed – the mortar should be thick but still spreadable.
  • Let it slake (sit) for 10 minutes, then remix before using.
  • Only mix as much mortar as you can use in 30-45 minutes before it starts to harden.
  • To prevent skinning over or hardening too quickly, re-stir the mortar occasionally during use.
  • Don’t reconstitute mortar once it’s started to harden. Always mix fresh batches.

How to Spread Mortar on the Wall

Applying mortar smoothly and evenly is essential for proper installation:

  • Apply a thin layer of mortar adhesive to the backsplash wall using a notched trowel.
  • Hold the trowel at a 45-degree angle to scrape the mortar adhesive firmly onto the wall.
  • Apply enough pressure so the trowel notches fully imprint in the mortar.
  • Spread mortar across the entire installation area to ensure full coverage.
  • Additional mortar can be added to low spots as needed to level the surface.
  • Work in sections so the mortar doesn’t dry out before you can tile over it.

How to Back-Butter the Tiles

“Back-buttering” each tile with mortar provides maximum adhesion:

  • Spread a layer of mortar on the back of each tile using the flat side of the trowel.
  • Apply mortar to an area slightly smaller than the tile to avoid squeezing out.
  • The mortar layer should be about 1/8-inch thick after the tile is pressed into the wall mortar.
  • Back-butter one tile at a time as you go to prevent the mortar from drying out.
  • Firmly press tiles into position so the mortar on the wall and tile adhere together.
  • Use spacers between tiles to create even grout lines as you go.
  • Work in small sections so you can finish positioning tiles before the mortar skins over.

How to Apply Grout

Grout fills the spaces between tiles with color and texture:

  • Allow the mortar to cure fully according to manufacturer’s directions before grouting.
  • Apply grout by holding the float at a 45-degree angle and forcing it deeply into the tile joints.
  • Move diagonally across the tiles to prevent dragging grout out.
  • Let the grout sit for about 15 minutes until slightly firm. Then scrape excess grout off the tile faces with the edge of the float.
  • Wipe tiles clean with a damp grout sponge in a circular motion. Rinse the sponge frequently.
  • Allow grout to cure overnight. Then seal grout lines with a water-based sealer for protection.
  • Finally, buff tiles gently with a soft cloth to polish them up.

And your beautiful mortared backsplash is complete! Proper maintenance will keep it looking great for years to come.

Mortar Backsplash Maintenance Tips

Here are some tips for keeping your mortared backsplash in top shape long-term:

  • Use a gentle cleaner like dish soap and water to clean tiles. Avoid harsh chemicals.
  • Re-seal the grout lines annually to prevent staining or erosion.
  • Repair any cracks in grout or caulk right away to prevent moisture issues.
  • Re-grout any areas that show signs of shrinking or cracking.
  • Don’t use abrasive scrub pads or cleaners that can scratch or dull the tile.
  • Wipe up spills quickly, especially acidic foods like citrus that can etch the finish.
  • Consider protective sealers designed for your tile material to prevent stains.
  • Use a soft cloth or sponge for daily cleaning. Never use steel wool.
  • Check for any loose or cracked tiles and re-adhere them promptly as needed.

With proper installation and care, your mortared backsplash can stay looking fabulous and withstand heavy use for many years in your home.

Frequently Asked Questions About Mortaring a Backsplash

What’s the easiest way to cut ceramic tiles?

Use a manual tile cutter with a carbide scoring wheel. Measure and mark your cut line on the tile, position the tile in the cutter, then press the handles together firmly to score the clay body. The tile should then snap cleanly apart along the scored line. A snap cutter tool is also handy for straight cuts and mosaics. For intricate curves, a mini wet saw works best.

How long does mortar take to cure before grouting?

Mortar needs 24-48 hours to cure enough to start grouting. Exact mortar cure times depend on the product used, temperature, and humidity levels. Always follow manufacturer’s directions for recommended mortar cure times in your environment before grouting tiles.

What’s the ratio of mortar to water for backsplashes?

A standard mortar to water ratio is around 2 to 2.5 parts powder to 1 part water by volume. However, every mortar product is slightly different, so always follow label instructions for exact mixing ratios and water amounts. Adding too much or too little water can affect performance.

Should backsplash tiles be staggered or stacked?

Offsetting tiles in a staggered brickwork pattern provides more stability than stacking them vertically. However, stacked layouts can also work fine on backsplashes when installed properly over a solid substrate. Choose whichever pattern you prefer visually.

How do you apply mortar on walls evenly?

Use a notched trowel at a 45-degree angle to firmly scrape and spread the mortar onto the wall. Apply even pressure so the trowel notches fully imprint into the mortar. Ensure full coverage across the entire installation area. Fill any low spots as needed to level the surface.

What is the minimum backsplash height in a kitchen?

Standard backsplash height is a minimum of 4 inches from the countertop. However, taller backsplashes are also popular, ranging anywhere from 8 inches to full height. The National Kitchen and Bath Association recommends a 4-8 inch range for functionality and cleanability.

Is thinset the same as mortar?

Thinset is a specialized type of thin mortar used specifically for installing tile. It contains polymers and additives not found in standard mortars, giving it enhanced adhesion and flexibility. Thinset is ideal as a mortar bed for most tile projects, including backsplashes.

Can I use premixed mastic instead of mortar?

Premixed mastic adhesives are not recommended for backsplashes. Mastics lack the strength to properly support heavy wall tiles in wet areas. They can degrade over time. Mortar is the best choice for a durable bond on backsplashes.


With the right prep, materials, and techniques, you can achieve beautiful mortared backsplash results in your home. A mortared backsplash offers a custom look full of texture and visual appeal – well worth the effort for handy homeowners. Just follow the steps outlined here for mixing mortar, spreading it smoothly, back-buttering tiles, proper grouting, and ongoing care. Take things slowly and let materials fully cure. Before you know it, you’ll have a stunning new backsplash to enjoy for years to come.