What Trowel to Use for Backsplash

Installing a backsplash in your kitchen or bathroom can greatly improve the look and feel of the space. However, choosing the right trowel for the job is essential to achieve a smooth, even application of tile adhesive and proper adhesion. This guide will examine the factors to consider when selecting a trowel for your backsplash project.


A trowel is a hand tool used to apply adhesive or “mastic” when installing tile. Using the proper trowel ensures you apply the right thickness of adhesive for the tile you’re working with. The teeth on the trowel create ridges to comb the adhesive and allow optimal contact between the tile and substrate.

Choosing the right trowel size and tooth configuration prevents applying adhesive too thin or too thick. Proper coverage allows the tiles to adhere correctly to the surface beneath them. Under-applying adhesive can cause tiles to dislodge or crack. Over-application leads to adhesive squeeze-out between tiles, increased cleanup, and tile shifting.

Below we’ll explore what to look for when selecting a trowel for your specific backsplash tile project.

Factors to Consider

Tile Size

The size of your backsplash tile determines the size trowel you need. Larger tiles require deeper grooves to achieve proper adhesive coverage. As a general guideline:

  • Use a 3/16” square-notched trowel for mosaic tiles up to 2” x 2”.
  • Use a 1/4” square-notched trowel for 4” x 4” wall tiles.
  • Use a 1/2″ square- or U-notched trowel for tiles 8” x 8” or larger.

Refer to your tile manufacturer’s recommendations for the best trowel size for that particular product.

Tile Material

The type of tile you’re installing is another consideration, as some materials require more adhesive than others due to porosity and texture.

  • Natural stone tiles are highly porous and need a trowel size upgrade to ensure adequate adhesion in the deeper grooves and pores.
  • Large format tiles and tiles with very textured backs also benefit from a bigger trowel size.
  • Mosaic sheets may require a trowel with smaller notches to prevent adhesive squeeze-out between the tiny tiles.

Adhesive Type

Some adhesive types also impact the trowel you should select.

  • Latex-modified thinset mortar allows for a smaller trowel size versus non-modified thinset.
  • Medium bed mortar often requires a larger notched trowel size.
  • Refer to the adhesive manufacturer’s guidelines for recommended trowel size.

Substrate Type

The material you are tiling onto influences trowel choice as well.

  • Smooth drywall requires a smaller trowel size versus rough surfaces like cement backer board.
  • Non-porous surfaces like existing tile may call for a larger trowel.
  • Absorbent substrates like plaster need more adhesive applied.

Trowel Types

Beyond size, there are a few common trowel types to consider for your backsplash installation:

Square Notch

This is the most common trowel for backsplashes. The square notches create ridges perfect for combing adhesive in straight lines across the substrate. They come in a range of sizes from 3/16” up to 1/2″ or more.

U Notch

U-notched trowels have rounded notches that form U shapes. These work well for smoothing adhesive in curves or circles, such as mosaic medallions. U-notch trowels cover a bit more surface area than square notch.

Double Dipped

These specialty trowels combine two sizes of square notches in one. Typically the notches are different lengths and widths rather than depths. Double dipped trowels allow smoothing in different directions.

V Notch

V-notched trowels have angled teeth in a V shape. These are ideal for working with large format tiles. The grooves help grip thicker adhesive and support heavier tiles.

How to Choose Your Trowel

When selecting your trowel, follow this process:

  1. Determine the size of your tile and planned pattern. Measure tile depth if installing a brick pattern.
  2. Look at the tile manufacturer’s instructions for any specific trowel recommendations.
  3. Identify the type of adhesive you’ll be using and see if a trowel size is specified.
  4. Consider the substrate material and condition to determine if you need more or less adhesive.
  5. Start with the trowel size guidelines earlier in this article based on your tile size. Adjust up or down based on tile material, adhesive type, and substrate.
  6. Choose a trowel with the appropriate size square or U-notches. V-notch for large tiles.
  7. Select a high-quality, stiff stainless steel trowel. Softer metals like aluminum can bend during use.
  8. Test the trowel on scrap materials first to ensure it achieves full adhesive contact and transfers properly.

With the right trowel for your project, you can achieve a stunning, long-lasting backsplash installation. Don’t hesitate to reach out to the manufacturer for guidance. Happy troweling!

Frequently Asked Questions

What trowel should I use for 12×12 backsplash tiles?

For standard 12×12 ceramic or porcelain backsplash tiles, use a 1/4″ x 1/4″ square-notched trowel. This size notch will achieve proper adhesive coverage on each tile.

What size trowel for large format backsplash tile?

For backsplash tiles 12″ x 24″ or larger, use a 1/2″ x 1/2″ square-notched or 1/2″ rounded notch U-notched trowel. The wider grooves provide enough adhesive for these heavy tiles.

What if my backsplash is irregularly shaped?

A U-notched trowel is a good choice for an irregular or curved backsplash area. The rounded notches allow you to apply adhesive in curves more easily. Use the same size as you would for the tile – 1/4″ or 1/2″ notch.

Do natural stone tiles need a special trowel?

Due to the porous, uneven surface on the back of natural stone tiles, it’s recommended to go up a size on your trowel. So use 1/2″ notches for 12″x12″ stone tiles versus 1/4″ for ceramic. This compensates for the extra adhesion needed.

How do I clean adhesive off a trowel?

Carefully scrape off excess adhesive with a trowel cleaning tool or old gift card while it’s still wet. Then wash the trowel vigorously with warm, soapy water using a scrub brush. Avoid solvent cleaners which can break down the finish.


Installing a beautiful, durable backsplash requires having the right trowel for applying adhesive. Matching the tool to your specific tile size, materials, and substrate ensures proper coverage for a long-lasting end result. With the guidelines provided, you can confidently choose the ideal trowel for your upcoming backsplash tiling project. Happy DIY tiling!