A DIY tile project can be both a fun and productive way to spend your time, not to mention a great way to save on an amazing home upgrade! We’re confident that laying tile is something pretty much everyone can do with great success, and we’re here to provide the best tips to ensure your project is everything you’d hoped for! 

Some of the most common mistakes first time tilers make come down to preparedness and tool selection. Luckily that’s an easy fix and we’re here to help!

How to Choose the Right Trowel for your Tile Project

One of the most essential and yet most overlooked items for a successful DIY tile project is the right trowel. It’s not as simple as just picking up any old trowel and expecting to get neat and tidy results! Sure, at their most basic level you need a piece of metal with a handle that’s used to apply adhesive for your tiles, but the picking the right tool is essential to successful bonding and the longevity of your tiles. 

Choosing the right type and trowel size for tiles you want to install will set you up for success!  If you’re planning a DIY tile project, we highly recommend you keep on reading to choose the right trowel for your next tile project! 

What is a Tile Trowel? 

Let’s start with the basics! Basically, a trowel’s purpose is to spread tile adhesive onto the substrate – i.e. your floor, wall, or ceiling - and control how much adhesive you’re putting on.  It has a handle and a flat metal plate that is designed to scoop up and spread the adhesive, ensuring that you’re laying down the same amount of adhesive (mortar) every time to ensure a smoothly tiled finish.

More than just a tool to spread mortar, your trowel creates a level surface with the right amount of mortar to install the tiles properly. This is where choosing the right trowel makes all the difference, as it helps you apply the proper mortar coverage for your chosen type of tile!

What is Mortar Coverage?

We know that we need the right trowel to ensure proper mortar coverage when laying tile, but what does that actually mean? 

ANSI (American National Standards Institute) sets the standards for proper coverage of any tile in wet and dry areas – 95% coverage is the minimum for wet areas such as showers or outdoors, and 80% is the minimum for dry areas such as bathroom floors, backsplashes, fireplaces, etc. 95% coverage is also recommended for natural stone tiles wherever they’re installed. 

Keep in mind that mortar coverage becomes particularly important as tile sizes get larger and longer, especially for large format tiles with one side that is 15” or longer. The flatness of your surface is important too; if you’re laying tile on a floor with a little slope, you’ll probably need to spread your mortar thicker than the general guidelines.

Tip: A quick way to double check that you have enough coverage is by placing the tile after you’ve put your mortar, then pulling the tile up and checking the back. 

You should see the adhesive completely spread out on both the back of your tile and the substrate - gaps in coverage on either surface means that you do not have enough mortar to fully bond your tile to the substrate. 

If you see more than 15% of the back of the tile is not covered in mortar, more is needed to ensure a solid bond to avoid cracking or chipping after installation.

With the diversity of tiles available today, achieving full mortar coverage has become even more important and challenging. As different materials and sizes of tile require different amounts of mortar, a ‘one size fits all’ trowel and approach won’t work. The variety of options can be overwhelming when searching for the right trowel. Size and shape are the two most important factors to consider when choosing the right one for your tile job!

So which trowel is right for your project? Read on to find the right trowel to pair with different types of tiles and installations!

Trowels with Different Shapes (Notches)

A trowel’s tooth shape - which is also called the ‘notch’ – affects how much mortar is sandwiched between the tile and the substrate. The notches not only help apply the mortar in even lines but also create spaces between the lines of mortar. This allows air to escape when tile is pressed into the mortar. The three shapes important to know are: U-Notch, V-Notch and Square-Notch trowels. 

Read more about how your trowel notch can affect your mortar coverage!

Trowels with V-Shaped Notches:

RUBI Tools 11" Open Rubiflex Triangular V Notched Trowel (1/4" x 3/16")

As the name suggests, a V-notch trowel has V-shaped edges, a continuous zig-zag (or a sawtooth) pattern. V-notch trowel are the ideal trowel for mosaic tile installations on a mesh backing or squares less than 4”, as they spread the least mount of mortar. V-notch trowels are also a good size trowel for wall tiles and ceiling applications as they dispense less mortar than Square-Notch trowels.

Trowels with U-Notched Notches:

RUBI Tools 11" Open Rubiflex U Notched Trowel (3/8")

The U-shaped teeth allows them to spread more mortar compared to the V-shaped trowels. This design is primarily used for tiles with at least one edge larger than 4”.

Trowels with Square-Notches: 

RUBI Tools 11" Open Rubiflex Notched Trowel (1/4" x 1/4")

They typically dispense more mortar than the other two, and their square or rectangular notches create mortar rows with flat spaces between them. As with the U-notch, you can use the square-notch for any tile that is over 4”. Square-Notched trowels are usually used for most floor tiles.

Spreading Mortar with a Square Notch Trowel for Flooring Tile

Tip: The general rule is to use a v-notch for a Mosaic tile and a Square-notch for large format tile.

Most average-sized tiles will benefit most from using a U-notch or Square-notch trowel, as the difference in adhesive spread is minimal.

Picking the right Trowel Size for your Tile Install

Besides the notch shape, your trowel’s size will make a big difference when applying your adhesive. Keep in mind that by using too little adhesive, you run the risk of broken or cracked tiles, while too much can create a mess and be a major pain to remove.

In order to apply the proper amount of adhesive, your trowel size will depend on three factors;

1. Tile size 
2. How thick you need your adhesive to be under the tile 
3. The surface type (e.g., floor or wall)

Once you have these factors determined, make sure to understand how trowels are measured. 

Generally, with V-notch trowels, you will see that there are two numbers to factor in, measuring the width and the depth of the notch. 

On the other hand, with Square or U-notch trowels usually come with three numbers to consider: the first number is again the width of the notch, second is the width of space between the notches (which is not a factor in V-notch trowels) and finally, the depth of the notch. 

You can find this information in the product specifications of most trowels.

Tip: If a trowel has only two numbers, it means that the width of the teeth and width between the teeth are the same. 

One of the good ways to confirm the correct notch size is to install several tiles and then lift them and check if enough mortar contacts the surface of the tile and subtract.

Ok, you have all your details in place, but what trowel do you actually need?  

The Most Common Trowel Sizes

Although the size and thickness of your tile (along with your application area) will help you determine the right shape and size for your trowel, we also have a list of the most common trowels and what they’re used for – a quick guide to help simplify your trowel choice!

Fabrique Blue Grey Chevron Glass Mosaic Tile - mosaic tile sheets may vary, but include smaller tiles on a mesh that benefits from the smaller gaps in mortar made by a v-notch trowel.

Recommended trowel for mosaic tiles: *V-Notch Trowel 3/16” x ¼”: A typical size trowel for wall tiles and mosaic tiles up to 4 ½” 

Carrara Dots Etched Subway Marble Tile - 3" x 12"

Recommended size trowel for subway tiles: *U-Notch or Square-Notch Trowel ¼” x ¼”: Ideal for 4”x4” up to 8”x8” tiles and bigger subway tiles (e.g., 4”x12”)

Brick Brooklyn Blanco - 4.3" x 13"

Recommended trowel for longer tiles: *U-Notch or Square-Notch Trowel ¼” x 3/8”: Ideal for 8”x8” up to 16”x16” tiles

Dover Almond and Dover Almond Deco -  12.6" x 24.6"

Recommended Trowel for large format tiles: *Square-Notch Trowel ½” x ½”: Ideal for 16”x16” and larger tiles 

• See more tips on Installing Large Format Tiles

While choosing the right tile trowel for your next project is often simplified by the tile that you pick, you may still find yourself confused with the variety of options in the market. If you’re still in doubt, reach out to us or share your thoughts and concerns about choosing the right trowel in the comments section below and our team would be happy to help!