Installing a glass tile backsplash can be a great way to add style and visual interest to your kitchen. However, proper installation is key to ensuring the tiles adhere properly and look their best. An important decision you’ll need to make is what size trowel to use when applying the mortar that adheres the tiles. Selecting the right trowel size helps ensure proper coverage and allows the tiles to be set evenly.
Factors to Consider When Choosing a Trowel Size
When selecting a trowel for glass tile installation, there are a few key factors to take into account:
Tile Size
The size of the individual glass tiles you’ve chosen is one of the most important considerations. Smaller tiles require a smaller notched trowel size, while larger tiles require a larger trowel notch. This ensures you’re applying enough mortar to fully support each tile and cover its back surface.
Tile Shape
In addition to tile size, the shape also impacts trowel choice. For example, long, thin tiles like subway-style glass tiles may need a smaller notch trowel to prevent too much mortar from being applied. Square or rectangular tiles can typically accommodate larger notches.
Tile Thickness
Thicker tile materials like glass need a thicker layer of mortar beneath them. Glass tiles tend to be thicker than ceramic or porcelain, so they require a trowel notch size on the larger end of the spectrum. Consult the tile manufacturer’s recommendations to determine the needed mortar bed thickness.
Mortar Type
The type of mortar product you use should also be factored in when selecting a trowel. For glass tile projects, a latex-modified thinset mortar is typically recommended. Consult the mortar manufacturer’s guidelines on trowel notch size. They’re formulated to work together to provide the right amount of coverage.
Substrate Material
The material you’re applying the tiles to, such as cement board, plywood, or existing tiles, also affects the amount of mortar needed. Rough or uneven substrates may benefit from a deeper notch trowel size to allow more mortar for leveling. Smooth drywall often requires less.
Recommended Trowel Sizes for Glass Tiles
Most glass tile backsplashes are installed using a v-notch trowel. Based on common sizes and shapes of glass tiles, here are some general trowel size guidelines:
- Mosaic glass tiles 1″ x 1″ or smaller: 1/4″ x 3/8″ v-notch trowel
- Small glass tiles up to 2″ x 2″: 1/4″ x 1/4″ v-notch trowel
- Standard glass subway tiles 3″ x 6″ or larger: 1/2″ x 1/2″ v-notch trowel
However, it’s always best to follow the recommendations provided by the tile manufacturer and mortar manufacturer to ensure proper installation for your specific project.
The v-notches in the trowel create grooves for the mortar to adhere in a ribbed pattern on the substrate surface. The ridges provide the right amount of thickness and coverage for each size and shape of tile.
Using a notched-edge trowel with v-shaped notches, versus a square-notch design, also helps promote maximum contact between the glass tiles and substrate for a durable bond.
How to Choose the Right Trowel Size
When trying to decide on trowel size for a glass tile backsplash, follow this process:
1. Consult the tile and mortar manufacturers’ instructions – Check both the tile packaging and mortar technical specifications for the recommended trowel size and mortar thickness. This is the best reference for your particular products.
2. Consider the tile characteristics – Think about the size, shape, and thickness of your specific glass tile selection based on the guidelines above. Measure a few tiles for thickness.
3. Visually inspect the substrate – Is the surface smooth or will it need more mortar to fill in an uneven texture? This can impact trowel choice.
4. Choose a trowel size – Select a v-notch trowel size within the recommendations that matches up with your tile and mortar combination. Allow for a little extra mortar if in doubt between sizes.
5. Test on a small area – Try installing a few tiles with the selected trowel to see the mortar coverage it provides. Adjust if needed.
Opting for the right size trowel from the start makes efficiently installing the entire backsplash smoother. Don’t hesitate to adjust your trowel if the coverage doesn’t look adequate over the tiles.
How to Use a V-Notch Trowel
Once you’ve selected the appropriately sized v-notch trowel, proper technique is crucial when applying the mortar for glass mosaics or large sheet tiles. Here are some tips:
- Hold the trowel at a 45° angle against the substrate to evenly apply mortar.
- Spread mortar horizontally in a ribbed pattern over a section at a time.
- Apply even pressure with the trowel notched-side down to imprint ridges.
- Use the smooth side of the trowel to knock off any high points in the mortar.
- Maintain ridges running in straight horizontal lines rather than swirling.
- Don’t allow mortar to skin over before placing tiles. Time working in sections.
- Embed tiles firmly into the mortar ridges with some back and forth movement.
Applying high-quality latex modified thinset mortar with the proper trowel technique provides a durable bond and level surface for a stunning glass tile installation.
Common Mistakes to Avoid
When using a notched trowel for glass tile, it’s important to avoid some common errors:
- Using the wrong size trowel – Make sure the notch matches recommendations for the tile size. Too small and the mortar won’t all squeeze up between the tile and substrate. Too large can cause too much mortar and uneven tiles.
- Applying mortar in a swirled pattern – Straight, parallel ridges provide optimal contact and adhesion for the tile backing. Swirling can trap air.
- Leaving thick ridges or blobs of mortar – Collapse any high points with the flat side for an even depth. Excess mortar won’t allow the tile to sit flush.
- Not embedding the tiles properly – Set tiles with some pressure and movement across ridges. Don’t just place tiles flat on top of the mortar.
- Allowing mortar to dry or skin over – Work in sections and place tiles immediately before the mortar surface dries. This prevents maximal adhesion.
Trowel Size vs. Tile Size Chart
Here is a quick reference trowel size chart for common glass tile dimensions:
| Glass Tile Size | Recommended Trowel Size |
|---|---|
| Mosaic tiles up to 1″ | 1/4″ x 3/8″ v-notch |
| 1″ x 1″ mosaic tiles | 1/4″ x 1/4″ v-notch |
| 2″ x 2″ tiles | 1/4″ x 1/4″ v-notch |
| Subway tiles 3″ x 6″ | 1/2″ x 1/2″ v-notch |
| 4″ x 4″ tiles | 1/2″ x 1/2″ v-notch |
| 6″ x 6″ tiles | 1/2″ x 1/2″ v-notch |
This chart provides a quick guideline but manufacturer instructions take precedence for your specific products.
Trowel Notch Shape for Glass Tile
V-shaped notched trowels are the recommended style for nearly any tile project, including glass mosaics and subway tiles. The v-shape provides optimal adhesion power.
Square notch trowels are acceptable for very smooth substrates and smaller tiles no larger than 2 inches. However, the v-notch design is preferable.
U-notched trowels are occasionally used for pebble stones or large format tiles exceeding 12″x12″ when maximum mortar is needed. But v-notched trowels remain the most versatile for typical glass tile backsplashes.
Option: Trowel Spacers for Consistent Tile Spacing
If installing glass tile in a straight-set pattern, plastic trowel spacers can help maintain even grout line spacing. These snap onto the trowel edges to provide a guide.
Set the spacer width based on your desired grout line width. For mosaic sheets, 1/16″ or 1/8″ spacers allow narrow grout lines.
Bump the spacers against the last tile edges as you set each piece to keep rows straight and evenly spaced. This provides a clean look.
Just be sure to remove the spacers once the tiles are firmly embedded so they don’t get stuck in the mortar. Trowel spacers are an optional helpful tool for keeping glass tile spacing consistent.
Reviewing the Key Points
Selecting and using the right trowel for a glass tile backsplash installation ensures it gets done properly the first time. Here are the key takeaways:
- Consult both tile and mortar manufacturer instructions for the best trowel notch size.
- Match trowel size to factors like tile dimensions, thickness, and substrate.
- Allow for a little extra mortar thickness with glass tiles whenever possible.
- Hold the trowel at a 45° angle and apply parallel ridges of adhesive.
- Embed tiles into the mortar with pressure to make full contact.
- Adjust trowel size if coverage and adhesion seem inadequate.
- Avoid too small or too large of a trowel notch for the tile size.
With attention to substrate prep, using quality mortar, and the properly sized notched trowel, you can achieve a stunning glass tile backsplash design. Take time to get the adhesive mortar just right as the foundation of a durable installation.
Frequently Asked Questions
How important is trowel size for installing glass tile?
Choosing the right trowel size is very important for proper adhesion and an attractive end result with glass tile. The appropriate notch size helps ensure each tile makes full contact with the mortar and provides just the right amount of adhesive thickness and coverage.
Should I choose a trowel that’s slightly too small or too big?
It’s advisable to err on the slightly larger size if debating between two notch sizes for your tile. Insufficient mortar coverage can lead to failed adhesion. Slightly too much mortar can be managed by collapsing ridges and monitoring thickness.
Can I use a standard drywall taping knife instead of a v-notch trowel?
While tapping knives spread adhesive smoothly, the lack of notches means the adhesive won’t provide the right ridge profile and thickness for durable tile bonding. Notched trowels are specially designed to provide optimal tile coverage.
How do I clean mortar off a v-notch trowel after use?
Let the residual mortar dry slightly on the trowel without allowing it to fully harden. Then tap the trowel against a rigid surface to flake off chunks of mortar. A putty knife can help pry off any remaining stubborn deposits. Avoid using water to wash it initially.
Can I use the same v-notch trowel for both the substrate and applying mastic to the tiles?
It’s recommended to dedicate separate trowels for the wall and tile adhesives. Cross-contaminating the mortar on the substrate with mastic can result in bonding issues. Label each trowel for its intended use.
Conclusion
Installing glass tile can feel intimidating as a DIYer, but having the right adhesive mortar trowel makes the job much more manageable. Matching the trowel notch size to both the tile characteristics and the recommendations provides optimal adhesion. Combine that with proper mortar selection and application technique for a long-lasting quality installation and addition of beautiful glass tile shine to your kitchen or bath. With the right trowel as your tile-setting sidekick, you can install an eye-catching glass mosaic or subway tile backsplash successfully.