How to Install a Glass Tile Vanity Top

Step 1: Overview

This vanity top would be at home in any luxury bathroom. Even though we chose relatively expensive glass tile, the completed top was than half the cost of custom granite, marble or solid-surface tops. Glass mosaic tile like we used is perfect for a project like this because you can adjust the size of the top to use only full tiles and avoid cutting. Plus, you can choose from hundreds of colors, textures and patterns to create a look that’s perfect for your décor.

You’ll be able to finish this project in a weekend using standard carpentry tools and a 3/16-in. V-notch trowel, a grout float and a grouting sponge. A microfiber cloth works better than a cotton rag for cleaning off the grout haze. You can buy them at home centers, hardware stores and most discount retailers. You’ll also need buckets for mixing thin-set and grout and for rinse water. Don’t forget a pair of rubber, vinyl or latex gloves and safety glasses.

Figure A: Vanity Top Detail

Figure A: Vanity Top Detail

Save yourself some headaches and get better-looking results by sizing the base to fit the tile.

Step 2: Round up the materials

Start by choosing the tile. (This could be the hardest part!) If your local tile shops or home centers don’t have tile you like, shop online like we did for an almost unlimited selection and reasonable prices. To duplicate our project, choose a 3/4-in. square mosaic that’s 1/8 in. thick and has a mesh backing. Avoid mosaics that are held together with a removable paper face. They’re difficult to install. Plan to spend $7 to $24 per square foot for glass tile. Here’s a list of other materials you’ll need:

Plywood
We used two layers of 5/8-in. plywood, which, combined with the 1/4-in. backer board, resulted in a 1-1/2-in.-thick top, a perfect thickness for two courses of our 3/4-in. tile. If your tiles are a different size or you want a different top thickness, adjust the plywood and backer board thicknesses accordingly.

Tile backer board
We used a lightweight tile backer board that you can cut with a utility knife. Cement backer board would also work well.

Thin-set mortar
Look for special glass tile mortar. It’s white and specially formulated to stick well to glass tile. It’s available in a powder that you mix with water. Standard modified white thin-set will also work.

Cement board screws
Choose screws that are labeled for use with cement board. They have a special corrosion-resistant coating.

Cement board tape
Check the label—it must be cement board tape so the mesh will hold up to the alkaline cement products.

Grout
We used nonsanded grout because we wanted smooth grout lines. You can also use sanded grout. Make a sample board by gluing a few glass mosaic tiles to a scrap of wood and grouting them to make sure you like the result.

Step 3: Size the base

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Photo 1: Design the top to avoid cutting tile

Cut a paper pattern the size of the vanity cabinet and lay it over the tile. That makes it easy to size the top for full tiles.

Glass tile is a nightmare to cut. Save yourself some headaches and get better-looking results by sizing the base to fit the tile. With the tile in hand, you can figure out exactly what size to build the plywood base. One easy method is to carefully lay out the sheets of mosaic with an equal grout space between the sheets. Make a paper pattern of your vanity cabinet including the thickness of the door or drawer fronts. Arrange the pattern over the sheets of tile and adjust the position until there’s an equal-width tile on each side. Use the pattern to determine the overhangs, based on where full tiles occur. Aim for about a 1/2-in. overhang on the sides and between 1/2-in. and 1-in. past the drawers on the front. Cut the mesh backing so the sheets of tile are the size of the top. Now carefully measure the width and length of the tiles. This will be the finished size of your countertop after it’s tiled.

The plywood base has to be smaller than the size of the finished top to accommodate the backer board, tile and thin-set. To figure the size of the plywood, add the thickness of the tile (1/8 in.), the tile backer board (1/4 in.) and the thin-set (1/16 in.) and subtract this amount from the width (front to back). Deduct twice this amount from the length (side to side). It’s critical that you cut the plywood to exactly the right size, so double-check all your math (Photo 1).

Step 4: Build the base

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Photo 2: Build the plywood base

Two layers of plywood make a stiff, strong base for the tile. Mark and cut the plywood carefully to make sure the top is perfectly square.

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Photo 3: Cover the base with backer board

Tile backer board forms a waterproof layer for a long-lasting countertop. Quarter-inch-thick backer is all you need over the strong plywood base.

Cut both layers of plywood, being careful to make exact cuts. Then plan the sink location and make the sink cutout. Self-rimming sinks usually include a template that you can use to trace the cutout onto the plywood. Cut the backer board to the same size as the plywood and make the sink cutout. You’ll also need strips of backer board to cover the edges.

Screw the two layers of plywood together. Space screws about 8 in. apart. Then screw the plywood to the vanity cabinet, making sure the overhang is even on both sides and that the front edge is parallel to the vanity cabinet (Photo 2).

Next, cover the plywood with backer board (Photo 3). Cut and test-fit the backer board first. Then mix powdered thin-set mortar with water to about the consistency of peanut butter. Spread it onto the plywood with a 3/16-in. V-notch trowel. Finally, screw the backer board to the plywood, placing screws about 8 in. apart.

The last step before tiling is to wrap the corners of the backer board with cement board tape. Start by vacuuming and then wiping the top and edges with a clean cloth to remove dust. Wrap the adhesive- backed tape around the corners and press it down. Then cover the tape with a thin layer of thin-set mortar. After the thin-set hardens, scrape off any lumps and dust off the top again to prepare it for tiling.

Step 5: Tile the countertop

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Photo 4: Comb out, then flatten the thin-set

Use a 3/16-in. V-notch trowel to spread a layer of thin-set over the backer board. Then flatten it with the straight side of the trowel.

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Photo 5: Start setting the tile at the corner

For perfectly aligned grout joints, start by setting a strip of tile on the front and side edges, and a full sheet of tile on top. Adjust the tile until the grout lines on the top line up with the grout lines on the front and sides.

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Photo 6: Embed the tile with a wood block

Tap the top of the mosaic tile with a flat block of wood to level the surface and ensure a secure bond with the thin-set.

Photos 4 – 6 show how to spread the mortar and embed the tile. Before you start, cut the mesh backing to form strips of tile for the edges and make the sink cutout. Trim the mesh tight to the tile so you don’t have any mesh whiskers sticking out. Then arrange the tile in the shape of the vanity and within easy reach of the vanity top so you can easily reach it after spreading the thin-set.

Mix and spread the thin-set. Pay close attention to Photo 4; it shows an important tip. Flattening the mortar after you spread it with the notched trowel prevents thin-set from filling the grout spaces when you embed the tile. Any thin-set that gets into the grout spaces has to be cleaned out before you can grout the tile, so this tip will save you a lot of time and effort.

Set the tiles on the top and edges as quickly and accurately as possible (Photo 5). You need to work fast so you can make slight adjustments to the tile before the thin-set starts to set up. When you’re satisfied that the tile top and edges are perfectly aligned, embed the tile (Photo 6). Let the thinset harden overnight before grouting.

Step 6: Grout the tile

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Photo 7: Grout the tile

Work the grout back and forth in different directions to completely fill the joints and eliminate voids. Well-packed joints are the key to a lasting grout job.

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Photo 8: "Tool" the grout with a damp sponge

Wait until the grout starts to set up before tooling. Wring out the sponge until it's just damp. Then rub it over the tile in a circular motion to smooth and shape the grout and fill tiny voids and pinholes.

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Photo 9: Buff off the grout film

Wait until the grout is hard before buffing it. Then polish it with a microfiber cloth to remove the haze.

Photos 7–9 show how to grout the tile. Start by mixing the grout according to the directions on the package. Let it rest for about 10 minutes—this is called “slaking.” Then mix it again. It’ll often thicken a bit after slaking and require a bit more water. The grout should be the consistency of mayonnaise.

Here are some grouting tips:

• Work the grout from all angles with the float to completely fill the joints (Photo 7).
• Scrape off the excess before it starts to set.
• Wait until the grout starts to harden before cleaning it with a sponge. If you can’t make a fingerprint, it’s hard enough.
• Keep the rinse water clear and wring all the water out of the sponge when you’re cleaning the grout. Use a clean side of the sponge for each cleaning stroke.
• Use a damp sponge to tool the grout after it sets up (Photo 8). Wait about 15 minutes after cleaning before tooling the tile.
• Coat the grout with a grout sealer to help prevent staining and make it more water-resistant. Wait two or three days before sealing.

Step 7: Finishing touches

We added a backsplash before setting the sink. A backsplash could be as simple as tiles attached to the wall with thin-set, or something more elaborate. We screwed 3/8-in. plywood to the wall, covered it with 1/4-in. backer board and surrounded it with 3/4-in.-thick oak trim. Then we tiled over the backer board, grouted the tile and caulked the seam between the countertop and the backsplash with a fine bead of clear silicone caulk.

Glass tile mirror

Glass Tile Mirror

The mirror frame is made From a 3/4-in. x 4-1/2-in. oak board with a 1-5/8- in.-wide dado on the face to accommodate a band of tile and a 3/8-in. rabbet on the back to hold the mirror. We cut the dado with dado blades mounted on a table saw. A router would also work. We sized the frame so we wouldn't have to cut tiles at the corners. After mitering the parts and staining the frame, we set the tile strips in a thin bead of construction adhesive. Then we finished it off by masking the wood and grouting the tile.