How to Install Mosaic Tile
Mosaic tile can be used on floors, walls, countertops, or backsplashes to create intricate designs for sparkle and visual interest. Mosaic tiles do not need to be installed individually. Mosaic tile today comes in the form of multiple tiles pre-attached to a mesh fiberglass backing. This makes mosaic tile far easier to install than if dealing with individual tiles.
Before You Begin
The substrate (or base) for the mosaic tile must be perfectly flat and smooth. Cement board applied over a plywood subfloor or directly against wall studs is suitable. Mosaic tile can be laid directly on plywood or wallboard in non-wet locations.
To cut cement board, score it with a sharp utility knife, guided by a steel carpenter's framing square. Snap at the score lines. Secure the boards with a gap of about 1/8 inch between boards. Cover the seams with 2-inch wide fiberglass cement board tape and cover with thinset.
What You'll Need
Equipment / Tools
- Rubber tiling float
- Notched trowel
- Tape measure
- Tile nipper or wet saw
- Framing square
- Pencil
- Utility knife
- Level
- Chalk snap line
- Clean rags
- Two-by-four scrap
Materials
- Mosaic tile sheets
- Thinset
- Grout
- Grout haze remover
- Grout sealer
- Tile spacers
Instructions
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Plan the Tile Layout
Measure the length and the width of the room. Determine the halfway point and mark this on each of the four walls. Snap a chalk line in each direction to draw intersecting perpendicular layout lines.
Starting at the center of the tile field lets you install full sheets of mosaic tile until you reach the edges of the field. At the edges, cut the mosaic tile sheets to size.
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Lay the First Sheet of Mosaic
At the center of the layout lines, spread thinset mortar with the square side of the notched trowel. Work in sections about 2 to 3 feet square. Press the mosaic tile sheet in the thinset.
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Continue to Lay Tile Sheets
Install adjoining mosaic sheets. Use tile spacers to ensure that gaps between sheets are the same as the gaps between tiles within the sheets. With mosaic sheets, the small tiles are staggered so the sheets interlock. Keep the grout seams uniform throughout the tile field.
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Press the Tiles
Press the mosaic tile sheets occasionally with a clean rubber tile float or with a small piece of wood (about 12 inches square). Do so gently to prevent squeezing thinset out.
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Cut the Tile Sheets to Fit
Approaching the borders, cut the tile sheets by cutting the fiberglass mesh backing. Cut between the tiles.
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Cut the Individual Tiles
To cut individual mosaic tiles, use a wet tile saw, tile nipper, rail cutter, or hand-held angle grinder.
- Wet tile saw: Slowly feed sheets of mosaic tiles through the wet saw in the same way larger tiles are cut.
- Tile nipper: A tile nipper, which looks like a pair of modified pliers and can be used to nibble each tile square within the sheet.
- Tile rail cutter: Use a rail cutter (or snap tile cutter) to score an entire row of tiles. Then, snap the tile apart. Do each tile by itself.
- Grinder: Cut mosaic tiles with a 4-1/2 inch grinder fitted with a diamond wheel.
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Complete the Remaining Quadrants
With one quadrant of the tile job done, repeat the preceding steps to complete the other three quadrants, one at a time. With each quadrant, work from the center point of the layout outward to the edges.
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Install the Trim Tiles
Install trim or accent tile pieces like bullnose edging, cove tiles, or baseboard tiles. After all the tiles are installed, allow the installation to harden before grouting.
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Mix the Grout
Mix a batch of grout in a five-gallon bucket. Use unsanded grout for tiles with grout seams that are 1/8-inch or narrower. Use sanded grout where the seams are wider than 1/8-inch. Follow the manufacturer's directions for mixing.
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Apply the Grout
With the rubber float, spread the grout over the top of the tile. Force the grout into the joints by holding the float at a 45-degree angle to the surface. Alternate the direction of the grout float to ensure that the grout fills all joints.
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Clean the Tile
Allow the grout to harden slightly, according to the manufacturer's directions, then wipe the face of the tiles with a clean cloth to remove dried grout.
After the grout is fully cured, remove the remaining grout film with a liquid grout haze remover.
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Seal the Grout
Brush grout sealer on the grout after the grout has cured. Sanded tile grout must be sealed to protect the underlayment. With mosaic tiles and their many grout lines, it's easiest to apply sealer by brushing or rolling the entire surface. Wipe excess sealer from the surface.
When to Call a Professional
Installing mosaic tile is painstaking and often more difficult than laying larger tiles. Controlling thinset seeping through the seams is tricky. Also, it can be hard to keep the tile sheets flat.
Call an experienced tile setter to install your mosaic tile if you have these or other concerns.