How to Install Marble Mosaic Tile in a Shower

What You'll Need
Utility Knife or Backerboard Knife
1/2 -inch Cement Backerboard
Backerboard Screws
Thinset Trowel
15 lbs Roofing Felt
Marble and Granite Thinset or FlexBond
2-inch Fiberglass Tape
Staple Gun or Hammer Tacker
Grout Float
Marble Mosaic Tile
Grout Sponge
Penetrating Grout and Tile Sealer
Margin Trowel
Tile Spacers
Joint Knife

Unlike porcelain or ceramic tiles, installing marble mosaic tile in a shower gives a feeling of richness and depth. A natural material, each marble mosaic tile will appear to be different in terms of patterns and color tones which make the shower unique. Follow the step-by-step guide below to install these tiles in your shower.

Step 1 – Apply Penetrating Tile and Grout Sealer

Apply a layer of penetrating tile and grout sealer over every marble mosaic tile. This prevents the dye of the grout seeping into the marble tiles.

Step 2 – Check for Mold

Remove the existing drywall and shower items. Check the studs for mold. If mold is found, apply bleach on the affected areas. Air-dry it completely before proceeding to the next step.

Step 3 – Install Roofing Felt

Cut the roofing felt (15 lbs) into pieces and fit them over the studs. Use a staple gun or hammer tacker to attach the roofing felt onto the studs.

Step 4 – Install Cement Backerboard

Cut the cement backerboards and screw it onto the studs with backerboard screws. After doing so for all the backerboard, apply the thinset over the joints with the joint knife one by one. Next, cut the 2-inch fiberglass tape and place it over the applied thinset. Excess thinset is to be scraped away using the joint knife. Repeat the thinset process for all the joints.

Step 5 – Moist the Backerboard

Remove any debris and dust from the backerboard’s surface. Using a slightly damp sponge or spray bottle, moisten its surface.

Step 6 – Apply Thinset onto Shower Walls

Mix the thinset consistently in a bucket and make sure that you have enough thinset to finish the whole project. After mixing the thinset, let it rest for 15 mins. Then, use a joint knife or margin trowel to remove the thinset to load on the thinset trowel. Apply the thinset with upstrokes onto shower walls.

Step 7 – Install Marble Mosaic Tiles

Spread the thinset onto the marble mosaic tiles and install onto the shower walls. Use tile spacers to create straight and consistent grout lines.

Step 8 – Apply Grout

Let the marble mosaic tiles dry for 1 day. Then remove tile spacers from the marble tiles. They can be kept for future tile projects. Mix the grout in a bucket to consistency and let it rest for 15 mins. Then, use a joint knife or margin trowel to remove grout from bucket and load it on the grout float. Apply the grout onto the tiles and grout joints with upstrokes. Apply the grout with force into grout lines so that there are no gaps or spaces. Let it dry for 20 to 25 minutes. Excess grout is to be wiped off from the tiles with a damp sponge.

Step 9 – Apply Penetrating Tile and Grout Sealer

Let the grout stand for 3 days. Then, apply 2 layers of penetrating tile and grout sealer onto the entire surface of grout lines and tiles.