How to Install Marble Tile Wall Fireplace

Lay your tiles on the floor near your fireplace so you have a basic design for your wall. This will make the installation process easier, since you can simply pick up the tiles and follow the same pattern.

Disconnect the mantel from your fireplace. If you cannot disconnect the mantle, mask the edges of the mantel with painter's tape. This will protect the surface from thinset and grout.

Mix thinset and additives per specific product instructions. The thinset should have the consistency of peanut butter when you are finished. Different products may require different additives or different ratios for mixtures.

Spread the thinset over the entire wall surface with a 1/4-inch by 1/4-inch finishing trowel. This size trowel allows proper coverage for heavy marble tiles. Smooth the surface over, creating a completely even surface on which you can install your tiles. Allow the thinset to dry overnight before continuing.

Mix a second batch of thinset per product instructions. Spread the thinset across your installation area, covering an area that you can tile within the next 15 to 20 minutes. Use the notched edge of the trowel to create lines in the thinset for better adhesion.

Lay your first tile at the center of the top of your firebox. Continue to add tiles in your designated pattern working outwards. Check the level of the surface after every three to four tiles. Tap tiles deeper into the thinset gently with a rubber mallet or add a little more thinset beneath a tile to achieve a level surface.

Clean excess thinset from the joints between tiles with a damp cloth. Continue to install the tiles in your designated pattern, adding more thinset as necessary across the surface. If necessary, use a wet saw to cut the tiles to fit in their designated areas. Allow all thinset to dry overnight before continuing.

Scrape away any dried thinset in the joints or on the tile surfaces with the flat edge of a putty knife. Mix grout and water per product instructions.

Spread grout across the tile surface with a grout float held at a 45-degree angle. The angle will force grout into the joints. Go back over the surface with the flat edge of the float to remove excess grout from tile surfaces. Allow the grout to dry overnight before continuing.

Buff the surfaces of the tiles with a dry cloth to remove any residual grout or haze from the grout. Allow all thinset and grout to cure for at least three days before using the fireplace.