How to Install Glass Tile on a Fireplace Surround

Use masking tape or painter's tape to cover any exposed edges where you don't want to get thin-set mortar.

Mix a batch of thin-set mortar with a latex additive if your fireplace surround surface is uneven. Apply the thin-set mortar to the surface of the surround with a finishing trowel to create a smooth surface or base for your tile. Let the mortar dry and harden overnight.

Use a measuring tape to measure the length of the surround and find the center of the surround space. Mark it with a pencil. Use a straightedge and a pencil to draw a straight line from the firebox to the edge of the surround, marking the center.

Use a circular saw to cut a piece of 1-inch by 3-inch board the length of the surround. Place the 1-inch by 3-inch board under the top edge of the firebox opening. Use a level to make sure the board is straight and even with the top of the opening. Attach the board to the fireplace surround on either side of the firebox using 2-inch masonry screws and a drill. This creates a support ledge for the tiles along the top of your fireplace surround.

Mix more thin-set mortar with a latex additive following the manufacturer's instructions. Use a trowel to apply the thin-set to the surface of the surround over the center line, flush with the support ledge. Use the comb edge of the trowel to create grooves in the mortar. Flatten out the grooves to create a smooth surface. Apply more mortar to the back of the glass tile with the trowel. Position the center glass tile over the center line. Fit it in place. Tap on the surface lightly with a beating block or rubber grout float to make sure the tile fits snugly into place.

Apply mortar to the rest of the area above the support ledge with the trowel. Place a spacer flush with the first tile. Cover the back of the next tile with mortar. Fit it into place. Tap the surface with a beating block or rubber grout float to make sure it fits snugly. Peel the paper off the back of each tile, if needed, once it's been set. Repeat the process until you've tiled the entire area above the ledge. Leave the tiles to dry and set overnight.

Unscrew the support ledge from the surround. Set it aside. Use a measuring tape and a tile to estimate the size of cut tile required at the bottom of each leg of your surround. The size of the cut tile will depend on the size of the tile you're using and the size of the surround. Use a circular saw to cut a 1-inch by 3-inch board to size to fit in the space. Use a drill and 2-inch masonry screws to screw the 1-inch by 3-inch board piece to the surround flush against the floor in the spot where the final tile will go.

Apply a layer of thin-set mortar to one leg of the surround. Apply mortar to the back of the first glass tile. Fit it into place on the surround leg at the bottom against the board. Tap the tile securely in place with a beating block or rubber grout float. Remove the paper back from the tile once it's set. Place a spacer against the tile to create an even grout line. Repeat the process until the leg is completely tiled.

Tile the other leg of the surround using the same procedure you used on the first. Leave the tiles to set according to the manufacturer's instructions on the thin-set.

Remove the wood supports at the bottom of the surround legs. Measure the space. Use a tile saw with a carbide-tipped blade to cut a tile to fit in the space. Mix and apply thin-set mortar to the surface of the surround and the back of the glass tile. Set the tile in place. Tap it gently into place with a beating block or rubber grout float. Peel the paper back off the tile once it's set. Repeat the process on the other leg. Leave the mortar to dry and harden overnight.

Remove the spacers. Use a putty knife to get rid of any excess mortar between the tiles.

Follow the manufacturer's instructions to mix the grout. Use a grout float to apply the grout to the surface of the tiles on a diagonal, pushing the grout in between the tiles. Remove any excess grout by scraping the edge of the float against the surface of the tiles at an angle. Let the grout dry for about an hour. Wipe away any excess grout on the surface of the tiles with a damp sponge or cloth. Leave the grout to dry overnight.