How to Install Ceramic Tile Over a Painted Brick Fireplace

Remove any trim surrounding the painted bricks, using a pry bar to pull the trim away from the wall surface. Place the pry bar between the trim and the wall where the nails secure the trim in place. Apply pressure to the pry bar to pull the trim along with the nails from the wall, then place the trim aside for reinstallation.

Place a dropcloth onto the floor at the base of the fireplace and place a strip of masking tape along the edges of adjacent surfaces.

Remove any loose paint from the bricks with a wire brush. Scrub at the loose paint until it drops onto the dropcloth. Score the rest of the painted surface with 400-grit sandpaper. Run the sandpaper over the surface of the paint, creating small scratches that will allow for better adherence of the tile adhesive. Use a vacuum to remove the paint and dust created by the paint removal and scoring from the installation area to keep dust from interfering with the adhesive.

Test the placement of the ceramic tile across the brick surface by fitting the tile in place. Lay a strip of the masking tape across the tile to hold it in place when testing the fit of the tiles. The best tile fit uses as many full tiles as possible, leaving partial tiles for the edges of the fireplace. Move the tile around until you find a pattern and fit that you're comfortable with, and mark down the tile placement on the bricks with a piece of chalk. Remove the tiles from the bricks to begin the installation.

Mix a batch of quick-dry thinset mortar in a bucket, using an electric drill with paddle bit attachment. Substitute acrylic additive for water in the thinset to create a stronger holding adhesive. Let the mix sit for 10 minutes before use to allow time for the chemicals in the mix to begin reacting.

Press the mortar into the joints between the bricks with a parging trowel until the joints are even with the brick surfaces. Switch to a notched trowel and apply the mortar to the rear of the tiles with the flat edge. Tilt the trowel 45 degrees and then run the notches over the mortar to create ridges in the surface for a better grip.

Place the tile onto the bricks, positioning them according to the test fitting. Press firmly on the tile, using a slight wiggling motion to spread the mortar on the tile back fully over the painted bricks. Place tile spacers between adjacent tiles to create uniform spacing.

Cut the end tiles with a tile cutter. Measure the space on the row edges and mark a cutting line on the tile face to fit the measurement. Place the tile onto a tile cutter and score the top of the tile with the cutter blade. Move the tile to the metal bar along the base of the cutter and press down on both tile sides with the score above the bar to snap the tile in two. Place the mortar onto the rear of the time and place it onto the bricks. Allow the mortar to dry according to the manufacturer's recommended drying time.

Remove the tile spacers and use a grout float to fill the gaps between the tiles with grout. Push the grout over the tile and into the gaps with the edge of the float until you've filled the gaps to the same level as the tile tops.

Wipe away any grout left on the tiles with a damp sponge. Wait two hours and wipe again, this time with a lint-free cloth. Allow the grout to dry for 10 days, then brush the grout lines with a tile and grout sealant. Wait 48 hours for the sealant to dry before using the fireplace.

Nail the trim surrounding the fireplace back into place, using a hammer.