Lay out a drop cloth in front of the fireplace. Spread it out to cover the floor in your work area.
Brush the surface of the brick mantel with a wire brush to remove any debris that will prevent a solid tile application.
Spread an even layer of tile mastic, using a notched trowel on the front, sides and top surface of the brick mantel.
Press the tile in place on the ends and the front, in rows, starting at one end and working your way across the mantel.
Lay out the tiles on the top surface of the mantel in the same manner as the front and ends. Insert spacers between each corner tile joint to ensure even spacing between all of the tiles.
Allow the tile to dry for 24 hours and remove the spacers from the joints.
Grout the joints between the tiles by dragging a grout-loaded grout float across the joints at a slight angle. Allow a haze to form over the tile after approximately 15 minutes.
Wash the tile surface with a sponge. Rinse the sponge and continue cleaning until the water wrung from the sponge comes out clean. Allow the tile to dry for 72 hours before placing anything on the mantel.