By Mike Morris More in Floors
Use a notched trowel to spread the adhesive over the floor (Image 2). For mosaics and smaller tiles (less than 8 inches), use a trowel with 1/4-inch notches. Larger tiles require a 3/8- to 1/2-inch notch, depending on the size and thickness of the tile. Start at your layout lines and press the mastic against the floor for a good bond, then set the trowel on edge and rake the mastic to create ridges equal to the notch depth. Be sure your layout lines remain visible.
Work in an area about 3 to 4 feet square to prevent the mastic from drying as you cut and fit the tiles as needed. Some mastics have strong, noxious fumes and may be volatile, so be sure to extinguish any pilot lights and provide adequate ventilation to the work area.
Begin at the intersection of your layout lines and carefully set the tiles into the adhesive (Image 1). Work from the centerlines out toward the walls, and plan your installation so you will not have to step on or disturb any of the tiles as you proceed. It helps to have two people when tiling — one to concentrate on laying and bedding the tiles, while the other provides a constant supply of loose tiles and makes cuts or retrieves tools as needed.
Use a rubber mallet, or hammer and wood block, to gently but firmly tap and bed each tile into the mastic. Do not press or shift the tiles around to avoid having the mastic squeeze up into the grout lines between the tiles. If a tile cracks when tapped, remove the pieces and “butter” the back of the replacement tile with a small amount of mastic before setting it in place.
Place plastic spacers between each tile as you proceed (Image 2). The mastic will not stick to the spacers, which are easily removed before you begin grouting the joints. Use a 4-foot level, or a smaller level to ensure that the tile edges are aligned and the tiles are level across their surface (Image 3).
Allow the tile mastic to set for at least a day before removing the spacers and grouting the joints (Image 1). Premixed grout is easier to use than bulk grout, and it is available in a wide range of colors to match or contrast with your tiles. Because grout can stain or stick tightly to porous or unsealed tile, your tile distributor may recommend applying a sealer to the tile faces before you begin grouting.
Mix the grout in batches that can be applied within a half-hour or so to prevent it from drying as you work. Use a rubber float to squeeze the grout into the joints (Image 2). Ensure that the grout completely fills the spaces between the tiles (Image 3). As you work, clean excess grout off the tile faces with a coarse cloth or damp sponge, but be careful not to wet the grout, which will weaken it (Image 4). Wipe diagonally across the joints to avoid pulling the still-fresh grout out of the grooves.
After the grout has dried thoroughly, use a release agent to clean any grout haze from the face of the tiles, then apply a grout sealer according to the product directions.