Installing tile of varying shapes and thicknesses will add a different look to your tile surfaces, and in many cases adds a professional custom look. This enhanced look, however, comes at a price of increased installation time and complexity. The average homeowner can handle this increased level of complexity by adhering to a few basic tiling concepts, and by using the proper tools and sound techniques.
Lay out every tile in the appropriate pattern. Look for difficult areas such as where the tile thickness varies, or the tile surface mates with another surface. Tiles that must be cut should also be laid out as closely as possible to the intended shape.
Measure the height differences between all areas where adjacent tile thickness varies. Mark with a pencil on the back of each "low" tile the net difference in height to the adjacent tile. For example, the blue tiles may be 3 mm (1/8 inch) lower than the rest of the tiles; write "+ 3 mm" on the back of these tiles.
Sort the tiles by order of installation sequence. Keep in mind you should begin the tile job so that when finished, you will not need to walk on the wet tiles to leave the room.
Mix acrylic additive to the thinset mortar mix. Spread the thinset mortar mix with a notched trowel to a small area and begin laying tile in your preferred design. Spread the mortar mix evenly and be precise with the notched trowel so that the mortar mix is always spread at a consistent depth.
Turn low tiles over when you arrive at a section that requires a tile of different thickness and measure how low they sit. Add extra thinset to the area beneath this tile, elevating it to the proper height in relation to the surrounding tiles. In some cases, using a larger notched trowel will aid in compensating for the increased thinset depth. Set such tires properly by twisting gently as you apply them to the thinset mortar mix. This will remove any air bubbles and provide a solid foundation.
Level the tiles with a small level to make sure they are flush with all surrounding tiles. Pay particular attention to the corners of each tile, which have a tendency to rise or fall the most when not properly set. As you progress with the tile installation, apply tile spacers between all tiles to maintain the proper spacing for your grout lines as the thinset dries. Allow the fresh tile to dry for 24 hours.
Remove the rubber tile spacers. Mix acrylic grout additive to the grout mix. Spread the grout with a rubber grout float, packing all grout lines tightly. After 30 minutes, damp-sponge the tile to remove any grout haze. Rinse the sponge frequently, and continue until all haze is gone. Allow the grout to dry for 24 hours before using the surface.