On a large work surface, lay out the pattern of the rug to get accurate measurements and design. To prevent color variations, mix up tile from different boxes before starting. Use a pencil to number each tile or stack the tile in order so you can easily transfer the design to the floor without losing track of the pattern.
To make a 4' x 6' rug, we used 7" x 12-½" tiles, bordered with 2" x 2" tile and a 1/8" space in between the tiles. Check with the tile manufacturer to see what size spacers they recommend for your tile.
If you're working in a bathroom, it is best to lay cement backboard on top of the subfloor or lay down some type of waterproof membrane.
Work in small sections, starting with perimeter; use a notched trowel to apply thinset to the floor. Lay the tiles in place. Plan your installation so you will not have to step on or disturb any of the tiles as you proceed. Use tile spacers to keep the tiles even and in place. Do one row at a time from top to bottom.
Use a level to ensure that the tile edges are aligned and the tiles are level across their surface. A rubber mallet or hammer and wood block can be used to gently but firmly tap each tile into place. Do not press or shift the tiles around to avoid having the thinset 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 thinset before setting it in place.
Let the tile set for 24 hours before walking on them and grouting.
If your tile is porous or unsealed, the tile manufacturer may recommend applying a sealer to the tile before you grout. Grout can stain or stick tightly to porous or unsealed tile.
Mix the grout to proper consistency (premixed grout is a lot easier to work with than bulk grout). Remove the tile spacers and start adding grout in the furthest corner from the door to avoid walking on finished grout that is still wet. Working in sections, apply grout liberally with a rubber float. 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. 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 grout haze from the face of the tiles, then apply a grout sealer according to the product directions.