Set each ceramic tile straight down with a slight twisting motion. Do not slide it into place. Then press firmly into place with your hands and tap with a rubber mallet to set. As you work, make sure the tiles are level with one another. Grout will not mask unevenness but will actually make it more apparent than it is now.
Keep everything clean as you work. Wipe the face of the tile with a damp rag. Set the next tile the same way. Insert plastic tile spacers between the tiles as you work. Move or leave them in place to be grouted over, if desired. After every few tiles, check your work to be sure it is square and level. It may help to use a flat piece of plywood about 3 feet square; set it on the tiles you’ve been working with and tap gently if any unevenness is detected.
Mark for straight cuts by measuring or by holding a tile in place. Don’t forget to take the width of the grout line into account. Set the tile in a tile cutter, butted up against the guide and positioned so the cutting wheel will cut your line. Score a single line by pressing down and sliding the handle forward. Snap the cut by pushing down hard on the handle. If you need to cut a number of tiles to the same size, use the adjustable guide. Use tile nippers to cut tiles to fit curved shapes.
Once all the tiles are laid, do not let anyone walk on the floor for at least a day. Under humid conditions, you may need to wait longer. To ensure that the adhesive will dry, direct a fan to blow over the surface.
Remove the spacers. If recommended, apply grout release to the tiles. Mix the grout according to directions. Spread it diagonally over the tiles with a grout float, working it well into the joints by holding the float nearly flat and pushing down as you move it in sweeping arcs. Sweep across all the joint lines in at least two directions. Work small sections at a time. Then tip the float up and use it like a squeegee to remove the excess grout from the tiles without removing it from the joints. Move diagonally to the lines. Let the grout stand until the joints are firm. Wipe the tiles clean with a damp sponge without removing grout from the joints. Let the grout set for 72 hours, then wash the floor with clear water and polish the surface with a soft cloth. Seal the grout and the tile as the tile dealer recommends.