Part 4 of this guide is where you get to finally see what you have been working towards. Here we will cover the laying of the adhesive (also known as mastic) and the actually method of laying tiles. We will also deal with the method used to apply the grout (known as grouting).
Now, put all your tiles to the side and start spreading the mastic with the notched trowel. Again, only work in one quadrant and always start at the center point. Follow the pattern you set in the rehearsal which follows the floor tile designs that you made. Spread the adhesive evenly and using the notched edge of the trowel, make a raking motion. The grooves you make should neither be too shallow, nor should they be too deep. Set your first tile at the corner of the center point, pushing it firmly but lightly. Set the tile spacer and continue. Always remember to set tile spacers after each and every tile so that the tiles do not look like they have been placed unevenly.
Use your level to make sure the level of the tiles are all equal. Despite your prep work, not all surfaces are equal and this is the last chance you will have to make sure everything is as perfect as possible before you complete your perfect floor tile design. If the level is uneven, you can adjust it by adding more force to the tile or in the opposite case, adding more adhesive to make it higher. This will help you keep everything level. Once you have finished off the quadrant, proceed to remove the tile spacers so that they do not set into the adhesive. Follow this process until all four remaining quadrants are finished. Always make sure that you check the level as you go along. Caution is paramount.
Now what you have to do is wait. It is recommended to wait at least one day (or at the very least overnight) for the adhesive to dry, or cure, before you start adding the grout to the joints.
Once the days waiting has finished, you can begin adding the grout to the joints. Using a rubber float, apply enough grout to be able to work with it, but never ever too much. Do this as you have done everything so far, one quadrant at a time. Diagonally press grout into joints to an even level with the tile. Skim the excess grout from the tile with the rubber float. You will notice a slight “grout haze” on your tiles. Repeat this process on the remaining 3 quadrants.
The wall joints and floor interface is best filled with caulk. The main benefit to using caulk instead of grout in the wall joints is due to the contracting and expanding nature of tiles. You do not want a crack in your floor tile design, so best use caulk. Caulk will act as a buffer to expansion and contraction due to changes in the temperature.