The last step in laying a tile floor is applying and sealing the grout. After the tile adhesive has set, apply grout to the joints using a rubber float. Grout comes in a variety of colors, but darker grout tends to show less stains. Stainproof grout is also available, though it isn’t as easy to work with as regular grout.
Once the grout has dried, apply a grout sealer to the joints to prevent stains from occurring. If grout is stained already, use a grout stain pen to make the grout a uniform color.