Installing Floor Tiles
Once you've established the layout, you can start setting tile. But first, be sure your floor surface is thoroughly clean of dust and debris.
Prepare only enough tile mortar to be used within 30 minutes, this will prevent it from drying out.
Set all of your full tiles first, leaving any cut tiles around the perimeter of the room for last.
Scoop a glob of mortar on the floor. Spread it evenly within one section using the straight edge of a notched trowel. Try not to cover up your layout lines, you'll need them to align the tiles.
Using the notched edges of the trowel, comb out the mortar. Hold the trowel at a consistent angle (around 45 degrees) so the top of the mortar has a uniform height. The pattern of the ridges isn't important. If the mortar is too dry, the ridges won't comb out evenly; there tend to be gaps. If it's too wet, the ridges won't hold and they'll all blend together.
Again, work right up to the layout lines, but try not to cover them up.
Setting and Spacing Tile
Lay the first tile in a corner, pressing down and twisting it a little to set it into the mortar. Test this first tile by prying it up by its corner and looking on the back side. About 70-80 percent of the tile should be covered with mortar. If you see nothing, the mortar is too dry. If you see only parallel lines of mortar, the ridges are too shallow.
Set the remaining tiles, aligning them to your outside layout lines. Keeping consistent spacing between the tiles is critical for straight, uniform grout lines. And remember that for two sides of the box the tiles should be set right up to the layout lines, and for the other two sides you need to leave a gap for a grout joint between the edge of the tile and the layout line. (One tile setter we know ALWAYS sets the tiles tight to the front line and the right line of each section, and leaves the gap on the left side and the back side.)
Once the tiles are roughly in place you want to set them into the mortar and get them all at the same height. You can sometimes use a rubber mallet or grout float to push a corner or edge of tile down a little. You will probably also have to pry up some tiles to add or remove a little bit of mortar, just to get them all level across the tops.
After setting a section, clean up any mortar that has squeezed up between the tiles. A putty knife or pencil works good for this. Also, sponge off any mortar on the tile surface.
And before you move on the to next section, that’s when you give the tiles one last eyeballing for spacing. You can drive yourself crazy trying to get the spacing perfect as you’re leveling and cleaning them. Wait until this moment to get it perfect. Then move on to the next section.
Setting Perimeter Tile
One good plan of attack is to set all of your full tiles one day and come back the next day to measure, cut and set the tiles around the edges. This way can rent or borrow a tile snapper or a tub saw for a single day and you can take your time and get each cut tile just right.
It's a good idea to do measure each cut tile individually
because the walls may not be square and you'll have to cut each tile a different width.
Sometimes you won't be able to trowel the mortar directly on the floor, like under cabinets or in small areas. That's when you need to "back butter" the tiles individually.
Spread the mortar on the back of the tile with a notched trowel. If the tile is too small you can also use a margin trowel to spread the mortar.
Set the tile giving it a little twist to insure good contact with the underlayment.