Lay floor tiles

1.1  A concrete subfloor must be smooth and level.

1.2  A plywood subfloor needs to be 1¼" thick, i.e. the thickness of two 5/8" panels, which must be laid with the joints staggered.
The panels must be screwed to the joists every 6" around the edges and every 8" across the rest of the surface. Leave an expansion gap of ¼" between the panels of the top layer. If using synthetic lath underlayment over existing plywood, staple it to the plywood and cover it with a suitable thinset mortar.

1.3  A cement backer board subfloor is ideal since these panels are very strong, moisture resistant, and also act as a fire retardant.
When laying cement board over plywood, try to stagger the joints as much as you can. Use reference lines as a guide. Spread mortar over the first panel and comb ridges with the notched edge of the trowel. Set the panel down onto the plywood and fasten with screws every 4". Cover the entire surface of the plywood, leaving an expansion joint of 1/8" between each cement board panel. Fill the spaces between the panels and smooth the joints.

1.4  Remove doors, door casing and trim, as well as anything else in the room that might be an obstacle and which can be moved out of the way.

1.5  The surface to be tiled must be clean, dry and even.

1.6  Have a bucket of water and sponge handy.

2.1  Snap a chalk line on the floor at right angles to the room's main entrance, from the centre of the wall to the other end of the room.

2.2  Snap another line at right angles to the first (i.e. parallel to the entrance wall).
Make sure that the second line is square and that the end of the first row of tiles will not be directly touching the wall.

2.3  Lay out a dry row of tiles (without mortar) along the longest chalk line, starting from the point where the two lines meet and working out towards the wall. Use a spacer between each tile to ensure even joints.



2.4  When you reach the end of the room and can no longer put down a full tile, lay out another row of tiles along the other (perpendicular) line.

2.5  For each of the two lines, measure the space between the last full tile and the wall.
Based on this measurement, shift your reference line parallel to the wall until the tile space is the same at both ends of the row.

2.6  Snap new chalk reference lines as applicable.
The intersection of the new lines will be your starting point.

2.7  If the room is irregularly shaped or has several obstacles, lay out the tiles in such a way as to minimize the number of cuts.

3.1  With the flat edge of a notched trowel, spread the mortar along one edge of the layout line, covering an area equivalent to a row of two or three tiles.
Skim the mortar as straight as possible; do not "swirl" the trowel or you may create air pockets that prevent the tiles from bonding properly. Hold the trowel at an angle of 45o to 65o. Make sure that the reference lines stay visible.

3.2  Lay two to three tiles at a time.

3.3  Comb ridges in the mortar using the notched edge of the trowel; the ridges should all be made in the same direction.
For tiles measuring 4" × 4", 4" × 6" and 6" × 6", use a 3/16" trowel. For tiles measuring 8" × 8" or more, choose a ¼" trowel.

4.1  Lay the first tile, twisting it a little as you press it firmly into the mortar.

4.2  Use the reference lines to make sure the tile is positioned correctly and squarely. Adjust if necessary.

4.3 Tile the whole area, using spacers to ensure even joints.

4.4  Check that all the tiles are the same height.
Use a rubber mallet or block of 2" x 4" to lightly tap or press down on any uneven tiles.

5.1  Remove the tile spacers as you work, before the mortar sets.

5.2  Avoid treading on the newly laid tiles.

5.3  If your tiles are very thick and the spacers are embedded in the joints, you can leave them in place and simply grout over them.

5.4  When the entire surface is tiled, leave it to dry for 24 hours.
After that time, you can safely walk on the tiles in order to cut and install the border tiles.

6.1  To cut the tiles for the perimeter of the room, lay a tile on top of the last full tile installed near a wall.

6.2  Put some kind of spacer up against the wall (a tile standing on end will do nicely).
Lay a third tile on top of the previous two and slide it towards the wall so that its edge touches the spacer.

6.3  Prop up the unsupported end of the top tile to keep it stable.
Draw a line across the middle tile (second tile), following the edge of the tile on top (third tile).

6.4  Put the tile to be cut (second tile) into the tile cutter and hold it firmly against the guide while you score along the line you just drew.

6.5  Score the line only once. Push down on the handle to snap the tile along the score line.

6.6. Set the cut tiles the same way as you laid the full tiles.

6.7  For complex cuts, use tile nippers or a tile saw.

6.8  You can use cut tiles as base trim for finishing.
To do so, set the cut tiles into mortar along the bottom edge of the wall, taking care to insert spacers under them for the grout joint. Make sure that the visible (top) edge is the finished edge of the tile.

7.1  Wait at least 24 hours after setting the last tile before starting to grout the joints.

7.2  Lightly dampen the tiles with a sponge and clean water.
This will thin the grout mixture a little and make it easier to spread. The grout will also have less tendency to stick to the surface of the tiles, making it easier to wipe off afterwards.

7.3  Pour some of the grout directly onto the tiles and work it well into the joints with a rubber float.

7.4  Work section by section, covering an area no bigger than 10 sq. ft. at a time. Hold the float at a 45° angle.


7.5  Grout mixture dries very quickly.
The best way to proceed is to work with someone else; one of you applies the grout while the other wipes off the excess a few minutes later, both working in the same direction.

7.6  Use a damp sponge to remove the excess grout from the entire tiled surface.
Rinse the sponge often, using as little water as possible so as not to dilute the grout between the tiles.

7.7  Repeat this process at least two or three times for good-looking results.

8.1  After about ten days, caulk the expansion joints with silicone sealer.

8.2  When the silicone is dry, clean the tiles with a soft, dry cloth.