How to lay floor tiles
Tile can be installed over various types of subfloor. The most suitable materials for the subfloor are concrete, plywood and cement board. A plywood subfloor needs to be 1¼ in thick, which is the thickness of two 5/8 in panels. Another option is to lay a thin synthetic lath (about 3/16 in thick) if you don’t want to raise the floor level too much.
Prepare the room
- 1.1 - Start by taking out all doors and baseboards.
- 1.2 - You may also need to trim the doors and door mouldings. To do this, mark the height of one tile against the door or the moulding, and cut at 1/16 in above the mark, using a saw.
Prepare the surface
- 2.1 - The surface to be tiled must be clean, dry and even. If the subfloor is made of plywood sheets, it’s preferable to solidify it by screwing the plywood sheets every 4 or 5 in with 1 ½ in floor screws. This way, the floor won't move and tiles won't crack.
Draw reference lines
- 3.1 - Snap a chalk line horizontally and another one vertically to create a cross in the center of the room.
- 3.2 - Starting from the point where the two lines meet, lay out a dry row of tiles (without mortar) along the longest chalk line.
- 3.3 - Use a spacer between each tile to ensure even joints.
- 3.4 - Repeat this along the other (perpendicular) line. Laying tiles from the center of the room will allow you to place cutted tiles near the walls, where they’ll be less visible.
Draw the starting line for the layout
- 4.1 - Based on the remaining space on each end of the rows, determine the shifting necessary to obtain equal spacing on each end.
- 4.2 - Based on that measurement, draw a second line marking the length of the room at the right distance. Where the new line crosses the line marking the width will be the right spot to lay your first tile.
- 4.3 - If your room is quite irregular, lay the tiles in a way that minimizes the necessary cuts.
Spread the mortar
- 5.1 - Remove the tiles.
- 5.2 - With 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.
- 5.3 - Comb ridges in the mortar using the notched edge of the trowel; the ridges should all be made in the same direction.
Lay the tiles
- 6.1 - Lay two to three tiles at a time using your reference lines.
- 6.2 - Twist the tiles a little as you press them firmly into the mortar.
- 6.3 - Use tile spacers to ensure even joints.
- 6.4 - With a level, check that the tiles are at the same height.
- 6.5 - With a rubber mallet, lightly tap on uneven tiles.
Remove spacers and let dry
- 7.1 - Remove the spacers as you work, before the mortar sets.
- 7.2 - When the entire surface is tiled, leave it to dry for 24 hours. Avoid treading on the newly laid tiles during that time.
Do the perimeter
- 8.1 - Lay a tile on top of the last full tile installed near a wall.
- 8.2 - Place a tile standing on end and lay a third tile on top of the previous two. Its edge should touch the spacer.
- 8.3 - Draw a cutting line across the middle tile (second tile), following the edge of the tile on top (third tile). Cut the tile with tile nippers, a tile cutter or a wet-cutting table saw.
- 8.4 - Cover the entire floor.
- 8.5 - Let dry for 24 hours.
Apply the grout
- 9.1 - Once the mortar is completely dry, lightly dampen the tiles with a sponge and clean water. The grout mixture will be easier to spread.
- 9.2 - Pour some of the grout directly onto the tiles and work it well into the joints with a rubber float. Work section by section, while holding the float at a 45° angle.
- 9.3 - Use a damp sponge to remove the excess grout as you lay new tiles.
- 9.4 - Repeat this process at least two or three times for better results.
- 10.1 - After 48 hours, when everything has completely dried, apply grout sealer on the joints. The sealer will protect the grout from stains.
- 10.2 - Wait 30 minutes and apply a second coat.
- 10.3 - Put the doors back in place and install mouldings.
Caulk the expansion joints
- 11.1 - After 10 days, caulk the expansion joints with silicone sealer.
- 11.2 - When the silicone is dry, clean the tiles with a soft, dry cloth.