You will need the following tools and materials to install your tiles properly:
ALL THE MATERIALS AND TOOLS LISTED ABOVE CAN BE OBTAINED IN ANY LOCAL HOME DEPOT OR LOWES STORE.PLEASE USE CAUTION WHEN CUTTING THE TILES FOR TRIM TO AVOID SERIOUS INJURY!
The tiles may be laid on ceiling and walls covered with lime, lime-cement, gypsum or dry plaster, chipboards, aerated concrete, construction ceramics (bricks, hollow bricks), silicates, popcorn (if it is dry and stable) etc. The surface should be even, dry, hard, stable, without any dust or grease.
Do NOT apply the tiles over soft, unstable popcorn. If popcorn is soft and unstable, it needs to be removed before applying the tiles. This can be done by soaking it with water and scrubbing it off the ceiling.
Preparing the surface
Clean the surface so as to remove any dust, grease, wax or other dirt. Remove old, flaky coats of paint. Any cracks or other flaws should be filled with special fillers, gypsum or mortar.
1. Finding the middle of the ceiling - your starting point.
To lay tiles evenly, you should start your work exactly in the middle of the ceiling (Hint: very often your ceiling lights or fans are located exactly in the center of the ceiling). To find this point, use two strings drawn along the ceiling diagonals (Figure 1). Ideally, this should be done with another person's assistance. Now, through the middle of the ceiling, draw two perpendicular lines to divide it into four equal rectangles (Figure 2).
2. Putting mastic on a tile.
On the back of a tile, put a half-inch to one-inch thick layer of mastic (Figure 3). The thickness of the mastic on the back of the tile should depend on a surface you are putting the tiles on. If the surface is too porous, for example popcorn ceiling, you might need to add some extra mastic. On the other hand, if the surface is flat, you may need to reduce the quantity of the mastic. The mastic should be placed close to the corners of the tile and in the middle of it. If you feel it is necessary, add the mastic in a few more places. Some extra mastic won't bother. The mastic pieces should be a couple of inches in diameter, and they should have cone-like shapes. Don't spread the mastic so that it is completely flat. Each piece of mastic you place on the back of a tile should look like a little hill. When you press the tile against the ceiling, the mastic will spread under the tile, making it adhere properly to the surface of the ceiling.
3. Laying the first tile.
Lay the first tile at a right angle to the walls, with one of its corners places exactly in the middle of the ceiling that you found earlier (Figure 4). Make sure its edges follow the perpendicular lines.
4. Proper gluing.
When laying tiles, you should make sure they are pressed hard enough for the mastic to adhere thoroughly to the surface without damaging the tile.
5. Parallel rows.
Lay the subsequent tiles in parallel rows (Figure 5). Make sure there are no big gaps left between their edges. Move the tiles as close to each other as possible.
6. Applying caulk.
After all the tiles are finally glued to the ceiling, you will need to fill existing gaps between the tiles with caulk (Figure 7). Even if the seams are almost invisible, it is still recommended to use caulk, for it helps to make your ceiling look seamless and solid.
The caulk is playing the same role here as the grout when you are putting floor tiles. Use matching color or clear caulk so that it wouldn't be very obvious to a naked eye. Using a "caulking gun," spread a thin strip of caulk between the joints of the adjacent tiles along the entire length of the gap. Since the caulk will be staying on the top of the gap, you will need to squeeze it with your finger so that it gets inside the gap between the two tiles.
Some of the caulk will still stay on the top of the tile after this procedure, so it needs to be removed by wiping it off with a wet sponge. Wash the sponge occasionally and squeeze out excess water so that it stays clean and wet.
Don't let the caulk stay too long on the surface of the tile because it will dry fast and so will be difficult to remove.