Set up a step ladder. Move around the room, removing loose paint and debris from the ceiling with a metal paint scraper.
Tack the end of a chalk line in one corner of the ceiling with a thumb tack. Move the ladder to the corner across the room, hold the chalk line in the corner and snap the line across the ceiling. Move the chalk line to the other corner and repeat the process to create an "X" across the ceiling.
Measure the distance from the wall to the center of the "X" with a tape measure.
Move the step ladder to one end of the room. Measure off the wall you measured the distance to the "X." Place a mark on the ceiling at the dimension you measured with a carpenter's pencil. Move to the other end of the room and repeat the process.
Tack the end of the chalk line to one of the carpenter's pencil mark with a thumb tack. Move to the other pencil mark, align the chalk line with the other pencil mark and snap a line dividing the room in half.
Pour contact cement into the paint roller pan.
Roll contact adhesive onto the back of the PVC ceiling tiles and the marked ceiling with a 4-inch paint roller.
Align one edge of the glued PVC ceiling tile with the pencil line. Press the tile against the ceiling to stick the tile in place. Move along the pencil line, pressing the PVC ceiling tiles in place.
Continue attaching the tiles until you reach a point that you need to cut the tiles.
Measure the distance from the edge of the last row of tile to the wall.
Cut the PVC tiles to length with a utility knife. Glue and press the tiles into place as described earlier.