Measuring the ceiling, marking the panels for cutting, gluing the panels in place, and caulking all of the seams are the steps to installing 4-by-8-foot ceiling panels. A second person is required to help for a neat and clean job, due to the size of the panels.
Stack all of the panels needed face up on a drop cloth. Measure the ceiling with a tape measure, and mark the center. Align the first panel just to the right of the center mark, and check for any protrusions from the ceiling, such as light fixtures, vents or outlets. If there are obstacles, carefully measure and mark them on the ceiling panel. Cut out the marked spots with a keyhole saw, making sure to leave them about 1/2 inch larger than the protrusion.
Use an ample amount of construction adhesive placed in a crisscross grid on the back of the panel with the beads about 2 inches apart. Carefully put the panel in place, and press it down firmly. Repeat the process as needed to finish the room. Use a T-square and a razor knife for long, straight cuts.
When all of the panels are in place, seal each seam and cutout with caulk. Smooth each bead of caulk with your finger. Have a wet towel handy to keep your fingers clean. Allow one hour for the caulk to cure.