You can paint some types of Armstrong acoustical ceiling tiles. If the tiles are fiberglass, or laminated with Mylar or vinyl, you can't; but it's fine to paint their mineral fiber tiles, as well as the metal grid variety. The Armstrong company realizes that over time, customers may want to repaint when tiles get dingy or stained. They have published recommended methods and materials and even suggest faux painting tiles to look like metal for an authentic vintage tile effect.
Things You'll Need
Duster, broom or vacuum cleaner
Rolling pan or bucket and grid
Spraying Armstrong Ceilings
Clear the work area. Remove as much furniture as possible, and cover what you can't move with plastic sheeting. Take everything off the walls, including window coverings--spray painting is very messy. Cover the floors with drop cloths.
Clean the Armstrong ceiling tiles with a duster, broom or vacuum cleaner.
Set up your sprayer, and strain and thin the paint according to the manufacturer's directions. Apply one even coat of paint to the ceiling--this should be sufficient unless you are painting the ceiling a different color.
Remove the ceiling tiles and spray them flat on a protected floor or work bench, if you have the space to do so. Wait until they have dried for at least four hours before replacing them. This way you don't have to mask and cover the room.
Rolling Armstrong Ceiling Tiles
Remove the Armstrong tiles unless they are fixed into the grid--otherwise the pressure from the roller will simply push them out of place. Lay them out on a work bench.
Roll the tiles using a 1/4-inch nap roller--a 100 percent lambswool roller will work best, especially if the tiles are textured. Paint a coat on both sides of the tiles to prevent them from warping or cupping.
Roll the ceiling grid, if necessary, with a 6-inch trim roller. If you're not planning on painting the walls, use 2-inch blue painter's tape to mask the walls. You should be able to neatly roll right up to the wall with a trim roller, saving you the time of using a brush.
As a general rule, Armstrong mineral fiber ceiling tiles are soft and porous. The fiberglass and laminated tiles have a hard, shiny coating and shouldn't be painted. If in doubt, take a tile to an Armstrong dealer and ask if you can paint it. Only use latex (water-based) paint on the tiles. Use metallic paint, or decorative painting techniques, to create the effect of aged metal, or to add interest and dimension to your ceiling tiles.
Be careful when handling ceiling tiles--they can break or crack easily. Painting them may reduce acoustical, sound-dampening properties, according to Armstrong. Painting Armstrong ceiling tiles will void the warranty.