How to Install a Knockdown Ceiling

Arrange the room to prepare for the plaster project. All furniture should be removed. Protect floors by laying out drop cloths and tarps. Tape plastic sheets to walls with painter's tape. Stick painter's tape to the edge of the walls, where the ceiling meets the walls. Burnish and rub tape down well so there is a tight seal between the tape and the wall.

Mix drywall compound with a drill and attachment used for plaster. Inspect the plaster to ensure it is not dry or crumbly. If the mud is not moist, add a bit of distilled water to the plaster.

Place the mud on a drywall trowel. Use a putty knife to dab small amounts over the smooth blade. Hold the trowel perpendicular to the ceiling and stamp the plaster onto the surface. Move the trowel to a slight angle and knock down all peaks created when stamping the plaster on the ceiling.

Continue the application until the knockdown texture covers the entire surface. Let the plaster dry about 24 hours. Lightly sand the mud with a medium-grit sanding block and wipe the surface clean with a damp rag. Roll on paint with a texture roller. Two coats or more are often needed for adequate coverage.