An acoustic ceiling can present some special challenges when it comes to painting it. Acoustic ceilings have a very rough texture and are commonly called "popcorn" ceilings. This texture was mostly done in houses built around thirty years ago in order to save on labor costs. This ceiling texture requires a good amount of both primer and paint in order to fill all of the little crevices. The most commonly-used painting techniques are rolling or aerosol spraying.
Using a Paint Roller
How easy it will be to roll your acoustic ceiling depends on whether it has been previously painted. An unpainted acoustic ceiling is quite absorbent and will need larger amounts of paint for complete coverage. The rough ceiling texture will create more splatters, drips, and ceiling debris, so protective clothing and drop-cloths are a must. Be sure you use a paint roller with a longer handle; this will reduce chances of straining the back or shoulders.
Using a Paint Spray Gun
A paint spray gun allows for a less labor-intensive painting project. For the best results, select a flat acrylic paint and have it mixed with the correct amount of paint thinner according to the spray gun manufacturer's recommendations. This will prevent clogs in the spray gun and create an even paint coat.