How to Repair a Popcorn Ceiling. Though its appeal varies, the popcorn ceiling treatment has several advantages. It is cost-effective, is relatively easy to apply and has some acoustical advantages. One of the several disadvantages, however, is that repairs can be tricky. If you don't match the texture of the existing ceiling well, your repair can be noticeable. In addition, if you don't resolve the underlying reason for the original damage, your repair won't last.
Determine the reason for the damage and fix accordingly. If it's a hole from a ceiling hook or other similar damage, you only need to fill the hole or dent before you apply the texture. If the damage is from water or other leaks, fix the leak and take care of any underlying damage before you repair the textured area of the ceiling.
Prepare the damaged area by sanding it smooth and removing all old texture from it. If any of the damaged texture remains, your new texture may not stick. Prime the damaged area.
Match your texture. For a more personalized match, use a paint additive as opposed to a premixed spray-on texture. This allows you to have more control over the size and concentration of the aggregate used to get the popcorn effect. You can buy fine-, medium- or coarse-grade aggregate. Mix a small batch and paint it on a spare piece of plywood or drywall. Gradually add aggregate until you've matched the existing ceiling.
Protect your nontarget areas by covering them well, because this texture technique is quite messy. Have water and rags or sponges available for quickly cleaning any messes that may spread beyond your protected area.
Apply the texture. You can use a roller for most areas. If the repair is close to a wall, you can use a brush or edger to get into the areas the roller can't reach. Apply the first pass until it overlaps the existing texture.
Randomize the effect. Without dipping your roller or brush back into the paint, go back over the area in several directions, applying from the wet areas to the dry areas. This minimizes any pattern that may develop from the first application. Don't overwork the area. You should stop after a minute or two of working.
Allow the area to dry. If the repaired area has less texture than the existing ceiling, you can add a second coat of texture. If it's acceptable, paint the repair using the same paint used on the rest of the ceiling.