10 Tips for Painting Plaster Walls

As a homeowner and professional handyperson in New England for fifteen years, I’ve encountered many plaster walls in need of repair, paint or both. Through trial, error and experience, I’ve learned how to paint plaster walls with terrific results. Any homeowner can follow these tips and paint like a pro.

Gather Materials and Tools

For painting, you’ll need drop cloths, a 2 to 2-1/2-in. angled paint brush, nap roller cover, roller frame, flat-head screwdriver, paint tray, stepladder and extension pole. Materials include primer, latex paint, gloves, a dust mask, painter’s tape, trash bags and rags.

Depending on the condition of your walls, you may also need a Plaster Magic repair kit, joint compound, acrylic caulk, mesh joint tape, four-inch putty knife, various-size taping knives, mud pan, 3/8-in. and 1/2-in. drywall, 1-5/8-in. coarse drywall screws, Plaster of Paris, a Phillips driver bit and a drill.

Prepare the Space

Prepping and painting plaster walls can be messy, so cover your floors and furniture with plastic. Remove all pictures and curtains from the walls and store them in a separate room. Unscrew switch plates and outlet covers.

Test for Lead

Exposure to lead can cause serious health conditions, so make sure to test your walls for it.

Houses built before 1978 may contain lead or lead products. Old plaster walls often contain lead, so test and take appropriate removal or encapsulation steps before proceeding. The First Alert LT1 Premium Lead Test Kit offers an easy and reliable way to check.

Inspect Plaster Walls for Damage

Smooth walls produce the best final paint job, so carefully inspect for nail holes, cracks, chips and divots that require repair. Also press walls to find any areas of loose plaster, often (but not always) near a crack. Any areas that move when pressed should be repaired.

Fix Small Holes and Cracks

Small imperfections will show. Repair them to get a fully finished product. Fill small nail holes with joint compound, and minor cracks with acrylic caulk.

Use Drywall and Joint Compound for Larger Repairs

More seriously damaged plaster must be repaired or will worsen with time. Cover large cracks with mesh drywall joint tape and smooth them over with several coats of joint compound. Feathering the compound away from the crack at least 18 to 24 inches will make the repair less visible.

Holes 3/4- to 1-in.-dia. can be filled with Plaster of Paris, covered with mesh tape and smoothed over with joint compound.

For larger holes, cut drywall to fit the size of the damaged area and attach it to the laths with drywall screws. Plaster walls are often thicker than typical 1/2-in. drywall, but 3/8-in. plus 1/2-in. drywall often matches the depth. Cover the joints with mesh tape, finish with three layers of joint compound and sand when dry.

Glue Loose Plaster Back in Place

Loose plaster must also be repaired or will worsen. For this task, your best bet is Plaster Magic, a patented, DIY-friendly, three-step system that glues the plaster back to the laths with minimal wall damage.

Sand and Wash a Final Time

For the smoothest walls, do a final sanding of all surfaces with 220-grit sandpaper. Check for overlooked wall imperfections and feel for rough areas.

Next, wipe down your walls with warm water. Take care not to over-saturate. Allow 24 hours for the walls to fully dry before proceeding.

Use a High-Quality Primer and Paint

Plaster walls require primer for best paint adhesion, so skip the all-in-one paint-and-primer products. Use a high-quality latex or oil primer instead. Oil primers offer superior stain blocking, adhesion and durability, but can be difficult to work with and emit strong fumes.

Latex primers can also work well, but opt for a high-quality product like Zinsser Gardz. Apply with a roller and wait out the manufacturer’s recommended dry time before beginning to paint. If using a dark paint color, tint your primer.

Choose a quality latex paint, like Benjamin Moore Regal Select, in any sheen and color you prefer. Eggshell and satin are popular finish choices for interior walls, but matte or gloss also work fine on plaster.

Apply two coats for the best durability and color accuracy. Paint the wall edges first with an angled brush, carefully avoiding woodwork. Use painter’s tape for added protection.

Next, paint the remaining surface with a roller frame and cover. If your walls are really smooth, a 1/4-in. nap roller cover works best, while a 3/8-in. to 1/2-in. nap will perform better on rougher finishes.

Clean Up the Right Way, Right Away

For the fastest results, clean up immediately after finishing. Remove any painter’s tape from the woodwork, wash brushes, pads and trays with soap and warm water and close paint cans to avoid spills.

To avoid dust sticking to newly painted walls, wait until the paint dries before removing protective plastic from the floor and furniture.

Enjoy Your Newly Painted Walls

Once the paint dries, put your room back together and admire your hard work.

A good paint job takes a lot of preparation but is well worth it for beautifully smooth walls that look good for years to come. Painting plaster walls can take more work. But with these tips, any homeowner can feel confident tackling their next paint job on their own and achieve professional results.