Can You Paint Over Plaster Walls? Yes, But Take These Steps First

You’re staring at peeling, outdated paint from decades gone by and wondering if you can paint over plaster walls. The short answer is yes, but only if you take a few essential steps first. Whether your plaster is cracked, damaged, or showing other signs of age, thorough prep is key to achieving a smooth, long-lasting finish. Here’s everything you need to know about painting over plaster walls so you can have a fresh, beautiful finish, no matter what color you choose.

How to Prepare Your Plaster Walls for Paint

Plaster can provide a beautiful, durable surface for paint, provided it’s in good shape. Before you get started, follow these prep steps:

1. Clean the walls with a microfiber cloth and plain or slightly soapy water to remove dust, dirt, and oils.

2. Check for damage, such as cracks or water damage, and make any necessary repairs (more on these below).

3. Repair any imperfections using joint compound or plaster patches.

4. Sand repaired surfaces with fine-grit sandpaper to create a smooth finish.

5. Prime the wall with a high-quality primer to help the paint adhere properly.

Make sure the wall is fully dry before you proceed with painting.

Painting Old Plaster Walls

Painting old plaster walls takes time and patience, but the results can be wow-worthy. Expect uneven texture or minor crumbling, which you’ll need to scrape and sand before continuing. Since plaster is fairly porous, be prepared to apply multiple coats of primer and paint.

Painting Over Water-Damaged Plaster

If your plaster walls have fallen victim to a leak, you’ll need to take extra precautions. Painting over water-damaged plaster without treating it first can lead to peeling, bubbling, and mold issues if the leak is ongoing, not to mention an uneven final product. Follow these steps to repair water-damaged wall plaster before painting over it:

• Identify and fix the source of the leak.

• Clean the surface with a damp cloth or sponge with soap.

• Remove the affected plaster with a putty knife.

• Use a stiff brush to dust off the surface you just worked on.

• Let the wall dry completely. To be extra sure, use a moisture meter, which is available at hardware stores and online for around $50.

• Make repairs with joint compound or patching plaster, allow it to dry completely, and sand it to smooth.

• Apply a stain-blocking primer to seal in discoloration.

Painting Over Cracked Plaster

Hairline cracks are common in older plaster, and they can worsen if not repaired. There are several ways to fix cracks in plaster walls:

• Fill in cracks with joint compound or patching plaster.

• Sand smooth after the compound dries.

• Prime before painting, then paint over as usual.

If cracks keep coming back, your plaster might be shifting or separating from the lath beneath, which means it’s time to call a plaster repair specialist near you.

Best Primer for Plaster Walls

Primer is an undercoat that helps create smooth surfaces, hide stains, and potentially allows you to use fewer coats of paint. High-adhesion bonding primer is ideal for plaster. For water-damaged areas, make sure you use a primer that also includes stain-blocking capabilities. 

Best Paint for Plaster Walls

The overall best type of paint for plaster walls is acrylic latex paint. Its breathability allows the plaster to release moisture instead of becoming trapped inside the wall. A flexible hold provides some elasticity, which can help ward off hairline cracks. For best results, look for a paint specifically labeled for use on plaster. If your walls have imperfections, matte or eggshell paint can help blur them.

DIY vs. Hiring a Pro

Painting over plaster walls can be a solid DIY project, provided the walls are relatively damage-free. But if your walls show signs of deeper issues, such as crumbling areas, large cracks, or soft spots, it’s best to bring in a pro. It takes skill to match the texture and hardness of the original plaster, and you may find that the time and cost of tools will add up to more than you’re willing to invest.

Plaster repair supplies cost approximately $50 for small areas, and the supplies to paint a room range from $200 to $300, plus $50 to $70 per gallon of paint. If you hire a professional, plaster repair costs between $100 and $300 for small repairs and up to $1,200 for more extensive work. The cost to paint a room with the help of a local interior painter averages between $400 and $1,100, depending on factors such as the room’s size, ceiling height, location, and the project’s complexity.