How to Repair Water Damaged Ceiling Plaster

Seal up your ceiling 

Painter painting a ceiling
Photo: South_agency / E+ / Getty Images
Painter painting a ceiling
Photo: South_agency / E+ / Getty Images
C.E. Larusso
Written by C.E. Larusso
Contributing Writer
Updated October 26, 2023

Difficulty

Simple

Flex your DIY muscles.

Time to complete

58 hours, 20 minutes

We’ve included the time for materials to dry, which doesn’t require labor from you.

Cost

$100–$500

If you already own the tools, this DIY is a no-brainer.

Need professional help with your project?
Get quotes from top-rated pros.

What you'll need:

TOOLS
  • A microfiber cloth, rag, or sponge
  • Nylon brush
SUPPLIES
  • Putty knife
  • oil-based or quick-dry primer-sealer
  • 6- or 8-inch drywall knife
  • Joint compound
  • Coarse or medium sandpaper
  • 120-grit sandpaper
  • Latex paint
  • Piece of lattice molding (optional)

Finding a leak in your ceiling is never a pleasant surprise. Whether it's due to a leaky roof, a burst pipe, or an unexpected downpour, water-damaged ceiling plaster can become a stressful eyesore. In this guide, we'll walk you through the process of bidding farewell to any stubborn stains, unsightly cracks, and annoying bubbles—a DIY project that can be completed in just one weekend. 

Prepping to Repair Water Damaged Ceiling Plaster

Before you begin to repair your water damaged ceiling plaster, confirm that you have fixed the ceiling leak or you’ll be repairing the damaged area again in a short while. 

If you don’t know where the leak is, look around your home for other signs where water could be getting in—ceilings are often damaged due to water leaks from the roof, plumbing, or HVAC systems. Walk around the exterior and see if there are any discolored shingles, or use a moisture sensor to find areas with higher moisture and humidity. 

With a plumbing leak, you’ll want to shut off the water supply to the pipe as soon as you can. In the case of an HVAC malfunction, shut off power to the HVAC system. After you are confident you have shut off the source of the water, give the plaster time to dry out before proceeding with the repairs.

  1. Remove Any Damaged Plaster

    Man removing baffles from ceiling paint
    Photo: Aitor Diago / Moment / Getty Images

    Any damaged materials—paint, plaster coats, lath—need to be removed. Using a putty knife, lift away any flaking paint or damaged plaster. The material should be soft and easy to dig out and discard. Work your way outward from the innermost area of damage, removing all soft material until you reach hard plaster. At this point, give the area a quick cleaning using a stiff nylon brush, and sweep away any dust and debris.

  2. Secure the Surrounding Area

    Push on the ceiling area around the damaged section and see if it feels weak. Any area that moves or gives under your hands should be secured to the lathe with 1-5/8 inch drywall screws so it doesn’t buckle.

  3. Apply Primer

    Woman painting the ceiling
    Photo: elpidio costa junior / iStock / Getty Images Plus / Getty Images

    Coat the area with an oil-based or quick-dry primer-sealer. The primer will prevent any stains from bleeding through your paint, and help the patching compound bond better. Coat the entire affected area with the primer, and let it dry before moving on to the next step. Most primers require 24 hours to dry, but quick-dry primers dry in about one to two hours. 

  4. Repair Any Cracks

    Using a 6- or 8-inch drywall knife, apply joint compound to any cracks or gaps present. If you are repairing a large area, you can use a long, thin board such as a piece of lattice molding to go over the area with the joint compound in one large sweep. This will also help you smooth our the application. Allow the joint compound to dry for 24 hours before proceeding. 

  5. Smooth the Surface

    Man repairing ceiling before painting
    Photo: Marccophoto / E+ / Getty Images

    With some coarse or medium sandpaper, smooth out any bumps or small imperfections in the joint compound. Use your nylon brush to sweep away any dust or debris and wipe the area clean with a damp rag or sponge. 

  6. Apply a Second Coat

    Apply a second coat of joint compound in the same manner as before. Make sure to completely fill in the deeper parts of the damage. You should only apply a thin area on top of the unaffected spots surrounding the main source of the damage. Let the second coat dry.

  7. Sand and Paint

    Hand painting a ceiling
    Photo: Stefania Pelfini, La Waziya Photography / Moment / Getty Images

    Sand the area one more time, with 120-grit sandpaper. Wipe the area clean once again, and prime is once more using your primer-sealer. This last coat of primer-sealer is essential; it should prevent any residual water from preventing the fresh coat of paint to bond. Allow your primer-sealer to dry before applying your latex paint. 

DIY vs. Hiring a Pro 

The cost for professional water damage restoration to your ceiling is $350 to $2,000, on average, and depending on how extensive the damage is. A small, isolated area of damage—one where you can quickly identity and shut off the water source—is an easy weekend DIY task, but for major fixes, it’s always better to call in a professional water restoration expert. Water damage can quickly grow from a small problem to a big one, so don’t hesitate to investigate getting expert help.

Frequently Asked Questions

Look for flaking paint or air bubbles that burst and then flake away. Paint will begin to flake after being exposed to minimal moisture or water, so it’s a good indicator of any water damage. If you notice your paint starting to flake, feel the plaster underneath to see if it is soft or damp.

Need professional help with your project?
Get quotes from top-rated pros.
Learn more about our contributor
C.E. Larusso
Written by C.E. Larusso
Contributing Writer
A professional content writer, C.E. has written about all things home, family, and wellness for a variety of publications, including HomeLight, Noodle, and Mimi. A third-generation Los Angeleno, she is always looking for ways to make the most of the sun, whether it be building an urban garden or decorating with the help of some low-maintenance, air-purifying plants.
A professional content writer, C.E. has written about all things home, family, and wellness for a variety of publications, including HomeLight, Noodle, and Mimi. A third-generation Los Angeleno, she is always looking for ways to make the most of the sun, whether it be building an urban garden or decorating with the help of some low-maintenance, air-purifying plants.
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