Painting Plaster Walls in 5 Easy Steps

Painting plaster walls is not at all difficult.  If your house is old, it will have plaster, sometimes called ‘horsehair plaster’ on the walls. The old workers used the tail hair from horses to mix in with the plaster to give it strength.
Painting Plaster Walls
Painting Plaster Walls Photo painting plaster walls is not at all difficult. Runder

Plaster Walls are worth saving and painting

Plaster walls are harder than the modern drywall, but it is great to save them, and that will probably cost you less in the end.  Often plaster walls have a lot of lime so mold cannot grow in them.  Great news.

Also, just as a point of interest, the reason people put wallpaper over the plaster walls was not just for decorating.  The wallpaper also gave strength and stability to the walls!

This plaster wall is usually cracked but is worth saving. If the plaster wall is still firm and has just separated from the backing “lath” which was usually cedar strips, you just need to re-attach with drywall screws.  This will cause some cracking which you just patch up with spackle (sand all when dry).

Painting plaster walls in 5 steps

  • Use a putty knife to remove any loose plaster. If you see a brown discoloration, that is probably water stain from years of moisture and maybe leaks in the roof etc.  You’ll have to prime that with a white pigmented shellac such as spray Kilz or liquid Kilz or a good product called 1-2-3. For mold, please read our post about mold resistant paint.
  • One trick is to fill tiny cracks with a paint-able caulk.  It’s faster, and it gives a little whereas other spackle and mud compounds will not.  You have to assume those cracks will keep moving.
  • Patch the hole with pre-mixed drywall compound and give it a day or so to dry, and add a second or even 3rd coat if the dried patch keeps shrinking.  Deep patches will shrink no way around that.
  • Large repairs will need tape and you can find how to do that in this post.
  • Sand with rough then transition to finer sandpaper and prime with drywall primer (apply one coat). Please don’t buy paint-and-primer-in-one: here is why.

You should be ready to paint at that point. Paint your walls with 2 coats of paint.

Make sure you have all the painting tools that you need.

If you are working with a lot of sanding, read our respirator mask guidelines.


How to paint plaster wall – summary

Painting plaster walls is just like painting any other drywall. The primer that you use is the key. You need to us the best primer for plaster walls to seal the wall. On that point, watch the toxins you are putting into the air that you and yours are breathing.

Plaster walls will drink anything you put on them, so you want to put an end to that with the primer, and at the same time if you have any stains you want to seal them at that level: most water stains from plaster walls will bleed through every coat of latex painting work. After your primer, you painting on plaster walls is just like any other interior paint job, which you will read about all over my site.  Write to me with any question about how to paint plaster walls!

18 thoughts on “Painting Plaster Walls in 5 Easy Steps

  1. We are moving into a home that was built in 1960 by a man who was a Colonial Williamsburg enthusiast. All of the walls are raw plaster with the trim being the only thing painted. The walls now are all dingy. I believe they are lime plaster. I assume following the instructions on your site will work for us when we go to paint the walls but there is one wall in the dining room that has a mural painted directly onto the wall. I would like to save the image but the wall itself is dingy like all of the others. Is there any technique I can use to either bring back the wall to a brighter white or seal the whole wall with some tinted sealer that will give the plaster an antiqued color but still allow the image to be retained?

    • Hi. Without seeing the wall, I’d say ‘no’ from within the world of painters, but I am sure that there are sealants that are used in professional sign-making etc… That can seal it for you. You don’t want it to yellow over the years, and that is going to be hard to find. All those old houses with dark wood trim were not always that way: the varnish darkened. For many years, it was much lighter. But chemistry has come a long way.
      Send a photo if you like and I’ll ask my painter buddies around the world for a recommendation. It is not what we do ordinarily. An art store would be a good first stop. They chat too.
      I also know a woman who restores old Tibetan art. That is very expensive…museum-level work, but if you find out what they use to clean the paints, you could do it yourself perhaps.
      Good luck and thanks again.
      ps, yes, the primers we recommend will seal in the other plaster walls’ dingy spots. Buy a small can and test on the worst spots, then get more. Try to stay as low-toxin as you can and open windows etc to stay healthy.

  2. Hey Brad,

    Here is a full shot of the plaster wall with simple mural on it and two close ups of the birds in the mural. How would I brighten, or clean the white background of the mural wall while saving the artwork on it? Can I do a wash over it all to give it all an aged look and then seal it? I am at a loss as to how to attack this. The other walls have nothing painted on them so I was going to follow your instructions for painting plaster walls but this one must be handled differently.


    • Plaster with mural

      Hi again.

      What is the mural attached to? A painted wall? Or plaster?

      If it is a painted wall I would suggest carefully cleaning around the images and painting carefully around the images. Even if it is a plaster wall I would suggest the site. But as for the images, I would take a damp soft cloth and carefully clean it.

      Remember that if the wall is already painted, it does not necessarily need a primer. The primer never hurts, and it depends on the color that you want to apply but is not necessary to seal anything if the wall is not porus. Primer and sealer is only for a porous wall as you know.

    • Got it.
      So my advice would be to paint around the images with a small artist’s brush, then a larger brush as you have room, then roller for 3 coats: 1 primer, 2 color.
      To clean the images, probably a damp sponge/rag. Test a small spot to see if water dissolves the paint: I bet it will not.

      Good luck.

  3. Hi Brad,

    We’ve bought a fairly new home with plaster walls and as we begin to paint the very white walls, we’d like to know what brand/s you recommend for drywall plaster.

    Thinking of using RustOLeum.

    Thanks! Elaine and Steve

    • Hi and thanks for writing.
      I am not sure if the walls are ‘very white’ because they have new plaster (unpainted) or white paint.
      If paint, just have at your favorite (check out the Benjamin Moore Historical Series—all warm and soft)

      If plaster, then use the primer I mentioned in the article above, then paint as you like.

      Key point is that some primers also seal stains: if you don’t have stains, just use the simple primer (not primer-sealer).
      Yes, the Rustoleum is a good one and there are many others as well. Stay well-ventilated, like the Rolling Stones! Get it?! Ha ha.

  4. I have a hallway that I’ve scraped the paint and repaired the cracks in the plaster. Now I’m almost ready to paint. My question, I know I need to wash the walls after all the sanding but did I also wash over the repaired areas..making them moist again?

    • Well, don’t really ‘wash’. Is it greasy? If it is just dusty, no need for fact you’ll damage drywall and patches with water. Just use broom at first, then maybe vacuum, then use dry rag or wide dry paintbrush type tool, then mop floor (so you don’t kick dust up into wet primer/paint).
      So do all this after the last of the sanding is done. How to make sure it’s done? Use a good light up close to see the sanding/patching job.
      Hope I helped!

  5. Hi, I have taken all the painted wallpaper and glue off this old plaster wall. Cleanned real well with TSP. The old walls are very smooth with few waves. My question is do I need to sand all these walls and ceiling or can I just use a good oil based primer over these walls without sanding everything down. Will the primer adhere to these slick walls? Thanks in advance

    • Hi Charlie. You sound like you are all set to prime. Why oil based? Not necessary from what I can tell. Do you have water stains? Just use basic drywall primer and if stained areas, use BIN or some quality sealer. Stains will bleed through the primer and all paints forever, so you have to seal.
      If in any doubt, do some drywall primer in one square meter, let dry, put some paint and see if you like it. The hard work is done !
      Have fun.

  6. Hello,

    I will be painting my bedroom wall, which is drywall or plaster, my house was built in 1920 and I think my bedroom has the original walls. What would be the best sheen to use? Should I use a primer, the walls are white.

    • Hi Jason. Unless the walls are pristine, which I doubt at 100 years old, you would want to lay a primer on: this seals any stains and ensures your final paint will not have stains (latex paint will not do this for you). So, have a look at some low-toxic primers with some sealing qualities. They are not too expensive and you can apply quickly.

      Sheen is totally up to you: flat is nice unless you have little ones with messy hands on walls. If so, eggshell still looks nice and you can clean it well. Some flats today, esp Ben Moore, can also be cleaned but may show some wipe marks.

      Good luck. Let us know the result. Photos before and after are always helpful to others.


  7. Hello:
    I have plaster walls throughout the house, circa 1860, and have noticed a dark patina above and around the walls of cast iron radiators, hot water, not steam. The dark patina shows the outlines of the underlining lath. The house is only mildly insulated. Could the dark skeletal image of the lath on the walls be caused by mold or the combination of cold plaster and rising hot air?
    I notice the further along the wall from the radiator the less dark is the image. Also, the ceiling directly above the radiator does not shows signs of darkness.

    I suppose I could wait until warmer weather, clean the walls, and see what happens but would like to attack the problem now.

    • Hi Mike. Depending on your location and atmosphere (near water?), and age of last paint job I would think it could be mold, but that is obvious: black spots, colonies of cells. If you can send a pic, that would help me, but for now, I’m guessing the on/off heat cycle near the radiators has allowed common dust to settle into the wall leaving a permanent mark. This does happen over time. If this is the case, we hope it is, just paint a test section with your top coat and see if the mark bleeds thru. Certainly, not a bad idea to hit it with a bleach solution first, but please open all windows for some time and/or wear a chemical respirator. Bleach is a deadly poison. I have a post recommending the best respirator for the money. When you are done, if you can reply here, and I can post the pics of before and after. This will help others in the future. Good luck!

  8. file:///C:/Users/mikes/Downloads/image1.jpeg

    Thanks for getting back to me so quickly: I think if you copy the link above and paste you should see a good picture of the problem.

    The ceiling has about a 60 degree slant at the top – which is where you will see shadows of the lath extending from the corner for another 8 feet. The shadows also do extend downward toward the radiator and slightly across the adjacent wall, also somewhat across the ceiling above the radiator. The walls and ceiling are old plaster painted with latex. The walls had been previously papered ( approximately 50 years +-) with vinyl paper.


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