Hi. How do I repair the cracking plaster walls shown in the attached photo? What causes this? These walls started doing this about 10-15 years ago. The plaster is original and the house is a row home in Philadelphia and is about 75 years old. Thanks in advance for any help!
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Replies
Looks to me like the original finish plaster is what's showing through where the surface has cracked. The top (cracking) layer may be some sort of textured paint or spackle mix. Is this an outside wall? A masonry wall? The top surface may be less permeable to moisture than the plaster, and infiltrating moisture is "pushing" off the top layer.
You can try scraping off the loose stuff, then use joint compound or plaster to skim coat everything smooth. Then paint with an acrylic paint that would allow moisture to pass through. If there's excessive moisture, however, you may need to solve that problem first (leaking gutter, compromised brick or mortar, etc.).
Allen
Thanks Allen,
This wall is an interior wall between two rowhouses meaning it's a shared "firewall" -I think they sometimes call it. I believe that under that plaster coat are bricks. It's on the second floor - the roof is above that wall. The roof was re-done 4 years ago.
I also should say that this wall just happens to face the door to the bathroom about 5-6 feet away. Could the steam and humidity be causing that-like when the door is opened after a shower or bath? That bathroom doesn't get much venting during the summer since the skylight remains closed during that part of the year. BUT I must also say that this peeling phenomenon is also occuring in a few other areas of the house but to a very very lesser degree in those areas.
Thanks everyone.
looks to me to more of a peeling action than a cracking..
scrape.. put on a sealer / binder and refloat the walls or texyure...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Looks to me like peeling paint or "skim coat". From what little I can see the plaster underneath looks sound.
This can be due to moisture coming through from the other side (check for water leakage into the wall/ceiling), or can be due to poor adhesion, incompatible paints, etc.
Sometimes the problem is a coat of "milk paint" under all the other stuff. "Milk paint" is like Teflon -- nothing sticks to it for very long.
Or it could just be that too many coats of paint have been applied over the past 75 years, and the walls simply can't hold any more.
Sometimes the problem is a coat of "milk paint" under all the other stuff. "Milk paint" is like Teflon -- nothing sticks to it for very long.
I know what you mean but that's not milk paint, I think it's called white wash or something like that. It's the only kind of water-based paint available before latex, kind of a chalky suspension in a weak binder and after it dried the surface became chalky.
What he's showing is multiple layers of modern formula paint on top of the original chalky paint.
All accounts I've heard said it was milk (casein) paint.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
The worst areas will need to be scraped and skim-coated, probably. Areas with only minor cracking may be able to be fixed by using a sort of wallpaper (I forget the specific term) that goes on horizontally and is designed to be painted or papered over.
Yo! Pizza, I'm also in Philly. (south philly).
You sure your place is only 75 yrs old? That's an infant.
In addition to the good ideas you already got, what is also common was for the plaster walls to get coated with a plain (no pattern or real color) wallpaper, which over the years was then painted with a gazzillion layers of paint.
You can get it off with plain water, but the tough part is getting water to the paper and old paste through the paint.
Try getting a bit of water down between the plaster and whatever you have there. If it starts to bubble and peel spontaneously after a few minutes, you got pasted on paper. Continue the process (and get yourself a quality wide blade razor scraper) and you can get it all off without hurting the plaster.
"Let's get crack-a-lackin" --- Adam Carolla
Yo philarenewal!! Thanks for the advice. ya-no-whad-I-mean?
Yo philarenewal!! Thanks for the advice. ya-no-whad-I-mean?
fugetaboudid. ;-)
And best of luck with it!
PS: that wall is lookin' fugaazy right now. ;-)
"Let's get crack-a-lackin" --- Adam Carolla
I agree with Dan. That is peeling paint you see in the picture. It's not the finish coat of plaster-it's too thin for that.
Scrape off anything that comes off. Lightly sand. Feather in with joint compound to remove the paint lip.
Prime and paint.
Pete Duffy, Handyman
Thanks for all of the suggestions. But let me give you a bit more history on these walls because I doubt that that is layers of paint coming off. You see, when my parents bought that house in 1954, there was wallpaper on the walls. In the 60's, I remember helping my parents take all of it off throughout the house. I specifically remember the chore of wetting and scraping all of it off completely- paste residue and all. Then we painted over the newly exposed walls. Since that time we must've painted those walls maybe three times - tops. That doesn't look like 3 layers of paint-unless these walls were painted long long ago before the paper was even put on. What do you all think?
Also, what do I skim coat it with? Any suggestions on a good binder /sealer brand prior to finishing it?
Thanks.
Well, we can't tell very well from that picture (good picture, just limited ability to actually touch the thing), but it looks like the surface behind the peeling stuff is white and smooth. If the plaster itself were peeling it would probaly separate between layers, and you'd probably have a brownish coat showing through.What you may have, though, is moisture behind there, with oil paint over it. The moisture, over time, would "disassemble" the very topmost 1/8" or so of plaster, allowing the paint and a very thin layer of plaster to peel, and leaving a slightly rough (sort of "orange peel") surface.But it's also possible that there was indeed more paint on the wall, under the wallpaper, or even more layers of wallpaper.Finally, is it possible that, during all that scraping in the 60s, some areas of the wall were damaged enough that they had to be skim-coated?
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
you got a layer or 6 of WP glue under there that is letting go...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
Peel off a few chips and look at the back of them. How thick is the chalky layer (if there is one at all)?
Check the surface underneath. Is it pretty smooth (like finished plaster) or is it maybe the texture of orange peel (or something else you can describe)?
Where is the peeling occurring, and where it is worst? Is it mainly ceilings, mainly exterior walls, mainly interior walls, etc?
I'll do that Dan and let you know what I find as soon as I get back over there. Thanks!
If I skim coat it after scraping off all the loose stuff, is it easy to do it with plaster? I have experience with joint compound but no plastering experience.
To answer somebody's question earlier, I don't recall my Dad repairing any bad sections up there after removing the wallpaper. But then again my memory sometimes goes on the fritz- if ya know what I mean.
He probably did it in the dead of night so you wouldn't hear the cussing.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
LOL :)
If I skim coat it after scraping off all the loose stuff, is it easy to do it with plaster? I have experience with joint compound but no plastering experience.
There's no reason you can't skim coat with joint compound. Granted, it's not as hard as plaster, but unless you plan on playing handball against this wall, you'll never know the difference. I do prefer setting compounds for this type of repair since they don't shrink (fewer coats needed) and cure harder than regular joint compound.
You could also increase the hardness of compound (either regular or setting) by adding plaster to it, but you'll have to experiment a bit to know how much gives you the desired results. I did that once and it came out great, but it was more of an experiment than an actual need. Since then, I just use compound.
It's very important to prime the repair areas BEFORE applying compound. Some plaster is so slick that any compound and/or plaster will not adhere properly.
-Don
What do I prime it with before repairing it/ applying the compound?
Some regulars here have said that it's best to prime it with an oil-based primer, especially if it's new plaster.
I've only ever used a good quality all-purpose latex primer and I've never had a problem.
-Don