My house was built with plaster and lath walls. Then things have been reconfigured and replaced. So some is drywall. I'm thinking that there are probably places that drywall mud was used over plaster and it hasn't held up well. Mostly on ceilings but some walls too, like inside closets.
So, assuming I can validate this isn't an active water intrusion issue, what is the best way to fix? I'm worried that even areas not showing issues now will in the future, and I'd like to fill my house with drywall dust as few times as possible.
Sure that's just not failed paint?
From my experience with a hundred year old house with plaster walls, getting drywall patch to stick has a lot to do with prepping the plaster. Treat cleaning it like cleaning a car body for paint. There are all kinds of slippery things that coat the surface over time and it's surface is extremely smooth when applied. Grease remove with acetone then sand to create tooth. DO NOT use lightweight filler. I have had the best luck with the USG bucket stuff with a little extra water added for a creamy texture. And apply in multiple coats.
SkinnyG (Forum Supporter) said:
Sure that's just not failed paint?
Nope - not sure at all. How do I tell and how do I prevent it from failing again?
A: That sure looks like failing paint to me. Wrong product was used and the layers adhered poorly. Show these pics to a paint pro (Sherwin Williams store comes to mind) and see what product they recommend.
B: Here at the hospital the standard repair to a plaster wall (and we have many) is to chip away everything loose and use 20 minute drywall compound. It comes in a bag and "sets" more than "dries". And be aware of how long it is from when you mix it, it'll set up in your mud pan.
I have a good bit of plaster in my house and it seems to hold drywall mud just fine. Granted, it's only been about 4 years.
That totally looks like a paint issue to me, but I've been wrong before. After a while even latex paint gets hard, and expansion/contraction from temperature and humidity causes the layers to break the bonds between the layers.
If it were me, I'd bust off the cracked parts, skim coat with mud, and prime/paint. If it comes back in 10 years, it was probably time for a color change anyway.
I think paint, combined with humidity.
Patching an old dry wall can have its issues, too. Whether its plaster or drywall compound, if its going onto something that is super dry, the moisture can get sucked out of the bonding layer and make a weak joint.
Latex paint over oil can cause trouble, but that more outside. The latex bonds to the old oil paint, but it expands and contracts with the heat a whole lot more than the oil base stuff can, and it will tear it off the wall. I had little bits of cedar stuck to the underside of the paint blisters that were coming off my house.
I hate paint.
That is a humidity issue, it appears.
Or skim coat was too dry when applied.
Surface prep could be an issue as well.
I'm leaning towards the first because of the location, the texture coating in the skylight and similar humidity trap areas is falling off in my house from the previous owner's lack of fan use. Fan was wobbled out, when I took possession. And no fan in the upstairs bath where similar issues have presented regarding texture separation. None at all in other areas of the house where I assume the same texture was used (all original). I replaced the Fan with the quietest and largest practical unit and also relocated it high up in the skylight wall to purge that area well.
Don't forget KILZ or similar primer. I've had this happen simply because the previous "handyman" failed to prime.
In a slight variation of what some have said, I'd chip off the loose stuff, prime, mud, sand prime again, and paint. I like primer.
Looks like a paint issue. Wet a section with a spray mist bottle of water and you can probably remove it easily in sheets with a wide blade taping knife or popcorn remover. The sand paint we used to use for swirl ceilings back in the 60's-80's (on sheetrock) wouldn't stick to old plaster long term and peeled just like what you have over time. Wet it and it practically falls on it's own.
Well...
The more I scrape the more comes down. This is about 30 minutes of chipping with a putty knife.
The thickness does seem to be too consistent to be anything but paint. The drywall behind is weird though. Very hard (I can't stratch it with my fingernail), and surface feels almost waxy. I'm already considering just putting another drywall piece on top (bottom) of this and calling it a day.
Well, it's clearly 2 layers. So I think it is skim coat or something and paint.
I went nuclear last night.
Don't judge my awful mudding tonight
My general mudding technique is to use a ton, and then sand it back with a random orbital. Yes, it makes a huge mess. But I'm not good enough with a knife to make it mostly flat before sanding.
Here we are after 2 coats of primer (2nd coat was probably unnecessary, but when you already have it all out, might as well).
And done. Just like 14 other spots to fix now.
