I'm working on an older 1920's house and chips of paint are coming off the walls and ceiling. Chips are several layers of paint and go down to the plaster which is backed by a composite board called Celotex Lath.. And advise on solution, fix or cause?
Re: Peeling paint
Plaster walls were origionally painted with oil based paints. They didn't penetrate into the plaster and moreso layed on the top. Over time oil paint gets brittle and with expantion, contraction, moisture vapor and other reasons the paint simply flakes off. The fix would be to sc**** everything off that is loose. Then prime all of the exposed plaster with an oil based primer. Kilz or Zinnser,etc. would be fine. To smooth the walls back out after that it is okay to do it with sheet rock mud. After it dries sand the edges smooth and prime the entire wall with a good quality primer.
Any cracking in the plaster can be fixed using fiberglass mesh tape and sheet rock mud. The taping is important to keep the crack from coming through the repair. Do this after spot priming the exposed plaster. Any water or water based products do not need to make contact with the plaster or it will disolve it. That is why it is important to use an oil based primer.
Now the wall is repaired and primed to create a neutral surface to receive a latex based paint that should hold up for years.