Forum Title: Failed Skim Coat Situation
Failed skim coat situation. I have my own suspicions, but wanted to get some feedback from those with more experience with plaster rather than sheetrock. I have a professional background with sheetrock and painting, but very little with plasterwork. I live in an apartment (long term renter) with plaster/wood lathe construction. Thereís been construction here to repair a collapsed ceiling due to joist failure from water damage (I was not the contractor). During this construction the owner agreed to skim coat several other rooms, which due to the decades of neglect and were not looking so good. This was a mini renovation of sorts. The contractor doing the skimming is not licensed with my city (though no license required for work not requiring a permit, such as skimming). He had the usual illegals doing the actual work. The workers were very good mud guys at least with regard to their hand skills. However these walls are 80 years old, have numerous old coats of oil paint and also have numerous coats of latex/acrylic paint over the oil. This is par for the course in an apartment like this in NYC where landlords in apartment buildings looking for a quick buck with no money layout use the cheapest paint possible, unskilled chump labor, fix leaks and every manner of repair (even plumbing) with more ëplaster and paintí to conceal it, and cut every corner imaginable. Of course, thatís why the ceiling collapsed. One problem at the outset is I am 100% certain that when the first latex coats were painted over the oil decades back, no primer was used. In some areas, the thick coats of latex could be almost peeled off the wall, as there is a very poor bond to the oil substrate. Prior to skimming I observed the prep work. In some areas they scraped the loose plaster/paint but not 100%Öjust where it came off easily with a knife. Often this scraping revealed an old oil coat layer with a fair amount of sheen to it, perhaps originally an eggshell or even semi-gloss. That was the only prep work, at bestÖand other rooms got even less, or no prep work at all. The walls were not deglossed, or cleaned with TSP or other cleanser, or even wiped off with a dry cloth to remove dust. In a hallway, which had numerous thick layers of semi-gloss latex paint, the walls were not prepped AT ALL. No cleaning, no wiping of dust even. Nothing. The skim went directly onto this unprepped substrate. I am not the owner and I am not paying for the work. The collapsed ceiling is getting repaired only because I sued the owner. The owner did the skim coating voluntarily it was his idea. I observed and commented to the contractor and his workers the necessity to do one or more of the following: a) scrape all old latex paint off to the depth of the unprimed interface between oil/latex, b) sand or use liquid deglossing agent, c) clean thoroughly with TSP or other suitable cleanser and rinse if necessary, d) apply a bonding agent to the wall (PlasterWeld, etc), d) mix a bonding agent into the mud. The contractor said he knew what he was doing and he left the scene, rarely returning except to give directives to his workers. The workers looked at me and shock their head yes when I commented on potential bonding issues and how prep, then they went ahead and ignored me: they didnít do any of this. Instead they mixed about 25% plaster Paris into USG Green label premix JC. I suggested Durabond as a first coat, but the contractor said he preferred to use this mix as heís familiar with it and it works for him. The mud guys as I said have very good hand skills. They toweled, knifed, and sanded and got some nice results, one room easily a level 5. The contractor is the one used for all this ownerís buildings, so I was willing to accept he knew what he was doing with regard to the skim coat on these wall types. And as I said, the wall looked good. I stripped the doors, molding and trim, caulked, then primed and painted with Ben Moore First Coat/Regal line. This was between about 4-5 months ago (some rooms less than that). As predicted, the hallway skim coat, which received zero prep, is failing. A network of dispersed cracks is appearing. Some cracks are still under the surface while others have broken through. Some areas the skim coat is pulling away from the substrate and cracking. On other areas that to the eye look fine, if I drag my fingernail or tap with my fingernail, I can hear the sound difference where there is a gap behind the skim coat where it is separating from the wall. In some areas a large area (approx. 12î in dia.) although not cracked, has pulled away from the substrate and I can push it back against the substrate about 1/16î-1/8îÖthereís an air pocket behind it suggesting a failed bond. With winter here in NYC and lots of heat and lower humidity in the apartment, the problems are accelerating. Thatís the situation. Again, Iím not familiar with plaster, painted/plaster substrates and want some feedback. Based on what Iíve written, would you say that this skim coating was unprofessionally and/or incompetently done? The contractor had returned once to patch a few areas, but each week more and more cracks appear and he does not want to redo the job. In my opinion the place is a ticking time bomb for this skim coat to crack and delaminate, and I dread having to vacate those rooms again and deal with the workers and dust on a redo.
Post By: Nick L (Tuscaloosa, AL), 02/27/2018