Hi All,
We just bought a 1900 year old cottage in need of some love.
Spent the last few weeks repairing the lathe and plaster walls in an upstairs room. Finally began painting this weekend – coat of latex primer – but this morning I came up to do another coat and discovered a ~1″ by 3 foot vertical section where the plaster is delaminated/bubbling in a line. It definitely was not there before, but it is aligned with two delaminated patches we repaired previously. When the bubbles were cut with a utility knife, we found completely crumbled plaster.
some background: the walls were previously covered in vinyl wall paper, no trace of having been painted before. We washed off the glue and have been using setting type joint compound for repairs and Wallys Plaster Magic where the plaster has separated from the lathe. In this area there was only some delamination, so we painted with bonding agent then plastered. Upon closer inspection today, this section of wall is somewhat spongy, but not as terrible as other sections of the wall were (before repair). By my math (assuming all they studs are evenly spaced) this area is not on a stud.
Also, it rained today – could this be moisture coming from the attic?
What’s going on here? Could the painting have caused this? The rain? I don’t want to make a Bandaid repair if the solution is to fix my roof!
any guidance deeply appreciated! thank you!
Replies
The bubble appears a straight line. Would these be horizontal or is the picture flipped?
Bonding agent? I’ve used with no problem, Plasterweld. In some old plaster lime mixes and or moisture transfer maybe, priming the areas with Plasterweld
has solved the problem. Water entry, it won’t solve that.
The picture is flipped, the damage is in a vertical line
Think it could be moisture entry?
I would have to stop by and take a look.
The straight line is odd. From outside, does it line up with anything above that looks suspect?
Did you use any paper or fiberglass tape there when you mudded it up?
While I sometimes use Plasterweld before applying compound, I then spot prime before paint with It also.
Damp crumble, probably water if you let the succeeding coats dry between application.
Cut the plaster out that in that line and see if the lath is wet. A moisture meter might help localize the source.
Honestly, with over 45 yrs in the trade, almost anything is possible.
going to sound "odd" but did you "stick a pin" in the bubble to find out what's there? if you get water, you've got a leak. If it's just a bubble with air, you have a moisture problem with moisture that's trying to go from a wet area to a dry area thru the paint/finish