Repairing Water Damaged Plaster Walls
LESLIE: Carrie from D.C., you’re on The Money Pit. What can we do for you?
CARRIE: I have a brownstone that was built in 1847 in Washington, D.C.
TOM: (overlapping voices) Ooh, sounds nice.
LESLIE: Oh, that sounds great.
CARRIE: Yeah, it’s fabulous. (chuckling) But I’m having some water problems. The north facing wall on the first floor is having some water issues and the plaster is starting to …
LESLIE: Now, is this north facing wall – is it attached to a building next door? Is it the end?
CARRIE: No, it’s the free-standing north facing wall. However, the east wall – they just built some construction and they did tie a wall into that wall.
TOM: So when you say you’re having water issues, Carrie, what exactly are you seeing?
CARRIE: The plaster is buckling at the top framework – the top moulding plaster.
TOM: OK, but I mean do you know that this is from a water issue or could it be a problem with the plaster separating from the lath?
CARRIE: I definitely think it’s a water issue. It could be a problem from the plaster but I really think it’s a water issue. I did have the back wall re-pointed and I was wondering if they had trapped water, maybe, into the wall when they …
TOM: It would be dried out by now. But here’s what happens if you get a leak with plaster lath. The plaster pushes through the wood lath, generally, and has sort of like a finger that attaches to the back of it. And if that gets wet, the plaster will release and buckle. In a house that’s that old, it wouldn’t be unusual for the plaster to come loose and it might just be that what you’re seeing is deteriorated plaster. If it’s buckled, regardless of whether it’s caused by age or by leak, it has to come down. Because that stuff is really, really heavy. And if it comes down unexpectedly, it could really hurt somebody.
So you’re going to need to remove that damaged plaster to the point where you are back to having solid plaster and then you’re going to have that area repaired. And in doing so, you could also, at the same time, further investigate whether or not there was evidence of water leakage in that particular area. For example, a roofing contractor or a tradesman with the right tools can use a moisture meter to see if there’s excessive dampness behind that and then rebuild that area. But considering the age of the house and the fact that you’re not seeing dripping water, it might just be that the plaster needs to be repaired.
CARRIE: OK, well you’ve been helpful.