Bubbling Plaster Could Mean A Leak
LESLIE: Joanne in Florida is having a problem in the bathroom. The plaster is bubbling up. Tell us what’s going on.JOANNE: Alright, I have a house that was built in 1967. It’s a block house and in my bathroom it’s plaster on top of the block.TOM: OK.JOANNE: Between the window and the corner of the room, there’s a section about two feet tall and about a foot wide that the plaster keeps getting soft and bubbling up. And I’ve tried spackling, years ago, and that bubbled out; and I’ve tried a plaster patch repair and, over time, that bubbles out.TOM: Hmm. It sounds to me like you have a leak, Joanne …JOANNE: A leak?TOM: … and we need to get to the bottom of that. Yeah. You mentioned it’s a concrete block house. The thing about concrete block is it’s very hydroscopic. It’s going to absorb water and that water can not only sort of fall down with gravity but it can actually get drawn up and across the wall. So the first place I would look is right around that window to make sure that we’re not letting any water in there that’s getting drawn into the block and pulled across to the wall. Because what you’re describing is exactly what happens when that block gets wet and, as such, the plaster can’t attach to it; it gets very saturated and sort of keeps falling off. Could be happening very slowly over time but we’ve really got to get to the bottom of this leak and I’m pretty sure that’s what’s happening.JOANNE: OK.TOM: So take a look at the window, take a look at the flashing, take a look at the caulking around it and try to seal it up as best you can and then keep an eye on it and see if it repeats itself. And by the way, the next time you patch this and get it all nice and dry and smooth, make sure you prime the wall with an oil-based primer. That would help as well.JOANNE: OK. Great.TOM: Alright, Joanne, good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.