Basement Walls: How to Remove White Stains
LESLIE: Sander in Kentucky, welcome to The Money Pit. What can we help you with?
SANDER: Hi. I have a CBS (ph) basement. And in the one corner of the basement it looks like they’ve used some kind of a waterproofing material …
SANDER: … on the brick. And it’s like flaking off in one corner.
SANDER: Now there’s no actual moisture or there’s no real sign that there’s wet there. But like there were boxes up against the wall and they got kind of destroyed.
TOM: Does it look sort of white and crusty?
TOM: Well, what you’re seeing is mineral salt deposits. So what this means is you have moisture that’s getting into that foundation wall and then as the moisture kind of wicks through the foundation wall and then evaporates into the air it leaves behind its mineral salt; its mineral deposits. So you have to do a couple of things here. First of all, to clean what you have I want you to mix up white vinegar and water. That will sort of melt those salts away.
LESLIE: It makes it disappear like immediately.
TOM: Yeah, it works really well. And you may have to go over it with a bit of a wire brush to kind of get it all nice and clean.
SANDER: No, I tried using a wire brush down there because I was thinking of just trying to sand it down and then recoat it with the waterproofing material. (inaudible)
TOM: Yeah, but that’s only part of the problem here, OK?
TOM: We want you to clean up what you have but the more important step for you to do is to stop the moisture from getting there in the first place. The two areas to look are grading and drainage.
LESLIE: Yeah, and they’re really easy to fix. You want to make sure that you stay on top of maintaining your gutter system on your house. You want to make sure that the gutters are clean and not overflowing because if they’re full, that moisture’s just going to fill up and over the gutter itself and then end up right at your foundation wall. So make sure they’re clean. Make sure those downspouts are running smoothly because if you don’t have any screening on top of that downspout, branches and all sort of yuck can get down there and just really clog it up.
Well, you want to also then look at to where your downspouts are depositing the water. They don’t want to be just dropping that water right against your foundation wall, which a lot of people do. You want them to come out.
SANDER: They’re going into like the drain tiles, which takes it to the back corner of my yard into a little creek.
TOM: OK, then you need to make sure that the drain tile does not have a break in it. Because that’s actually a very common condition, where you get a break underground. That moisture that you’re seeing in that corner is coming from your roof or it’s coming from the surface grade. Now, if your downspouts are clean; if they’re free flowing and if they’re going into an underground pipe, I bet that you have a break in that pipe somewhere that’s allowing the water to leak out. That’s the only possible solution. It’s not going to come from any place else. It’s going to be coming from drainage above that’s leaking into the wall and you’ve got to figure out where that’s happening and dry it out. The grading and the gutters.
LESLIE: (overlapping voices) Yeah, and then you can recoat the interior of the basement.
LESLIE: But until you fix what’s going on outside it’s just going to keep happening over and over again.
TOM: That’s right. That’s the last thing you need to do. OK?
SANDER: Unfortunately it’s not a really good spot to go looking at because I think it’s underneath my deck, right where the stairs come down. So there’s no clearance.
TOM: (chuckling) OK.
SANDER: (inaudible) house and driveway. But I’ll go looking (inaudible)
TOM: There is one – there is one other thing you can do. If it’s really an issue that you want to get to the bottom of, you can hire a drain cleaning service with a drain cleaning camera. They actually have a camera that can go through that pipe and see the inside of it and pick up …
LESLIE: (overlapping voices) And tell you exactly where this problem is.
TOM: Yep, exactly. (Sander chuckles) They do it for sewer pipes all the time.
SANDER: It might be simpler just to run another drainage pipe away from the house right there. (Leslie chuckles)
TOM: Perhaps. But that’s going to be the source of the trouble. Thanks so much for calling us at 888-MONEY-PIT.