Ways to Waterproof your Basement

LESLIE: Jerry in North Carolina, how can we help you today?

JERRY: I have a basement that is damp and I want to put drylock on the concrete block walls down there. The previous owner had painted it.

TOM: OK.

JERRY: Do you have some sort of a recommendation as to getting that paint off the wall?

TOM: Well, couple of things you can do. First of all, the reason you have a damp basement needs to be addressed and putting a water-resistant paint or sealer on the walls is not the only way to address it.

LESLIE: It’s like the last step, actually.

TOM: Yeah, it is. It’s the very last step. It’s not the first step. But you know, what you’re doing, Jerry, is not that unusual. Most people want to try to seal those walls, as if they could eventually allow your house to float but that ain’t going to happen.

So what you want to do is look outside and look at the grading and the drainage around that foundation perimeter. You want to make sure that the soil is sloping away from the walls on all sides and then the other thing you want to do is look at the gutter system; make sure it’s clean, it’s free-flowing and it’s moving the water away from the house. Now that doesn’t mean dumping it into the two-foot-long splash block that’s typically at the corners of everybody’s house. If you have a damp basement problem you need to put extensions on those leaders (ph) and get them out away from the house. Now, if you’ve done those things that’s going to reduce the volume of moisture.

Back to your paint question. I would simply suggest that you wire brush to get the loose paint off so you don’t have any flaking paint and then you prime the walls with an oil-based primer. The primer is designed to stick to the raw concrete; it’s designed to stick to the old paint and it’ll give you a neutral surface and then you could put a topcoat over that. But I would follow those steps in that order. Start outside then work to the inside and I think if you do those both you’re going to find that place to be a lot drier moving forward.

JERRY: OK, well I thank you very kindly.