Prevent White Stains on Basement Walls

Learn how to prevent white stains on basement walls. Find out how to reduce moisture in your basement and what product to use to seal cinder block walls to prevent mineral deposit stains from forming.

LESLIE: Marilyn in New Jersey, it seems like you’ve got a wet basement. What’s going on over there?

MARILYN: Yes, I have a basement that has cinder block walls and a little work room. And I see a little water coming through and a little bit of dust is in there. And I wanted to know if I could use some kind of special paint or something to seal the cinder block.

TOM: Well, you can. The white dust that you’re seeing …

LESLIE: Is that efflorescence?

TOM: Yes, it’s efflorescence. It’s mineral salt deposits that are left over from water that gets into the block and then evaporates and leaves its mineral salts behind.

There’s a multi-step process here, Marilyn. First of all, we want you to address the drainage conditions at the outside of your house so that we cut back on the amount of water that’s getting there.

LESLIE: Yeah, you want to make sure that your house has gutters, number one. If the house doesn’t have gutters, put some up. If it does, make sure they’re clean and make sure that those downspouts deposit that water far enough away from the house. And make sure you have enough gutters just to really cover the house and do a good job of keeping that water away.

And you want to look at the grading of the property as well. You want to make sure that any soil that’s leaning up to the foundation flows away from the house so it’s sloping away. And you want to get down about six inches over four feet. Not too drastic. Just enough to get that water moving away. And doing that will keep that water just from saturating that soil right next to the foundation.

TOM: Exactly. Now as far as those stains are concerned, I want you to mix up a solution of white vinegar and water. That’s going to help melt those salts away. They’ll make them evaporate away. And then in terms of painting the walls, that is your very last step and you can use a basement wall paint and that will certainly help seal in those walls and prevent any normal soil dampness from coming through.

So, you see, Marilyn, this is really a multi-step process. It’s really involving water management more than anything else. If you keep the water away from the walls, you’ll keep the basement dry and you won’t be seeing those stains any time soon.

MARILYN: Thank you very much. That helps tremendously.