Clean Salt Deposit Stains from Cement Basement Floor
LESLIE: Heading over to Illinois to chat with Mary. How can we help you today?
MARY: Yes, in January of last year we had – a sewer backed up into our basement and it got on our cement blocks. And so we washed it with strong bleach water and it was strong enough water that we had to have the windows and the door open so that we wouldn’t get the fumes.
MARY: And then painted back over the brick walls and now I notice it’s coming through again.
TOM: You’ve not had another backup?
MARY: No, no.
TOM: OK, so what’s going on here is this: you have the beginnings of a water infiltration problem. The concrete block is very absorbent. It’s called hydroscopic. And if there’s water on the outside of that block or it pulls up water from underneath it, it will draw back up into the block just like as if it’s a sponge and, now that it’s painted, it probably will push out almost blisters in spaces; you may see stains; you may see sort of white, crusty material. Does this sound familiar?
MARY: No, it doesn’t look crusty. It looks like little fibers like on it.
TOM: OK. Well, what you’re seeing are mineral salt deposits. Now the solution here is not in the basement; it’s outside the house. You’ve got to take a look here, Mary, at the drainage conditions at the foundation perimeter. You want to make sure that your gutter system is clean and free-flowing and you want to make sure that the soil around the house is sloping away from the walls. Those two things, if they’re done correctly, will reduce the amount of moisture and the amount of water that’s around the outside of those foundation walls. That will stop it from drawing inside. So you’re on the right track; you’re just not quite there yet.
LESLIE: Now, that white residue that you’re seeing in the house, you can easily get rid of that with a mixture of white vinegar and water. If you just mix some …
MARY: Vinegar and water? OK.
LESLIE: Mm-hmm. If you mix them up in a spray bottle or however you want to work with it and just wipe it on there, you’ll see it goes away immediately.
MARY: Oh, alright. So I won’t need to rebleach the walls then?
TOM: No, no; because it’s not mold. It’s a salt deposit.
MARY: Oh, OK.
TOM: So nothing to worry about, OK, Mary?
MARY: Yeah. Thank you.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.