Black Mold in Bathtub Caulk
LESLIE: Now we’ve got Alice in Michigan on the line who’s dealing with mold in the shower. Tell us where you’re seeing it.
ALICE: Hi. I am having issues to where my caulk keeps having black mold come through. I strip it, I redo it and the mold just keeps returning. What can I do to stop that?
TOM: A couple of things. You’re talking about the – just the shower or the shower/tub kind of a thing?
ALICE: The walls are separate from the actual tub, so I’ve got the caulk that attaches on.
ALICE: And I will strip it, I put bleach on it and then I put new caulk down but it just keeps coming through.
TOM: Have you tried DAP caulk? And the reason I bring that up is they have a kitchen-and-bath caulk that’s treated with an additive called Microban. And Microban absolutely, positively will not grow mold or algae in it.
ALICE: I don’t think I’ve tried that.
TOM: You might want to give that a try. And the other thing that I would do is – and I know you’ve been through this all before but remember to pull out all the old caulk. You can use a caulk softener, which is kind of like a paint stripper for caulk, to pull that out. You want to wipe that down and spray with a bleach-and-water solution in a spray bottle, up into that gap so that we make sure we get up in there and kill any algae spores or mold spores that are left behind.
Now, this is on a tub?
TOM: OK. So next thing you do is fill the tub with water all the way up. And while the tub is full, caulk the seam between the walls and the tub. And then after the caulk dries, let the water out. That lets the tub sort of come back up and compress the caulk and helps seal it better so that moisture won’t get behind it and it won’t sort of tear out again.
ALICE: Oh, OK.
TOM: And then, finally, make sure you use the caulk that I suggested with the mildicide. And there are others but I just happen to have good experience with that particular one. It’s DAP Kitchen and Bath Caulk with Microban; that’s the additive.
ALICE: Oh, perfect. OK. Well, I really appreciate that. Thank you so much.