LESLIE: Andrea from Ontario, Canada is on the line with a black mold question. How can we help you today?
ANDREA: My question is regarding black mold. And it’s behind my sink. Between the sink and the backsplash, there’s a little bit of space and this black mold settles in. There’s a lot of moisture, obviously. They’re running the water and it splashes, so – behind and around the sink, as well as around my tub.
I tried bleach. I scrubbed it. We, at one point, took out the caulking and recaulked it but it came back. So I’m at a – kind of a loss what to do with this.
TOM: Mold is going to grow any place that you have an organic material, which could be drywall. Or it could also be, believe it or not, soap scum. It can have organic matter in it and that can feed mold. And so, you have a condition there that’s going to be prevalent to black mold regrowth. Even when you clean it, it’s going to come back. You’re not going to permanently prevent it unless you change the environment – the climate – that exists in that particular area.
So, with respect to the tile area, let’s deal with that first. When you retiled – when you recaulked, I’m sorry – did you pull all the old caulk out?
ANDREA: Pulled it all out. Took it all out. It was actually our contractor who said, “Keep it very dry.” “Bone dry,” he called it. And then once we had it all dried out, then he came back and put a layer of this white material. I’m not exactly sure what it was but he finished it all.
TOM: OK. So you’re not quite sure what the product is.
Here would be the steps. When you pull the old caulk out, you need to spray the joint between the tub and the tile with a bleach solution. That’s going to kill any mold spores that are left behind. Then, after that’s dry, one additional step: fill up the tub with water because it makes it heavy and it pulls it down. And then you caulk it.
And when you caulk it, you want to use a product that has mildicide in it. Now, DAP, for example, has a caulk that has an additive called Microban. And Microban will not grow mold; it will prevent it from growing. And so, if you use the right product and you take the step of treating it with a bleach solution first, before you apply it, that helps it to last as long as possible. But again, if you don’t control humidity conditions, eventually it will come back.
As for the sink, the same advice applies. You not only have to clean it, which takes away the visual, but you have to spray it with a mildicide. And so you could mix, say, a 10- to 20-percent bleach solution with water. And then let it dry and that will help prevent it from coming back.
ANDREA: I’ll try that.
TOM: Alright. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.