Idea for Hard to Paint Surface

If you've got a hard to paint surface, like a wall that is concrete block or one that is damp, you can get advice on how to paint that surface so that the paint adheres.

LESLIE: Bruno in Canada wants to talk paint. How can we help you today?

BRUNO: I’m looking for some suggestions on what I can do with a wall that I have. It’s a staircase that leads from the – pardon me – from the garage to the basement. And the wall that the – is part of the garage that it’s backfilled against, every time I try to do anything with it – any kind of paint, any kind of finish – it always bubbles.

TOM: It’s got to be moist. That’s what’s going on there.

BRUNO: Yes, yes. However, it’s a cement-block wall and I drilled holes at the – right across the bottom, at every core, to see if there is any water and it’s dry. But I agree that it’s got to be moisture but it’s maybe just damp, not actual water.

TOM: Yeah. I don’t think it’s water. What happens is a concrete block is really absorbent and it’ll draw moisture up into it, kind of like a sponge. And if it’s going to be damp like that, it’s not going to hold paint. Are you using the paints that are designed for block walls?

BRUNO: I’ve tried this paint that was supposed to be waterproof.

TOM: Well, the other issue is that once you put the first coat of paint on, you’re kind of cursed. Because if that’s separating from the block, anything you put above it is going to separate, too.

BRUNO: So it’s separating from the first coat of paint.

TOM: Correct, exactly. If that is not adhering well, then the paint is just going to peel off. So what you really need to do is to strip it down.

BRUNO: OK. And is there a special product that would seal it much better than any paint? Is there anything else I could use?

TOM: Yeah. Is this wall going to be finished in any way, shape or form?

BRUNO: Well, it’s – what it is is a cement-block wall and then a plaster parched over it.

TOM: When you say “plaster,” you mean you physically plastered over the cement block?

BRUNO: To get a texture – a finished texture – rather than just painting the block.

TOM: Because if you wanted to really finish it, like in the sense as if it was an interior wall, what you could do is – Georgia-Pacific makes a product that is like drywall but it’s fiberglass-faced. It’s called DensArmor. And it’s specifically designed for damp locations. And because it’s fiberglass-faced drywall, it can’t grow mold.

So if you really want to do something and make it look completely finished and just get out of this sort of painting nightmare, what you might want to do is attach furring strips to that wall and then attach DensArmor drywall to it. Then you can finish it like a real wall.

BRUNO: OK.

TOM: Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.