Install Tile Flooring Over Concrete

LESLIE: Judy in California finds The Money Pit on KSRO. And you’ve got a flooring question. What’s going on?

JUDY: Well, I’ve had a linoleum floor for 10 years and it was put down over concrete. In the past couple of years, I’ve noticed some dark spots appearing on the floor. And at first I thought it was dirty but it wasn’t. And I’ve tried to remove these spots with bleach and all kinds of things and I’m – I know it’s mold coming up.

LESLIE: So there was no vapor barrier or any sort of coating or …

JUDY: That I don’t know. I don’t know if there was or not. But my question to you is I want to put a new floor down and I want to put tile.

TOM: OK.

JUDY: Do I have to remove this linoleum or treat it in any way or can I just tile over it?

TOM: I would think you probably have to remove it because you’re not going to be able to get good adhesion for the tile adhesive with linoleum.

LESLIE: Especially if it’s containing a ton of moisture.

TOM: Yeah, I would take it up.

JUDY: And what would be the process of that? Is it really difficult to remove it?

TOM: It depends. If the linoleum is glued to the concrete it could be very difficult. But most likely it’s not. It may just be glued at the edges. And once you get it up, hopefully it’ll peel up pretty easily.

LESLIE: And then, Tom, would you put an underlayment or just go directly; building a subfloor out of some ply?

TOM: I would probably go right on top of the concrete with the tile adhesive. Because that’s the best way to get a good bond.

JUDY: Since I’m putting tile on concrete, I wouldn’t have to seal the concrete, would I?

TOM: No, absolutely not. No, you should be able to glue it right down on top of the concrete.

JUDY: OK, with just some mortar.

TOM: Well, you’re going to use a tile adhesive and it’s specifically designed to glue tile to concrete or wood floors.

JUDY: Oh, OK.

TOM: Very gooey stuff but it does the job. And stinky stuff, too.

JUDY: OK.

TOM: Lots of windows open when you do that one.

LESLIE: So ventilate well.

TOM: Or you’ll be floating away, if you know what I mean, Judy.