LESLIE: Listening on Free FM, WJFK, we’ve got Grant from Maryland. How can we help you?
GRANT: I have an old house that has ¾ oak floors, you know, built in 1940; tongue-and-groove oak floors with linoleum – I’m sorry – the linoleum tiles on top of it. They’ve been there for 60 years. And I want to tile the floor. And I just want your advice on should I put a cement board down on top of that or is that a stable enough structure for that?
TOM: You want to put a …
GRANT: And then …
TOM: You want to put a ceramic tile over that?
GRANT: And the second part is I want to put ceramic tile on the walls and it’s the same kind of thing; the plaster on the walls. And should I put a cement board down on top of the plaster or is plaster stable enough where I could put the cement tile – or the ceramic tile directly on the plaster walls?
LESLIE: Well Grant, before you go putting any tile up on anything, make sure you buy two completely different tiles for the floor and for the wall. What you’re going to …
LESLIE: OK, what you’re going to put on the floor is going to have something that’s got a slip resistance to it so you’re not putting down something that’s got a very high sheen and very slippery. And then on the walls you can put down whatever you want. But on the floor, make sure you’ve got a high slip resistance so you don’t go slipping and sliding.
TOM: Now Grant, as far as the kind of floor that you put down, putting a cement board down on the floor is not going to change the factor that you need to consider, which is the stiffness of the floor. If your floor is not stiff enough, you may have to put down a mud floor or put down some woven wire mesh and have a thin set of ply which will stiffen it up. Just putting the cement board down is not going to have enough stiffness to solve that problem.
LESLIE: Because if you’re dealing with a floor that’s got a lot of movement – especially if you’re using a largish tile floor; you know, maybe like 10×10 or larger – if there’s a lot of movement underneath, number one, you’re going to get the grout lines cracking but if it’s a large tile, you could get cracks straight across those tiles.
TOM: Yeah, exactly.
GRANT: Yeah, I really don’t think that there’s any stability issue with it.
TOM: Then I think you could probably just – the next question is what you’re going to adhere it to and you mentioned that there was linoleum down. You’re probably going to have to put down some sort of a subfloor that might be something as simple as a ¼ inch of luan plywood, so that you have a good surface. And then you could use a tile glue and attach it right to that. As long as you don’t have any – as long as the floor is flat, so you don’t have any dips or anything like that or crowned areas where you’re going to try to make this …
GRANT: No, it seems – it’s a well built house and I – from what I’m hearing from you, you don’t think that the mortar that I’m going to use to adhere the tile will stick to the linoleum.
TOM: It may not. I mean you could check with your tile supplier to see if they have a glue that’s rated to do that, but I – you may have to put down some sort of a subfloor over that in order to get proper adhesion.