Fix Cracks in Concrete Floors
LESLIE: David in Myrtle Beach, South Carolina is working on a tiling project. How can we help you get the job done?
DAVID: Well, first off, let me say I really enjoy your show. I’ve gotten a lot of good tips through the years.
TOM: Thanks, Dave.
DAVID: But what I’ve got is a concrete floor …
DAVID: … and it’s got some minor cracks in it; 1/8-inch cracks to 3/16 …crack in the concrete. One crack runs the length of the slab. And I built these things in 1996 but will they crack anymore or do you think the settling is done? And I’m leaning towards painting a membrane on them and the specs say about 30 mils thick, which is about the thickness of a credit card. Or there’s a roll of plastic type crack guard and another that’s rubber, that’s self-adhesive. Which is the best or are they all about the same to go over the existing cracks so that it doesn’t crack anymore?
TOM: Alright, so the membranes you’re looking at are specifically designed as anti-fracture membranes, correct?
DAVID: Yes, that’s correct.
TOM: OK. Well, the thing is that the floor is probably not going to crack anymore but it is going to expand and contract.
TOM: And that movement by itself can open up the tile joints. So it is a good idea to put down an anti-cracking, anti-fracture membrane. I am not familiar with the liquid type that you roll on. I’m more familiar with the sheet products.
TOM: And they do seem to work quite well and are definitely recommended when you’re going over a floor like that where you expect some movement.
DAVID: OK, let me ask you another question. Some people said I could leave the old vinyl down as long as I roughed it up and just took up what was loose and that would act as a crack guard. But I’m kind of the old school; I think you need to take it down to the concrete and then do a preventive [same way] (ph).
TOM: I wouldn’t want to trust the adhesive on the vinyl to hold my tile down. Because if you glue the tile to the vinyl and the vinyl adhesive releases, guess what’s going to happen? You’re going to have tiles popping up all over the place. So you don’t want to mess with that. I think you want to make sure you have a really secure installation. So I’m kind of with you. In this case, I would pull up the tile til I got to a solid surface and then build it up from there.
DAVID: OK, I think that’s kind of the answer to the question. I know I need to protect that floor from those cracks, so I’ll go ahead and do what I need to do.
TOM: Alright, well good luck with that project, David. Thanks so much for calling us at 1-888-MONEY-PIT.