Filling a Wide Crack on a Concrete Garage Floor
LESLIE: Steve in New Hampshire, you’ve got The Money Pit. How can we help you today?
STEVE: I’ve been in this house 15 years. But the crack was there before. It’s in the garage.
STEVE: At the most, it’s probably a ½-inch wide. But the floor is almost buckled a little bit along the crack line.
TOM: OK. Yep.
STEVE: And I’m just trying to figure out what would be the best way to try to repair that. I know that where my driveway meets my garage floor, the snow comes in, the rain and everything else. And I do have a drain in the middle of the garage, so the water does go down the drain. But it goes into this crack and I’m just trying to figure out if there was a way to repair that. I was thinking about maybe breaking it up and cleaning it out and regrouting it or something.
TOM: You don’t have to do anything quite so dramatic. So here’s what you would do. Because it’s so wide, you’re going to need not only a crack filler – and I would look at crack fillers sold by QUIKRETE. They have a number of crack-fillers, including one that is for wide cracks. It’s more like a flowable kind of a product.
And before you apply this to the crack, you’re going to put something inside of it called a “backer rod.” So a backer rod, it’s kind of like a foam tube. You know those foam tubes that kids play with in the pool?
LESLIE: It’s like a pool noodle. Pool noodle.
STEVE: Yeah. A noodle. Like a noodle.
TOM: It’s like – right. It’s like a miniature version of that.
TOM: And you press it into the crack so that it basically holds up the crack filler. You’ll press it in so that it leaves maybe a ¼- to ½-inch of space from the top of the backer rod to the top of the concrete. And then you apply the flowable filler on top of that and that will stop additional water from getting in there. And by stopping additional water, you’re likely to get less movement, because it’s kind of a vicious cycle where you get water in that crack, it displaces some of the soil and then the slab will settle.
Now, in terms of where the door meets the floor, if that’s not lining up, you may have to do some work for that door. Is it a wood door?
STEVE: No, no. It’s a – what I was talking about there was where the driveway comes into where the slab of the garage meets the – where it meets the driveway. So the crack has protruded beyond and it’s like …
TOM: Oh, beyond it? OK.
TOM: Yeah, well, you can – then you can complete the crack repair all the way out to the exterior the same way.
STEVE: Alright, guys. Thank you very much.
TOM: Thanks so much for calling us at 888-MONEY-PIT.