Repair a Sinking Garage Floor

LESLIE: Rod in Colorado’s got that sinking feeling. What’s going on?

ROD: Well, I have a garage floor. It’s sinking in the middle inside of the garage door/back door and it’s sunk about three-and-a-half inches …

TOM: Wow.

ROD: … and I don’t know whether I have to tear it all out or whether I can just fill it in with concrete [1].

TOM: Well, let’s first talk about why that happened. How old is your house [2], Rod?

ROD: About 50 years old.

TOM: Yeah, well you know, typically what happens is as the home is constructed there’s a lot of soil disturbance in the garage and also it tends to be the last place to have the floor put down so it ends up being a lot of debris that gets tossed in the garage in many situations.

ROD: Yeah.

TOM: And so that erodes and decays over the years and all of those soil voids get filled in or open up and then the concrete sinks and sort of fills that in. So that’s what’s happening. The good news is that the garage floor is not part of the structure of the home and so…

ROD: No it’s not.

TOM: … you’re really just dealing with a cosmetic issue. If it’s sunk that far I think the best thing for you to do is to break it up and pull it out and put a new one in.

ROD: Oh.

TOM: If you poured another layer on top of it, chances are you could have more movement underneath of it. You don’t know what the situation is there and it would be a shame to put the new floor on top of the old one [3] and have it crack again. I know that’d really break your heart. So my suggestion would be for you to tear up the old floor. It’s actually not that hard to do, especially if it’s 50 years old and already starting to crack. A jackhammer can probably do some pretty serious damage in there in a couple of hours.

ROD: Yeah.

LESLIE: (chuckling) And be noisy and fun.

ROD: (chuckling) Yeah. OK, thank you.

TOM: You’re welcome, Rod. Thanks so much for calling us at 888-MONEY-PIT.