How to Pour a Three-Bay Garage

Find out how to pour concrete for a three-bay garage with an above-ground lift. Get tips on putting a lot of extra concrete underneath the lift post. Also learn why you should divide the slab into thirds and put two…

[mai_avatar size="40" margin_right="-4px"][post_author_posts_link before=" by "][post_date before=" — "][mai_icon icon="comment-alt-lines" style="light" display="inline-block" size="1em" margin_left="12px" margin_right="-8px" margin_bottom="-4px"][post_comments][post_sponsor][shared_counts]

LESLIE: Ed in North Carolina is about to tackle a concrete project. How can we help you with that?

ED: Yes. I’m getting ready to pour a three-bay garage in my backyard.

TOM: Nice.

ED: I’m going to be putting an above-ground lift in.

TOM: OK.

ED: And what I’m planning on doing is I’m planning on pouring the concrete about 5 inches thick in where the garage is or in the whole garage, except for where the lift post would be.

TOM: Right.

ED: And I thought I’d pour it 6 or 7 inches deep; just scoop out a little bit and pour a little extra concrete where the post would be.

TOM: OK.

ED: I, of course, going to put plastic and wire down. I’ve got a foundation that’s like 3 foot thick of screenings that’s been packed with a packer, so it’s hard as a rock.

TOM: OK. So that’s my question. You’ve got to have a really solid base underneath this and you’re saying that you do.

ED: I’ve got – in one corner, I’ve got about 4½ feet of screenings and I used one of these vibrating packers; about every 4 or 5 inches, I’d pack it for a while, you know.

TOM: OK. But the soil underneath the slab has been tamped down with a vibrating tamper?

ED: Yeah.

TOM: OK. Well, I think you’re good to go. I might go a little bit deeper underneath where the lift post is. I would probably go 12×12 underneath that area, so I’d do like a 12x12x12 sort of pier there. So, no reason not to have a lot of extra concrete right there.

ED: I’ve got one more question.

TOM: OK.

ED: And (inaudible at 0:10:14) as far as making expansion joints in the floor, it’s going to be three bays and I was planning on getting one of these little toes that you just run across the concrete and cut – it cuts at about an inch deep to – and just run three joints; in other words, have …

TOM: Right. Mm-hmm, yes. Yeah, it’s not going to be enough. You’re going to have to put spacers in between those slabs because if you do that, I mean it may crack on those – you’re talking about a scoring tool. It might crack there; it might not. But I would probably put at least two expansion joints in there, divide that into thirds and have a full expansion joint installed so that those pieces of concrete can move independently. Otherwise, you’re more likely to get cracks.

ED: Yeah.

TOM: Alright, Ed. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.