Surface Cracks in Concrete
LESLIE: So I thought I was the only person with cellulite but apparently Rod in Colorado has some concrete that has it as well. (Tom chuckles)
ROD: (chuckles) Oh, I hadn’t thought about it that way. (Tom and Leslie laugh)
LESLIE: And I’ve just totally ratted myself out. (Rod laughs)
LESLIE: OK, Rod, describe it and don’t talk about me anymore.
ROD: No, I won’t talk about you anymore. I had my concrete driveway put in – about 35 feet wide and the regular length – but when I get it wet to wash it off, in areas of it, it looks like it’s got cottage cheese; little cracks all over it and everything just in certain areas. And I was reading an article in a paper somewhere and they said that that was a sign of improperly-poured concrete and I just wondered if you guys had ever heard of that.
TOM: Do you see the aggregate exposed? Do you see the little stones?
TOM: Well, it may not have been floated properly. See, when concrete was put down, it basically has a lot of aggregate in it and the mason will usually float the surface and as they kind of bounce the concrete, those stones start to …
LESLIE: Which is called tamping, right?
TOM: Right. They kind of – those stones sort of sink in the concrete and they get below the surface and you get sort of the gravy of the concrete comes to the top. Now if it’s not been floated properly, you could get a lot of that aggregate that’s showing.
ROD: No, it’s not a lot of aggregate; it’s just these little, tiny cracks that’s all over it that looks like a real small roadmap.
TOM: But it’s only like that when it’s wet? You don’t see it when it’s dry?
ROD: When it’s wet. Yeah.
TOM: Yeah. Well at this point, Rod, I wouldn’t worry about. I don’t think in the long run it’s going to have a real bad effect on the longevity of that concrete.
TOM: I think it’s really mostly going to be a cosmetic issue. The repair to that is probably not worth doing and that would be to resurface the whole driveway with an epoxy compound.
ROD: Yeah, you know where they put the cracks on purpose in the concrete?
TOM: Yes, the expansion joints. Yes.
ROD: Those cracks, are they supposed to just continue to crack open and leave them that way or should you fill those in with QUIKRETE or some other kind of a filler to keep the moisture from getting underneath there? Because what happens is our moisture here is that clay-type dirt …
ROD: … and it just moves on you and when it gets wet and dry, it shifts.
TOM: Yeah, it expands.
ROD: And that’s what tore my driveway up to begin with.
TOM: Yeah, that’s called expansive clay soil and anything you can do to keep that area around that as dry as possible is the hot ticket. So if you do get cracks that form, especially in those joint areas, you want to fill them with a urethane sealer, a urethane filler. Yeah, flowable urethane. You don’t want to use anything that’s like a concrete – you mentioned a concrete product – because that’s not going to seal them. A flowable urethane sealer or a silicone caulk would work well.
TOM: Just a maintenance issue. You’re slowing the water down there.
ROD: Now my neighbor a couple of blocks away, he put a kind of a paint that he painted his driveway with.
TOM: Well, that’s another option. That’s what I was going to suggest. You can use an epoxy patching compound, right, or epoxy paint. But you know what comes after paint, Rod? Repaint. (chuckles) Yeah.
ROD: Repaint, yeah.
TOM: Yeah. So you know, I don’t think it’s a real severe problem. If you can live with it, I would recommend you do that. But your other options are to use an epoxy compound on there.
ROD: Well, I sure appreciate that and I’ll do that and we’ll see what we come up with.
TOM: OK, Rod. Thanks so much for calling us at 888-MONEY-PIT.