Cracking concrete patio

[benz_890]

I had a patio poured at the end of last summer (2011) and many slabs had started to crack down the middle over the winter (after a couple of months). Is this normal ?

[Jeeper1986]

yes the ground is settling in

[r3ccOs]

Originally posted by Jeeper1986
yes the ground is settling in

yes... thats the reason
is this normal?

I don't think so for a well poured concrete patio...

I have a stampeded concrete pad
I dug the ground down by a good 9", then poured 7 inches of crush, tamped down to about 5, then layed rebar around 8 inches on center (overkill) then got some colored concrete and a finisher who put control joints in every 4 x 7 (deck is 20x14) to handle settling

mine hasn't cracked... the concrete is about 4-5" thick with more rebar than what is needed on even a driveway, so it can handle a my bbq, a few people on deck chairs and a table

[sillysod]

It's normal to have the odd small hair-line crack appear, but it is NOT normal to have a bunch of large cracks.

[lilmira]

How new is your house? If the ground wasn't compacted properly, it will settle eventually over time. Concrete doesn't bend, it cracks.

Hairline crack is normal since concrete does shrink a bit as it ages. If you can fit a coin in there then no.

[benz_890]

^ Its an older 70s house which we had added a patio to. There's quite a few hairline cracks and at least 1 bigger one which can have a coin fit into there. Some of the slabs have 2-3 cracks in them. What can I do to it so it doesn't get worse?

[lilmira]

If ground settling is the problem, mudjacking can bring it back up. I don't know how much it cost. Is the concrete uneven across the crack?

Once you bring the concrete back up, you can just fill the cracks yourself, it is more for the appearance at that point.

[CanmoreOrLess]

Post a photo to show the damage. As above said, mud jacking and filling is all you can do at this point.

[benz_890]

Sorry guys, had a hard time finding my camera cable. Here's some pics. Most of the cracks are like this pretty much.

[benz_890]

Heres a pic of one of the steps

[benz_890]

Originally posted by benz_890
Sorry guys, had a hard time finding my camera cable. Here's some pics. Most of the cracks are like this pretty much.

[benz_890]

Originally posted by benz_890
Heres a pic of one of the steps

[theken]

Concrete shrinks as it cures. Cracking is normal.

[benz_890]

Originally posted by theken
Concrete shrinks as it cures. Cracking is normal.

Is it normal to crack only after 2-3 months?

[lilmira]

The 1st pic doesn't look too bad. It could be shrinkage or settlement. Normally shrinkage crack should occur at the control joint though. The second pic looks like settlement/movement to me. If they don't get any bigger, you might be able to just fill it. You mentioned that it first occurred in the middle of winter. It could mean water trapped in the base, froze and expanded cracking the concrete. If the base wasn't build properly trapping water, it will move with the freeze/thaw cycle. You'll most likely get more cracks in the future. If you can get the original contractor to look at it that would be the best. Otherwise, keep an eye on it for another year and try to divert water away from the area.

[sillysod]

That is normal breakage. Nothing can be done about it.

Majority of the reaction is done within the first 28 days. The steps though is not normal. That is a problem with the dirtwork done first or not enough rebar in it.

Definitely worth bringing up to the contractor.

[Zorac]

you shouldn't see cracking in the middle of the slabs. all the cracking should take place at the contruction/trowel joints.

sometimes you see cracking from poor finishing, but that looks more like a base issue. if they poured over topsoil, or didn't compact the gravel base, that can happen.

[nzwasp]

Originally posted by theken
Concrete shrinks as it cures. Cracking is normal.

Is this why its common to sometimes see a crack on your basement floor?

[sillysod]

Originally posted by nzwasp


Is this why its common to sometimes see a crack on your basement floor?

Yes and the fact that there will always be some settling. That's why there are break lines cut in the sidewalks. Concrete should crack along the breaks if you have them. My yard is mostly stamped so there are no break lines I have a few cracks, but nothing larger than 1/16".