Basement floor crack in New construction

buhockey

Took a stroll out to the new construction site today and noticed a 10 foot long crack (see pics) that is about 1/8" wide, 6" deep, and extends from one wall to another in our new basement floor. The floor is still even at the crack with nothing offset. It was poured 2 months ago, right before the brutal February winter. Could it have something to do with this near 70 degree weather in PA last week or is it just part of the settling process. Note, we do have a sloping lot.

Thank you

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Daniel Holzman

That is a remarkably straight crack, you might want to see if it isn't a control joint.

buhockey

Your right, the crack was almost straight as a ruler. I'll confirm with my builder tomorrow. Thanks again

Termite

Doesn't look straight enough to be a control joint in the top picture to me.
Could be an illusion in the picture though. The bottom picture looks a heck of a lot like a control joint.

You should check your contract documents regarding the crack. Most builders have "acceptable standards" in their contracts that make clear how severe cracks have to be before they're required to do anything about them.

There are a number of things that could have caused the crack. It sounds cliche, but it is a fact that all concrete cracks. The degree to which it cracks is the thing that varies. Sometimes the cracks are microscopic, sometimes they're like yours, and sometimes you trip over them.

BigJimmy

Thanks, KC. When I was a young buck in construction, I asked my PM "why do we put control joints in our concrete pours?" His response was "Concrete will always crack. The control joint is our way of dictating where it will crack.

And BTW, in that first photo, it didn't look straight enough to be a control joint.

Jimmy

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jomama45

I actually think it is a "Zip-Strip", or a plastic control joint that may have been set a hair low, creating a little less straight crack.

firehawkmph

BH,
Doesn't look like a control joint. Just about anytime you have an inside corner in a concrete slab, it will generate a crack. As long as the crack doesn't widen anymore than it is now, and doesn't displace itself, I wouldn't worry about it. You could caulk it with the vinylized mortar caulk just to seal it up, wouldn't hurt anything.
Mike Hawkins

jlhaslip

Separation is the bigger issue. As long as it stays together, your house will be fine.

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itsreallyconc

its a crk - put some plaster over it & see if the floor ' moves ',,, probably not a big issue,,, i'll guess its due to a column entrant crk,,, ' could it have been prevented ? ' isn't a good question at this point, is it ?

think jo's pulling your leg - zip strip my patoot !

LiquidSlap

It probably is a control joint. Every single house in my new construction neighborhood has the same crack in the basement and I was told that it was done intentionally. Mine isn't a perfect straight line, but it is fairly straight.

itsreallyconc

if that's a control joint, i'm farah fawcett i'd sure as hell like to know HOW it was cut crooked-est straight cut i ever saw diamond blades don't ' fall off ' a line that way, either - they curve

if you've got the same in your bsmts, someone sure didn't know their work however, it IS possible the contractor used stay in place keyways,,, they'd reflect as a jagg'd line IF not set at the right elevation but, unless spec'd, no 1 i know'd spend the addl $ contractors being such tightwads as they are

LiquidSlap

The crack didn't exist originally, but came within the first couple months after basement was poured and they said it would happen and it should be the only one...

jomama45

IRC, that's what a "zip strip" is, stay in place control joint that's below the surface.

http://www.formtechinc.com/other_expansionjoint.htm