We are in the process of building a new custom home and it's only been a week since the slab has been poured and we already have several cracks in our slab. I realize that most slabs crack due to shrinkage. We have crack in the center of the slab that are just hairline and are smooth when you rub your finger over them. So I don't feel any unevenness. I can live with that. However, there is one crack that goes from one side of the foundation to the other side all the way down on each end as far as I can see in the dirt And when you rub your finger over it in places, it is rough and uneven. It's almost 1/8 inch crack. It seems like the foundation is cracked completely in two pieces.

The builder said its normal and that he would get the concert guy to check it out and if they needed to bring out the engineer they would. This is also a post tension slab and he said that we should wait until they tighten the cables and that might fix the crack. But I can't think that a foundation that is cracked in two pieces is normal or is it?

The other thing was they started framing the very next day after the slab was poured. However they didn't have much of the framing up until 2 days after the slab was poured. It also seems like the crack is getting worse. Also my other concern is we are plannig on putting concerte tile roof on our house and that is very heavy and will put a lot of weight on the foundation.

The day the poured the slab I was there and the engineer did not check each truck for the proper mix. We had 17 tuck loads of concete. And the major crack is where the L part of foundation.

What I am worried about is them coming back saying that everything is ok and there is no need to do anything. When does a foundation need to be repaired and I should be covered under the builders warranty correct? We do have it. But wouldnt the engineer company be responsible for fixing this? We will hire a third party to look at this as well. Also if we decided to sell later down the road this crack that runs down the side of the slab will show up to that potential buyer. That's bad news!

Any advice?

Thanks

 

It's impossible to say for sure without seeing what you have but a crack 1/8" wide in concrete one week old is not good.

You did not say anything about how the house is constructed or include a location in information to help guess about it's construction. It would help if you can post a picture of the area in question. Do you have footers, cement block foundation walls with the wood framed walls on top and the slab poured inside the perimeter? Do you have integral footers poured with the slab and your walls sit directly on top of the slab?

 

Welcome to the forum.
What was under the slab before it was poured?
Did they put in drainage gravel?
How thick is the slab and how big?
Was there rebar, mess, or similar in the concrete?
Oh, and what area are you from?

The testing of the trucks (all of them) is not normal for this kind of construction. Generally a slump test is done on one or two trucks. Bridges and other high stress structures see most or all trucks tested.

 

Thanks all -

Here are some photos. It maybe a little less than 1/8 inch.. The photo was taken on day 3 after the pour and I don't have a updated photo. I'll try and get one today.

 

I've posted photos.

The slab is 4 inches thick. No they did not put in drainage gravel. They did put in rebar in a few places and they did put in a rebar they said where the crack happened at. We are in Houston Texas

 

Are those blue things tensioning cables? If so, you must have some interesting soil conditions.

 

Yes those are tension cables. They also had to dig down 3 to 4 feet and replace the soil under neath. Then the brought in good dirt and raised the house 3 feet.

 

You do not have a traditional system there. I think talking with your Engineer would be the best course. There is a reason they have heavily cabled your slab which I assume will be tensioned in about a month. I've seen it done in some footers but never in a blanket pattern across a slab floor like that.