Cracks in Concrete basement floor after long sawcut.

[carlucci29]

I am in the process of building a house and the builder forgot to install plumbing for a sink in the basement. The builder sawcut the slab for about 15-20 feet and 12 inches wide. After this cut, I noticed a crack in the floor that runs the entire width of the house from front to back. The crack is maybe 1/16 of an inch and 1/8 of an inch is some spots. Is this crack something to be alarmed over? I am an IT Engineer, so this isn't my forte, but I assume that the sawcut relieved pressure on the slab and caused the crack. I am starting to notice more cracks now, running from the saw cut, as well as near the foundation walls in the corner. Is this just aesthetics, or is there a need to start hollering at the builder? Also, when they filled the sawcut back up they used a very rough looking cement that is drastically different from the slab. What questions should I ask the builder to ensure that they used the correct concrete to fill the cut?

I realize that cracks are part of concrete... I just don't trust the builder at this point and I want to be sure that a 25 foot crack isn't going to be a problem in the long run. I feel like there should be some other measures taken when making such a large cut in a concrete slab...but then again, I am an IT Geek, so what do I know? Any input would be greatly appreciated. I posted a pic of the crack...I can post a pic of the sawcut too, if needed... thanks!

 

[shaneelliss]

A crack in the slab typically isn't an indication of a long term problem. If the crack widens drastically in a short amount of time and the floor elevations on either side of the crack become different in a very short amount of time, then you MAY have some problems, but those problems were likely there before the contractor cut into the slab. Cutting into the slab may have changed the timing of when those cracks were going to appear, but most likely they were forming already and the release in compression allowed them to open a little. Again, most likely not an issue.

The rough looking cement was probably just a plumber trying to do concrete work and it turned out ugly. Most likely not an issue if you are going to cover it with carpet or some other surface. No structural issue, just aesthetics.