Hello:

Another cracked driveway question.  

My driveway is cracking and it gets worse every year.  I'm in NJ, so I'm covered for construction defects on new construction for up to 6 years.  I started noticing hairline cracks about a year or two after the house was built.  Concrete cracks, I get it.  I planned on trying to address them on my own.  However, they have gotten worse every year.  Not only in width, but in the number of cracks.  

The builder says I had a large truck park on the driveway, which caused the cracks.  He also suggests that large trucks used the driveway as a turnaround, which caused the cracks.  The interesting point here is that there are no cracks (yet) at the entrance to the driveway.  All of the cracks began at the top of the driveway.

One thing I noticed is the control joint for the driveway does not line up with the control joint for the garage floor.  I find it odd that the first crack followed the garage control joint and not the driveway control joint.  

The specs for the driveway called for 4 inch thick.  I did some research, and on sandy NJ soil, a 5 or 6 inch thickness is recommended.

I had a concrete guy that I trust take a look and he says that 99% of the time cracking like this is due to poor sub compaction.  The only way to confirm that is to have an engineer take some core samples (estimated cost is $5K). Instead, I'm going to have him replace it (estimated cost $16K) and document what he finds when he pulls it up.

I would appreciate any thoughts or suggestions on how to proceed, what to look for, etc.  

Thanks.