My house was built just under 5 years ago (late 2013) in the Chicagoland area. This was just before that crazy cold winter we had (if that's relevant). About 2 years after I moved in, I had a 25' x 35' concrete bball court put into my backyard.

I did notice my driveway after a couple years had dipped in certain spots. We had a couple guys come out and they said there was no rebar used in this originally, and I've heard differing opinions on if that was right or wrong. I'm no expert, but i would assume it should have been used??

In any case, I had a mudjacking company re-level my driveway. It's since dipped ever so slightly again, but I'll have the company come out and re-do it under their warranty.

My question is on the basketball court... there are some spots there where the mudjacking company did raise it and the guy told me whatever packing they had done underneath was now hollow. Now in other spots on the basketball court, when I dribble the ball I can hear it sort of have a very different sound and feel. You can almost feel that it seems thinner or less solid in those spots. It almost sounds hollow, if that makes sense (tough to describe in words).

Should I have the mudjacking company put the sludge underneath those spots as well as a preventative measure to beef up the support under the court to avoid future settling or cracking problems in the concrete? Or am I overthinking this and this would be spending money just to spend money before any issues have actually occurred?? Any advice on how best to preserve the court is much appreciated.

Thanks in advance!