improper probe depth

[CCR]

I've found more often than not on a renovation project, no one knows, or will take the time to find records of slab depths, and you have to place the sensors NOW.

I keep a 12" length of coat hanger with a pre-formed hook at the end in my tool case. I trill a 3/8" hole all the way thru the slab (after determining there is now rebar there with my Bosch sensor), push the wire thru, pull up til the hook catches and you have your depth. Obviously slab depths can vary, so it's up to you and the GC or Flooring Installer how many areas you drill thru and it adds time to your testing costs. So, I just establish a cost per hole and let them make the call. Just make sure you document everything agreed to in your report