How do you guys verify the thickness of the slab? Do you core drill are look at original specs or take a an owners word?
Well, I guess I just ask! I check the prints, look for cored holes, cut-outs at HVAC shafts, whatever, but I need to rely on the owner or General's knowledge of how thick the slab is.
That said, there is always risk that the slab isn't what they think it is! Multiple tests will help show discrepancies, so watch for those. Poured in place slabs or even poured-in-pan can vary several inches in thickness from edge to center. Your probes will show patterned variations usually.
I document the thickness and note that the testing is done at 'X' depth, based on the GC / Owner's statement of exiting conditions. If they tell me the slab is 4" thick and it's really 14", well whose fault is it that I am only in 1.6" now?
And believe me this can and does happen!
Concrete Answers for Flooring Problems