How thick is your floor?

[Rubensgt40]

I've noticed this brought up on other threads- how can you be sure you're adhering to the letter of F2170 without knowing the exact slab depth?

I suppose if it went to a claims court you'd argue that the builder's specs were the only credible source.

And... if you drilled a depth test hole, wouldn't that puncture the under-slab retarder?

That StructureScan toy might not be such a bad idea. How expensive can they be?