I know the depth under cement is normally 4 " with RNC, but just wondering if the depth could be the same with paving stones? The job I'm on is having pavers put down around their pool ( proffesionally ) with gravel etc. and the installer said you would have to drill the pavers out. As far as I know the code don't specify this as an option, but what do you think an inspector might say about this?? I'll probably go the 12" rule for circuits that are GFI protected and rated 20 amps or less, but in this case it would be NICE to have it the same as concrete. I hate to bug the inspectors any more than I have to. I've called on them quiet a bit lately. Thanks, Steve