So, I've made a big stink with the flooring guys about how they have installed the Hardiebacker cement board for our tile. They skipped putting down the thin set under the cement board even though the installation instruction specify that it is required.
Apply a supporting bed of mortar or modified thinset to subfloor using a 1/4” square-notched trowel.
The flooring guy called me and said that JamesHardie company tech support said that if he used screws instead of nails they could forego the thin set under the cement board.
So I called JamesHardie tech support and their offices are currently closed... So I can't verify this claim. This seems quite shady.
Am I wrong to push the issue or should I just let him use the screws and go about the job? They have umpteen years experience doing this stuff.
Also, will this cause problems down the road, and should I continue pushing the issue?