Good deal on the Durock, Mike. It's just that USG even says to add a membrane on their installation instructions for waterproofing. And having had to re-tile a stall shower because of it, just thought I'd warn. My tiles aren't cheap, so it cost the owner a bunch.
Yep. We just restored a custom tile shower that wasn't originally installed with the membrane. It was a mess. Expand contract expand contract over time makes that board disintegrate. Then it gets to the wood.