We are about to remodel a bathroom (after some serious leaking of the old shower) on the main floor of our tri-level home (no basement underneath this bathroom). A few things:

_The previous owners converted this from a laundry room to a bathroom and did it on the cheap. They built fake walls to enclose a super-cheap fiberglass shower that was basically balanced on top of some studs, with a PVC pipe underneath that *kind-of* ran from the shower drain to the floor drain about a foot away. Obviously, we ran into trouble here!

_We've taken the bathroom to the studs, and discovered they built a stud wall in front of the exterior wall, so we removed it to get the most usable space out of this room we can. This exterior wall has partial earth-contact outside, and is made from cement blocks to about 40 inches off the floor, then it is topped off with a "normal" exterior stud wall.

Questions:

_Do we need to attach firring strips to the cement block and then attach hardiebacker/durock to those? Or can we just attach directly to the cement block?

_Where does vapor barrier fir into all of this? Is it required between the cement block and the durock? And, if firring strips are required, between those and the cement block too?

We are probably going to use Kerdi, and I've been reading all the great posts on this site for advice, but haven't seen anyone with this exact question. Thanks for your help!!!

Jamie