If it's an exterior wall, you should insulate and put some sort of vapor
barrier to keep moisture from migrating toward the outside and damaging
paint on the siding. I've used cement backer board (1/2") behind two shower
stalls in my house, tiled over it, and it solid. This stuff is not
flexible---especially when screwed down every six inches on a 16" center
framing.

Honestly, drywall, then cement board is overkill.


"JimC622911" wrote in message
...
I'm ready to tackle my new shower. Right now I've got 6 by stud walls and
insulation (no sheetrock). I'm putting up 1/2 backerboard then tile. Do
I
need to put some sort of waterproof layer under the backerboard, such as
plastic sheeting, or can the backerboard be screwed directly to the studs?
I'm
sure this has been addressed before, but-- any compelling reason to chose
concrete backerboard over Hardiebacker?