3 of the walls are interior - one wall - the one opposite the water - is a foundation wall that I have framed in. I plan to use durarock- or some equivalent. I did read in the information you provided the durarock is to be positioned 1-2 inches above the top of the shower pan - correct ? Do need to do anything "special" to the foudnation wall side ?

Hi Dana:

I would recommend that you get an unfaced batt insulation and then insulate that foundation wall. Cover the wall with a 6 mil. Plastic sheeting and then install the durock as needed.

I install the concrete board about 1/2" off the shower pan and then fill that gap with thinset mortar to help prevent a "wicking" effect on the concrete board.

Back to you...

MARK