I am building a new shower and bathroom, the exsisting room had a tub and drywall that all went south and molded. I ripped out all the old and used all new stud walls and new sub floor then I put OSB on the walls and then over the walls and floor installed concrete permabase edgetech 3 x 5 material. I installed a floor drain and prior to thinset and tile I was going to float out a new shower floor so that it sloped inward toward the drain using bedding mortar, however I was curious do I need to use a membrane even though I am using concrete permabase flooring and walls? And, if so, do I float out the floor first then install the membrane or can I simply float out the floor and then install the thinset and then the ceramic tile? Any help you could offer would greatly be appereciated.
Thanking you in advance.