Hello everyone.
I am new to this forum and have done lots of reading about how to build a custom shower. Fantastic info and pics! However, my problem is this: I purchased a home that was largley unfinished inside. There is a large, shower off of the master bedroom that has a standard type drain (not a Kerdi drain), rubber liner and Durock sheet installed floor to ceiling on the walls (joints are unfinished. The outer curved wall (approximately 8 feet in length), visible to the bedroom is open except for a six inch wood curb that is covered with drywall. There is a similar curb that would be the entrance from the master bathroom. The ceiling of the shower area is drywall. The previous owners had planned to build a glass brick outer wall, which i now plan to do something similar. There does not appear to be any kind of pre-sloped mud bed under the rubber membrane. Is there a method that I can use to correct this or should I tear it out and start fresh with a kerdi drain and proper build up as recommended on this site. I should add that I am no tile expert by any means, but am adventurous enough to give it a try. Any thoughts and suggestions would be much appreciated.

The liner definitely needs to come out.

As far as the drain is concerned, you would need to decide on what type of waterproof system you want to employ, then we can give you advice based on that. Not all parts from all systems are interchangeable, so you don't want to start off with one method then change midstream.