I am adding a 3/4 bath in a very wide portion of a hallway on the 2nd floor. 4'x8' for the bathroom. I have the walls up and the plumbing in. The sub-floor is 1x pine. The problem is, it is not level. The pan is 34" x 48". The floor has about 1/2 dip and slightly sloped. I will be using tile for the floor of the entire bath with the exception of the shower pan. Wondering the propper way to prepare the area under the shower pan. Specificially what to use for leveling and supporting the pan? I have read to use mortar, but what type? Should I lay down underlayment first?
Also opinion on walls. We are going to tile half way up the walls. Is greenboard good enough, or should I go with duroc or some other backer? Then what about top half? Never done a bath before.