I’ve just gutted my downstairs shower room, its ~1200 x ~3500 with the shower at one end. The reason for gutting was that there were 2 layers of tiles on the plasterboard. I also stripped out the ceiling as well. I was planning on lining the shower end, in cement board or aqua panel or hardybacker. Does anyone have any advise on this, I am leaning toward Hardy backer as its 1200x800x12 so I would need 3 to go from floor to ceiling (2400mm) therefore no cutting required. (Aqua panel is 900mm so would need cutting). Can I screw straight onto the timber frame, would I need to dwang/noggin where the horizontal joints of the board are? I was also planning on insulation all the walls (for heat and noise), I have 100mm deep timber frame, should I also put a vapour barrier in or do I just do this on the external frame? Any advice much appreciated.