I am thinking of tiling the bathroom. Two walls are currently plasterboard with tiles on top, and I don't expect to remove the tiles without chewing up the plasterboard beneath. I think the other two walls are tiled on top of plaster on masonry. I'm not convinced I could tile evenly onto an uneven wall, so I am thinking of lining all four walls.
Should I use aqua panel all around or is that only necessary by the bath? If not aqua panel, should I use plywood or plasterboard?