Have finally got hold of a shower tray (1200x800 cast resin/stone ). It says that it absolutely must be laid on thin dry mortar bed 5mm min supporting the whole thing and the edge. Sounds reasonable but in fact this is virtually impossible to achieve. It's very heavy and impossible to manouevre to sit close between three walls and to fiddle about with mortar etc to get it perfectly level. At best one could drop it in place but any adjustments after that would be impossible whilst retaining a perfect mortar bed. Hardest at the edges where the rim is only 12mm wide - and the centre panel part isn't flat as it has a tilt for drainage. Part of the prob is that if I attempt to move it I'll get mortar on my hands etc and scratch the surface. There isn't much to hold on to once it's down. Any suggestions? I'm beginning to think I should have bought one of those expensive ceramic ones with an adjustable foot at each corner.
cheers
Jacob