Block and plastered walls . Also would backer boards run to the floor behind tray or to top of tray. I am my money's worth lol.What are the current walls at the moment? Block or stud? Cheers
Do you think I could pack the board out 25mm at 1 end ? Yes got fixings ready. Hey thanks for the info, behind the tray it is then.Run the boards to the floor behind the tray. Then seal the tray to the boards with a good quality sanitary Silicon sealant (Dow Corning, Mapei or BAL) tile then seal again. If you try to make up the difference with backer boards use machanical fixings as well as adhesive 👍