I'm fitting a new shower and suspect the joint between shower tray and wall will someday leak. I've gone to great lengths to avoid this but I would welcome any comments. I'm using formica laminated wall panels, glued to the wall. I've bedded the tray in cement mortar as per the recommendations and ensured there is no movement. I'm bedding the wall panels with silicone. The day before fitting the panels I put a bead of silicone along the bottom edge of each panel. The idea is the rubbery silicone bead becomes compressed during fitting and stays that way. I will finish it off with another fillet of silicone bridging the small gap between tray and panel. I dont believe the sales stuff about "permanently flexibility". If the silicone seal is in tension, as it would be after shrinking during curing, the adhesion between panel and tray is doomed from the start. I'f it fails I'll ....