Hi not tiling strictly but a question about plastic wall pannels from B&Q,I have used these to line my shower-room,including inside the shower enclosure,I now have leaks down behind the tray.I followed the fitting instructions and put a bead of silicone down every t&g joint,the tray is sealed well to the boards and the wall and yet I still have several dribbles when the shower is used.The only place that I can see as a likely place to leak from are the vertical joints,anyone else had trouble?,any tips for putting it right?,it looks like it may all be coming back out this weekend otherwise.As a last chance before that happens I am thinking of putting some clear silicone on my finger tip and rubbing it into the joints after I have let the water dry off during tomorrow when I am in work.Any feeback apreciated thanks.