Shower Silicone leaking after 8 weeks. It adheres to shower tiles well but not to Shower tray itself

ouraggie

i had this same problem when we had a new en-suite installed. Kept leaking. Nearly drove us mad. I tried several times just like you. Eventually one tradesman i used realised that the idiot builder who installed it had omitted to remove a very thin, transparent, practically invisible, plastic protective coating on the shower tray. It just peeled off but he hadn’t bothered to read the instruction booklet. So basically the sealant was not stuck to the tray itself but to a layer of plastic! Could it be this?