Are you 100% sure water isn't getting under the screen ?
Well, all I know is that the tiler scraped out all the grout on the wet side of the screen and replaced it with epoxy, which still looks intact, then we put a large amount of clear Silicon where the metal frame of the screen meets the tiles. So I would say it was almost impossible for water to get under the screen from on top of the tiles. Strangely, the grout does not get wet on the 'dry' side until a couple of inches away from the screen!
Is there a chance there's a leak somewhere? Maybe?
It seems it could be creeping in the adhesive bed... How is the drain sealed at the tile edges ?
one was a leak from the shower control where the plumber had not compressed the olive enough and the water was soaking throgh the adhesive and coming out in the grout joints on the floor and the other was a badly sealed wall jet and the effect was much the same as the first one. the plumer fixed the leak and the problem was solvedThat's very interesting, deanotile! So where exactly was the water coming from in the shower? Do you mean from somewhere in the tray? And, more importantly, how did you fix it?