Leaking shower cubicle again

[RrogerD]

Shower cubicle on 1st floor is leaking again. It appears to be along the base of one of the screens. I'm assuming, water getting under and then running along to the end and off the tray where it meets the tiles.
As per instructions and advice on here I had applied sealant up the tile face and butted the screen up to it and then sealed along the outside joints between screen and tray and screen and tiles. Everything worked great, for about two years. Now, it appears to all need all doing again. It's a right ball-ache as, being a square corner enclosure, disturbing one screen means disturbing it all. Plus of course the nightmare of removing all of the existing sealant from everywhere.

How do I stop this repeatedly happening? Why has it been ok and then all of a sudden, not?

Any thoughts and suggestions?

 

[HERTS P&D]

You should of siliconed it on the outside.

Andy

 

[RrogerD]

You should of siliconed it on the outside.

Andy

I did

 

[HERTS P&D]

And not on the inside.

Andy

 

[RrogerD]

And not on the inside.

Andy

That's correct.
I think though from further research that it is perhaps movement from using the shower, breaking the hidden seal between screen-trim and tile at the base / corner.
The tray is mounted on silicone on to an 18mm chipboard base on to the joists. Floorboards cut back. It is possible that the joists weren't braced enough or the board supported enough, due to the position of the waste run.
The corner that repeatedly leaks is also right next to the room door (a stud-partition wall). I suspect the constant banging of the door closing may be causing movement and breaking the sealant seal.

 

[Madrab]

18mm chipboard base

That could very well be your issue. Chipboard really shouldn't be used anywhere there's water or any decent load bearing. Anything more than 400mm centres too and there will almost certainly be deflection from chipboard, so needs extra supports. If the boards also weren't supported by joists or inserts all the way around the outside edge footprint of the tray, then again it will almost certainly flex.

Was the floor wet space tanked and then the tray fully sealed along the bottom outside edges, all along all the wall contact points and the tray slid in and then fully along the top edge? The the wall covering on and fully sealed again even before the enclosure was anywhere near it?

Only way to be sure IMO