tiled wet room shower tray leaking

[marcus1066]

Hi There, I recently tiled a wet room for someone, after only 2 weeks of use i was called back to investigate a leak. it appears that the pre formed tray is flexing and when you stand on it a 1mm to 2mm gap opens along the back wall. Are these trays supposed to flex like this? or is the tray not quite fitted properly. I dont want to try and repair this leak if the tray is the problem, can anyone advise me please?

 

[The D]

did you use tanking tape ??

 

[marcus1066]

Yes, I used the ardex tanking compound with tape after applying silicon all around the tray as normal.

 

[Dan]

It's not one of those tray types that needs reinforcing from under it somehow is it?

 

[marcus1066]

The tray has been laid on 2 x 1 battens over the joists but there is still quite a lot of flex in it, when you stand on it a 1mm to 2mm gap opens on the joint between the wall and floor.

 

[Time's Ran Out]

Did you not notice the movement before it was tiled!
We always have the joists recessed and 18mm plywood laid into the tray area.
No doubt 400mm joist centres will allow too much flex in these trays.

 

[marcus1066]

I must say I did not notice any movement at the time, I was a difficult job to do and was concentrating on the tiling not what the plumber had done. wont make that mistake again.
It appears the plumber used spray foam all underneath the tray to fix it to the joists as well which I have not seen before, and only found out when I pulled the ceiling down to find the leak. what a mess!

 

[Rizzle from the Portizzle]

how was the rest of the floor joined to the tray ie tanked .you say you can get acess from under neath the tray cut the foam out then check where the leak is coming from as a leak can travel and point you in the wrong place once you have cut the foam out wiegh down the tray with a few buckets of water.now run the shower to pin point the leak . look at where the tray joins the rest of the floor and how this was tanked between the two .you can now cut 18mm ply and fix under the tray to surport it once you take the weigh off . but i think you are going to find this is a tanking issue doubled up with the tray .so i think you and the plummer are going to have to sort this out between your selfs

 

[Rookery]

Sounds to me that its a pre-formed marmox type wetroom former and it also sounds like it wasnt underboarded. For me, thats the original problem and because of it, the tray is moving when stood on. I would take it up and re-do.

 

[kilty55]

plumbers fault not the correct install method imo hes at full fault,did you subby him or was he contracted seprately