Shower leaking behind the try. What can I do?

[manwith]

Background:
I've moved into a house 3 months ago that I have been renovating for a while. I have done a lot of the work myself but I left my builder to do the plumbing and tiling while I was away for work.

If I spray the tiles in the shower for 5 mintues, water starts tricking out from behind the shower tray. I have uploaded pictures here
(You can see the shower tray is not flush with the wall)
I re-siliconed around the tray / tile boundary and I tried a grout sealer which seemed to stop the problem for a few weeks but now the issue is back again.

I know on the wall he tiled straight onto green plasterboard and used Bal Micromax 2 grout.

1. Do you think the grout has failed? Would this happen if we did not let the grout cure for long enough? How long is not long enough?
2. Should I expect the grout to be waterproof? If not is their waterproof gout on the market?
3. Would removing the grout and re-grouting fix the problem?

I also thought about removing the bottom row of tiles and trying to reseat the try against the wall but I am not sure that will help either...

He was a nice guy so I am sure this is how he always does it and I know he has done 50+ jobs without issue (unfortunately he has moved country so I have lost contact with him and cant even bounce some ideas off him to troubleshoot)

Thank you so much for your help in advance...

 

[Qwerty]

Here are the photos......

 

[Chalker]

It's probably leaking between the shower screen wall profile where it meets the tray.

 

[Qwerty]

Welcome to the forum.
The grout isn't likely to be the problem here. The issue is how the tray has been fitted and how the tiles have been fixed afterwards.
The tray should be pushed right back and fixed securely. I always tank my walls in any wet zone along with the corner and tray joints but there are some that don't. For the small cost, the tanking kits are worth every penny. Tiles should have then been fixed with a small gap between them and the tray which is later siliconed. The corner needs to be Silicon as well.
If he has fixed it down and plumbed it in properly then there is no quick or easy way you will be able to move the tray back.
Yes there are waterproof grouts (epoxy grout) but if you ate looking at that option you would be better off starting over

 

[manwith]

Thanks for your reply

 

[manwith]

Welcome to the forum.
The grout isn't likely to be the problem here. The issue is how the tray has been fitted and how the tiles have been fixed afterwards.
The tray should be pushed right back and fixed securely. I always tank my walls in any wet zone along with the corner and tray joints but there are some that don't. For the small cost, the tanking kits are worth every penny. Tiles should have then been fixed with a small gap between them and the tray which is later siliconed. The corner needs to be Silicon as well.
If he has fixed it down and plumbed it in properly then there is no quick or easy way you will be able to move the tray back.
Yes there are waterproof grouts (epoxy grout) but if you ate looking at that option you would be better off starting over

Thanks for your reply
1. Is your theory that the water is getting in between the tiles and the tray? Even though I re-siliconed where the tiles meet the tray?
2. Why are you so sure its not the grout?
3. Should I cover the tile/tray boundary with a bin liner and gaffer tape and spray the tiles again to prove if its the boundary join or the grout?
4. Why do you think re-grouting with an epoxy grouts is like starting again? (I dont mind redoing the grout but would hate to have to retile, especially given the cost of new tiles...)
5. What am I missing?

Thanks so much for your help guys!