Shower tray advice

[guyank]

Hi,

A crack appeared in our shower tray so I’ve removed it to replace it. Underneath I’ve found that it was glued to tiles which have obviously not survived the tray being removed. Underneath the tiles is 9mm ply and then the original tongue and groove flooring. The hole cut in the ply and flooring for the waste is clearly too big. The cause of the cracking is now clear as the floor is flexing underneath this point. My plan is to remove the 9mm ply and tiles, fit 18mm ply and then fit a new shower tray. Is this the right way to go?

Also, the plaster underneath the bottom layer of wall tiles has disintegrated. What can I use to fill this gap before replacing the wall tiles?

Thanks

Guyan

 

[Madrab]

Looks like the tray has leaked along most of the edge where it met the wall, obviously past the tray to tile silicone seal. Couldn't have been sealed to the wall properly to start with. I would dig out all the damp/disintegrating wall which I presume was plaster or plasterboard? Use something that will end up being water proof, a mortar would be ideal.

You need to cut the floor tiles and clear the adhesive etc where the tray will sit to ensure the base is flat and the tray can be levelled properly. Yes, 18mm ply would be a good base but you need to ensure the floor below it is stable too. Looks like chipboard so I'd ensure it isn;t compromised/weakened by the water ingress.