Tiles are moving after laying - problem with the bathroom floor?

[Katek]

Hi all,

 

We just completed our project of converting a bathroom into a wetroom and discovered that the tiles are moving approx 1mm up and down leading to the cracks and soft grout.

 

We're now investigating the possible reasons and one that seems more probable is that the floors weren't correctly strengthened so they allow for the movement.

 

The way they are laid now is that there's chipboards on top of joists (new chipboard under the wet area as it had water damage and the old one everywhere else), then cement boards, then durabase ci ++ membrane. What could have been the problem here?

 

There's also a wet tray former directly underneath a shower.

 

 

[nod]

Probably not the answer you want to hear 

They will have to come up 

Sounds like the matting has delaminated 

Cement board is very dry I would have stuck the Dura directly to to the floor