We've had a damp problem in our bathroom which has manifested with discoloured patches on the walls in the room directly below the bathroom.
I started to take the grout out between the tiles and found some of the tiles very loose which I have also removed. See picture. http://s8.postimage.org/f8wl720b9/Tiles_1.jpg
The wall behind, which I assume is plasterboard, is damp.
Whilst there aren't any gaping holes clearly the surface of the plasterboard is uneven.
So do I need to replace the plasterboard completely or will letting it dry and smothering it over with plaster do? Or perhaps there is a different solution.