While repainting my house, I pulled some plaster off the hallway ceiling and ended up with this beauty:
It's about a meter wide. Underneath is a layer of some kind of board, and a damp patch with some mould, which I suppose has caused the plaster to peel. Then a layer of wallpaper, then a thin layer of plaster and finally paint.
This seems complex. Can anyone suggest the best way to repair it? Could I just plaster over? Should I deal with the damp first? The house's outside needs its concrete render redoing which is probably where the damp comes from, but I can't fix that for a month or two; is it a good idea to repair this before doing that?