We recently moved into a new property with a basement kitchen. I've just found a damp patch in the cupboard under the stairs, so a non external wall. There is no skirting and there is a gap between the plaster and the floor, and upon sticking my hand into the gap I can feel damp.
The floor is tiled on top of concrete so I think these areas under the walls in the cupboard under the stairs might not be properly damp proofed - I'm hoping it's not the entire room floor but I can't see any other damp areas. It's really obvious in the cupboard because there are salts forming on the plasterboard. Can I just remedy this area and potentially replaster within the cupboard?