Hi, we have an old terraced house which before we bought had a single skin single story extension added to form a bathroom, it was riddled with damp so we lined the Walls with damp proof membrane then battened and boarded with 25mm polystyrene backed plaster boards (as recommended by builders merchants) all's been ok except for the ceiling which was purely foil backed boards and some wool type insulation which I think may have been touching the metal profile roof sheets, the ceiling went black and where the single skin boarded Walls joined the old stone Walls we suffered badly from condensation. We have stripped all of the plasterboards out now as we are altering the rooms layout and discovered large amounts of condensation running down the Dpm behind the boards, can anyone point us in the right direction, worth bearing in mind we can't reduce the size of the room by much more than a batten and insulated board thickness as it is really at it's limit for use as it is.
Thanks
Thanks