Hi, we have a property which is a stone build backing onto to a small very damp yard, with water coming from the hill above. It is probably at least 150 years old. The damp has been penetrating into the property and we need to get it sorted. Our builder has suggested plastering the bottom 4 feet of the wall to keep damp out. My worry is, will this trap the damp inside the wall of the property and cause more problems? I was thinking of putting insulated plaster board on the inside of this stone wall in an attempt to keep heat in but is that advisable in old houses? The property is used as an office but that room is always very cold and of course damp. Very many thanks for any thoughts or suggestions as to how to deal with this matter.