The small art museum for which I worked for 11 years had a similar situation with gallery walls plastered, in some cases over brick outside walls. Hanging frequently changing exhibits on the outside (uninsulated) walls was a problem, but never from condensation. Often the brick presented a -too hard to hammer into- surface, and also had tendency to relax hold on the nail and actually drop the picture. Not good! The best solution we found was to mount 3/4" particle board on the walls and cover it with a forgiving surface of fabric (we used burlap) or napped carpet or woven sisal type of floor covering. Nail/screw holes are easily hidden if they ever show up, and the particle board never lets go. Carol Morgan Lancaster, PA Peter Read, Senior Museum Assistant West Coast Historical Museum, Hokitika, New Zealand asked: "I feel uncomfortable about this decision for two main reasons: We are currently in the midst of the restoration of a Carnegie Library building to serve as an extension to our museum. One of the rooms in this building will become a gallery for hosting temporary and travelling exhibitions. It was intended to line the walls of this gallery with Gib. board to enable us to hang artworks. However I have now been told that it is too expensive to proceed with batoning and lining the external gallery walls. The plastered brickwork will be repaired and painted but will remain unlined. 1. I fear a potential condensation problem on these unlined external walls. 2. I foresee potential difficulties in hanging paintings on the walls without being allowed to hammer some form of hanger or fastener into the plaster and being able to reposition hangers/fasteners for each new exhibition without damaging the plasterwork."