I recently bought a mobil home and have noticed that the ceiling panel sags in one of the bedrooms. This is an area about 2 feet long and the panel is about 18 inches wide that runs the lenghth of the room. Also, there is a smell in that room that we can't get rid of. Could it be mold or caused by dampness? A second roof was put on the place several years ago. What do I need to know about taking down the ceiling and is it possible to save the panels and the strips that separate the ceiling panels so that they can be used again if they are okay?