My son lives in an old mobile trailer with a steel oval roof. There used to be insulation glued to the inside of the roof but has come off and when it gets cold over night and warm the next the water droplets drip down onto the ceiling and has caused the ceiling to bend and the water is dripping in to the bathroom.What can a person use to put on the inside of the roof to prevent this. And what kind of board can be put on the ceiling.