Got tired of my bathroom ceiling peeling so I put in a drop ceiling. One tile consistently gets water stains right next to the exhaust fan. I upgraded to a 110 cfm fan and replaced the tile. Same problem. With the new fan the exhaust hose is at the opposite side from the old fan and so is the water mark. The vent has an elbow and then the exhaust must go verticle for about 2 feet and out the roof. Can this elbow be collecting moisture from the damp air and then leaking it out onto the tile? The bathroom is only about 40 sq. ft.
Answer:
If the ducts for the fans are not insulated from attic floor to roof decking, they certainly will cause condensation. Drop ceilings are not meant for bathrooms as they hold too much moisture and then things start to rot.
