08/11/2026
Have you noticed spots similar to this on your bathroom ceiling?
Most exhaust fans come with a plastic backdraft damper that sometimes get warped, stuck open or not closing all the way (see pic below). This allows the hot humid air from outside that causing your ceiling to spot and grilles or lights to condensate.
With the weather we have had this Summer, this has been an ongoing problem. We usually add a metal butterfly damper that has a better rate of not failing.
AL # 14068