Hi, I got water around both bathroom ceiling exhaust fans. I went on the roof and found ice trails leading down both vents. I went in the attic and undid the flex-pipe. I found water in both of them. I took down one of the flex pipes. At the roof end they are screwed to the plywood thru three wings which someone seemed to have made by cutting rectangles out of the solid end of the flex pipe and bending them at right angles. I think the top of the pipe protrudes above the plywood of the roof. there was no sealant around the pipe. my question is is this how they should be installed. either way does anyone know how i can prevent water from going down the pipe. i’m guessing the water came from a ice dam forming due to exhausting warm air which hit the outside cold ( btw, i am in n.y. which temps are around 30’s now) and then the ice backed up into the pipe which melted and came down the pipe. what do you think. anyone have this problem before.
thanks for your help
Replies
I've run into a similar problem in a client's house. The solution in that particular case was to wrap layers of insulation around the duct, to prevent the warm and damp bathroom exhaust air from condensing on the inside of the duct in a cold attic.
As Pierre said, there may be nothing wrong with your connections at all. Water from warm, moist air from the house condenses inside the pipe and drips back to the fan and leaks out of other joints along the way. Try insulating the pipe, replacing it with insulated flexible duct and/or shortening the run and pitching the pipe away from the fan.
Al Mollitor, Sharon MA
Insulate the duct, and use solid duct if possible.