Insulating bathroom exhaust ducts
I’m deep in a project insulating my cathedral attic. I’ve gotten a lot of great guidance from this site. Most recently, I was advised to seal off the gable that juts off of the main attic space and covers the bathrooms. This would create a ventilated space above the bathrooms that would help provide ventilation to the connecting roof face (since there was no soffit venting there for intake air). I’m following this advice, which will involve air sealing and insulating the attic floor in this gable section and then making sure the soffit and ridge vents are opened up.
As you will see in the photos, there is some duct work connecting the exhaust fans from the two bathrooms below to a penetration in the roof. When I was in there earlier today, I noticed some water pooled below one of these flexible pipes. I don’t see any sign of roof leaks and so I think there is a small leak in the flexible pipe that is allowing condensate out. The ductwork is less than 2 years old, and this is the first time I’ve seen any water like this. I’m thinking of redoing the ductwork.
1. Should I redo the ductwork with as much rigid piping as possible or is the flexible piping safe to use?
2. Should I insulate the ductwork (it will now be in an unconditioned, vented space once I seal it off)? I saw that they make insulated flexible tubes.
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