# bathroom fan



## Vikeologist (Aug 2, 2006)

i installed a bathroom exhaust fan, and the hole is a bit bigger than the actual fan in the ceiling, so there is a gap around the fan. I have had some water when i take down the fan cover. 

I cannot tell where it is coming from exactly, but it looks to be coming from the corner between the drywall and the fan itself. I have blown in insulation all around the fan, but there is a space between that and the drywall around the fan.

Can i use spray foam and foam all around the fan to seal it up to keep warm air from escaping into the cold attic and condensing?

I dont want a water problem.


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## Just Bill (Dec 21, 2008)

Water is likely coming from the exhaust duct. The warm moist air condenses inside the pipe and then runs back. Insulate the pipe all the way to the exit point. But good insulation around the drywall is not a bad idea, either.


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## Vikeologist (Aug 2, 2006)

no, im pretty sure its coming from around the fan. I have an insulated flex duct. 

Also, I have not run the fan yet, because I do not have it vented out through the roof yet.

What is a good way to insulate around the fan in the opening in the ceiling? just fill it with a bunch of foam? how does it seal where there is no ceiling joist? will it expand enough to still make a nice seal?


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## Ron6519 (Mar 28, 2007)

If the hole is too big, cut it even larger and patch in the correct size. The job you're describing will look half assed.
Ron


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