DIY Baffles for Cathedral celing
stephenr
| Posted in General Questions on
Hello, I read the advice in this article…
https://www.greenbuildingadvisor.com/article/site-built-ventilation-baffles-for-roofs
My neighbor wants to do DIY baffles out of 2 inch foil faced polyiso to bring his roof assembly a higher r value. It seems that non permeable material is ok for this as long as the baffles are air sealed. Any problems with this?
Cathedral 12/12 Maine zone 6 hrv probably a vapor barrier.
Thanks
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Replies
Since you're talking about "baffles", I assume this will be a VENTED catherdral ceiling assembly. That venting makes things a lot simpler in terms of what you need to worry about! Because of the venting, moisture has a way to leave the assembly, so you don't have the risk of mositure accumulation that you have with an unvented cathedral ceiling assembly, and it's usually the unvented assemblies that have problems.
I see no issue using 2" polyiso to get some additional R value in this assembly, especially if you're already tight on space. I WOULD tape the seams though, since sealing the interior side is a plus here -- it will limit how much interior moisture can make it's way up into the roof assembly. The vent channel should safely remove any moisture that does sneak up there.
Bill