A question on cellulose and vapor barrier. If the stud bays are filled with cellulose and 1/2 rigid polyiso or polystyrene is used on the inside wall as a thermal break, and the exterior is wrapped with Tyvek is this considered a vapor barrier on both sides of the wall?
My understanding is this would be a problem with cellulose.
Thanks. Allen
Replies
Tyvek is permeable to air, so it's not considered a vapor barrier.
Woodguy99 got it, Tyvek is designed to "breath".Garett
"Tyvek is permeable to air, so it's not considered a vapor barrier. "It is permeable to MOISTURE, not air.In fact it is suppose to be an air barrier..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Yer right, except it's permeable to VAPOR, not moisture. Rain is moisture.
Bill is actually right. Tyvek is an air barrier, prior to nails/staples. It is vapor permeable. It is not a vapor barrier.
Expanded polystyrene is not a vapor barrier, in general.
Extruded Polystyrene is a vapor barrier if greater than 1" thick.
Polyisocyanurate is faced with something which determines its vapor permeability.
All three rigid foams above are air barriers, provided they are sealed correctly.
Not a word about tuck-tape. I'd be fine if all seams were taped with tuck tape,(red tape), taking sure to seal bottom and top to whatever is there. yup,, sounds fine!
dIts a horse thing!
in a cold climate it would be a good system
What would you define as a cold climate? I am slightly north of you in MA.
> What would you define as a cold climate?Our house, after my wife opens the credit card bill for my Mulitmaster.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
you and i both live in cold climatesMike Smith Rhode Island : Design / Build / Repair / Restore