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Is 28 perm rating too low? – GreenBuildingAdvisor
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Large shop … 4500 sq ft … 16 ft walls … one man build …
First … I have three rolls of Tyvek here …10 x 100 .. about 5 years old but they have been stored inside the house so I am guessing they are OK?
Because I am such a slow builder (I started framing this shop 4 years ago), I am worried that Tyvek is only OK for 120 days in the sun.
I see Tyvek has a commercial wrap. 10 x 125 ft … good for 9 months exposure! At least this will give me a shot at getting it covered in time. I am thinking I will be lucky to get the Tyvek up and start siding in spring.
The standard Tyvek has a perm of 54
Commercial Tyvek has a perm of 28
Water Penetration is almost identical.
Then I read 10 to 20 perm is ideal ????
Thanks so much !!!!!!!!!!
Mike