How to seal plastic vapor barrier
dukekoch
| Posted in Energy, Heating & Insulation on
During a remodel, I pulled the 5/8 sheetrock on an exterior wall that was about 10 years old. Behind it, there was a 6 mil poly used as a vapor barrier. The original install used duct tape to seal rips and to join pieces, but it had badly deteriorated. I’ve always used the teflon tape sold for tyvex, but now I’m beginning to wonder if it, too, fails after a few years.
Has anyone seen if the teflon tape lasts? Is there a better tape to use? A local building supply store suggested the plastic tape that’s used to make the temp storm windows, but I doubt that would last more than a season.
Replies
Dear Duke,
I wish I had a name like that.
Anyway, don't bother sealing the poly. But if you are truly compelled to do it, use a butyl caulk between the laps. Then throw your work clothes out.
We're all hoping that Tyvek tape lasts as long as Tyvek housewrap. About 20 years. I doubt it will, but nobody knows.
Regards, Ace
[email protected]
Edited 4/3/2002 1:12:02 AM ET by Fred
I use a combo of butyl" Black Death" caulk and red tyvek tape.
Hi ya. It might not make a difference in warmer climates, but up here in Alaska where the dew point is about 1/3rd of the way into the wall, I always use an accustical caulking at the poly seams and at the poly to framing seams. If you don't bother to seal the seams, then why bother to put the poly up? Or why bother to put felt below your roofing? Or TYVEK below your siding??? It is all a prvention in making the house last longer and be more energy efficent.