Still okay to leave Tyvek exposed during construction?
ranson
| Posted in General Questions on
In this older thread, the consensus seems to be that tyvek lasts just fine if left exposed for a few months, based on manufacturer’s recommendations and past experience
In the study referenced by this article on GBA, both HDPE products weakened by 30%, shrank 30-40%, and lost 10% of their water resistance. Tyvek is made from HDPE. Given this research, are people still comfortable leaving Tyvek exposed?
I note the presentation slides compare products based on change from original performance, but don’t give a baseline comparison of absolute performance.
–John
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Replies
John,
You need to draw your own conclusions.
First: I don't see anything in Allison Bailes's blog that mentions shrinkage of 30% to 40%. From personal experience, I can safely say that Tyvek does not shrink 30% to 40% when left exposed -- even when left exposed for years. (Here in northern Vermont, Tyvek and Typar are the poor man's siding. These products are is used for a very long time.)
Second: If a product loses 10% of its water resistance, that means that it still has 90% of the water resistance that it had when it was brand new. Not bad at all.
Third: The research referenced by Bailes was commissioned and paid for by Cosella-Dörken, a Tyvek competitior. Cosella-Dörken presented data that discredited its rivals. This fact raises lots of questions.
Fourth: Tyvek provides a warranty for its products when installed according to manufacturer's directions. According to the manufacturer, Tyvek can be exposed for up to 4 months.
-- Martin Holladay
This is just an observation from our house build using Typar. We had a time period of approx 10 months between housewrap and siding completion. I'd say the only thing I noticed was fading (of the lettering/graphics) on the south side of the house. If the housewrap was weakened in some aspect because of exposure, I'm not that worried about, particularly because we built a rain screen into our wall.
If you're just talking a few months, I wouldn't worry about it at all...and I'd focus on other aspects of the wall and exterior (good flashing, a rain screen, etc) that are much more important.