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Thread: Tyvek strength

  1. #1
    Join Date
    Mar 2009
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    Default Tyvek strength

    In 1995 or so, I purchased a big roll of tyvek for a siding project. It was pretty tough stuff. I cut a piece and slept on it for 100 nights thru California. Was still good to go at the end of the trip although a little softer.

    I pulled the same roll out of the shed recently. It tears like paper. Stored in the dark but hot and humid.

    I recall the tyvek postal envelopes used to be extremely tough to tear. I tested a couple recently and one would not tear and the other was more like paper.

    What's up? Is it just a matter of age? Or has it changed over the years? Or just random?

    I was thinking of mocking up some sunshades and sails out to the stuff and hesitate to use my current stock.

    Anybody know or care to speculate?

    Tom

  2. #2
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    Default Re: Tyvek strength

    Must be uv exposure some how or another.

  3. #3
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    Default Re: Tyvek strength

    <<EDIT: This was what I read around 10 years ago. Something must have changed since then (See subsequent post#8) Since the OP has 20 year old Tyvek, this could be valid. Tyvek no longer has any warning and DuPont currently does recommend its use on OSB.>>

    Tyvek will deteriorate on contact with OSB. If the roll was stored on OSB, the outer layers that were in contact with the OSB might be the only bad material. Same for UV, it might still be OK a few layers in. OTOH, it could just be 23 years of heat and humidity and the whole roll is junk.

    Tyvek is normally very tough. You can make Tyvek sails that stand up to strong winds. They might not be as good as a real sail, but you can mock up and try several different sails for the price of dinner in a dive while a real sail will set you back more than the price of my car. (My car is older than your Tyvek.)
    Last edited by MN Dave; 03-09-2018 at 12:30 AM.
    Management is the art of counting beans. Leadership is the art of making every being count. --Joe Finch

  4. #4
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    Default Re: Tyvek strength

    Tyvek makes great kites. You can drag a three year old across the lawn with one.....

  5. #5
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    Default Re: Tyvek strength

    Tyvek house/building wrap is routinely installed over osb and plywood. How can either of those materials harm it?

    I have read reports that some brands of tyvek are not up to the same quality as that of DuPont. It's been a while though. My last remodel project was several years ago so I'm out of touch.

    Jeff

  6. #6
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    Default Re: Tyvek strength

    I used it to mockup a boom tent and it worked so well I haven't felt the need to replace it as intended with silnylon as I had intended, I used 1443r Tyvek which is the lightweight kind kitemakers use, seems plenty pretty strong to me and stuffs down nicely into a drybag.

  7. #7
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    Default Re: Tyvek strength

    Manufacturersí claims for Tyvek and Typar have always been overblown. Espescially the early versions. Some of the early stuff was seriously degraded by the ultraviolet in sunlight. Like in less than a week of exposure. Yet builders often didnít get siding on to cover it for months. Those are the houses where the osb sheathing is now rotten behind the siding. Sadly Iíve made thousands of dollars working on these houses. Some just 10 years old. The sheathing is mush - carried to the dump contractor bags.

  8. #8
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    Default Re: Tyvek strength

    Quote Originally Posted by jpatrick View Post
    Tyvek house/building wrap is routinely installed over osb and plywood. How can either of those materials harm it?

    I have read reports that some brands of tyvek are not up to the same quality as that of DuPont. It's been a while though. My last remodel project was several years ago so I'm out of touch.

    Jeff
    I agree that it seems illogical that OSB would have any effect on polyethylene. My information was old. DuPont nay have changed something or some change to OSB like the reduction in formaldehyde fumes from OSB may have eliminated the problem. The current Tyvek literature that I just found online now recommends using Tyvek over OSB.

    About 10 years ago when I was adding onto my house, I did read that Tyvek would deteriorate badly after several years in contact with OSB. It did not make sense, so I looked into it and found that there was credible evidence that that it was true. The DuPont Tyvek literature at that time did recommend against using Tyvek over OSB.
    Management is the art of counting beans. Leadership is the art of making every being count. --Joe Finch

  9. #9
    Join Date
    Sep 2007
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    1,160

    Default Re: Tyvek strength

    I suppose there is a chance it has been attacked by fungi. There are fungi that alter polyethylene, they are called lignin-degrading fungi.

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