Replies

1. 
   Guest_ | May 30, 2000 02:49am | #1

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   Jim,

   We only use it for bulk water barrier so any kind is ok with me. I guess I like the ones you can see through the best, the poly types. Tyvek is really noisy.

   Tom

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   Guest_ | May 30, 2000 02:30pm | #2

   *the tests i've seen published say that Tyvek is the only one worth considering but is not that much better than 15# felt and in some instances.. worsethe rest of the bunch are so much eye-wash...

1. 
   Guest_ | May 30, 2000 10:34pm | #3

   *Jim:What Mike said pretty much sums it up, but first, before discussing the virtues of the different brands of house wrap, you must understand that there are 2 different types. One is a perforated film; the other is more of a spun fabric. Tyvek is the later, and I believe (not sure) that Typar is too. I believe that the Weyerhouser brand of housewrap is a perforated poly, but can’t remember for sure as it has been a whole 3 weeks since we installed some and I’ve been on vacation and lost a few brain cells in the interim!To learn about the perforated/fabric first hand, closely examine (perhaps with a magnifying glass) different brands of housewrap. You will readily see the difference between perforated film and fabric types.Don’t mean to sound like an advertisement for Tyvek, but check out Dupont’s Tyvek web site. Dupont will send you a free sample and sales literature which explains about perforated and fabric type of housewraps. I do feel that Tyvek is the best of the housewraps, based on my readings, and personal experience. It is the most water proof while maintaining it’s permeability (ability to pass water vapor). Tyvek’s only down side is that it cannot be left exposed for long periods (I think the cut off is 3 months?), as it degrades with exposure to direct sun light. Still, it's not much better than builder's felt, except that felt has a potential built in airleak every 2.5' or so where the courses are overlapped. As with many building topics, the “devil is in the (installation) details”, specifically, the flashing associated with the housewrap/felt job. If you go to the above referenced web site, and click the installation instructions link, some of these “details” are addressed. I believe that these items are more important than the brand of housewrap that you select.There was an article in JLC, 11/98 comparing different brands of housewrap and builders felt. You may want to read it.

1. 
   Guest_ | Jun 01, 2000 03:50am | #4

   *But,Does Tyvek really pass water vapor? We got caught last winter between inspections with an exposed basement wall, insulated but with no vapor barrier. OSB, tyvek and vinyl. What happened was after about a week of heating, ice formed on the inside of the OSB about a half inch thick. Why didn't this escape?Made me wonder.

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   Guest_ | Jun 01, 2000 01:33pm | #5

   *md.... the assembly in your case was overwhelmed..wether u like vapor barriers or vapor retarders.. either one might have made the difference...the insulation (((fiberglass ? ))) was passing the moisture to the condensing surface faster than it could pass thru the Tyvek / vinyl siding..probably.. even 15# felt would not have passed it fast enough..b but hey, whadda i no?

2. 
   Paul_Ingram | Jun 28, 2000 07:03am | #6

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   Why doesn't anybody have anything to say about good old Grade I building paper. It comes in standard 10 minute [a measured amount of water will take ten minutes to pass through in a lab test] or heavy 60 minute water resistance. Both have excellent vapor permeability characteristics. I would never put asphalt saturated felt on an exterior wall. It is almost a vapor barrier, which will rot the walls. If you are installing only one weather barrier under wood siding, Tyvek or other air infiltration barrier is a good way to go. I believe these products are redundant under a stucco finish. Stucco does not have the same air infiltration problems as siding.

3. 
   Jim_Cullison | Jun 28, 2000 02:15pm | #7

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   Sales peps give me all kinds of stories why their promoted brand of house wrap is best. I'm totally confused. Is there really a difference between brands? I've looked at Tyvek, -Wrap, Weyerhouser(up), and another that I can't remember just now. Any comments appreciated.

4. 
   Guest_ | Jun 28, 2000 02:15pm | #8

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   Paul -

   Are you familiar with the research that shows that most "air infiltration barriers" barely even slow down water penetration, particularly under wood siding? Only Tyvek seems to have decent water resistance when exposed to repeated wettings or to surfactants that leach out of the wood siding.

   "I believe that these products are redundant under a stucco finish."

   Please tell me that you do not believe that you don't need a secondary drainage plane under stucco. IMHO, I wouldn't use Tyvek under stucco either, but I would use #15 or #30 felt. Stucco may or may not be resistant to air infiltration, but it is definitely not water proof.