Tyvek housewrap moisture test. Is it worth the cost?

[John Raabe]

This is a simple test of the ability of Tyvek and a "orange box" house brand housewrap to deter water penetration. I wish standard building paper would have also been tested.

https://www.youtube.com/watch?v=T55CEuKfdP8

[flyingvan]

   Well, it's a good test for half the job of a housewrap...The other half is, will it allow moisture out?   He makes mention of 'breath-ability'.  Some demonstration of that would be good too, like lay the products being compared (Yeah I'd include building paper too) over soaked sheets of paper towels and see which ones dry first. 
    I'm sold on Tyvek because we used them a lot when I was on the HazMat team.  They provided good splash protection but they'd breathe great---you wouldn't get sweat soaked like you would in the level 'B' suits.
     I wonder if DuPont sponsored that video

[Patrick]

Here is a pretty good read on house wraps they tested alot of them using a little more scientific approach http://bct.eco.umass.edu/publications/by-title/housewraps-felt-paper-and-weather-penetration-barriers/

[John Raabe]

Thanks for that report Patrick. It does a far better test of housewrap options and also tested the time proven standby 15# felt or tar paper. The author's final comments are interesting.

"I have felt paper on my own home, and if I could choose between felt and housewrap and do it over again, I'd still choose felt. That's because I believe that under certain circumstances, felt outperforms housewrap."

PS: I'm sure that little video has sold a few rolls of Tyvek!

[Patrick]

I'm sure it has ,It reminded me of the old maxi pad commercials! I have just read so many stories about house wraps turning into dust I dont think I'll ever use it. maybe they have fixed that issue i dont know,what I do know is that every old rotted out siding i have removed from 60-80 year old homes still have the tar paper in tact and sometimes in very good condition.

[Don_P]

The cellulose fibers that paper and wood are made from swell when they get wet and shrink when they dry. Tarpaper is made of these fibers covered with waterproof tar. When dry the paper shrinks, draws up taught, and becomes vapor porous, letting the wall dry during drying conditions. When the paper is wetted the fibers swell, closing the gaps between tar covered fibers. This decreases the permeability of of the paper. None of the other housewraps can do that. In tyvek's favor is the ability to build a better air barrier to the wind.

[flyingvan]

THis thread made me look at this closer---I'd been kicking myself for using tar paper on my first build instead of tyvek---back then it was cheaper.  Now I'm wishing I'd used it on the second build.   One site that's run by a home inspector made another interesting point, though----the best housewrap in the world won't make a bit of difference if your house isn't flashed properly.

[Erin]

what I do know is that every old rotted out siding i have removed from 60-80 year old homes still have the tar paper in tact and sometimes in very good condition.

This has been my argument in tar paper's favor, as well.  Maybe it's different elsewhere, but I've torn down enough buildings over the years to have seen how effective it is.