# To tyvek or not to tryvek?



## cindilu (Jan 27, 2008)

To tyvek or not to tyvek, that is the question??

My mom and I have this debate going on right now so I wanted your opinions. If I am building a tiny house, do I use it or not use it? Is it good or bad, does it make a difference? What are y'alls thoughts on using it or not using it?


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## 1shotwade (Jul 9, 2013)

It's a moisture and wind barrier so it depends on what you want the inside of your house to be like.Just my thoughts.


Wade


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## farminghandyman (Mar 4, 2005)

I know I am old fashion but I would most likely use 30# felt, 

second product would most likely use is the Tyvek.


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## jwal10 (Jun 5, 2010)

No Tyvek, I have seen rotten sheathing after a year or two. IF water gets behind it it does not let it work its way out. Never use with cement sidings the two will not breath, just traps moisture....James


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## TnAndy (Sep 15, 2005)

Not seen it rot stuff....it's supposed to pass water, but block air infiltration.

BUT the main reason I wouldn't use it is IT IS CRAP. 

Take a piece of it when new....you can't tear it by hand to save your life.....REALLY tough stuff. NOW, look at some that has been on a house for 20 years or so.....the stuff is like Kleenex....falling apart !! 

*How many people ever take the siding off a 20-30 year old house ? * Well dang few, for sure.....but I did it on mine to reside ( vinyl replacing wood )....and I did it on a project for someone else, vinyl siding to replace aluminum siding...both cases ( mine 25 years old, the other one about 23 ), the Tyvek was all to pieces.....
Hunt around the internet. Mine is not the only such experience. Dupont is "supposed" to have fixed the problem.....well, fool me once...

REALLY a disappointment because it was high dollar stuff when I did my house. And since I bricked about 1/2 my house, THAT part isn't ever going to get replaced.

Like farminghandyman, I now use 30lb felt. I've felt off 100 year old houses, and it looks as new as the day you put it up. No more high tech house wrap crap for me.


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## cindilu (Jan 27, 2008)

Okay, that was what I wanted to know, opinions. And I also did a google search on the stuff and really got a lot of mixed messages. If not installed correct it seems to actually cause a mold problem. And I like the idea of felt for some reason, less plastic.


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## wharton (Oct 9, 2011)

Have you taken a look at 30lb felt lately? I can guarantee you that it's nothing like you might of found a decade or two back. It's thin, extremely brittle and literally cracks if stressed while you handle it. I don't know the answer for the OP's question. I always like Typar the best. As for the $75/ roll micro-perforated, or woven poly garbage that most use since they don't want to drop 3X as much for Tyvek or typar, that stuff is some scary crap.


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## homstdr74 (Jul 4, 2011)

wharton said:


> Have you taken a look at 30lb felt lately? I can guarantee you that it's nothing like you might of found a decade or two back. *It's thin, extremely brittle and literally cracks if stressed* while you handle it. I don't know the answer for the OP's question. I always like Typar the best. As for the $75/ roll micro-perforated, or woven poly garbage that most use since they don't want to drop 3X as much for Tyvek or typar, that stuff is some scary crap.


While I have not bought it for awhile, in my experience the condition you describe for "tarpaper" (30# felt) has always been that way. Unless the manufacturer has done something to encourage rapid deterioration, your dealer may have had it for years, then it gets brittle and unuseable. Look thru his stock and if you don't find what you want, go somewhere else where they have a better turnover of their product.


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## wharton (Oct 9, 2011)

homstdr74 said:


> While I have not bought it for awhile, in my experience the condition you describe for "tarpaper" (30# felt) has always been that way. Unless the manufacturer has done something to encourage rapid deterioration, your dealer may have had it for years, then it gets brittle and unuseable. Look thru his stock and if you don't find what you want, go somewhere else where they have a better turnover of their product.


 Yea, you certainly haven't bought it in a while. Talk to a roofer and ask him how the new and improved "30 lb" felt is compared to what he was using a decade ago. As for your claim that it would be spoiled by sitting around a covered warehouse, is that the same product that you would nail on a building, expecting decades of protection from? The best analogy I can come up with is this. Old style 30lb felt feels, and works, like a sheet of light fabric, saturated in asphalt. New stuff is like a piece of thick paper, painted black on both sides. 

This is from a manufacturer's website

Currently the âtraditionalâ asphalt roofing felt has also had many improvements made with the recent introduction of asphalt coated glass reinforced felt underlayment. Many manufacturers of this ânewerâ roofing felt equate this as the ânew and improvedâ 30# because of its strength and toughness. The roofer likes this new product because of it lays flatter and that it comes in a 4 square roll vs. the 30#, which comes in a 2 square roll. 

Pay attention to that last sentence. Old felt was 200 sq. ft. per roll. The new "30 lb" product is 4 squares a roll. At the old numbers, a 4 square roll would be 120lbs. per roll, or to heavy to be practical.

I'm not saying that it is, or isn't, an acceptable weather barrier for sidewall construction. However, thinking that it has anything in common with the good old fashioned 30 lb felt of the old days is wrong. It's thinner, lighter, and quite different. The new "15 lb" stuff is such scrap that my roofers won't use it. It cannot be walked on, once stapled flat. It tears easily, and in their opinion, just too dangerous to bother with.


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## homstdr74 (Jul 4, 2011)

wharton said:


> Yea, you certainly haven't bought it in a while. Talk to a roofer and ask him how the new and improved "30 lb" felt is compared to what he was using a decade ago. As for your claim that it would be spoiled by sitting around a covered warehouse, is that the same product that you would nail on a building, expecting decades of protection from? The best analogy I can come up with is this. Old style 30lb felt feels, and works, like a sheet of light fabric, saturated in asphalt. New stuff is like a piece of thick paper, painted black on both sides.
> 
> This is from a manufacturer's website
> 
> ...


OK, I'll defer to your experience in this. I don't recall any of the old tarpaper tearing---in fact it was tough to cut. 

However I was given some recently that is either fiberglass reinforced or fiberglass fabric, it's porous and coated with some sort of oil-based product. The person said it was used for concrete work(?) It wouldn't be good for a vapor barrier, but I have used it for other purposes. I don't think that's the stuff you're talking about, but maybe, because I can easily tear it.


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## ihuntgsps (Mar 10, 2008)

http://bct.nrc.umass.edu/index.php/p...ky-housewraps/

There has been a lot of testing done and asphalt saturated felt paper has been proven to transfer moisture between the sheathing and housewrap better than Tyvek. Felt paper will actually expand in the presence of moisture and become more permeable, allowing for better drying. This is known as hygroexpansion. 
If it were me I would go with 30lb felt paper (even though the new stuff stinks compared to what you used to be able to buy).
I would also make sure to use a quality self adhesive window wrap on all windows and door flanges to keep moisture out.


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## RichInPA (Nov 13, 2013)

Whatever you choose, use button cap nails. In most areas, staples are no longer to code. Regardless of code or not, we always button cap.


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## wharton (Oct 9, 2011)

Excellent, extremely informative article on the subject.


http://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-water-resistive-barriers


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## farmgal (Nov 12, 2005)

just wrap in no name tyvek, its cheap enough and acts as a wind barrier. You will probably only need one role for a tiny house. watch craigslist for materials. I see roles on there cheap.


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## wharton (Oct 9, 2011)

farmgal said:


> just wrap in no name tyvek, its cheap enough and acts as a wind barrier. You will probably only need one role for a tiny house. watch craigslist for materials. I see roles on there cheap.


 You are talking about micro-perforated poly. It may work great, it may create a rotted mess, it may have zero plasticizers in it, and be nothing but a dusty, crumbled shadow in a few years. Great way to save a few bucks, eh? 

OR........Find the best "30 lb" felt you can, after reading the links, and educating yourself about the subject. Put it on with cap nails, seal the window flanges and other penetrations with Zip-Sheathing tape ( 4" wide, and widely viewed as some of the best tape ever made) run a piece of tape down every corner as a secondary precaution, in case the paper gets brittle and cracks at a fold. Spend less that a roll of crap fake Tyvek, and end with a building that will be water tight for the next few decades. I like that plan better.


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## Bret (Oct 3, 2003)

This may or may not apply. I had two Tyvek paint suits that I brought to toss on over jeans when a traveled a short way a few nights to learn how to artificially breed cows. I kept them at the farm for when I showed up and cows surprised me by being ready to breed when I hadn't dressed for the occasion. I found that the Tyvek material will pass green liquid through to my skin, and clothes while keeping out the fibers and the breeze.


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## TnAndy (Sep 15, 2005)

It IS supposed to pass moisture, not trap it like plastic would. It's not supposed to pass air (easily anyway).

My beef with it is the long term life of it seems to be nonexistent. To me, a house wrap ought to last the life of the house.....not 10-20 years, then fall apart.


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## farmgal (Nov 12, 2005)

wharton said:


> You are talking about micro-perforated poly. It may work great, it may create a rotted mess, it may have zero plasticizers in it, and be nothing but a dusty, crumbled shadow in a few years. Great way to save a few bucks, eh?
> 
> OR........Find the best "30 lb" felt you can, after reading the links, and educating yourself about the subject. Put it on with cap nails, seal the window flanges and other penetrations with Zip-Sheathing tape ( 4" wide, and widely viewed as some of the best tape ever made) run a piece of tape down every corner as a secondary precaution, in case the paper gets brittle and cracks at a fold. Spend less that a roll of crap fake Tyvek, and end with a building that will be water tight for the next few decades. I like that plan better.


Quit being rude, you dont know everything. Proof has shown its not the brand of house wrap that makes it leak, its the shoddy installation and poor taping that will make them leak.


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## wharton (Oct 9, 2011)

farmgal said:


> Quit being rude, you dont know everything. Proof has shown its not the brand of house wrap that makes it leak, its the shoddy installation and poor taping that will make them leak.


 
Don't know where you got this proof from, but there is plenty of research regarding questionable performance of All types and brands of housewraps. I didn't even touch on the fact that most housewrap is installed so poorly, that you pretty much have to ask yourself, "why bother".
Specifically, my comments were geared toward two potential issues. First, the documented fact that some of the products are pretty questionable when it comes to vapor transmission in an outflow direction, or breathability. So, saving a few bucks while creating a water tight, rot creating exterior vapor barrier isn't a real good idea. 
Secondly, as others have pointed out, experience and having the opportunity to inspect existing installations, after long periods of use, can be invaluable. ThAndy discusses finding failed Tyvek while doing renovations. In my case, I have repeatedly seen the products you discuss, specifically woven plastic wrap that had degraded to being dry, dusty and transparent after a decade of use, behind vinyl siding.

Rude is subjective. Suggesting that I claim to know everything is silly. Preventing somebody from creating an unhealthy, rotted, moldy mess of a dwelling is pretty important to me, sorry if that offends you.


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