Tar paper vs tyvek

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EliD
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Tar paper vs tyvek

Post by EliD » Thu Oct 05, 2017 2:47 pm

I am pretty sure I am going to use tar paper as opposed to Tyvek or the like. I have been looking into it and I know the tar paper is the old way of doing it, but old does not mean bad. Personally I believe it is impossible to keep moisture out of the walls if your in a humid climate, and tar paper breaths better. Second, if water does get behind the moisture barrier via nail holes or what not tar paper will wick away moisture where tyvek has to wait for the water to eventual evaporate before it can dry out. Third, tar paper has stood the test of time, there are houses that are 100 years old with tar paper still doing its job, I have heard many stories of tyvek and the like being destroyed after 10 years. 4th I will be installing it myself and since my labor is cheep it will be less expensive. 5th felt paper changes its permeability with moisture content, something synthetic products can't do, meaning when it gets wet it gets more permeable allowing it to dry faster as water diffuses to the dry side faster.

With all of the advantages of tar paper, the only disadvantages I can see is that it is more labor intensive to install, and maybe a tiny bit lower energy cost. Is their any reasons I am overlooking that would make it silly to return to the old school method that is tried and true? The climate I live in is not extreme in any season, so if their is a slight energy savings to tyvek I would not see much of it, and the potential for mold is much bigger worry to me than a tiny bit smaller energy bill.

Just curious everyones thoughts on this, I read through the forum a bit, and it seemed tar paper was getting a bad wrap from what I have read elsewhere.

Thanks,
Eli

ref: https://bct.eco.umass.edu/publications/ ... ousewraps/
https://bct.eco.umass.edu/publications/ ... -barriers/
(great study I found researching this)

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Shannon
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Re: Tar paper vs tyvek

Post by Shannon » Thu Oct 05, 2017 3:42 pm

You can use either. Most house wraps do breath if that is the issue you are concerned with. One think to consider is that the #15 felt of today is not the same as the old heavy felts they used to use 40 yrs ago. I think I would consider using #30 felt if i was going that route but maybe that is unnecessary ? We will see what the other guys here think?
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A. Spruce
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Re: Tar paper vs tyvek

Post by A. Spruce » Thu Oct 05, 2017 4:00 pm

To be honest, I am not sold one way or the other, I think they both have their strengths. I suspect the biggest popularity of using house wrap is the dimension and weight of the material, it's a whole lot faster to wrap a house with an 8' roll of lightweight material than it is 3' strips of a much heavier and more cumbersome material. Also, housewrap will stay flat and smooth whether it is covered immediately or not, whereas felt or kraft paper likes to shrink and warp if it gets cold, wet, or left hanging in the elements for very long. I've used them all, house wrap is the easiest to install and make look good, beyond that I don't have an opinion on which one does the best job.

Ultimately, it will be up to your local building department, since you'll likely need a permit to reside your house and they'll want to inspect the work.
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EliD
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Re: Tar paper vs tyvek

Post by EliD » Thu Oct 05, 2017 4:31 pm

Thanks for the reply :) here is what my local code says "15# asphalt felt complying with astm d226, or other approved water resistant barrier." I think felt went out of fashion because like many things labor savings is king in modern society, potential problems 10 years from now are not what they care about, if installed right I am sure both are fine, but as I am doing the work myself and am not a pro, I feel felt is more forgiving if I do make a mistake and water was able to get behind it. I am pretty careful and detail oriented but until you have a few under your belt its easy to overlook something. Those research articles are very good I think, and particularly he is clear to point out if you do get water behind the moisture barrier from a roof leak or anything else, it is much better to have felt which can absorb it away from the wood then evaporate it out of the wall, rather than others that only allow vapor to pass. I was thinking of using 30# I am not sure yet, it is 2x the cost though would still be less than tyvek. I should also add that the felt preformed very well (at least as good as the synthetic) at keeping moisture out according to his studies.

I am far from sold on the theory or the synthetic house wraps, houses need to breath or else they mold in humid climates. I am also doing a closed crawlspace with the HVAC inside, I think this is the newest way of doing it, and has very sound principles for doing it that way, moisture control and more efficient HVAC are both big benefits, also if you put down a rat slab you have a huge amount of conditioned storage for very little extra cost $2000 or so for the cement, but it adds the benefit of ease to install everything as well as ability to put in a drain.

What the thoughts on vented vs closed crawlspaces?
Last edited by EliD on Thu Oct 05, 2017 4:40 pm, edited 1 time in total.

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A. Spruce
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Re: Tar paper vs tyvek

Post by A. Spruce » Thu Oct 05, 2017 4:39 pm

When it comes to HVAC and other systems, personally I prefer to have these units in an interior closet or garage where it is easily accessible for maintenance and servicing. Anything put under a house is going to be neglected because it's a pain in the arse to crawl under there to do anything. If you're going with a basement, then that would be a good place for the HVAC equipment.
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EliD
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Re: Tar paper vs tyvek

Post by EliD » Thu Oct 05, 2017 4:45 pm

It is a 4' crawlspace, with a 36x36 door in the garage to it, should not be too bad to maintain I don't think, esp with concrete floor. though I have no experience to justify this, I was also going to put the water heaters down there so they don't eat up room in garage or have potential of leaks in attic, the biggest benefit is you don't have mold issues with the crawlspace in the south in US vented ones have constant mold problems, not to mention the insulation becomes soaked and does not work well. the other benefit is all ducting is in conditioned space so all leaks go to conditioned space and no need to insulate the ducting.

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A. Spruce
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Re: Tar paper vs tyvek

Post by A. Spruce » Thu Oct 05, 2017 6:04 pm

The problem with crawl spaces is all the crawling. You will never find a comfortable working position, even at 4'. If you're going to have 4' of clearance, what would be the cost for 7' or 8' to have better accessibility and storage?
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emtnut
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Re: Tar paper vs tyvek

Post by emtnut » Thu Oct 05, 2017 6:11 pm

I would never put anything like HVAC or water heaters in a crawl space. I guess this may be a regional environment thing, but around here, unless your insulating and heating/cooling that area, they will rust out in no time.
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EliD
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Re: Tar paper vs tyvek

Post by EliD » Thu Oct 05, 2017 6:38 pm

It is a sealed crawlspace and yes it is conditioned space. if your building a new house in the south I think your crazy not to seal the crawlspace and condition the space, some areas of the country it is becoming very common to seal up existing crawlspaces after they have become damp mold producing cesspools of filth. There are just too many benefits with minimal effort not to do it. here is a decent article but their are many others. http://www.greenbuildingadvisor.com/blo ... rawl-space I should have added everything is electrical no gas at the house.

EliD
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Re: Tar paper vs tyvek

Post by EliD » Thu Oct 05, 2017 7:16 pm

A. Spruce wrote:
Thu Oct 05, 2017 6:04 pm
The problem with crawl spaces is all the crawling. You will never find a comfortable working position, even at 4'. If you're going to have 4' of clearance, what would be the cost for 7' or 8' to have better accessibility and storage?

It is a result of the sloping land, there is not really a basement the land just slopes about 3 feet from the high corner to the low corner, I dont plan on living down there but hopefully wont be too bad running plumbing and electrical and ducting through there, will use a wheeled stool if I have to :) heck if had to could us a creeper or something like that. IDK will find out when I get their I guess, I hope its not to painful working in their as will probably be down there a bit. worst case scenario I teach the 4 year old nephew to plumb and run wire, he is perfect height for that :p

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