A question on Tyvek

Hello folks,

I have a few questions for anyone out there that can help me out.

Where can I purchase Tyvek online, and how much would a square yard cost? What kind works best for a tent rainfly?

I take people trekking in tropical jungles; and although I have a preference for hammocks, a lot of my clients prefer to sleep with their backs flat against the ground, in tents.

Tents are cumbersome in the jungle because humidity is very high and condensation makes you feel like you're in a sauna when the rainfly is on. If you take the rainfly off, then it gets comfortable, but you run the risk of getting wet from a flash shower at night.

So I figured that I could get rid of the manufacturer's tent rainfly and probably use a larger piece of fabric and pitch it high over the tent, so as to allow more ventilation. The fabric has to be extremely lightweight and waterproof.

Someone recommended Tyvek, but I haven't found enough information online to decide what kind or where to buy it.

Any help will be greatly appreciated,

Morales

Tyvek is lightweight and waterproof, but it is not extremely lightweight and waterproof. I would suggest 1.1oz or 1.9 oz silicon impregnated nylon, or silnylon.

For tyvek, try http://www.questoutfitters.com/

For silnylon, try outdoor wilderness fabrics with the link from this site, or you can try quest outfitters as well.

There is a lightweight Tyvek available that weighs about 1.25 oz per yard. Quest Outfitters or Kitebuilder.com are sources. I use the light Tyvek for a tent groundcloth.

morales you do not want a Tyvek rainfly, because it will keep the heat in when it's not raining, and eventually soak out if it is raining; making it a heavier wet mess to deal with than any silnylon ever will be IME.

Tyvek is not, repeat NOT, waterproof. Somewhat water resistant, yes, but not suitable for wet situations, either as a ground cloth or shelter. You might try silnylon...extremely light weight, and waterproof enough to keep the rain out. Not much good for groundsheets, though...use 3-mil polyethylene or similar.

How about a Ray-Way style tarp & net-tent? You can pitch the fly as high as you want.

The regular Tyvek Homewrap, available in 8 and 10 X 100 foot rolls at most builder supplies sheds water better than standard 1.35 oz. silnylon. the Silnylon will have some mist-through. Tyvek will not. However, it is not suitable for groundsheets on wet ground because it will weep. Compared to anything else, Tyvek is extremely breathable and its bright white reflects a lot of the sun's heat. However, any enclosed tent will heat up in the tropics. A high set-up with lots of flow-though ventilation is a good idea. In that case, any waterproof fabric will do. Therefore, you might as well go with the lightest you can find. I like double coated silnylon which is really waterproof, unlike the regular stuff.

Your clients don't want to hammock, huh? Do they know about all the creepy crawlies down there?

I just took a piece of Tyvek Home Wrap (printed right on it, new, wrinkled but not laundered) and ran some water (maybe a pint) into it, and held it up like a bag. The water soaked through and began to drip within a few minutes. This doesn't happen with silnylon unless you apply some pressure. As far as shedding water, Tyvek isn't particularly repellent, that is, water doesn't bead up on it. I'm not sure what accounts for the difference between our experiences...are there different types of Homewrap?

Some Tyvek IS waterproof. Homewrap is not, it breaths. Early in this thread I posted a link to DuPont and it's various versions of Tyvek. The trick with this stuff is finding anything BUT Homewrap out there. The stuff that Priority Mail envelopes are made from is much tougher and water tight, but I've never been able to identify the type of Tyvek they are made from. Tyvek hazmat suits are water tight and puncture resistant. Painter suits breath and are flimsy. Lots of different Tyvek out there.

Silnylon on the other hand is 'spec'd' to be waterproof down to three feet. I read that on the manufacturers literature when I bought a bolt of it a few years ago.
Sometimes 'mist-through' can be confused with condensation building on the inside. I think it's made by more than one mill so who knows what we're getting these days.

You do not have to get it on line. You can get it from any hardware store like home-depot or Lowe's.. It isn't expensive but usually you have to purchase large quantities of it (on rolls) that it does get expensive. What I did at first is, I stopped by construction sites and told the guys that I needed their scraps and they were fine with it. I went back in a couple of days and they had it stacked 6 feet high. The "mother Load" of Tyvek, and I have been having fun with it every since. Hope this helps...Happy trekking...sabre11004...

P.S. I use it for all kinds of stuff too!!!!!



The first step that you take will be one of those that get you there... <img src="/forums/images/graemlins/grin.gif" alt="" />

Are you sure or was it just a dream? <img src="/forums/images/graemlins/wink.gif" alt="" />

Right on. I might have some scrap soon. It is just the 'regular' kind that you can get at Home Depot. I am in the 37934 area code. How much do you need and how much would it cost for shipping? Shipping would be on you.

oops....yer right... twas another thread that ran a week ago.
Here:
http://www2.dupont.com/Tyvek/en_US/index.html

Homewrap is not waterproof - just extremely hydrophobic. You cannot make a water bag out of it: the hydrolic head exceeds its capacity. On the other hand, if you make a tarp out of it and set it up in the rain next to a normal silnylon tarp, the silnylon will have mist-through, but the Tyvek will not. its pores are not continuous -as are the pores in silnylon. When a raindrop hits a silnylon pore some water will squirt through. That does not happen with Tyvek.

On the other hand, the pores of silnylon are quite small, so sylnylon will hold a higher head of water than Tyvek. All that means in practice is, make water bags and ground sheets out of sinylon and tarps out of Tyvek, not the other way around.

The misting phenominon is complicated. It has been confused with condensate being knocked off the tarp. In fact, that does happen. But there is also bono fide splatter through that happens on a tarp that is bone dry on the under side. It is not intuitively apparent because it would seem inconsistent with the fact that silnylon will hold a few inches of head without weeping. The answer lies in the instantaneous pressure that portions of a rain drop can exert. That pressure can easily exceed the resistance of the microscopic pores in silnylon. Sn doesn't leak easily because of a combination of the hydrophobic polarization of silicone and the surface tension of water. A fast moving rain drop will sometimes generate enough pressure to overcome both sources of resistance.

Does that mean it has rabies?

I think he means it has an "unreasonable fear of water". Nothing medication can't handle. <img src="/forums/images/graemlins/grin.gif" alt="" />

I'd like to get my hands on some of that hazmat suit or USPS envelope Tyvek. It's really waterproof and extremely tough. Homewrap can be torn easy with your fingers.

I used some Tyvek suits that were all fancy with booties and elastic cuffs and such. They worked great, except I accidentally wore my girlfriends, and she wore mine. Setting up the campfire, i split my suit across the bag, and she almost blew away a couple of times in the high winds. At least we could laugh at ourselves <img src="/forums/images/graemlins/smile.gif" alt="" />

EXACTLY what I was trying to illustrate...campfire humor <img src="/forums/images/graemlins/smirk.gif" alt="" />...You can tell us, "was it the chili that made you split the tyvek suit?, 'Cause I've heard that tyvek is kinda delicate in the woods" <img src="/forums/images/graemlins/grin.gif" alt="" />

No. It does not have rabies. It just gives you rabies

I bought my tyvek from "frequentfire" on ebay, he has a fair price and has fair shipping pricing, WATCH OUT some sellers on ebay will try to profit on shipping charges. you can also google "frequentfire" HOPE THIS HELPS!

So I got a Forestry Suppliers catalog today and there were some Tyvek coveralls in there. Three different kinds, depending on what you are to use them for, but there are definately some Hazmat kinds in there (good enough to be used in radioactive environments). The link to Forestry Suppliers, and the three different kinds are there. Looks to me the General Purpose suit is used in dry environments, whereas the other two can be used in wet environments. The Special Purpose suit is made from Tychem QC and the Superior Protection suit is made from Tychem SL (basically beefed up versions of Tyvek). The links to the .pdf files on the last two suits provide info oz./yd2, thickness, tearing and breaking strenghs if you wanna check that out.

I'm thinking I may try out the Special Purpose ones, and will probably even splurge the extra $0.55 to get the hood and elastic cuffs! <img src="/forums/images/graemlins/grin.gif" alt="" />

Has anyone else tried these (or similar) coveralls? I'm thinking they'll be hot because they are coveralls, and we'll see how the durability is. But the model I'm looking at being only $9.50, not too big of a loss if they suck.

JAK, from the Tyvek Jacket thread, have you tried the coveralls out?

And oh yeah, the catalog claims 8 oz. for the hooded General Purpose and Special Purpose suits (M-XL sizes) and 13 oz. for the Superior suit.

I've worn one once..

See a long time ago I was on a community league board. We had three giant poplar trees, on city property, tearing up the community league structures, also on city property..

The city duly responded to our complaints and said, yes, we could pay to have the trees taken out,
or the city would take them out for free if they were dead. The city would come girdle the trees, but the giant poplars would simply shrug this off and shoot up more desctructive shoots. We got quotes from 30,000 to 50,000 to have them removed. Now the city would only girdle them, because it's bad bad bad to use any chemicals on city property....

Let us say that at 2 am a certain two community members donned tyvek hazmat suite and blue bump hats with sunglasses and eye protection to look official, and payed a visit to the trees with an axe and a sprayer full of double strength roundup. In the fall right before the leaves go they suck up stuff like mad.

Come spring they were deader than doornails with limbs falling off "quick it's a hazard" we called the city and they duly came out and immediately removed the three giant monsters. A few weeks later we got the lecture from our city rep reminding us we couldn't use chemicals on city property, and we duly responded "oh yes, we've never done that..."

Anyway, chopping or doing any kind of activity in a tyvek hazmat suit kind of sucks. I don't think I'd like one for backpacking - they don't exactly have a nice fit either...

I tried a Tyvek suit. Didn't work for me.

If you plan to use the suit as raingear you'll have to seal the seams and that's a PITA. And the zipper is not waterproof. And I agree that the fit sucks.

And good luck when you need to go #2 <img src="/forums/images/graemlins/grin.gif" alt="" />

I'm guessing that the XXXXL with hood could be used as an emergency shelter for 2 people, one per side? LOL.

I have a tyvek painter's coverall as an emergency windbreak or vapor barrier in my rescue pack. I don't think I'd use it on a regular basis while, say, actually hiking.

Many moons ago my first ex-husband was in hazmat, and I met up with him one summer day after he got off a job but hadn't taken off his tyvek yet. When I pulled into the parking lot he was pouring about a quart of water out of his rubber boots. I asked if he'd jumped in a pool or taken a shower before taking off his stuff, and he said "no, that's sweat". Ewwwwwww! The super heavy duty chemical-safe tyvek suits definitely do not breathe... however, if you want to recycle the water you drink in and then sweat out... <img src="/forums/images/graemlins/shocked.gif" alt="" />

MNS

The difference in silnylon and Tyvek is that silnylon is "NOT" totally water proof and tyvek is. Most silnylon is rated at around 2lbs of pressure per square inch and if any pressure is put on the silnylon it "WILL" leak water. I have all types of silnylon tarps and ground sheets and the stuff is really good quality. I have a 1.1 oz. silnylon tarp (10X12) that I carry with me most of the time in case of emergency.When I first made this tarp I pitched it in my back yard and left it there for around three weeks. It got every kind of weather that you could throw at it and it never leaked. I know this because I had all sorts of older gear under the tarp the entire time that it was pitched in my back yard... Silnylon is mostly what I like to refer to as "hydra phobic". That is that it does a great job of repelling water but it is simply not water proof. You can coat nylon with different coatings to make it water proof but then that greatly increases the weight of the tarp therefore defeating your purpose of the light weight tarp. I guess what I trying to say is that all your silnylon will work better over you than it will under you... Any way I just thought that I would add that ..Hope this helps...Happy Trekking...sabre11004....

The first step that you take will be one of those that get you there !!! <img src="/forums/images/graemlins/wink.gif" alt="" />

I don't know what type of tyvek you had but the normal "house wrap" tyvek will not leak. If it did every home in America would be wet rotted. This is the material that goes on to seal 90% of the homes in America.They depend on it not leaking, however, with that being said, there are different types of tyvek and they all probably are not water "proof" but then used for something different.Hope that helps...Happy Trekking...sabre11004

The first step that you take will be one of those that get you there.... <img src="/forums/images/graemlins/wink.gif" alt="" />

I have been using tyvek as a ground cloth in the most in climate weather you could imagine and it has "never" left me wet. Hope that helps...Happy Trekking...sabre11004...

The first step that you take will be one of those that will get you there !!! <img src="/forums/images/graemlins/wink.gif" alt="" />

Actually, most houses have a layer of construction (siding, brick, stone, etc.) over the Tyvek. Its purpose is to block air infiltration, not water.

This is not correct - Tyvek is not completely waterproof - only highly water resistant, at least according to DuPont.

Silnylon will not 'leak' under high pressure. It will 'mist' very gently under extremely high hydrostatic pressure. However, most shelters made out of silnylon are shaped to resist any sort of pooling of water and reflect such pressure. In my experience I have only had misting one time, and it was ever so slight, during a 40 mph rain / wind storm. I was unable to use any natural wind breaks in the area.

It was not the "chili" that split the suit, but you wouldn't believe me if you saw how it split. I will also say this about the Tyvek I used, if you touch anything, the water will come through. I'm sure the heavy duty suits some have mentioned are better at keeping water out, but make sure you know what type you're buying, lest you find yourself a victim of the "chili" <img src="/forums/images/graemlins/grin.gif" alt="" />

They are a nice emergency item to have, that you don't have to worry so much about taking care of, though using a sheet of Tyvek as a type of blanket would probably work better than wearing the suit, for various reasons

People don't understand tarps that are "different" from the norm...some people are just "hydrophobic" about them . We should just be tolerant of other tarps life choices, is all i'm saying <img src="/forums/images/graemlins/grin.gif" alt="" /> Don't be so "hydrophobic!"

BF <img src="/forums/images/graemlins/cool.gif" alt="" />