View Poll Results: Have You Used a Vapor Barrier Layer (VBL)?

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  • Yes, although my clothes/insulation got really wet!

    19 5.03%
  • Yes, I think they work great.

    74 19.58%
  • No, I am skeptical that VBL's work at all.

    30 7.94%
  • No, I've never really looked into VBL's.

    255 67.46%
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  1. #71
    Senior Member ka8yiu's Avatar
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    Illustration - Vapor Barrier Liners (VBL)

    Sailor, as I read it, I think the VB needs to be between you and the insulation, not outside the insulation. This would cause the moisture to build in the insulation and collapse the insulation.

    Not sure as I'm still a novice on it.

  2. #72
    BillyBob58's Avatar
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    Quote Originally Posted by Michele View Post
    I'm really glad to see this being discussed as I've always figured VB's are the probably one of the few options for me to really get down into cold temps since I'm such a cold sleeper. Back in 2007 when I was going through GSMNP, a huge snow storm came through and we had 15 miles to go to get out of the park, and my feet were freezing from the trail being flooded with cold wet rain/snow/slush, so I had two thin newspaper sacks and decided to use them as a VB to keep my feet warm (never tried it before, just remember having read about it). I put the sacks on over my bare feet, then my socks over that and then my shoes. I was hiking in slushy freezing cold snow and my feet were totally warm UNTIL the thin plastic bags finally got small holes in them and then my feet were instantly flooded with freezing icy water. Talk about a shock to the system. Ever since I used those VB's I've been curious a/b them for sleeping in cold temps.
    Well, Michelle, if you can't keep your feet warm without them, then it looks like your next step is to find a VB sock ( or clothing or bag liner whatever ) material that is tough enough to withstand the use you put it too. Over many years I got some small holes in my 1983 era Patagonia VB socks, which I patched like one would patch a tarp. Not many though, as the material was pretty tough. I still have those but am much more likely to use my Stephensons Warmlight fuzzy stuff VB socks as they have a liner built in and feel better to me than my Patagonias with a thin separate liner sock. But I have never hiked much in either of them, so I'm not all that rough on them. I have mainly used them for sleep or as camp wear(SP?). But I can sure see they might have a place in very cold, snowy hiking. A loan of my Patagonias instantly solved a severe cold feet problem for a buddy of mine while we were fishing. That, to me, was a sign.

    Quote Originally Posted by ka8yiu View Post
    Sailor, as I read it, I think the VB needs to be between you and the insulation, not outside the insulation. This would cause the moisture to build in the insulation and collapse the insulation.

    Not sure as I'm still a novice on it.
    Yes, absolutely! You may be a novice, but you are right on the money! The VB -IMO and per general VB theory as fa as I know - is meant to be as close to the skin as possible. The only reason to wear anything under the VB is to decrease the unpleasant feeling of coated fabric and moisture on your skin, but nothing whatsoever is needed for the warmth function. A VB used any other way is pretty well going to leave a person hating VBs, and ending up wet and cold. Unless the VB is far enough away from your insulation so as to not cause trouble, like with a tarp for ex.

    Guys/Gals, I think VBs are hard for some folks to comprehend only because it is exactly opposite of every thing we have ever been taught about how to keep warm, and why we must keep dry to do that. It is very hard to over come that bias, to the point that to purposely limit breathability seems almost stupid. It seems to be going in the opposite direction of where we should be going.

    But in reality, like so many things here, once you get the theory it is all about as dirt simple as anything could be. Just think: opposite of breathable, but keep all the moisture close to the skin, keep it from evaporating ( evaporative cooling = swamp cooler/air conditioner), and keep that moisture- a little bit or a gallon- out of your precious insulation.

    If you leave out the increased warmth factor, and probably even more important leave out the huge benefits of dry insulation after a week or three in the wild, then I don't think a VB will ever be as comfortable as nice breathable system. (Even though my Stephensons WL shirt has been coming close most of the time). It is just not as comfortable to have a sensation of damp or outright wet against your skin, no way. But for me, when throwing in the other benefits has sometimes made it a no brainer trade off. Plus growing skill with use has been minimizing the sensation of dampness/uber high humidity.

    So, if you are a person who:
    1: has decided they are always going to sweat no matter what, then there might be an advantage to figure out how to keep that sweat from evaporating/cooling and finding a way to keep it out of your insulation.
    2: if you are in a group of folks who consistently find ( like a buddy of mine ) that after a cold week your quilts have a little less loft each day and weigh more at the end of a trip, even though no external moisture touches your quilts, you might want to figure out a way to keep your body moisture ( either vapor or liquid/sweat) out of your insulation in the first place. Rather than keeping on in the hope that all of that moisture making it to the outside of your insulation before it condenses into liquid. Maybe, but to each his own, and HYOH, etc.

    There are several different types of VB. Like a tarp or pad or an HHSS UC, not meant to function as a VB, because the VB space blanket is meant to (hopefully) serve as the VB which keeps your body's moisture from reaching it in the first place. Also VB bag liners, and VB clothing.

    But applicable to all of them, these general rules:
    1: keep the VBs warm by keeping them close to your skin. Vapor condenses on cold surfaces, not warm ones.
    2: Manage ( maybe reducing ) your insulation so that you don't over heat and sweat. Maybe even start out a little cold, add insulation as needed. You might need a lot less insulation than you do without a VB. Which might be a good thing, right?
    3: if you do over heat and sweat any way, it might be safer to keep the sweat next to your skin than allowing it to get into your insulation. Which you find out about when you stop to rest and suddenly freeze, because your insulation is wet from sweat/condensation, even though your rain gear has kept all external moisture on the out side.

    But, it is a learning curve! I'm still on this curve!
    For I consider that the sufferings of this present time are not worthy to be compared with the glory that is to be revealed to us....that the creation itself also will be set free from its slavery to corruption into the freedom of the glory of the children of God. For we know that the whole creation groans and suffers the pains of childbirth together until now.
    Romans 8:18,21-22

  3. #73
    Jayson's Avatar
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    After our recent trip on which temps. dropped into the -30*C range, I will not be out without my VB! I feel confident in saying they added at least 10*C to my insulation.

    I wore them while sleeping over-top of my polypro baselayer longjohns, and covered with any layers that I needed. My quilts and sleeping bag did not gain any weight after three nights and the only frost on the bag was from my breath.
    I never felt any clamminess or excessive wetness while sleeping and I did remove the VB in the morning. My wool clothing were plenty breatheable enough to deal with the moisture in my baselayer and it was dry in a very short time.

    For me any nights that will be at or below the freezing point I will be utilizing a set of VB clothes.
    The walmart sauna suit did not hold up to use in the really cold temps, I have decided to get a nylon wind shirt and pant set and give them the DIY silnylon treatment...should be much more durable!

  4. #74
    New Member ukarcher's Avatar
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    Great information BillyBob,
    You seem to be the go-to guy for info on VBLs. Having found an adequate solution for me personally, it never occurred to me that others might have such difficulty in finding a balance. Do you think people are having trouble because they are overheating, causing excessive sweating?
    As an experiment, I've been wearing a pair of merino baselayer pants, with my cheap rubberised waterproofs over them, all today while doing my normal chores. i just checked my legs etc. for moisture by the simple expedient of dabbing with a dry tissue. Result, it was completely dry.

  5. #75
    New Member zscott's Avatar
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    Great

    Great Illustration, so much talk about these VBL's but sometimes I don't think we always understand them.

  6. #76
    New Member ukarcher's Avatar
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    I just thought of a good analogy to the VBL principle.
    When scuba diving in cold water, I wear a 'dry' suit, over fleece coveralls. After an hour of moderate sub-aqua exercise, when I strip off, i'm still completely warm and dry.
    So, I guess the secret of a good VBL is to try not to get 'too warm'.

  7. #77
    BillyBob58's Avatar
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    Quote Originally Posted by Jayson View Post
    After our recent trip on which temps. dropped into the -30*C range, I will not be out without my VB! I feel confident in saying they added at least 10*C to my insulation.

    I wore them while sleeping over-top of my polypro baselayer longjohns, and covered with any layers that I needed. My quilts and sleeping bag did not gain any weight after three nights and the only frost on the bag was from my breath.
    I never felt any clamminess or excessive wetness while sleeping and I did remove the VB in the morning. My wool clothing were plenty breatheable enough to deal with the moisture in my baselayer and it was dry in a very short time.

    For me any nights that will be at or below the freezing point I will be utilizing a set of VB clothes.
    The walmart sauna suit did not hold up to use in the really cold temps, I have decided to get a nylon wind shirt and pant set and give them the DIY silnylon treatment...should be much more durable!
    Wow, could the results be any better? Warmer AND drier (i.e. drier outer layers of insulation), does it get any better than that? All just from using VBs correctly, and according to standard VB theory.

    Quote Originally Posted by ukarcher View Post
    Great information BillyBob,
    You seem to be the go-to guy for info on VBLs.
    Well thank you very much, but I'm not really the HF go to guy for VB info. Just look at the thread this is posted in by Dejoha, and Youngblood's older thread on the same subject ( is it a sticky? ). And the post by Jason I just responded to. And Fronkey should have a lot of info from recent and lengthy testing in severe conditions. I really look forward to that info. All I can claim is that I think I understand the basic theory plus have used them in various forms, on and off ( mostly off ) always successfully so far, for about 30 years. Plus, Stephenson's Warmlight has been a steady proponent of VB use for over 30 years. Still, thanks for thinking that! Maybe it just seems that way because I have been touting the approach more than others here for the last 6 years, in part for HHSS use? But that seems to be changing, several others seem to be greatly advancing our experience with VBs.

    Having found an adequate solution for me personally, it never occurred to me that others might have such difficulty in finding a balance. Do you think people are having trouble because they are overheating, causing excessive sweating?
    Yes, absolutely. If you are already plenty warm with a given amount of insulation, and you add a VB, you are probably going to sweat. A VB usually means less insulation for a given temp. That and many have not quite understood the theory. Do it wrong, and you end up wet and cold. Having the first VB on the outside of even some of your insulation (not counting a very thin liner ) will probably be a miserable experience. If it is not next to your skin, then all layers better be breathable.

    As an experiment, I've been wearing a pair of merino baselayer pants, with my cheap rubberised waterproofs over them, all today while doing my normal chores. i just checked my legs etc. for moisture by the simple expedient of dabbing with a dry tissue. Result, it was completely dry.
    Well, that is down right impressive. I stayed dry using a VB shirt and very little insulation walking very fast in cold, but above freezing and rainy temps. I even had a completely non-breathable rain wear sometimes(Packa). Bone dry. But when I did some harder work one cold day, I had to cut way back on my insulation because I started sweating. But I think my legs put out less moisture, I might have been OK with VB pants instead of shirt.

    Quote Originally Posted by zscott View Post
    Great Illustration, so much talk about these VBL's but sometimes I don't think we always understand them.
    I think the theory is pretty straight forward. Basically, just stop the vapor at the skin and maybe use less insulation than otherwise needed if you don't want to over heat and sweat. But if you do sweat, it's no disaster because the sweat can't get to your insulation.

    Quote Originally Posted by ukarcher View Post
    I just thought of a good analogy to the VBL principle.
    When scuba diving in cold water, I wear a 'dry' suit, over fleece coveralls. After an hour of moderate sub-aqua exercise, when I strip off, i'm still completely warm and dry.
    So, I guess the secret of a good VBL is to try not to get 'too warm'.
    That is certainly a major component of successful VB use. If you read about VBs on the Stephenson's Warmlight web site or catalog, ( heads up: they are nudists so the photos can get a bit different), they very much emphasize paying attention to if you are getting too warm and venting a bit as needed. Their VB info remains unchanged for about 30+ years. It is similar to info I used to get from the mountaineers at Patagonia also back about 30 years ago.

    Still, unlike your dry suit experience, virtually all of your insulation is outside the VB. So if you do mess up and over heat and sweat, no big deal as far as getting sweat into your insulation. Maybe food for thought for folks that say they sweat no matter what.

    PS: and what is that system you guys use over in the UK/Scotland, the total opposite of VB? Paramo? Not even water proof outer wear, but gear that is so breathable and wicks so efficiently and performs so well even when wet that it is great in wet weather? Even if you sweat it is quickly wicked away and the sweat has no effect on the very breathable insulation? I'm thinking Turnerminator(sp?) who just did the minus 40C trip used this gear? Sounds very interesting, though maybe heavy?
    Last edited by BillyBob58; 03-02-2013 at 11:08.
    For I consider that the sufferings of this present time are not worthy to be compared with the glory that is to be revealed to us....that the creation itself also will be set free from its slavery to corruption into the freedom of the glory of the children of God. For we know that the whole creation groans and suffers the pains of childbirth together until now.
    Romans 8:18,21-22

  8. #78
    New Member ukarcher's Avatar
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    Class result Jayson. Did you have to vent at any point during the night? I haven't had the chance to try temps that low, but I am pretty confident I'd get similar results. (Isn't it great when things turn out how you want).

    Billybob, i think 30+ years using VBL qualifies you as a go-to guy.
    I think in my scuba analogy, I was trying to say that even though i was sealed completely inside my drysuit, providing I didn't get too warm, I didn't sweat enough to notice.
    I have friends who swear by Paramo, and I would love to try out a Paramo baselayer, but every time i look into buying some, I convince myself that my lycra/spandex functions fine for me. (the 50 price tag for a shirt has nothing to do with it, honest)

    On sweat points.. I took notice yesterday when i got back from my run, where my body sweats from mostly. My head sweat a lot. On my shirt, it was heaviest on my mid to low back, under-arms, and the middle of my chest. Only my nether regionsand a little behind the knees suffered on my legs, which again surprised me, considering the legs have the bodys biggest muscles, and were doing all the work. My socks were damp at the toes. I don't know what use that information is, except perhaps to pinpoint where a localised venting system would do me most good during heavy exercise. (though its interesting to note that regardless of which muscles were causing me to overheat, it was my trunk that did most of the sweating.)

    sorry, I don't know how to insert quotes.

  9. #79
    Jayson's Avatar
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    No I didn't need to vent at all thru the nights. I went to bed each night wearing less clothes then I thought I would need with the plan to add as needed. Never needed to.

    I forgot my foot bags and found I needed far more layers on my feet then anywhere else...but I get cold feet easily.

  10. #80
    BillyBob58's Avatar
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    Quote Originally Posted by ukarcher View Post
    Billybob, i think 30+ years using VBL qualifies you as a go-to guy.
    I think in my scuba analogy, I was trying to say that even though i was sealed completely inside my drysuit, providing I didn't get too warm, I didn't sweat enough to notice. .
    Right, and point well made. I.E., if you don't get too warm, even if your insulation is on the skin side of a VB, you will still not sweat and your insulation stays dry.

    But condensation is a different issue. Still, even there you are making a good point, and without realizing it my testing has made the same point, which is: even condensation is probably only going to be so much, and not all that much. Your body - or so I read - puts out vapor to keep the skin moist, to keep it at a minimum humidity. Normally, as soon as this vapor appears, it travels out through your insulation, hopefully not hitting a cold enough temp to condense in your insulation. ( or if you sweat, that evaporates and then travels out, or is wicked out into the insulation). As it travels away, it is continually replaced by more vapor ( or sweat if too warm) production.

    But, also as I have read, once you get near to 100% humidity at the skin, your body stops producing this vapor and/or moisture. There is no feed back signal of dry skin saying "send me some moisture". And unless you overheat, no more will be produced. And with certain insulations, any condensation that occurs before the shut off switch is thrown is apparently not enough to be a problem.

    Hence, your "warm/dry" experience in a dry suit. Is that the normal experience of most folks in a dry suit? If so, why is your fleece not soaked after a long time in a dry suit/VB? It can only be - I think - because your body pretty quickly throws the "moisture shut off switch" as soon as adequate humidity is reached.

    So, for the same reason, I can sit around in even room temp or close, in my VB lined with Fuzzystuff, with no problems. Sometimes it feels noticeably humid, but when I take the shirt off hours later it feels dry and has no weight gain. So there has apparently been very little vapor produced, and most of that probably right after I put the shirt on. The shirt is either bone dry when I take it off, or it has had so little moisture pumped into it in order to reach 100% humidity that, when I take it off it very quickly evaporates so it feels bone dry by the time I can get my hands on it to feel any dampness.

    None of the above would apply to a VB that was further from the skin, like a sil-nylon sock several inches from the skin with a few inches of down insulation between it and your skin. It would take this space a while to reach 100% humidity, and you would just keep on producing this vapor. All night! Vapor which will readily condense when it hits an ice cold surface several inches from your body, so: wet insulation.

    As I think about it more, I think your dry suit analogy gives us even more valuable info than I first thought. We need to ask why your fleece is not soaked using a dry suit, unless you over heat. Is it because your body quickly shuts down vapor production, unless you over heat and start sweating?
    For I consider that the sufferings of this present time are not worthy to be compared with the glory that is to be revealed to us....that the creation itself also will be set free from its slavery to corruption into the freedom of the glory of the children of God. For we know that the whole creation groans and suffers the pains of childbirth together until now.
    Romans 8:18,21-22

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