Vapor barriers -what is your opinion?

[BillyBob58]

More VB goodness.

This morning I was cleaning about 4 inches of ice and snow off of my truck. It was about 25 degrees and I was wearing regular uninsulated mechanix gloves. By the time I was done the ends of my fingers were very cold, as if I was wearing the fingertip type gloves (actually, no fingertips).

I recently received the Warmlite glove liners, but had never used them. As a test, I put them on and pulled the same mechanix gloves over them and cleaned the snow off the van. You guessed it, my fingers were warm and even warmed up nicely from their previous frigid condition.

Call me the VB fanboy.

For some odd reason, you seem to have voluntarily joined the lunatic fringe. Surely you know this can not really work? I feel you pain. Maybe you need an intervention?

[Groundskeeper]

Conditions: 41F, humidity 77%, grey/clouds/no sun, wind out of north 7 mph

walk 1.8 mi at average speed 3.7 mph, plus 2 sprints of ~ 10 secs each just to generate more heat.

Gear tested: The long sleeved cotton shirt I was already wearing, with a SWL VB shirt over that, with the ~ 13 oz hooded PG jacket mentioned in my recent posts of the jackets ability to dry out and any warm when wet abilities. Plus cotton jeans and regular daily wear nylon socks inside my old mesh jogging shoes.

Why a cotton shirt, of all things? Just for the heck of it. I have been reading things from you guys with more than the recommended stuff under your VBs. Also, we have been discussing these films with the guys soaking themselves in a creek and then trying to dry out by putting synthetic puffies on and either moving fast or getting a shelter and inside a synthetic bag, plus hot drink/food. We have also been discussing emergency shelters. And with all of this, we have been discussing whether a VB would be helpful in all cases, and if so whether better wearing it next to skin, or over at least some of the wet clothes. Or maybe over all of them in the case of the emergency space blanket shelters. Etc. We have thrown out some theories and opinions, but don't have any testing to back us up.

So I just felt like trying the worst possible item for cold weather- a cotton shirt- under the VB and light jacket. Just to see what would happen.

Of course, this is only a short outing and uphill with a pack could definitely result in more heat output, although I was breathing pretty hard after my so called 10 sec sprints.

It was probably the most comfy I have ever been in a VB or without one. You may recall, on many similar tests by me, I have felt very warm, and or very humid, and even starting to sweat. And perhaps venting.

Results: From the start, I just felt very pleasantly warm, and stayed that way for the entire walk. Except for my legs and feet, which were a bit chilly, not surprisingly. When I still showed no signs of sweat near the end, I just assumed my cotton shirt had soaked it all up, and it just wasn't enough to be obvious yet. I still figure that must have happened. But when I got home and removed all layers, I could find no hint of sweat in either the cotton shirt or the lining of the SWL VB shirt.

Now this was very comfy, probably more than with any other combo. I figure the cotton shirt was less insulative than any layer it might have replaced, thus I was a little cooler, thus less sweat. Maybe? The shirt weighed 10.3 oz soon after I got back, I will weigh it later after giving it a good while to dry out, in case it absorbed moisture that I can not see or feel.

So, what useful info does this give us VB users, if any? Well, if the main goal is to keep ALL insulation layers as dry as possible and thus as warm as possible, then I think the best bet is still to have all insulation over the VB, which is as close to the skin as possible. That may also be best for completely stopping evaporation from the skin and maximizing warmth.

However, it appears there may be more versatility than I realized as far as what we can wear under a VB and get away with it and still stay comfy, and not end up soaking these garments in sweat. Now I am glad I tried this. Also, keep in mind that I had a light weight, wind proof puffy over the VB. Condensation occurs on colder surfaces, right? Without that layer keeping the VB warmer, perhaps- even without noticeable sweat- I would have had condensation when my body vapor hit that cold VB. Like many of us have experienced inside rain gear. Sometimes even inside rain gear that is supposed to be breathable. Maybe by keeping that layer warm my vapor remained vapor? So there is one more thing to test.

These results seem to indicate there is at least a range where the VB is self regulating. Didn't Jack Stephenson write that once the micro climate inside the VB hits 100% RH that you will stop producing insensible sweat? That is my memory. This is not to say you cannot overheat in a VB, but it seems to have some leeway.

I think too that you are onto something with the vapor remaining vapor. As a vapor, it can vent very easily. The SWL shirts are not air tight (neck hole, arm holes). One of the reasons I wear a thin base layer under mine is because when I wore it without a base layer I felt every puff of air around the neck hole when I moved, even a little bit. It was not real cold at the time, but if it were, it could have been very uncomfortable.

[cmoulder]

Thanks for the updates, BillyBob and Elmer.

I think we might be the only ones still on this train, but I am reminded that "analytical" starts with "a-n-a-l" lol.

My overarching question is whether I can utilize the LHG rain jacket as my primary shell, and thus far the results are very good, enough that I would be comfortable taking it for a multi-night trip for above-zero weather.

This weekend I did a rare, easy overnight group hike (local hammock Meetup) and wore it pretty much non-stop except for the hike in with some moderate uphill at approx 35°F, low wind and humidity, over 200wt fleece and polyester OR echo and old EMS techwick. I probably should have experimented by removing the fleece and putting the rain jacket over the poly layers, but missed the opportunity. No worries, I can do that locally next time I'm out.

Other than that, however, doing camp chores (even collecting some fire wood) and sleeping and sitting around (with light down parka and pants) I wore it non-stop and was very comfortable with very little moisture build-up inside. Easy to regulate temp by pulling the hood back and/or opening the very large pit zips and front zip.

I intentionally slept in the jacket and did not sleep in the rain pants to see if there was a difference in condensation on the quilt. There was no condensation in the lower half of the quilt, so my conclusion is that the low RH took care of that.... Evidence: overnight low was upper teens and there was no frost on anything.

[Groundskeeper]

@cmoulder. I just checked and there are over 5,200 views, so hopefully some folks are getting something out of this (or maybe just cringing in fear of the lunatics and putting us on some kind of blocked list).

Did you at any point have to wear another layer on top of the LHG rain jacket? If not, that goes to show how much warmer these VB's keep you. It seems that wearing a VB layer allows me to wear one less layer (at least) than I normally would wear at a given temperature without one.

I won't be caught without a VB layer in any kind of cool temperatures, so my VB experimentation will not end any time soon. Just this morning I was pumping gas in 22 degree window conditions, no VB, and I was was cold, waiting for that slow gas pump to fill it up. Seriously, I may start wearing VB's more often, even in real life...

By the way, I like that your jacket has the pit zips. They would be invaluable in keeping vented properly, allowing a wider range of activities.. most likely.

[BillyBob58]

Thanks for the updates, BillyBob and Elmer.

I think we might be the only ones still on this train, but I am reminded that "analytical" starts with "a-n-a-l" lol.

My overarching question is whether I can utilize the LHG rain jacket as my primary shell, and thus far the results are very good, enough that I would be comfortable taking it for a multi-night trip for above-zero weather.

This weekend I did a rare, easy overnight group hike (local hammock Meetup) and wore it pretty much non-stop except for the hike in with some moderate uphill at approx 35°F, low wind and humidity, over 200wt fleece and polyester OR echo and old EMS techwick. I probably should have experimented by removing the fleece and putting the rain jacket over the poly layers, but missed the opportunity. No worries, I can do that locally next time I'm out.

Other than that, however, doing camp chores (even collecting some fire wood) and sleeping and sitting around (with light down parka and pants) I wore it non-stop and was very comfortable with very little moisture build-up inside. Easy to regulate temp by pulling the hood back and/or opening the very large pit zips and front zip.

I intentionally slept in the jacket and did not sleep in the rain pants to see if there was a difference in condensation on the quilt. There was no condensation in the lower half of the quilt, so my conclusion is that the low RH took care of that.... Evidence: overnight low was upper teens and there was no frost on anything.

Well, we have had more "put it to the test" in this thread than I have seen before, certainly on this subject! Question: would we have to weigh, or measure loft, to be certain that there was no condensation or wicked sweat inside our down? True, frost is an obvious sign that condensation has taken place and frozen. But I'm thinking we can get some with out frost on our shells outer surface, or even frost at all?

@cmoulder. I just checked and there are over 5,200 views, so hopefully some folks are getting something out of this (or maybe just cringing in fear of the lunatics and putting us on some kind of blocked list).

Did you at any point have to wear another layer on top of the LHG rain jacket? If not, that goes to show how much warmer these VB's keep you. It seems that wearing a VB layer allows me to wear one less layer (at least) than I normally would wear at a given temperature without one.

I won't be caught without a VB layer in any kind of cool temperatures, so my VB experimentation will not end any time soon. Just this morning I was pumping gas in 22 degree window conditions, no VB, and I was was cold, waiting for that slow gas pump to fill it up. Seriously, I may start wearing VB's more often, even in real life...

By the way, I like that your jacket has the pit zips. They would be invaluable in keeping vented properly, allowing a wider range of activities.. most likely.

Yes, pit zips would probably be very handy. I have been surprised to find that, except maybe for my back, my arms, while hiking, have been what seem to heat up quickest and where I 1st notice impending sweat. I don't have pit zips on my VB shirt.

A couple of winters ago is when I first started experimenting in using VBs for other than extreme cold and/or inactive times. I was inspired to do that when reading of Andrew Skurka using them while shoveling snow off roofs at high elevation CO ski resorts(Breckinridge maybe?). There is no question the VBs keep me- while active- far warmer with less insulation, but I have also ended up soaked in sweat at skin level(but insulation still dry). So it is a definite learning curve. Perhaps an art form.

"I won't be caught without a VB layer in any kind of cool temperatures,". Yep, you have come a long way quickly into the lunatic fringe! I don't feel near as lonely as I did for years! It is nice to know of some fellow lunatics!

(see following post on less positive results)

[BillyBob58]

Conditions: 41F, humidity 77%, grey/clouds/no sun, wind out of north 7 mph

walk 1.8 mi at average speed 3.7 mph, plus 2 sprints of ~ 10 secs each just to generate more heat.

Gear tested: The long sleeved cotton shirt I was already wearing, with a SWL VB shirt over that, with the ~ 13 oz hooded PG jacket mentioned in my recent posts of the jackets ability to dry out and any warm when wet abilities. Plus cotton jeans and regular daily wear nylon socks inside my old mesh jogging shoes.

Why a cotton shirt, of all things? Just for the heck of it. I have been reading things from you guys with more than the recommended stuff under your VBs. Also, we have been discussing these films with the guys soaking themselves in a creek and then trying to dry out by putting synthetic puffies on and either moving fast or getting a shelter and inside a synthetic bag, plus hot drink/food. We have also been discussing emergency shelters. And with all of this, we have been discussing whether a VB would be helpful in all cases, and if so whether better wearing it next to skin, or over at least some of the wet clothes. Or maybe over all of them in the case of the emergency space blanket shelters. Etc. We have thrown out some theories and opinions, but don't have any testing to back us up.

So I just felt like trying the worst possible item for cold weather- a cotton shirt- under the VB and light jacket. Just to see what would happen.

Of course, this is only a short outing and uphill with a pack could definitely result in more heat output, although I was breathing pretty hard after my so called 10 sec sprints.

It was probably the most comfy I have ever been in a VB or without one. You may recall, on many similar tests by me, I have felt very warm, and or very humid, and even starting to sweat. And perhaps venting.

Results: From the start, I just felt very pleasantly warm, and stayed that way for the entire walk. Except for my legs and feet, which were a bit chilly, not surprisingly. When I still showed no signs of sweat near the end, I just assumed my cotton shirt had soaked it all up, and it just wasn't enough to be obvious yet. I still figure that must have happened. But when I got home and removed all layers, I could find no hint of sweat in either the cotton shirt or the lining of the SWL VB shirt.

Now this was very comfy, probably more than with any other combo. I figure the cotton shirt was less insulative than any layer it might have replaced, thus I was a little cooler, thus less sweat. Maybe? The shirt weighed 10.3 oz soon after I got back, I will weigh it later after giving it a good while to dry out, in case it absorbed moisture that I can not see or feel.

So, what useful info does this give us VB users, if any? Well, if the main goal is to keep ALL insulation layers as dry as possible and thus as warm as possible, then I think the best bet is still to have all insulation over the VB, which is as close to the skin as possible. That may also be best for completely stopping evaporation from the skin and maximizing warmth.

However, it appears there may be more versatility than I realized as far as what we can wear under a VB and get away with it and still stay comfy, and not end up soaking these garments in sweat. Now I am glad I tried this. Also, keep in mind that I had a light weight, wind proof puffy over the VB. Condensation occurs on colder surfaces, right? Without that layer keeping the VB warmer, perhaps- even without noticeable sweat- I would have had condensation when my body vapor hit that cold VB. Like many of us have experienced inside rain gear. Sometimes even inside rain gear that is supposed to be breathable. Maybe by keeping that layer warm my vapor remained vapor? So there is one more thing to test.

Test repeated.
Conditions 47-48*F and pouring rain. Same fast walk, but no 10 sec sprints. Some what different garments
1:long sleeved cotton shirt(same type as before)
2:VB shirt
3: Fleece jacket rather than the 13 oz hooded Polarguard puffy with WPB shell- I would not expect it to be as warm, even though actually heavier(22 oz) than the puffy(13 oz), even before counting the weight of the rain shell. But it is not as thick as the puffy.
4: Marmot WPB Precip hooded rain jacket
5: OR WPB rain pants over jeans
6: Vasque Sundowner GTX Boots instead of jogging shoes as it was quite wet, just to keep my feet drier.
7: fleece hat under rain jacket hood, rather than insulated PG jacket hood

I was much warmer and without question produced some sweat. Still very comfortable, but I could tell the difference. I also vented a bit for the last 1/2 mile. When I got home, I could feel some dampness in the cotton shirt. By no means soaked, but some slight dampness. I kept wearing it in the house(without the other layers of course), and it felt about normally dry in not a real long time. Of course, it was 7 or 8 degrees warmer for this walk, and I had rain pants over my jeans. In my experience, jeans exposed to the cold wind can really cool me down. So I was warm enough to sweat. And who knows, there may have even been some VB effect from those WPB rain pants?

So, definitely got some moisture on the inside with this combo of clothing, exercise and some what warmer weather. Even wearing what I thought would be a not as warm jacket. But that was also because I was noticeably warmer.

However, again, I often sweat while hiking. If I got to camp and stopped, plus I would not be wearing any cotton, would I suffer the severe cool down so often experienced- unless I quickly put on another warm layer ? Would it be as noticeably cold? Maybe even not cold at all, depending on temps of course? Yes, my shirt would be somewhat wet, but that moisture could not evaporate until I remove the VB. My bet is it would not be as bad as we so often notice once we stop after a vigorous hike. But, I'd still be better off with that shirt being over, rather than under, the VB.

The learning curve continues.

[Groundskeeper]

@BillyBob58. The test: The temperature (48 degrees) is probably well above the usefullness of VB's, except in certain situations. What are those situations? Who knows, that's why we continue to test. I think the real value is temps below freezing, but have value in higher temps. Of course humidity and actual rain change the equation also.

I think at 48* I would normally not wear a VB. Having said that, if its raining, as in your test, a VB on the skin or over the thinnest of base layers), then light insulation of some type over the VB, then rain gear, would make sense. As you experienced, you got wet with sweat, but were not cold.

Regarding your last paragraph, I strongly believe that with a VB, sweat or no sweat, you will not get cold the minute you stop. If you do, adding almost any insulation layer will stop it cold (see what I did there).

[SilvrSurfr]

I think we might be the only ones still on this train, but I am reminded that "analytical" starts with "a-n-a-l" lol.

I'm still around. Not much interested in vapor barriers, but I am interested in how many posts and number of words you guys can actually post on this topic. So far, 227 posts and I can't even imagine the number of words devoted to this topic! Given that there are only a handful of you participating, that's amazing!

[cmc4free]

And not a peep from the OP since the very first post. LOL

[SilvrSurfr]

And not a peep from the OP since the very first post. LOL

The OP got his money's worth, and then some!