# question on goretex performance



## warlo (Aug 3, 2020)

So i got myself a bivy sack (NL explorer hooped bivy sack to be more specific) and been using it for about two weeks now. Ive been under the rain with it 3 times already and im noticing that while im not getting wet myself, the inner part of the bivy is. I was about to throw a rant to the person who sold it but the fact that two of those 3 rainfalls where quite long and strong and i woke up dry make me doubt if thats how its supposed to be. 
I used to carry the camo woodland version of the USMC and that did not happen, also the fabric was way thicker and noticeable layered. Any input on whats going on?


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## Matt Derrick (Aug 3, 2020)

are you sure it's not condensation? maybe from your breath? i don't know a lot about gortex, but it would make sense that it's probably not that breathable.


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## warlo (Aug 3, 2020)

Oh, its very breathable. In fact, thats the point of goretex materials and the like. The thing is it only gets like that whrn it rains


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## Barf (Aug 3, 2020)




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## Deleted member 23824 (Aug 3, 2020)

Are you talking about the Dutch Army hooped bivy? I have one, extremely difficult to source in the U.S. I had mine shipped from the U.K. They are supposed to remain dry in standing water, known to be among the best ever made, but heavy.Only drawback is weak zippers in some of them produced by one of the two contractors that provided them to the military, the others are very solid, but can’t recall the vendors, or which are the good/bad ones.

You are going to get condensation, no matter which bivy you use, comes with the territory. There is lots of moisture in the air, that’s why it’s more noticeable then.


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## warlo (Aug 4, 2020)

Faceplant said:


> Are you talking about the Dutch Army hooped bivy? I have one, extremely difficult to source in the U.S. I had mine shipped from the U.K. They are supposed to remain dry in standing water, known to be among the best ever made, but heavy.Only drawback is weak zippers in some of them produced by one of the two contractors that provided them to the military, the others are very solid, but can’t recall the vendors, or which are the good/bad ones.
> 
> You are going to get condensation, no matter which bivy you use, comes with the territory. There is lots of moisture in the air, that’s why it’s more noticeable then.


yeah, that one exactly. I guess youre right then, cause it is wet but not enough to get me wet, just a bit too much maybe but makes sense if its raining buckets outside for hours.
just as a comment to the people who dont know it, its a great bivy, larger than the woodland camo from USMC and with the hoop and mosquito net window function. i dont think its so heavy or bulky, as the fabric is quite thin somehow. quality is great, I even read that the same factory produces the same bivy for consumer market and its 500 euros. I paid 120 or so for mine with shipping.

weight is 1.2kg, which is below 2.5 pounds kind of. I have the L version, the XL version is about 3 pounds and way too large. In the L version i have loads of space on the hooped part above my head for gear and i can put my day pack with loads of stuff after my feet.


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## Deleted member 23824 (Aug 4, 2020)

I have the larger of the two versions, it is about 3 lbs. That is almost two lbs. more than my Outdoor Research Helium, though that is much more cramped. I also have a Six Moons Design tent that is only 2 lbs., so, three lbs for a bivy is, to me, a lot of weight.


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## trashswag86 (Aug 4, 2020)

Simply put, the rain decreases its ability to breathe -that's why you're only getting condensation when it rains.


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## Rideslow (Aug 9, 2020)

warlo said:


> yeah, that one exactly. I guess youre right then, cause it is wet but not enough to get me wet, just a bit too much maybe but makes sense if its raining buckets outside for hours.
> just as a comment to the people who dont know it, its a great bivy, larger than the woodland camo from USMC and with the hoop and mosquito net window function. i dont think its so heavy or bulky, as the fabric is quite thin somehow. quality is great, I even read that the same factory produces the same bivy for consumer market and its 500 euros. I paid 120 or so for mine with shipping.
> 
> weight is 1.2kg, which is below 2.5 pounds kind of. I have the L version, the XL version is about 3 pounds and way too large. In the L version i have loads of space on the hooped part above my head for gear and i can put my day pack with loads of stuff after my feet.


Would you have a source for that bivy?


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## Deleted member 23824 (Aug 9, 2020)

Rideslow said:


> Would you have a source for that bivy?



Nearly impossible to find stateside, I bought mine from an ebay.co.uk seller. It is hard to find sellers over there that are willing to ship to the states, though.


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## TheDesertMouse (Aug 12, 2020)

Goretex is not breathable enough to prevent condensation. Especially after a few nights sleeping in the dirt. I’ve used gortex bivy’s for years and they almost always have some amount if condensation in them. It’s usually from my breath, but plain evaporation from your body will do it too. I usually wake up with a wet toe-box area.
So it’s normal, wearing socks and long underware helps alot. As well as assuring breath exhaled from your nose has a clear uninpeded path out of the bivy.
I usually stuff the top of the bivy around my head so the edges of the opening(zippers) are pulled tightly around my face so just my nose/mouth area is sticking out. With no bivy material directly below my nose.

It’s important to find a solid way to minimize condensation because in cold weather this can be a critical problem.


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