Bivy bags and bugs

I am considering purchasing my first bivy bag for summer use when I go solo, but I would prefer not to spend a fortune for one with built in bug netting. Do any of you sleep with your head exposed? Do you think a mosquito head net and a beanie over the ears is sufficient to ward off creepy crawlies? Thanks!

PS: Did sleeping in the open freak you out the first couple of nights? Are you over it?

I used to sleep exposed all the time in the service. If the skeeters were bad I would drape a t-shirt over my face. It seemed to work and you get used to the shirt.

Bivy bags are not for everyone. They can be as heavy and expensive as a tent. The ones that are not weather proof should be used with a tarp. None of them will protect your gear or let you sit up and move around in a rain storm. Good luck getting out to pee when it's poring rain and you have no tarp to keep the rain out of your sleeping bag as you exit.

A friend used a bivy camping in the snow a few weeks ago and woke up to a bivy full of ice - they can condensate pretty bad.

I use a tarp (won't catch me dead in a bivy, too claustrophobic) and have had no issues with bugs or snakes, but then again, I usually hang a hammock under the tarp. I've tarped on the ground with one incident of spider bites caused by my lack of care in site selection. You should mention where and when you are going to use it. "Summer" can mean spring conditions or really hot weather, depending on where you are going.

I like a bivy a lot. Agreed, some are simply mini-tents, with equivalent prices and weights. A "real" bivy will weigh a pound or less. No problems with bugs for me.....

I too have done 10-day trips in a bivy withoug a tarp - in the Sierra. I do not do bivy without a tarp if I expect a lot of bad weather. You could put on a mosquito headnet if your bivy does not have a built-in bug screen. I personally would not own a bivy without a bug net. Like others said, a bivy is not for everyone. You should borrow one and try it before investing in one. The bivy was designed to fit into very tight spots (like on a ledge up on a big climb) and provide protection from very foul weather (not expectation of comfort or ease of getting out to pee). There are a lot of bivys on the market nowadays that are basically sleeping bag covers- not complete protection. These are lighter. My complete bivy weighs 1 pound 5 oz. You do get wet getting in and out in a rain. You try to avoid this. Because of this, you want to be in a climate where you can dry things out. I find that afternoon thunderstorms and sunny mornings are OK for a bivy; a week of drizzly rain is NOT. Here are a few photos. The first two were on an 11-day trip in the Humphry's Basin area in August where there were afternoon storms, the last is on the way to Keweah Basin in September where it was clear but it froze hard every night. The second photo shows the mosquito net. I use my trekking poles to raise the head of the bivy- making it like a little tent. Yup- that is a mosquito in the photo!

Once you get into those fancy bivy sacks with the hoop hood etc, they become just as heavy as some one-man tents.

By the way, I put all my personal gear and my pack inside the bivy and use the pack as a pillow. The only thing left outside is the bear can and cook gear. I am small enough to pull this off. If you are big, it may not work.

Thanks so much for answering, everyone. I live in Southern California and our weather is about as predictable as Super Man's outfit. So I would not be planning to bivy in the rain, but it would be there mainly against wind and dirt.

If you venture into the mountains much you may find the weather to be less predictable.

You'll want to be ready for snowfall in summer at higher elevations... happens to me every August.

Might consider a bug (netting) bivy and a light tarp in case.

Cheers,

I'm leaning toward a Snug Pak Jungle Bag combined with a tarp and light ground cloth. My primary goals, bug protection, compact size, and light weight would be fairly well attended to.

Pack - 2 lbs
Bag - 1.8 lbs
Tarp & Ground cloth - 1 lb
------------------------
Big Three: 5lbs

For So.Cal deserts, this seems pretty good and I don't mind having an unsupported netting. I got used to sleeping in a wool-lined ball cap with ear flaps.

Nice pic of the mosquito WD.

Funny how bugs end up ruining a lot of my favorite photos!

If you do desert camping, coastal camping, or coast range, you have creepy crawlies such as ticks, scorpions, spiders, sand fleas that you will never keep out of your bag without a zip-in net. These are not as annoying or abundant as mosquitoes but can do damage. If you go the no-zip-in net route, be sure to check several times a day for any of these little critters attached to your skin and get them off. You also may want to put on fresh bug-dope before bed. And it is not only bugs- I once had a vole inside my sleeping bag. I generally do not use my bivy at lower elevations- only at higher altitudes where there are fewer creepy-crawlies.

Its sounds like you are pretty much set on a bivy sack but here's another consideration. I did a lot of hiking with Boy Scouts and we would arrive at our destinations on each day around midafternoon. Perfect time for a swim and a nap! I was the envy of the adults who were trying to take a nap in their bivy sacks trying to avoid the mossies while sweating their brains out becasue of the afternoon heat. I was lying on my pad in nothing but shorts in my Tarptent with the mossies doing nothing but banging on the door.

Thanks again for the advice. I have a Tarptent Moment but the foot print is a bit large for some of the places I enjoy. It also requires more time to set up. The bivy seems great for those long days when you walk until dark, eat something, and immediately bed down.

Funny how bugs end up ruining a lot of my favorite photos!

This is why Photoshop(tm) was invented!

You've probably already hit the trail to learn these things on your own, but in case you haven't or you or others could use some additional insight, here's my 2 cents:

I spent 4 months hiking the AT. It got old really quickly setting up my tarp or my hammock tent. As a result, I became fond of bivouacking it.

In the beginning, I did have this fear of camping out in the open that you mentioned. Fear is overcome by necessity and experience. You will learn your fears are largely just imagination working overtime. The exhaustion of hiking 20 miles a day gave little space for my nocturnal anxieties, as I quickly fell asleep, despite noticing several pairs of glowing red eyes staring back at me from a distance. In a short period of time, you will develop an understanding that animals will make room for your presence and come to feel a natural sense of belonging in this environment. A week is not unrealistic.

I used a cheap Coleman head-net, an Outdoor Research Radar cap sometimes combined with a polypropylene balaclava with good results, keeping the rest of my body down inside my Phantom 32 bag. I used a 24" wide strip of ripstop emergency blanket for a ground cloth and a 20x48" Thermarest air mattress for a pad. The bag shielded me from mosquitoes, and the cap kept the head net off my face. I had no bites on my ears, perhaps because my cap was sprayed with Permethrin. Since I mostly slept on windy vistas and cool areas near water, the bag wasn't too warm even in summer heat. Just don't fluff the down when it's hot.

It's a good idea to spray Permethrin on your ground cloth to keep ticks from getting to your sleeping gear, and to kill anything under it.

I carried a weather radio to plan dry bivouacs. My 7oz Golite poncho was an option as a rain tarp when I couldn't otherwise get into an AT shelter. Pyramidal style pitching with back to the wind ensured my bag stayed dry.

Sometimes in an unprotected bivouac, I did wake up to a few raindrops pelting my face, which resulted in a sudden panic to get the tarp over my bag to keep the down dry. This is the main reason I'm considering a bivy bag now.

The other reason is, in summer weather, a sleeping bag is more of a luxury item than a necessity. A bivy bag combined with the thermal layers I already carry for alpine transit and a simple SOL reflective emergency blanket should extend my range down to 45-50F and reduce my pack weight the 23oz my sleeping bag weighs. The two layers of the bivy bag, thermals and socks should prevent mosquito bite-through.

Most "waterproof" bivy bags I've researched are not adequate enough in the heavy rain of thunderstorms, although they are sufficient for light to normal rain.

A material rating of 1200 mm of hydrostatic head means the material can be immersed to a depth of about 3 feet of MOTIONLESS water without penetration. But as this water begins to move, an additional component of pressure called "dynamic pressure head", also quantified as distance, develops. Even when your bag is not immersed in water, the water of rain can develop enough pressure from movement to penetrate the hydrostatic rating of the material.

You need about 1200mm of hydrostatic protection in light to normal, free falling rain and 3600mm protection for a heavy rain (thunderstorm). A margin of safety is advisable to ensure you stay dry in your gear, as wind gusts add to the pressure of the rain.

Tyvek (olefin made from polyethylene or milk jug plastic), which is what the SOL Escape Bivvy is made from, has a rating usually between 1000-1200mm. I've seen numerous "waterproof" bivies sporting only this much waterproofing. Obviously a tarp is still necessary in this case, as a heavy thunderstorm will leave you soaking wet in your bag.

I want to shed the weight of a poncho/tarp. Getting in an out of a poncho, especially during intermittent summer rain, is not only a hassle, but hiking in it is hot, even with all the ventilation available. The sweat can really pour. I prefer the breathability and quick deployment of a trail umbrella instead, which is also useful for keeping cool in direct sun. Less sweat equates with drier hiking, too. The umbrella can also be deployed as a face cover for the opening of the bivy.

As of this present time, the Montbell Breeze DryTec UL bivy is my favorite lightweight choice. It's rated initially at 25,000 mm of hydrostatic head even after 20 washes. That is more than adequate for heavy rain. Breathability is extremely good at 15,000 gm/m2 in 24 hrs. Claustrophobic campers might prefer a short waterproof side zip which the UL bivy doesn't have (my only complaint), but one can be installed aftermarket. The 25,000mm rating of the Breeze DryTec material should be able to withstand penetration of rain up to just under 50mph according to my calculation.

Although I've used only a mosquito head net in the past, I'd like the option now of pushing the bivy down for hot nights and still having bug protection. 2 oz of Permethrin sprayed bug net fashioned into a half upper body tube with some elastic at the waist and thin dyneema cord to hold the netting up might work to keep netting off hands and face. If the cord slides through a narrow eyelet into the tubed netting, a spring-loaded cord lock can be used to take up tension from inside the netting. I can still bivouac on rock outcrops or treeless areas if I run the cord to higher ground or to nearby trees or bush.

The only drawback to bivy camping in heavy rain I can see is if your breathable bivy sack material uses a DWR coating on top of the porous waterproof barrier that can wear out. I have been advised that in this case, if and when the fabric "wets out", it can't breath, and internal condensation from sweat moisture develops. If you can't dry out your gear because of days of persistent rain, it could lead to a great deal of clammy, uncomfortable bivouacking and wet, useless sleeping bag down.

I'm still investigating this, but it seems to me that a porous material like Tyvek that has no DWR coating, can't "wet out" unless of course wind driven rain or depth of water first forces water through its narrow pores. It seems to me the only time water can wet out the exterior surface of a breathable waterproof fabric is if the fabric is laminated to a non-waterproof fabric on the top surface (like simple nylon) that could "wet out" without pressure. I'm not all that familiar with the construction of these materials, so If anyone has any insight here, I'd appreciate your input.

My Tyvek tarptent wet out, and the bathtub floor filled with water, in four hours in a Pacific rainstorm.

I was in the car up the hill after the first few drops hit my forehead. Got out and packed up after "dawn" (it was still raining) and dumped many gallons of water out of the tent before packing it into a trash bag and driving home. The tent was seam sealed per manufacturer instructions.

Don't trust Tyvek. It's for light, short showers, not sustained rain.

I appreciate your experience and insight. How would you characterize the rain during your Tyvek fiasco: light, normal or heavy? How about wind speed?

Yeah, that's the gist I got from the gear advisor--sustained rain for many hours on a porous waterproof/breathable fabric without sufficient DWR will wet out and fail.

I find Doppelgänger's response above fairly accurate. Also see my notes on bivys in the gear forum (just posted).

I occasionally use a bug net of the type described (comes to my waist). Works fairly well, especially when I hang the top from a loop in my poncho/shelter, but just s cap brim will keep it off my face. I find it a PITA to get in and out of, so use it only when bugs are really heavy. My first bivy (see above) did keep out almost all of a really heavy rain, and I liked the zip net (kept off mice and other criters as well), but it was just as heavy as modern solo tents.

Males find the midnight-in-driving-rain problem easier. I carry an extra bottle I do not use for drinking (but I also carry rain gear in addition to the poncho).

Comment about night fears is a giggle to me. As many nights as I've spent alone on the trail (I'm 77, started backpacking solo in high school), I tend to not sleep real well the first night or two (and the only critter larger than a mosquito that has ever attacked me in the bush was a moose).

Just for giggles, I've also never learned to get into my sleeping bag in the dark smoothly. It's always a PITA, especially if I'm a little damp.

best, jcp

Twas a Pacific rainstorm - it dropped several inches in a few hours. We were in a sheltered location and had no wind, thank goodness.

I was torture testing the tent, knew better and did it anyway. Some of the PU coated tents the other campers had failed miserable as well. It pays to have the right gear.

Some good advice: when bivouacked in Moose territory and you hear something in the distance akin to a brontosaurus trampling down brush--DON'T MOO. lol A mother and her calf had come tromping through my camp. I was lucky I had already packed my gear when that happened.

Thanks for your response and I'll take a look at the posts you mentioned.

Cheers

That was very helpful to understand the physics involved. Sounds like to me you were in a heavy storm with around 3600mm of rain pressure on a material having only 1000-1200mm resistance. (That would have been fun to watch--hehe.)

In my own experience with a North Face Firefly 25 years ago, I was swimming in water myself during a heavy downpour, but the water was coming in through the floor. My ground cloth was catching rain like a funnel and channeling it down into the tent. I later learned it was a really good idea to tuck the excess ground cloth under the tent floor.

A true mountaineering quality bivy sack will keep you dry. I have owned three and used them for many years, and have been in heavy rain and stayed dry. You do have to zip it all up and lay their like in a coffin. My mountaineering bivy (3-layer gortext top, coated nylon bottom) weighs 1 lb 6 oz. There are tents nowadays that are not much more than that. The UL bivies are not intended to protect you in a driving rainstorm. A bivy is really a bit fragile - after some use then end up with tiny prick holes in them with some of the waterproofing scratched off. For a cost of over $200, mine lasted only 3-4 years each. The best thing about a bivy is that you literally can sleep ANYWHERE! End hiking, hop in the bivy and you can even cook dinner in the cold while being cozy inside.

The bug net in a bivy is really light and honestly I do not see that it adds that much cost. I zip up the bug net a lot. I also rig the top of the bivy to my trekking poles so that the bug net is well above my face.

As much as I really like sleeping under the stars in a bivy, I now spend most nights in a Tarptent Moment. This tent actually cost less than my bivy.

The thing that appeals to me about the bivy is like you said, the ability to camp almost anywhere. I hiked the AT through, and I loved sleeping near loud streams. The white noise recharges me for the next day without fail.

Sometimes I slept on granite slabs near falls or on vistas, and there was no place I could plant a pole or stake to plant a tarp. I realize now that with a little line and/or a stake, there is almost always a place uphill or nearby to secure it to at least lift the netting off my face and arms.

How diligent were you (wandering_daisy) in keeping your bivy clean and the DWR maintained? I've been hearing many negative reports about the performance of even the best of the breathable/WP fabrics in persistent and/or heavy rain that it has elicited some hesitancy in my electing to use a bivy without a tarp during such weather.

Non-breathable tent coatings can pass water? haha Now there's a new concept for me to digest, so I checked the hydrostatic rating of my 2010 Golite silnylon poncho tarp. 1200mm! It was a soaking waiting to happen--no better than Tyvek! Fortunately, I never found myself in it during a heavy storm on my thru-hike (thank god that one night in Maine I was in a shelter and not under that tarp. Even the shelter leaked that night) My down bag would have been soaked.

I'll never buy another piece of rain gear again without checking the rating first. Holy cow, only 1200mm. Thanks for the heads up.

Google "silnylon misting" for hours of fun. Much controversy re. whether water is working through the fabric or if the force of rain is knocking off condensation.

Cheers,

Oh, now that's funny! haha! The same fabric nonsensical conspiracy theories are made out of ... Behold, the hand is quicker than the eye! Belief is suspended! The mind is momentarily restrained!

Good one!

Silnylon clearly leaks under lab conditions where there is no hiker sweating and breathing inches away from the fabric and the hydrostatic column of water. In my case, it took 1200mm of water to push a given amount of water in a given amount of time through the sample to quantify the waterproofing resistance of the material.

When that water trickles from the pipe and through the fabric, I can assure you, it isn't condensation knocked off the sample by a hammering rain.

That's not to say such doesn't happen with a sweaty, humid breathed hiker, all clammy and miserable in his nightmare of a tent. But that happening doesn't preclude the dynamic pressure of rain exceeding the rating of the fabric and leaking. It's not an either/or phenomenon. I can have a leaky crack in my car's windshield, and fog it with my breath till it runs, simultaneously.

Thanks for the heads up, Rick. I'll definitely Google that. I could use a good chuckle!

I've got the Jungle bag and it's great! very comfy, the bug net works well, but you've got to either get used to it being on your face/head, or buy a pair of fiberglass tent pole sections to form a half loop to keep it off your face. You can also add a liner of some type to stay warm if the temp lowers. I've used in temps ranging from 45 to 90. It's rated to 40, but you'll need to be dressed appropriately inside it for that to happen. It's a great warm weather bag. I've also used it with a piece of Tyvek for both ground cloth and tarp, along with a surplus gov't bivy sack. weighs out about 2.8 lbs total.

I think you are making some mistaken assumptions here. The problems with the tents were that they were cheap - very cheap car camping tents are frequently rated 600mm and not seam sealed, and it was mostly coming through seams.

1300mm silnylon endured a couple hours of downpour in Evolution Valley this past summer without a leak or a single drip - I have a great little Lightheart Solo tent that withstood it wonderfully. I seam sealed it before going out with it per mfr suggestion. However, in other conditions, such as last weekend on the coast (Point Reyes) where humidity was high and the ground muddy after 9 inches of rain over the past weeks, no one escaped heavy condensation inside and outside the tents - not the PU coated tents, not my tent, not the tarp. All were wet inside and out. But fortunately we know how to handle condensation.