Tarp as bivy?

[vaporjourney]

Since I'm in in my PCT preplanning phase, I'm considering a few gear updates. The one I'm thinking about right now is whether or not I should get a bivy for the desert section of the trip. I know that rain really isn't going to be an issue for the first 700 miles, but evening chill may be. I was considering getting a bivy to help cut the wind chill and add a bit of warmth while sleeping, but still allowing me to sleep out under the stars, cowboy camping style. This would also work well to keep dew off of my sleeping bag.

But...I already have a 8 oz tarp by Mountain Laurel Designs, and was thinking I could just use this as a bivy? The bivy I was looking at was made of silnylon, and so is the tarp. Could I just wrap it around myself and call it a bivy? It would add a bit of warmth, not cost anything, and if rain did develop, I could always pitch it for shelter. I initially assumed that wrapping yourself in a tarp would make you sweat inside because it isn't breathable, but it seems like this is how a bivy would work as well. Feel free to punch all sorts of holes in my theory...

[Frolicking Dinosaurs]

I made a sort of tube tent of 70D coated ripstop many years ago (before silnylon was available). It had a shaped flap of extra material on the part that became the floor that could be pulled up and attached to the ridgeline The flap could be attach to the ridgeline underneath the roof in rainy weather and this also made the structure warmer. I made it so the 'door-flap' left at least a 6" tall triangle of space open at the top so that the condensation issues were reduced (you could lower it to get more ventilation when temp or blowing rain were not issues) The set up served me very well in desert / dry environs and was OK, but not great in wetter environs.

I'll try to draw up some instructions if anyone is interested in using this idea

[jesse]

Feel free to punch all sorts of holes in my theory..

I would be concern with rolling around on the ground might punch all sorts of holes in my tarp.

[Jim Adams]

Most bivys have coated or sil nylon just on the bottom. If you wrap up in your tarp, you will definitely soak your bag with sweat. (yes I tried also...only once!)
Did 1000 miles of the PCT this past spring and was in 3 rain storms and 3 snow storms in the first 500 miles. I thought that it would be dry in the desert but...not always! I did cowboy camp probably 6 out of 7 nights w/o any chill or moisture. I just layed my tyvek ground cloth down, sleeping mat on top and then layed on the mat with my feet in the foot box of my 0* down bag and pulled the bag up over me like a quilt. This worked very well and actually I only zipped the bag twice from the border to Yosemite.

geek

[toddhiker]

I made a sort of tube tent of 70D coated ripstop many years ago (before silnylon was available). It had a shaped flap of extra material on the part that became the floor that could be pulled up and attached to the ridgeline The flap could be attach to the ridgeline underneath the roof in rainy weather and this also made the structure warmer. I made it so the 'door-flap' left at least a 6" tall triangle of space open at the top so that the condensation issues were reduced (you could lower it to get more ventilation when temp or blowing rain were not issues) The set up served me very well in desert / dry environs and was OK, but not great in wetter environs.

I'll try to draw up some instructions if anyone is interested in using this idea
Nice idea!

[Frolicking Dinosaurs]

Not sure this would work with Vaporjourney's 8 oz tarp, but I've done something very similar with my Campmor (Equinox) 10 x 12 tarp (http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=88644)(19 ozs)

This Information comes from page 29 of this 61 page document on tarps: http://www.equipped.com/tarp-shelters.pdf

Illustration so the instructions below make sense
(http://i16.photobucket.com/albums/b47/lowcarbscoop/Illustrationfortarpbivy.jpg)
·Fold tarp in half diagonally, then swing edges AB and AD inwards in a circular arc until they touch the midline fold AC.
·Points F, G, and the Cross-Folds point I are a matter of trial and error, and are variable based on the size of the finished doorway and the extended ‘awning’.
·Secure corner A to ground on Windward side.
·Fold triangles ABE and ADF under at fold lines AF and AE to make doubled up groundsheets.
·Secure groundsheets to ground, reinforcing fold lines with taut ropes.
·Support corner C in air on Lee side. Use rope or ridgepole to support midline AC.
·Spread triangles AEI and AHI to create walls.
·Fold CFI and CGI underneath EFI and GHI to create partial walls from EFI and GHI that frame a low doorway.
·Sections CFI and CGI can fold back against AEI and AHI, to rest above rope running from corner A.
·Pull top of doorway where F meets G forward to make a better awning.
·The doorway threshold may be flush, or may project forward, depending on exactly where the fold Corners are.
·When satisfied with doorway, secure folded cloth with Tarp Clips, lashings, pegs, etc.
·A 10’ x 10’ Tarp may be tight for head and foot space. A 12’ x 12’ tarp should be adequate.

[shelterbuilder]

Since I'm in in my PCT preplanning phase, I'm considering a few gear updates. The one I'm thinking about right now is whether or not I should get a bivy for the desert section of the trip. I know that rain really isn't going to be an issue for the first 700 miles, but evening chill may be. I was considering getting a bivy to help cut the wind chill and add a bit of warmth while sleeping, but still allowing me to sleep out under the stars, cowboy camping style. This would also work well to keep dew off of my sleeping bag.

But...I already have a 8 oz tarp by Mountain Laurel Designs, and was thinking I could just use this as a bivy? The bivy I was looking at was made of silnylon, and so is the tarp. Could I just wrap it around myself and call it a bivy? It would add a bit of warmth, not cost anything, and if rain did develop, I could always pitch it for shelter. I initially assumed that wrapping yourself in a tarp would make you sweat inside because it isn't breathable, but it seems like this is how a bivy would work as well. Feel free to punch all sorts of holes in my theory...

I wouldn't "wrap up" in the tarp, because you WILL sweat like crazy inside of it. HOWEVER, there are two "special" pitches that might work for you with your tarp. (You may have to modify your tarp for one of them, though.) Both of these assume a rectangular tarp.

The first is a simple sloping ridgeline pitch: the front opening is about waist high, but the ridgeline slopes to the ground in the rear. Anchor the two rear corners, and most of the sides, but DON'T anchor the two front corners.The corners will droop toward the centerline of the covered area, and can be weighted with rocks or equipment to keep from flapping in the breeze. If done correctly, you will have a slit-opening at the front of the tarp, running from top to bottom, which should provide ample ventilation to prevent condensation inside the tarp.

For the second pitch, you may have to add either a tie-out or a D-ring to the tarp's ridgeline (be sure to reinforce underneath the tarp and seal the stitches), about 1/4 of the distance from the end of the tarp to the center. (Again, this works better with bigger, rectangular tarps.) Use this point as a "peak suspension point" and hang this point about waist high. Anchor the REAR of the tarp, ONE side of the tarp, and the FRONT of the tarp down to the ground. On the other side, anchor the rear 2/3 of this side, and form your entrance out of the remaining part. Use a grip-clip (if there's no grommet or tie-out) to pull out the peak of the entrance. (This puts your entrance on the SIDE of the tarp, instead of the end.) This set-up can be done with a hiking pole instead of the added D-ring, but it doesn't work well with smaller tarps, because the pole gets in your way inside. Practice this one - it's easier to do than my explanation makes it sound!

[Dirtygaiters]

But...I already have a 8 oz tarp by Mountain Laurel Designs, and was thinking I could just use this as a bivy? The bivy I was looking at was made of silnylon, and so is the tarp. Could I just wrap it around myself and call it a bivy? It would add a bit of warmth, not cost anything, and if rain did develop, I could always pitch it for shelter. I initially assumed that wrapping yourself in a tarp would make you sweat inside because it isn't breathable, but it seems like this is how a bivy would work as well. Feel free to punch all sorts of holes in my theory...

Why don't you just use the tarp as a tarp????

IF you have a synthetic sleeping bag, and you are prepared to deal with sleeping in sweat soaked gear, then of course a tarp taco works, but the only situation I can see where this would have an advantage over just pitching the tarp in a low, stormworthy pitch would be above treeline, in a relatively dry region, and if you're camping in an area where the soil prohibits setting stakes, and there aren't enough big rocks to use as deadmen
...Or if you find that you're really dog tired at the end of a day of hiking. In that case, why not get a waterproof breathable bivy like the MLD Alpine Bivy, or their Soul bivy with the eVent top?

[vaporjourney]

I'm not sure that these sweet pitched would work with my tarp as its tapered toward the foot end, ideal for caternary pitches, and most definitely not a pure rectangle.

dirtygaitors: I could definitely get a bivy, but I was A) trying to save money, and B) making use for what I already had, especially since the weight of my tarp isn't really that much heavier than a bivy will be (assuming i spend less than $100).

keep the ideas coming. I suppose I could pitch the tarp ridiculously low to the ground, but that just makes it a pain to get in and out of, but it obviously blocks all wind, and maybe would trap in a bit of body heat, but i doubt much if it isn't touching me.

[Frolicking Dinosaurs]

VaporJourney, have you got the Monk (http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=21&products_id=41&osCsid=05536e98767b00d315ed6985a5e42ccd), the Graco (http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=21&products_id=31&osCsid=05536e98767b00d315ed6985a5e42ccd) or something else?

[vaporjourney]

Frolicking: I have the Grace Solo. http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=21&products_id=31&osCsid=43ff03e6caf86d0e5c2f8db56e51179d

[Frolicking Dinosaurs]

This tarp is 9' x 7' at the head and 5' at the foot - I would suggest using a ground cloth for the floor and tarping to the ground in a low flying diamond (http://hikinghq.net/gear/tarp.html) configuration rather than using the more standard A-frame and using a wind jacket or rain jacket as a makeshift door at the apex and your pack / other gear lower to conserve heat.

[Dirtygaiters]

I have a similarly sized tarp to the grace solo (maybe a little more tapered at the foot end) and I've been able to pitch it very low. Sure it's a little awkward to crawl in and out, especially if I don't have a groundcloth, because then I'm crawling in wet, sticky leaves, but with a groundcloth it's not so bad. But wouldn't it be even more awkward to get in and out of a tarp taco, especially in the rain? I just don't see the benefit a tarp taco has over a properly pitched tarp except for the single issue of not having to fuss about with guy lines and stakes. It will also abrade the fabric of your tarp.

[dloome]

A couple things: It can and does precipitate anywhere in Southern CA. Seems like most hikers gloss over the San Jacintos in their SoCal planning as well- You're up to 9,000' and NOT in a desert environment for at least a couple overnights, depending on your mileage. All of the PCT in SoCal is often referred to as "desert" which is not quite true. The practical implications for someone on foot are similar in that there is very little water, a lot of sun, and generally hot day time temps, but don't count on it being dry and warm all the time.

Condensation can be a big issue in desert environments- I mean waking up absolutely SOAKED. If you've never spent extended time camping in desert, know that it can get real cold at night, particularly in low-lying areas like drainage areas and canyons. My very first night on the PCT in Mid-May was 28 degrees at the base of the Lagunas.

As for gear, I used the following and would high reccomend it:
Primary shelter- Golite Lair 1 tarp.
Bivy- Bozeman Mountain Works Vap'r.

The bivy is not waterproof but is much more breathable than a traditional waterproof/breathable bivy, provides some warmth, protection from condensation, wind, bugs and rainspray. It also allows for more comfortable cowboy camping if you are squeaming about creepy crawlys. In the desert you probably should be squeamish actually. :) Oware makes a similar, but cheaper model for sale at backpackinglight.com. With some modifications, the combined weight of this setup is just a hair over a pound, VERY stormworthy, and more versatile than a tarp alone.

[Miner]

Using a tarp as a bivy. Bad Idea. You can damage the tarp leading it to leak on you. Despite the fact that it is normally sunny in the Spring in SoCal, it can rain/snow even in May. Some people are caught off guard when this happens and there was a PCT hiker death from exposure in the Angeles NF one May during a storm several years ago. Oh, I've also been snowed on in the Sierras in July, so don't assume you are free from snow storms until north of Yosemite (at least until you hit September in Oregon/Wash.).

So you need the Tarp as a Tarp. If you think you need a bivy for the additional warmth, protection from dew/rain then carry a bivy too. I carry a Titanium Goat Bivy that I bought for <$60 that weights ~5oz. It cuts the wind very nicely and the sewn in Bug Net keeps the mosquitos at bay when needed. As a resident of SoCal, I normally carry a bivy and tarp when I go out backpacking here and in the Sierras though I rarely use the tarp. That is why I bought the MLD grace Solo cuben fiber version that weights less then 5oz. I don't notice the weight so I don't mind the fact that I'm only carrying it for the occasional thunderstorm/freak storm.

[Frolicking Dinosaurs]

The last three gentlemen to post have brought up some excellent points. Due to the temp / weather extremes you can reasonably be expected to face during a thru of the PCT, carrying both a breathable bivy and at least a minimalist tarp would seem to be the best way to go for the weight, the protection and the cost.

[ScottP]

There's a reason that almost nobody uses a full bivy for 3-season hiking. They're sweaty, not that light, and just straight up miserable.

There's no reason to have a bivy on the PCT. Most people only get rained on 2-3 times before they hit washington.

What you might want is a sleeping bag with pertex, or some other water-resistant top to shed the dew. Also, be aware of where you camp. Are you near water? Do you see maritime fog rolling in? Can you camp undeneath some sort of tree to keep light dew off you?

The wettest my down bag ever got hiking was on the PCT when I cowboy camped by lake morena my first night on the PCT. Big deal? Nope. During my seista the next afternoon I hung it to dry in the 100 degree, 10% humidity, full sun.

Also, you should be aware of mosquitos. The PCT has some gnarly mosquitos from the beginning of the High Sierra until some time in early september.

[Miner]

There's a reason that almost nobody uses a full bivy for 3-season hiking. They're sweaty, not that light, and just straight up miserable.


Most people who hike the PCT are into the whole ultralight gear thing and many choose to go with the cottage industries because they are the main companies making gear for the UL community. So I'm puzzled why when most people will talk about Tarptents instead of mainstream tent makers, when it comes to bivies, people still try to compare those hot and heavy ones from the mainstream manufactures who make those same heavy tents that no one wants to carry. There are several companies (Titanium Goat, Bozeman(backpackinglight), Mount Laurel Designs, etc) that make very lightweight bivy sacks that weigh 4.5-6oz. This are made of thin material that do increase heat retention, but nowhere like those heavy bivies.

Thus they don't have to be heavy, just as a backpack doesn't have to weigh 4+lbs or a tent 5+lbs. My bivy sack with a sewn in bug net weights 4.8oz by the way. Depending on the material, you may get some condensation inside them on your sleeping bag(typically around the foot box), but this typically wipes up in seconds with a towel before you pack up. I've seen hikers wake up with ice on their sleeping bag in Socal and the High Sierras in the morning which I consider worse. The west coast isn't the east coast. The humity levels are typically low and thus the temperature at night drops more (no hot and muggy nights). I almost exclusively live out of a bivy sack while backpacking out west.

Another bonus, if you are a quilt user, they also help elimate draft issues.

[JAK]

I've been meaning to get some tyvec and tape it on one side and the bottom of a 72"x28"x3/8" blue foam pad and fold it over as a bivy, but I would use it with a poncho/tarp, but without a ground sheet. Could do the same with nylon maybe, or use the poncho and blue foam pad as the bivy and go to a slightly larger tarp. Hmmm. Thanks for the ideas.

I know that 28" is a bit wide for the pad, but its good to be wider in winter, and you can avoid using a ground sheet entirely, which makes up for the weight. There is still the bulk issue, but 28" works for me. I store it inside my backpack vertically. Takes up about 25% of the volume, but as long as I still have room to spare I am happy. Makes my UL backpack stronger I think. It a JAM2 large.

[Frolicking Dinosaurs]

JAK's post reminded me of an item I made and used back in the 1970's. It was piece of poly-tarp (the cheap blue stuff today but state-of-the-art back then) about 7' x 2.5 to 3' with about 10" of plain ripstop sewn to each of the 7' sides. The nylon was brought together and stitched and had a zipper that was probably 4' long that was located top / center when I was inside. The foot part was stitched shut. This was my winter ground cloth / bivy for tarping. Since I was a skinny-minnie back then, the poly part came up on the sides and blocked wind and rain splatter. I used my pack to block the wind on top of my head.

[Frosty]

JAK's post reminded me of an item I made and used back in the 1970's. 1970's :eek:

Did you also have hob-nailed boots, wool undies, a canvas tent, and a wooden packboard with a tump line? :D

[Frolicking Dinosaurs]

::: Frosty seen tending bitten toes :::

[mrc237]

I used an O-R bivy on the PCT from Campo to Toulemne no rain, no sweat. Miner in post 18 is giving you the best advice its always cold at night in the west!