I've never used a bivy and so have no experience with one. Under an 8 x10 tarp I have trouble envisioning the need for one for weather protection. Do y'all really encounter circumstances where you benefit from the extra warmth and insect protection of a bivy at the same time?

I remain open to the possible utility of a bivy in combination with my poncho/tarp, which I use on shorter trips when major storm fronts are not anticipated. But I do like the extra living space provided by a 1.5 oz polycryo ground sheet. Stakes and cord are virtually the same with either tarp choice. If its warm enough for bugs I'll likely be in my hammock.

I guess I need to try one out and see for myself. Hard to say no to a new piece of gear...

geoff

"Do y'all really encounter circumstances where you benefit from the extra warmth and insect protection of a bivy at the same time?"

many, many nights in the Rockies :) biting bugs are often out pretty good early and by morning there is often a little ice in the water bottle

I'm certainly not advocating a bivy for larger tarps, I use a small tarp/poncho (5x8'), so it's really not a luxury item :) but I think there are clearly benefits to using a bivy

Ah, my experience in your neck of the woods is limited to fire camps and some spike camps with heavier sorts of gear...

geoff

"Ron is leaving out the fact that you have to add back at least 2 ounces for a groundsheet. And, the lightweight bivies are around 6 ounces, so that cuts down any potential difference to 1 ounce.

The bivy
1. adds warmth
2. resists condensation
3. protects sleeping bag from debris
4. keeps out bugs"

My groundsheet weighs around an ounce and a quarter, so "at least 2 ounces" is not entirely true in all cases.

A bivy may add a slight bit of warmth by cutting drafts, yes
A bivy may resist condensation drips, but may be more likely to cause condensation inside it, which seems riskier to insulation integrity
The argument could be made that the bivy itself may collect debris, and make it more likely to dirty your quilt/bag.
If you already carry a headnet for bugs, the last could be a moot point as well.

In the end, it's different strokes for different folks. Both the big tarp/no bivy and small tarp/with bivy setups have merit, pros and cons abound for both.

Try tarp camping in the high deserts of the west and you will appreciate a bivy to keep
blowing dust and cold out of your sleeping gear. In particular, a waterproof/breathable
fabric will keep you dramatically warmer in high winds.

Oware makes custom sized bivys for people or two person one . I have one of his catbird tarp his stitching and design is great.
http://www.owareusa.com/

Thanks for the comments. I have always been a tent person and have little experience with a tarp, so was interested in Ron Moak's remarks. Not having to use a bivy would make the tarp combo definitely lighter than my tent (GG/Tarptent Squall Classic, 25.6 oz. without stakes).

In my case, my dog (part of my sleep system, lol!) is always with me, so I need a bug-free space not on muddy ground for him, too. I'd therefore need a 2-person (~8x10 ft.) tarp for us in any case--probably the GG SpinnTwinn (cuben is definitely way beyond my budget). That means a 2-person bug net. It also means a ground sheet--I don't want my gear nor my dog's CCF pad nor, for that matter, a bivy on muddy ground. The tarp also needs more stakes (~10) than the tent (6). That all combines to make the tarp combo plus bivy the same weight as my tent.

I have a cheap 8x10 flat tarp (bought for other purposes) and will do some trials with it in the back yard in bad weather, but from what most of you have stated here about the necessity for a bivy, I'd evidently be better off to stick with the tent!

Edited by hikinggranny on 02/24/2011 15:43:59 MST.

I wonder if a Lightheart Solo would be big enough for you and your pup, since it's got the 'side triangle' space.

The Lightheart Solo is heavier than the tent I have. I like my Squall Classic and don't plan to change unless I can save half a pound of weight without having to spend too many $$ (especially since with gas prices going ballistic, my trips this summer are going to cost a lot more).

"The Lightheart Solo is heavier than the tent I have."

Well, yes. But, looking at the pics, do you think it would work, or is it too small for a person and a pup? Thinking about it myself, only I'd get the cuben. Just wondering what you think of the size since you've backpacked with your pup extensively.

How well a tent works for solo hiker plus dog depends on several things, one of which is the size of the pup.

My dog, mostly Lab, is 80 lbs. He doesn't take up a lot of space while sleeping because he curls up in a ball on his 20" x 30" pad, but he close to doubles the amount of air exhaled into the tent. That means that a solo tent designed to ventilate for one person may have serious condensation problems when the dog is added. My experience is with a SMD Lunar Solo a few years ago. In good weather, when we were only in the tent to sleep, with everything wide open, it was fine. My dog just fit in the triangle at the back. When we were confined to the tent by rain for several hours before bedtime, though, it was too cramped. The dog needed more room and so did I! With the vestibule partly closed on wet nights, condensation was a major problem. The one good thing was that I could sit up while still in my sleeping bag, and wipe down all the walls. This worked out fine if I could get it done before my dog woke up and went into his morning tail-wag routine!

I suspect the Lightheart Solo would work fine (maybe not with a St. Bernard or Newfie, though!) when it can be wide open, but if it has to be closed down in rainy weather, that might be another story. I've never seen one so can't comment.

EDIT, later: I'm wondering if the porch or awning version would be better ventilated in wet weather? This might be something to take up with the Lightheart folks?

Back to the bivy/no bivy under a tarp issue: I'd love to switch to a tarp, mainly for the views, but don't see much point if I can't save weight while doing so. Of course I don't want to get wet, either!

Edited by hikinggranny on 02/24/2011 16:25:57 MST.

If I ever buy another "very light" (not waterproof on top) bivy, the thing I would prioritize, apart from weight, is how well it's reviewed as minimizing condensation. What I prefer to do when using a tarp (winter time is a great time for that IMO ...) is to carry a very light bivy and hope that I don't feel the need to use it. Because of condensation. So I'll normally start the night not in the bivy and pull it over the bag if I find that rain is blowing sideways or snow is floating in on top of me or something like that.

There's at least one thread going on this site about condensation in bivies; I've not looked at it in detail, but suggest that you do to select something that will minimize that issue for you.

the thread that todd started on a wet bivy was w/ a Epic top which is very, very water resistant

I think that's the reason why Ron switched to Momentum- more breathable (at some sacrifice to water resistance) for his bivy tops

I've had mine in some pretty soggy conditions and haven't had condensation issues (knock on wood :))

After talking to a few folks I've come to the conclusion it was more the thick fog and too much insulation (making me put off moisture) for low 50* temps.

^ good to know :)