winter tent of non waterproof fabric?

This may be a really stupid idea, and if so I'm sure that somebody will correct me, but why couldn't a pyramid style tent be made of non waterproof fabric for very cold climates? WB fabrics have issues with condensation and so do double wall tents if sealed up too well. Rain is not likely, and even if it does rain, wouldn't a DWR treated nylon keep the water from seeping through if you did not touch it? In the 70's and 80's I spent many nights in old canvas scout tents that never leaked if you did not put your hand on the walls. (The oil on your skin would provide a pathway for the water to leach through the fabric) Now admittedly cotton swells up when it gets wet, but most nylons are tightly enough woven to keep out the wind so with DWR shouldn't they keep water out?

Anybody care to comment?

I personally haven't found it makes much of a difference. I've used a cheap as heck nylon dome tent for my winter excursions for years now (the winter of my discount tent) and stuff can condense on that just fine too (even though the fabric will in theory, breathe). What matters a lot more is what you leave open or have vented, and what you do to decrease condensation in the tent (like a candle lantern hanging in the top.). I've done the canvas tents too, they also
end up covered in a nice frosty layer if they're buttoned up good. Vent Vent and more Vent - your
tent can't keep you warm.

So, theoretically, you should be able to build a cheap winter pyramd tent out of ripstop nylon or some similar material. Which is easier to build, square/hexagonal pyramids or round teepees?

Whatever takes less sewing, although I expect the rounder (hex) shape to do better in wind if it
is an issue.

Funny you should ask this, because after preparing to do the same thing myself, I couldn't justify
80 bucks worth of nylon and lots of my time (I'm a mostly inept sewer so I'm slow) against $150 for
a golite shangri-la 3 on ebay (the one I link in the pics in the make your own gear forum) - I splurged this year so that's what I'll be taking out a bunch.

I agree completely. I'm a reasonable sewer, but can't get myself to commit the time it takes to make my own shelter. All the seams are very basic, but a shelter requires a lot of time managing very large pieces of fabric.

"now (the winter of my discount tent)"

BRAVO PHAT!
I see all those years of watching Masterpiece Theater have paid off. As far as I know, the first Shakespearean pun to appear on this site. Well done, sir.

Nothing like a Man of Intellect hanging around with us Commoners <img src="/forums/images/graemlins/smirk.gif" alt="" /> Here, Here! <img src="/forums/images/graemlins/grin.gif" alt="" />

Breatheability in winter tents is not all that meaningful. The real issue is that you've got moist air coming in contact with a cold surface. How breathable that surface is won't matter all that much. Jack Stephenson of Warmlite realized that a long time ago, and so he started making his tents out of two layers of fabric - both coated! the idea beign that the two layers hold a little heat, keeping the inner layer warmer so there is less condensation. How well that works I don't know. But I've had plento of condensatin in conventional double-wall tents, and in single wall tents, and I agre that ventilation is the real key. The big trick is to maintain ventialtion when the storm is raging - not easy to keep the blowing snow out while letting the steam escape. My main strategy is to cook outside - cooking inside means steam, and lots of moisture, and makes for plenty of condensation.

Paul
I also cook inside my winter tent - my old bibler eldorado of nonfireproof material as it were. <img src="/forums/images/graemlins/tongue.gif" alt="" /> I can melt snow and have 10,000 Btu from my stove heating steam to heat my tent. Its like a sauna in the tent - yes when its below freezing, and I don't get condensation because the Goretex "Toddtex" fabric breathes and the roof vents in the single wall tent are excellent, and the heat pushes out the steam. I've been buried in 4 feet of heavy wet snow in the same tent and been completely dry.


If it weren't that many of us have exactly the opposite experience, it wold be easier to swallow some of the silly explanations for things that don't happen to all of us. We may live on the same planet, but we each live in our own little world. Like I have had frost on the outside of my winter bag, but never inside my winter bag.
Jim <img src="/forums/images/graemlins/cool.gif" alt="" /> YMMV
To get back on subject - a piece of canvas makes an excellent winter tent, water proof or not.

Jim - does the fabric on your eldorado have the fuzzy interior or is it the tricot? It has seemed to me that the 3-layer laminates, whether fuzzy or tricot, have superior breathability to the 2-layer ones, and that the fuzzy is the best. Why, I don't know. But it seems that way from my experience.
My experience in Goretex tents has not been what yours has, but then I've never had a Bibler. I made my own goretex tent once, and also tried an REI gretex tent many years ago when I was working there. Had condensation in both. I've also had condensation in conventional double-wall tents even without pitching the fly on the tent. So, single wall of fully breathable fabric - no coating or laminate at all, so one would expect even greater breathability than Goretex, - and yet I had condensation. So what to think? In other words, my experience has been that any fabric, breathable or not, can have condensation, and will if the interior humidity is high
I've been thinking of trying an experiment. I have a single-wall dome I made from coated nylon - have used it for snow camping for the last 15 years or so - and the coating is starting to fade. I made some stuffsacks from the same fabric, and I happened to wash one (it was my foodbag, and had gottten kinda grungy) - and the coating came completey off in the wash. Made me think about intentionally taking the coating off the dome for increased breathability and a little savings in weight. I never use it in the summer, just for snow camping. I've hesitated because it could rain on a backcountry ski trip - though I've never had it happen. But it would certainly be a good test of the relative merits of breathability, since it would be precisely the same shelter, first with and then without coating.

Fabric breathability is a weird thing. I have pants I made from EPIC frabic, and I love them- I find them very breathable and highly water repellent. I also have a BD Lighthouse tent, which I like so far for summer use. But I was interested to read this review:

http://pweb.jps.net/~prichins/tents.htm

Of the Lighthouse as a snow camping shelter. How the same fabric can seem so breathable in clothing and then get such bad condensation in a tent is confusing. Clearly the factors that affect whether a tent gets condensation are numerous

I spent six months in Antarctica doing field research during the 1968-1969 Austral summer. We had to deal with temperatures to -40 F, winds to 80 mph and a lot of blowing snow and sand. The tents we used were made of a tightly woven cotton with a frost liner hung on the inside and sod flaps around the bottom. The tents were sold by Abercrombe and Fitch; no rain fly was provided. They certainly were not light weight at about 15 lb but were comfortable and free of any condensation issues. They were not the pyramid configuration, rather they were the classic mountaineering A-frame style.

The cotton fabric used for the tent walls was pretty much the same as used on the popular single-wall Holubar and REI tents of the 1950's and early 1960's. When it rained, the fabric would get wet on both the outside and inside but would not pass the water through unless you, or your sleeping bag was in contact with the fabric (yeah, I know).

As long as the temperature remains reasonably well below freezing, I don't see any need for waterproofing of tent fabric since the tent is serving more of a wind protective function and certainly does not have to shed rain. Water vapor from cooking and breathing seemed to pass through the fabric of the tent we used.

I expect some of your opposite experience to mine may actually be the "winter of my discount tent" - my cheap nylon tent is exactly that - and small roof vents - I've seen those old eldorados and there is probably a lot of difference to be had even in the amount of ventilation you can get through the eldorado, which is probably a much better thought out design than a 20 year old canadian tire dome tent <img src="/forums/images/graemlins/smile.gif" alt="" /> - of course if you're covered in 4 feet of snow you're actually far less vulnerable to freezing - the snow will insulate you so you're
only at 0 C right at the tent wall .

I expect some of the difference also may be your weather - My deep winter experiences
are *bone dry* and cold. so frost aggressively forms on everything when there is any kind of moisture, and there is almost never a significant amount of snow on my tent, so there's
no insulation factor between it and the outside world. I also don't have a "good" tent
for this type of use like your eldorado. However I know I've had frosty ceilings even in canvas tents in the mornings too. So back on topic, while I agree waterproofing is mostly unnecessary, I personaly wonder whether "breathability" of the fabric matters as much as ventilation and good design for same - i.e. how much of your success with the eldorado is the todd tex, versus just good design and venting. In my experience it doesn't, in my weather - but itsounds like you see different - are we really talking about regional weather
differences in the amount of humidity in the air when it's cold?

Interesting statement in and of itself. I have I agree. It's been my experience the latter is more important than the former in both clothing and tents, which is a personal and subjective observation. YRMV.

MOST of the tents that have been used in extreme cold, as in Arctic and Antarctic explorations, i.e. Amundsen, Scott, Nobili, Nansen, Steger and the current Canadian Forces ARE of breathable material.

If, they were still available, the old Black's of Scotland or "Pioneer" of Vancouver, BC, tents made of "pima" cotton would be my FIRST choice for deep cold use and a Ventile one would absolutely rock....and cost more than a new Toy 4x4, I bet.

My choice for a tent to live in during extreme cold would be my Hilleberg Saivo, no question and with double poles, I would bet this against any tent available and I have used a few. It is quite air-permeable inside and vented so well that moisture has not been a problem....but, anything can happen.