Are there any waterproof or close to waterproof materials that are adequately breathable for a bivy or a tent? There seems to be a trade-off between breathability and waterproofness. The more waterproof a material is the more it condenses moisture from what I understand. The only possible exception to this rule that I’ve seen is the claim made by Outdoorresearch about their bivy sacks. Are the Outdorreasearch bivies really breathable and waterproof or close to waterproof? Is the 3 layer GORE-TEX used by Outdoorresearch the only breathable and waterproof material? How expensive are they? Thanks for any replies.

The Todd-Tex for Bibler and Intergral Designs is waterproof and breathable, but high tunnel vents are still needed. The fabric is heavy and expensive. They have been state of the art alpine tents for many years.

Epic is breathable and highly water resistent. Black Diamond makes tents and bivies that are light and expensive.

TarpTent makes a Tyvek tent that is highly water resistent and breathable. It is well designed and affordable.

The owner of eVent fabric will not allow eVent tents because of fire standards. I have an eVent bivy and it is light and expensive, but performs great.

I use a DriDucks poncho as a warm weather bivy. I like to sleep under the stars and pull it over me if it rains.

Good summary. I'm attracted to the Epic tents for breathability and relative low weight and cost, but would not rely on one in very soggy conditions. The membrane fabrics are more robust, breathe less well, harder to find and much, much more expensive.

And that's basically that.

Cheers,


p.s. The RAB Summit Extreme is made of eVent.

I have a couple friends who own the Epic tents (Black diamond) and swear by them. They've had them a long time and have used them in some very epic conditions, downpour wise. - Having seen them in action I'd have no problems personally laying out the ching for one of those - were I a ground dweller often enough to warrant it As it is when I sleep on the ground it's usually in a solo tent anyway, which the black diamond is not.

Hi Phat. Have you checked out the BD One Shot? Its siren call beckons your wallet.

Cheers,

Rick

Gore-Tex/Todd Tex and eVent are a membrane that gets laminated to some fabric. The membrane is stretched Teflon , that is the gray bit. So the fabric used to laminate that and in some cases a protective under layer , will determine the "breathability" as well as abrasion resistance and weight.
Rab have three tents made with eVent (they call them bivvies) , they are waterproof and windproof but they don't work well in high humidity. Essentially there needs to be a different temperature inside the tent from the outside to expel the condensation.
So they work best when almost fully sealed up in cold weather...
eVent is reported to be more breathable than the other type.
Epic and Soft Tyvek are more breathable but less water resistant. About 800mm waterhead. Silnylon ( as used by Tarptent/SMD and the like) is about 1200mm and some have problems with that.
Franco