Waterproof-breathable (W/B) fabrics have a place in the climbing world. Unfortunately, that place is often at the bottom of your backpack.
For as long as I’ve been a climber, much of the outdoor industry, led in particular by Gore-Tex, has pumped the fear of god into me that every drop of moisture that falls from the heavens is one drop closer to my own death by exposure. This brand of marketing has been so effective, in fact, that it has caused climbers like me to wear what amount to $400 Bikram-grade garbage-bags around their torsos and legs, even in perfectly sunny conditions, as they slog up snow, ice and rock toward their own sweaty summit victories.
Waterproof-breathable fabrics, as far as I’m concerned, may as well dump the word “breathable” from their classifications. Only in labs can we actually measure the degree of waterproofness and breathability within a fabric—and it’s worth mentioning that there are no universal standards for testing. Here’s how it’s done:
Typically, water resistance, or waterproofness, is determined by how much water, in mm, can be suspended above a piece of fabric before it penetrates through. (Also it may be sometimes measured in psi). Depending on who you are talking to, the classification of “waterproof” begins around ratings of 2,500mm to 5,000mm.
Breathability is the rate at which water vapor passes through the fabric, measured by grams of water vapor per square meter of fabric per 24-hour period (g/m2/d), often abbreviated to just “g.” There are typically four different tests that may be used to derive this measurement—and all four are prone to yielding different results.
Gear freaks and lab rats like to tweak out over such calculations, but true dirtbags don’t give a rip about any of that. The only rip we climbers give is the immediate crampon spike we put through our brand-new $400 Gore-Tex pants. DOH!
The marketing hype has you believe that the minute differences between each brand’s own recorded performance measurements will drastically affect outcomes in real-world climbing situations. But of course, we all know that that’s not true.
You’ll never hear a climber say, “We were only 200 meters up a gnarly new Himalayan wall, but in just 24 hours I’d produced over 9,000g of water vapor within the square meter that is my torso and armpits. Alas, my jacket was only rated to 4,500g … So, you know. We bailed. #MagnificentFailure.”
More to the point, I’ve always been skeptical about the claims that W/B fabrics perform as they are advertised. Doesn’t it make much more sense that all that sweaty vapor generated by your working body escapes through the neck, cuffs and waist of your coat? I’m not a scientist, but I do know that water always finds the easiest path. I have a hard time believing that water vapor is going to go out of its way to push itself through a dense plastic membrane when it could much more easily escape out of the neck of your jacket.
If that premise is true—that a majority of any shell jacket’s venting will occur through the openings in the neck/cuffs/waist—and I have no way of proving that this premise is or isn’t true (nor, I suspect, does anyone else)—then is there any real difference (beside the price) between a W/B jacket and a coated nylon shell?
Um … perhaps. I actually have experienced the true “joy” of a W/B jacket’s “breathability,” always in the following circumstances: several hours of hard uphill sunny glacier/mountain travel while wearing a zipped-up W/B jacket. In other words, I had to literally all but soak the inside of the jacket with my own sweat before I felt the fabric’s breathability start to kick in.
It begs a question that my shrunken brain was too dehydrated to ask: Why was I even wearing that W/B piece in the first place?
The weight of some behemoth marketing efforts have pushed us heavily toward opting for waterproofness—but in reality, what we as climbers and mountain athletes really need for most situations is breathability.
In recent years, a new breed of breathable, synthetic insulations have emerged that, in my view, are game-changers when it comes how we think about layering for alpine climbing and other mountain adventures. Polartec deserves major props for leading the charge into this new category with Alpha—which I tested (and raved about) last year with the Westcomb Tango Hoody.
But this season, Patagonia has rocked the category with their own proprietary FullRange insulation—which, among a few other subtle differences, seems to be even more breathable than Alpha.
This past spring I had the opportunity to test FullRange insulation in the newly released Patagonia Nano Air Hoody jacket. I brought the Nano Air Hoody rock climbing, ice climbing and skiing in Chamonix, as well as skiing and mountaineering in the Elk mountains of Colorado. I’ve worn it around whisky-soaked campfires in the cold Utah desert, on the sides of big-walls in the Verdon, and I’ve worn it while balling hard around town.
Over these past few globe-trotting months, I’ve changed the way I think about layering for climbing in the mountains.
The Nano Air Hoody, which also can be purchased without the hood, is warm and light (much lighter than fleece, which is a close cousin in terms of performance). It’s extremely breathable. It dries quickly (due to that breathability). It remains warm (due to the fact that it dries so quickly). And most important, it’s comfortable in an impressively wide range of situations—i.e., the Nano Air is cool enough to climb in and warm enough to belay in. Think of FullRange as a performance mid-layer that crosses well into outer layer territory as well.
People used to wear fleece as their mid-layer, with a W/B shell as an outer layer. But in recent years, I’ve noticed a new (disturbing) trend: light down jackets being used as mid-layers underneath W/B shells. Basically, this is the worst of both worlds! No breathability. Little stretch. Easy to lose insulation.
Climbing in the mountains is defined by periods of active performance (the climbing) followed immediately by periods of rest (the belay). You don’t typically climb in downpours, and unless an ice pitch is running wet, you’re often not in danger of getting fully drenched by the elements.
But you will always sweat. What you really need/want is a single piece that can do it all—or at least, perform well enough to do most of it. And breathe really well.
The Nano Air Hoody is the most versatile alpine-climbing jacket that I’ve ever worn. Period. It’s comfortable and stretchy enough to climb in, and breathes well enough to keep me cool and relatively dry even while active. But it’s also insulated and keeps me warm at most belays. Though if I’m really cold, I’ll throw on a big down puffy.
There are limitations to the Nano Air’s performance: namely, it provides nearly no protection against the wind, and despite its DWR coating, it will get wet if you find yourself in that type of situation. (Also, its DWR repellency seems to wash away in the washing machine after several cycles). But even when the Nano Air did get wet, I was blown away by how quickly it dried. One time I wore it up a dripping ice pitch and got fairly soaked. But by the next pitch, the jacket was literally completely dry. Amazing.
The real solution to the Nano Air Hoody’s few limitations is to pair it with a good waterproof layer that you can shove in your pocket and put on at a moment’s notice. I paired my Nano Air Hoody with the Patagonia Alpine Houdini Jacket—a lightweight woven nylon laminate shell with a DWR finish. It’s fully waterproof (10,000mm), packs down to the size of a small orange, and weighs only 6.6 ounces. I kept the Alpine Houdini shoved into the pocket of my Nano Air Hoody, or clipped to the back of my harness, so it’s always nearby and I can throw it on when I need wind protection, or if I’m about to lead up a wet-looking pitch, or even if it starts to rain or snow.
Essentially, I only wore this laminated jacket when I really need it—which was a lot less than my W/B-worshiping brain expected.
There are number of other shell jackets out there that you could pair with the Nano Air as well, some of which are beefier than the Alpine Houdini (I’d recommend the Patagonia M10). But regardless of which waterproof or W/B shell jacket you choose to pair with your Nano Air, expect it to do a lot more time sitting in your pack, clipped to your harness, or stuffed into the pocket of your Nano Air. Trust me, your sweat glands will thank you.
Photos courtesy: Max Turgeon/Patagonia