Synthetic insulated garments don’t compact as well as down garments, but they do pack down much smaller than equivalent-warmth fleece. However, compression is bad for synthetic fills, and repeated or prolonged compression can flatten the fill so it loses its loft. To get the maximum life out of my synthetic garments, I pack them at the top of the pack, using them to fill out any remaining space. I don’t stuff them into the small stuff sacks usually provided with them or load heavy items on top of them.
The Outer Layer
Keeping out wind, rain, and snow is the most important task of your outer clothing. If this layer fails in heavy rain, it doesn’t matter how good your other garments are—wet clothing exposed to the wind will chill you, whatever material it’s made of. In wet clothes you can go from feeling warm to shivering and being on the verge of hypothermia very rapidly, as I know from experience. Rain clothing must be waterproof; it’s more comfortable if it also lets out at least some body moisture.
Don’t, however, expect too much from rain gear. In heavy showers you can expect to remain pretty dry. At the end of a day of steady rain you’ll probably be damp, even in the best waterproof-breathable rain gear, because the high humidity will restrict the fabric’s breathability. In non-breathable rain gear you’ll be wet from condensation. If rain continues nonstop for several days so that you can’t dry anything out, you’ll get progressively wetter, however good your rain gear. This is where wicking inner layers and fleece mid-layers make a difference—they are still relatively warm when damp, and they dry quickly. A wind shell worn under your rain gear will help protect inner layers from condensation on the inside of the rainwear.
Rain jacket worn for protection on a damp, misty day.
If rain keeps up for more than a few days, it’s a good idea to head out to where you can dry your gear. The wettest walk I’ve ever done was an eighty-six-day, south-to-north trek through the mountains of Norway and Sweden. It rained most days, and on several occasions it rained nonstop for a week. The only way I could get my gear and myself dry was to spend an occasional night in a warm mountain hut or a village hotel.
Waterproof-Breathable Fabrics
When the water vapor your body gives off eventually hits your outer layer, it will condense on the inside unless it can pass through the fabric or escape through vents. Over time, this condensation can eventually soak back into your midlayers, leaving you feeling damp and chilly.
The first waterproof fabric that allowed inner moisture to escape with any success was Gore-Tex, which started the waterproof-breathable revolution back in the 1970s. Since then a host of waterproof fabrics have appeared that transmit water vapor to some degree, though Gore-Tex still leads the market. These fabrics work because of a pressure differential between the air inside the jacket and the air outside; your body heat pushes the vapor through the fabric. The warmer the air, the more water vapor it can hold. Since the air next to your skin is almost always warmer than the air outside your garments, it contains more water vapor, even in the rain. Condensation forms on the inside of shell garments when the air in your clothing becomes saturated with vapor that cannot escape. This vapor hits the inside of your shell and condenses on the cool surface. But a breathable fabric lets at least some vapor pass through as long as the outside air is cooler than the inside air. (Theoretically, waterproof-breathable fabrics can work both ways, but when rain clothing is needed the outside air temperature is always lower than your body temperature.) Breathable garments need to be relatively close-fitting to keep the air inside as warm as possible so the fabric can transmit moisture more effectively. However, ventilating any garment by opening the front, the cuffs, and any vents and lowering the hood is still the quickest and most efficient way to let moisture out.
Breathable fabrics aren’t perfect, of course, and they won’t work in all conditions. There’s a limit to the amount of moisture even the best of them can transmit in a given time. When you sweat hard, you won’t stay bone dry under a breathable jacket, nor will you do so in continuous heavy rain, despite makers’ claims. When the outside of any garment is running with water, breathability is reduced and condensation forms. It’s hard for water vapor to be pushed through a sheet of water. With the best fabrics, once your energy output slows down and you produce less moisture or once the rain stops, any dampness will dry out through the fabric. In very cold conditions, especially if it’s also windy, condensation may freeze, creating a layer of ice inside the garment. The easiest way to get rid of this is to take the garment off and shake it.
In wet-cold weather, you need warm clothing between your base layer and your shell. How much depends on your level of activity. Clothing that is too thick compromises breathability. Nick Brown of Páramo has calculated that more than 1/15 inch of insulation will significantly reduce breathability. Many heavy fleece garments are thicker than this. It’s best to wear only enough clothing to keep you just warm while moving rather than trying to feel toasty.
There are two main categories of breathable materials: polyurethane coatings and membranes (see sidebar, page 149). From all the fancy names, you’d think there were vast numbers of coated fabrics. Actually there are only a few, since many garment makers assign their own names to the same fabrics. Proprietary names include Triple-point Ceramic (Lowe Alpine), Helly Tech (Helly Hansen), H2NO (Patagonia), HyVent (The North Face), PreCip (Marmot), Elements (REI), Microshed (Solstice), Texapore (Jack Wolfskin), Omni-Tech (Columbia Sportswear), and Camp-Tech (Campmor). Many makers use Entrant, though not always under that name.
Waterproof (two- or three-ply laminate) (left) and three-layer laminate (right).
Coatings are as waterproof as membranes, but just as they started approaching membranes in breathability, new membranes came along that are definitely superior. I get damp more quickly in even the best coated fabrics (such as Marmot PreCip) than I do in membranes like eVENT and Paclite. However, there is a new polyurethane coating from Toray called Entrant G2 XT that is designed to be almost as breathable as the best membranes. I haven’t tried this yet but it sounds promising.
Membranes are arguably the most effective (and most expensive) waterproof-breathable fabrics. There are far fewer membranes than coated fabrics, with just one generally available—Gore-Tex. Sympatex is still around but is used by only a few makers. However, a new one, called eVENT, looks very promising. Pearl Izumi, Jagged Edge, Montane, and Rab all make eVENT garments. There are a few proprietary membranes, such as Alchemy (GoLite) and Conduit (Mountain Hardwear). An unusual membrane is 3M’s Propore, a microporous polypropylene membrane laminated to nonwoven polyurethane to produce a very soft fabric used in Rainshield clothing made by ProQuip. A similar polypro membrane and nonwoven polypro fabric are used by Frogg Toggs.
Gore-Tex and eVENT are microporous membranes (see sidebar, page 149) made from expanded polytetrafluoroethylene (ePTFE). Sympatex is a hydrophilic membrane made of polyester. Gore-Tex has become a family of fabrics, with the original version joined by XCR (extended comfort range), which is more breathable, and Paclite, which is lighter and more breathable though not as tough as XCR. First-generation Gore-Tex was very breathable, but once contaminated with oil, whether from sweat, sunscreen, or some other source, it leaked—as I found out most unpleasantly on a cold, wet, windswept mountain pass. In second-generation Gore-Tex a thin layer of polyurethane was put over the membrane to protect it. This solved the oil problem but reduced the breathability. However, BHA Technologies claims its eVENT membrane is oil repellent so that a polyurethane coating isn’t needed and water vapor can pass through the pores in the membrane without having to be absorbed into the polyurethane first, a process BHA calls “direct venting.” I’ve tried eVENT garments from Rab, Montane, and Lowe Alpine, and they are noticeably more breathable than any other membrane or coated fabric I’ve worn. Paclite, which has an inner layer consisting of carbon and an oleophobic (oilhating) substance, is the most breathable Gore-Tex material.
THE PICK OF THE BREATHABLES
In the past I found Sympatex to be the most durable fabric. I twice wore out Gore-Tex three-layer garments on walks lasting several months, and three Gore-Tex jackets failed during heavy rain. I gave Sympatex garments more use than the Gore-Tex jackets that failed and never had one leak. That was in the 1980s, though, and Gore-Tex has improved substantially since then. XCR is considered the most durable Gore-Tex, but I prefer Paclite for its lower weight. I have a first-generation Paclite jacket that has had many weeks of wear and is still waterproof. The third generation of Paclite and eVENT are still so new that I haven’t been able to test their durability yet, though I expect both to be pretty tough.
For durability Páramo is way ahead anyway, since there’s no coating or membrane to puncture or peel off. If a garment starts leaking, wash it in Nikwax TX-Direct and it will keep the rain out again. If a garment is torn, you can sew a patch on and the repair won’t leak. (Try that with a laminate!) Páramo fabric is also far more breathable and comfortable than coatings or laminates.
Coated fabrics have the advantages of lower cost and, in some cases, lower weight, but none compares in performance with laminates, let alone Páramo. I would choose a coated fabric only if I didn’t expect to wear rain gear very often. Of the coatings I’ve tested, Marmot PreCip and Lowe Alpine Triplepoint Ceramic perform the best.
My choices are Páramo for cold weather and eVENT or Paclite for warmer conditions or where weight is critical. Garments made with eVENT aren’t quite as light as those made with Paclite but the breathability is better.
Membranes can be laminated to a variety of nylon and polyester fabrics. The thicker the fabric, the more durable the garment. In three-layer laminates, the membrane is glued between two layers of fabric to produce a material that is hardwearing but slightly stiff. Because the membrane is protected by fabric on both sides, three-layer laminates are the most durable constructions. Less durable but softer are two-layer laminates, in which the membrane is stuck to an outer layer while the inner lining hangs free, and drop liners, in which the membrane is left loose between the inner and outer layers. Finally, there are lining laminates, also described as laminated to the drop, where the membrane is stuck to a very light inner layer. This design minimizes the number of seams, which is a bonus. Drop liners and lining laminates are now rarely used in hiking clothing.
Páramo: Soft Shell or Waterproof-Breathable?
The disadvantages of coatings and membranes are that the barriers aren’t very durable, can’t be reproofed when they start to leak badly, and transmit only water vapor, not liquid sweat. However, Páramo Directional Waterproofs, from the company that makes Nikwax proofing products, are very durable, can be reproofed, and allow sweat through to the outside. There are no coatings or membranes. Instead, Páramo mimics the way animals stay dry—a unique waterproof-breathable system that inventor Nick Brown calls the Nikwax biological analogy. This system requires a two-layer material.
The inner layer of a Páramo Directional Waterproof is a very thin polyester fleece, called the Nikwax Analogy Pump Liner, whose fibers are tightly packed on the inside but become less dense toward the outside, like animal fur. To replicate the animal oils that keep fur water repellent, Parameta is coated with Nikwax TX.10. Like fur, Parameta pumps water in one direction only—away from the body. It does this more quickly than rain can fall, so moisture is always moving away from the body faster than it arrives, keeping you dry.
To be effective on its own, the Pump Liner would have to be very thick, however. To keep it thin (and therefore not too warm or heavy), Páramo garments have an outer layer of windproof polyester microfiber that deflects most of the rain. The combination of these two fabrics allows more moisture to get out, including condensed perspiration, than any membrane or coating. It’s not dependent on humidity levels outside the garment or on the temperature inside. The whole garment, including zippers and cords, is treated with TX.10, so it won’t absorb moisture or wick it inside.
I’ve been using Páramo waterproofs since they first appeared in the early 1990s, and I’ve found them very comfortable and efficient. Because there is no coating or laminate, they are very soft and comfortable, feeling more like a soft shell than a waterproof. Reproofing works, and the garments last a long time. There are two limitations. The two-layer construction makes them rather warm and fairly heavy—the lightest Páramo jacket, the Cuzco, weighs 25 ounces. Effectively, you are wearing a wind shell and a base layer. This makes them too warm for me in summer, although some people find them comfortable year-round. From fall to spring, however, I find Páramo jackets and pants comfortable and have never gotten wet or suffered condensation in them. Because the garments are very soft and the lining wicks moisture, you can wear them next to the skin, so you need only one layer instead of three. They are far more effective than any of the new and much touted soft-shell fabrics because they are fully waterproof while being just as breathable and comfortable.
Nonbreathable Rain Gear
Nonbreathable waterproof clothing is made from nylon or polyester, usually coated with polyurethane or polyvinyl chloride (PVC), though occasionally with silicone. Its greatest advantage is that it’s far less expensive than waterproof-breathable fabrics. Polyurethane is much more durable than PVC, though both eventually crack and peel off the base layer. Cheap vinyl rain gear lasts about as long as it takes to put it on and isn’t worth considering, despite the price. Because moisture can’t escape through the fabric, condensation is copious if you wear nonbreathable garments for long. The only way to remove that moisture is to ventilate the garment, hardly practical while the rain is pouring down. One way to limit the dampness is to wear a windproof layer under the waterproof one, which traps some of the moisture between the two layers.
While you’re hiking you’ll still feel warm, even if you’re very damp with sweat, because nonbreathable rainwear holds in heat as well as moisture. When you stop, though, you’ll cool down rapidly unless you put on dry clothes. It’s far better to get damp with sweat than wet from rain, however. Until the late 1970s all rain gear was nonbreathable, and people still hiked the Appalachian Trail in the rain and slogged through the wet forests of the Pacific Northwest.
Weights of nonbreathable rain tops start at 6 ounces. Few name brands offer nonbreathable rainwear. Two that do are Sierra Designs, whose polyurethane-coated Backpacker’s Jacket weighs 11.3 ounces, and Stephenson’s Warmlite, whose silicone-coated nylon rain jacket weighs 6 ounces.
Garment Design
Material alone is not enough to ensure that a garment will perform well—design also matters. The two basic choices are jackets with full-length zippers and pullovers. I’ve tried both, and I much prefer jackets, since they are so much easier to get on and off. That old standby the poncho is still popular with some backpackers. Ponchos are versatile; they can double as tarps or ground cloths. They have good ventilation, too, but they can act like sails in strong winds, making them unsuitable for windy places. Ponchos are usually made of non-breathable fabrics. Examples are Stephenson’s Warmlite poncho and GoLite’s Ultra-Lite Poncho, both made from silicone-coated nylon, which weigh 8 ounces. Hilleberg makes a curious waterproof-breathable garment called the Bivanorak (18 ounces). It’s a poncho-style garment that covers you and your pack but has sleeve
s and can also be used as a bivouac bag or sleeping bag cover.
Length is a matter of personal choice. I like hip-length garments because they give my legs greater freedom of movement, but many people prefer longer ones so they don’t need rain pants as frequently.
Seams are a potential leak point in any waterproof garment. Only Páramo garments have seams that don’t leak without being sealed, because they are treated with TX.10 and are water repellent. In waterproof-breathable garments and the more expensive nonbreathables, seams are usually taped, the most effective way of making them watertight. In cheaper garments, seams may be coated with a special sealant instead. If you have a garment with uncoated seams, you can coat them yourself with urethane sealant. You also can do this when the original sealant cracks and comes off—as it will. Taped seams can peel off, though this is rare. Even so, the fewer seams, the better. The location of the seams is important, too. The best garments have seamless shoulder yokes to avoid abrasion from pack straps.
The front zipper is another possible source of leaks. Standard zippers should be covered with a single or, preferably, double waterproof flap, closed with snaps or Velcro. The covering flap should come all the way to the top of the zipper. Many garments now have watertight zippers, first introduced by Arc’teryx, which are coated with urethane and have flaps that close over the zipper teeth. In my experience these are near enough to being waterproof, though driving rain can sometimes work its way in. I’ve never had much rain enter, though, and I like not having to fasten double flaps. The lack of bulk and slight weight reduction is welcome too. Most zippers open from the bottom as well as the top. These are slightly more awkward to use than single-direction zippers and have no advantages that I can see except perhaps to allow ease of movement and access to pants pockets in very long garments.
Chris Townsend Page 23