The biggest dirty little secret in the outdoor industry is that waterproof/breathable rain jackets won’t keep you dry and will wet out. It doesn’t matter if you buy a high-end $450 Arcteryx Gore-tex Parka or wear your bathrobe, they’ll both Wet Out in continuous rain and leave you soaking wet.
What is Wet Out?
Most 2-layer or 3 -layer waterproof/breathable rain jackets and pants are coated with a Durable Water Repellent (DWR) finish that makes water bead up and roll off without saturating the exterior fabric. The breathable layer is often sandwiched under or between two fabrics that protect it or provide a second surface that moisture can evaporate from. Wet Out occurs when the external DWR coating wears off, the jacket’s outer fabric becomes saturated and prevents the internal membrane from passing out water vapor.
This is a good reason to maintain your DWR layer regularly by washing your rain garments and reapplying a DWR conditioner like Nikwax TX-Direct Spray-on Water Repellent Treatment to restore it, but it doesn’t change the fact that the DWR coating will rub off quickly, particularly on your shoulders where your backpack shoulder straps rub it off. It’s less of an issue for runners and downhill skiers because they don’t wear backpacks like hikers.
Wet Out Mitigation Strategies
If your rain gear starts to wet out, you run the risk of getting chilled or even hypothermic in cooler weather. Here are a couple of things you can do to mitigate this risk and still keep hiking.
- Hike faster, keep eating and drinking to keep your core temperature up. Dehydration can accelerate the onset of hypothermia, so keep drinking even if you don’t feel thirsty.
- Put on additional base and mid-layers. While these may eventually become saturated, additional layers will help you retain more body heat. They will also disrupt the transfer of cold from the surface of your jacket or pants to your skin. Your layering system should work to keep the layer against your skin dry and move moisture away from your skin.
- If you have pit zips on your jacket, open them to help vent moisture. Pit zips are underrated in this era of breathable, waterproof garments.
- If you can’t stay warm, set up a shelter and get into your sleeping bag to warm up. It will stop raining eventually.
After reading your LightHeart jacket review I decided to go that route and have never been happier. Thinking Frogg Togg rain jackets are the same thing except without pit zips, which is probably why they are less expensive than LightHeart. DWR coatings are great new or even refreshed but disappoint eventually. I can see the case for protection and features, and have a few higher end jackets, but seem to reach for the old fashipn silpoly the most.
Ditto on why I got a Lightheart, very grateful for that. Works like a charm.
How do you prevent the rain from coming in the open pit zips?
Pit zips are located in your arm pits and are therefore covered in rain. Rain doesn’t pour in.
Great article Phil… been a long time stalker of your page. But haven’t commented in forever. The group I backpack with have a joke that you can only ever get so wet. It just happens to be, whenever I go out on a trip. Great point about looking out for hypothermia. We’ve been out and run across people that aren’t as prepared for that eventual full saturation that will happen, regardless of the $1000 dollar gear or a trash bag with a hole cut in it.
I wear a Simms Guide rain jacket when fishing on a drift boat for 10 straight hours of rain and I have always remained completely dry.
But you’re not hiking. Standing still on a drift boat doesn’t really exercise the breathable quality of a 3Layer rain jacket or result in the same level of abrasion that wearing a backpack over a rain jacket incurs. Anybody can stand around in a $450 gore-tex jacket and stay dry.
Neat jacket though. Love those chest pockets.
I am glad to see that I am not the only one advocating for the use of bathrobes in the outdoors.
What i love about a poncho is that they can double as a dining/ reading fly, esp in the northwest…add an umbrella and moving around camp, even in ho rainforest is easy…decades of Pacific northwest hiking, climbing, backpacking, nothing has kept me more reliably dry than a simple, knee length poncho
Do you have any thoughts about the fabrics with the polyurethane layer on the outside like Columbia Outdry? Seems to me that they don’t wet out and may retain some of their breathability during sustained rain.
I also think that wetting out dramatically contributes to body cooling due to the evaporative cooling effect. All the water that is absorbed by the outer fabric has to dry out at some point and when it is windy will cool you down very quickly. The Outdry fabric doesn’t suffer from this nearly as much.
The only downside I see to the Outdry is that the waterproof layer is more susceptible to abrasion.
Beware, I am biased because I use several different Columbia Outdry raincoats and really like them.
Columbia has sharply curtained the availability of Outdry jackets. The problem with Outdry from a hiking perspective is that it’s very thick and very hot, so you perspire much more when you wear it hiking. I’ve also found the hoods of Outdry Jackets to be plain awful. I suspect they’re all sized for ski helmets instead of humans.
You can prevent wetting out from chilling you with a regular waterproof/breathable jacket by wearing a fleece or wool midlayer. You really only get super chilled if your skin is wet because water conducts cold about 25 times more efficiently than air. A midlayer, as long as it stays reasonably dry on the skin facing side, prevents that.
Good points about how quickly the DWR can wear off. Between wearing a backpack, wading through wet underbrush, getting sweaty and dirty, I need a jacket that will stay waterproof through all that abuse – I don’t want to have to remember to add DWR treatment between trips.
I’ve only tried a couple used high-tech wpb jackets and wasn’t impressed, but it’s probably because the DWR was gone. I’ve been impressed with some cycling jackets and a Columbia light winter jacket (don’t recall the name) I bought my daughter that don’t have “crinkly” water permeable layer but instead, I don’t know, feel more like neoprene – they seem to bead water forever no matter how much abuse they get, but are more like a rain-worthy insulating layer (and pretty heavy/bulky in your pack) rather than anything I’d want to wear/carry in summer.
For summer and shoulder seasons, I prefer an XL Frogg Toggs – covers my pack, ventilates a bit from the bottom, and surprisingly I’ve never ripped on underbrush/branches.
This is why I prefer to hike with an umbrella. I can’t get wet if the rain doesn’t touch me.
Where do you hike ? In the UK the rain is frequently sideways.
I don’t think the outer layer has to become saturated. In a good torrent, a layer of water will flow over the jacket blocking any breathability. Internal water vapour will have nowhere to go, and cause inner layers to wet with body vapour. I suppose with a waterproof breathable fabric, it may evaporate if the weather improves, but I doubt it will dry right up inside without removing the jacket.
DWR = PFAS/PFOS.
These chemicals are really, really bad.
Reason enough to avoid current formulations of DWR.
For years and years, I have been plagued with wet-out; but the cure is simple and cheap. A cape! I have used an old fertilizer sack cut open to give a hood and shoulder cover which to a large extent worked. A tent footprint as a cover-all cape and that though ungainly worked well. Now I have a tape-seamed sil nylon commercially made backpacking cape which doubles as my ground cloth and a pack cover. Now I stay dry and comfortable ……Great!
That’s a nice multi-use option, Big T.
When I first started backpacking in my youth all I could afford was an Army poncho. When I could afford it I purchased Goretex jackets and always experienced the inevitable wet out no matter how much I treated it with DWR products. As the years passed I tried a poncho again and realized for me that’s
the way to go. Protects me and my pack. Only downside is in strong winds it can be a bit unruly.
Hi Mitch, a length of bailing twine if to be found, a bungy or a designated belt or tie around the waist controls the wind or better still loops inside the poncho/cape that your hand can hold is best. (See large cycle capes)
Ray Jardine, more or less the originator of the light weight backpacking movement, made the same observations in his early books about his experiences on the Pacific Crest Trail, back in the early 90’s, with a bit more focus on the fact that sweat will soak you from the inside, and that’s on top of Wet Out. Maybe his major insight was using a trail umbrella in all “drizzle” conditions, and when that didn’t work, go to full waterproof plastic materials, and wear a little as possible under the plastic. Very lightweight umbrellas are now available. I used one to do the TMB in France, rained nearly every day, worked great, and its an EDC item in my summer day pack in the mountains.