Outdoor Clothing: Layering

Windproof jacket & base layer - my most worn layer system

Searching through old files recently I came upon this piece on clothing layers that I wrote for The Great Outdoors a decade ago. I've amended it slightly for posting here. I've left the field tests as they were - as examples they still apply though some of the specific items are no longer available. The pictures are from more recent trips.

I've been thinking about layers anyway as I've been working with Outdoor Gear Coach on its piece on this subject.  

And if you want to see and hear me on layering, there's a video on BMCTV. 

Traditional wisdom has it that several thin layers are better than one thick one, being both warmer and more versatile. This is known as the layer or layering system. Now I don’t always agree with the conventional view but in this case I think it’s correct. Despite all the advances in fabrics and designs layering works and works well. A simplified version of the layer system consisting of base layer, fleece top and breathable waterproof jacket is still promoted by many outdoor clothing companies. 

Base layer, fleece, waterproof - the simple three-layer system

The base-fleece-waterproof system is easy to understand. Each layer serves a different purpose. The base layer wicks moisture away from the skin, the fleece layer keeps you warm, the waterproof keeps rain and wind out. Ideally moisture vapour passes through all the layers including the waterproof shell so you stay dry inside. That’s the theory. In practice this three layer system doesn’t always perform well. Depending on its thickness and the temperature the fleece layer may sometimes be too warm or too cool. As the fleece isn’t wind or water resistant the waterproof layer is needed in cold breezes and light showers as well as heavy rain. However even the best sealed waterproof fabrics have limited breathability so condensation is likely to occur at times, leaving you damp inside.

To improve the performance and comfort of the basic three layer system more layers and different fabrics can be added. This makes the system more complex and more confusing though, especially as some fabrics combine the properties of two or three conventional layers. How well do different fabrics work together? Are wool base layers compatible with high-tech synthetic mid layers? How do the various types of soft shell garments fit into the layer system? Is there a place for old style windproofs? What about thin synthetic insulated garments? And Pertex/pile and Paramo? With masses of competing garments all claiming to be the solution to comfort in all weathers choosing the best clothing system can be difficult. Here I hope to provide some guidance. Over the last few years I’ve been trying a wide variety of different combinations to see how various garments work together.

First though, some words of caution. Everyone is different. Some people run hot, some cold. Some sweat heavily, some barely perspire. How your body functions needs taking into account when choosing clothing. If you always wear more clothing than companions then thicker, warmer garments will suit you. If you arrive on every summit soaked in sweat then fast wicking, quick drying, lightweight breathable clothing will be the most comfortable.

Also, a layer system needs to be used efficiently to be comfortable. Layers should be put on and taken off as conditions change. A base layer may be all that’s needed when climbing a steep sheltered slope even on a cold day. A windproof layer may be added to cope with the wind when you reach an exposed ridge and then a warm layer when descending from the summit, where you have cooled off while looking at the view or resting. Constant adjustment is the way to work a layer system.

Layers can be worn on the legs, head and hands but here I’ve concentrated on the torso, as this is the key area. Note though that appropriate leg, hand and head wear is needed to accompany a layer system.

Wool

The modern layer system requires fast drying non-absorbent synthetic base layers to work. So went the conventional wisdom. However merino wool and wool/synthetic mix base layers prove that this isn’t true. In fact I find thin wool base layers more comfortable over a wider range of temperatures than any synthetics. I’ve worn merino wool base layers under soft shells, windproofs, fleece, synthetic insulated tops and all types of waterproof shells and they have always worked well. They do sometimes get damp but so do synthetics and wool is warmer and more comfortable when wet.

Soft Shell without membranes

This category includes stretch woven fabrics like the various Schoeller materials and The North Face’s Apex fabric plus microfleece lined windproofs like Marmot DriClime, Buffalo Teclite, and Rab Vapour Rise. The stretch woven fabrics are less wind resistant than the microfleece lined windproofs but more abrasion resistant. Both are very breathable and similar in warmth to a lightweight fleece such as Polartec 100. They are water resistant but not waterproof. I find they fit well in a layer system in cold weather, replacing fleece. They can be worn as the outer layer in all but heavy or continuous rain, which means a lightweight waterproof is all that’s needed as it will be in the rucksack most of the time. I have tried wearing a microfleece lined windproof over a stretch soft shell and found the combination very good in very cold windy weather. Together the two garments resist all but the heaviest rain while staying very breathable.

Soft Shell with membranes

Sandwich a windproof membrane between thin layers of stretch soft shell and the result is a completely windproof and very water resistant garment. Gore Windstopper Soft Shell and Polartec Powershield are the best known fabrics of this type. I’ve tried several of these garments and whilst the weather protection is welcome in severe storms they’re not as breathable as I’d like, especially in damp conditions. Powershield is more breathable than Windstopper but I’ve got very damp in both. Underarm zips help with ventilation but overall I think these garments are best suited to cold dry conditions. Most will keep out all but very heavy rain so a waterproof shell isn’t needed very often. When I have worn a waterproof over the top I’ve had more condensation inside than usual. I think having two garments with membranes really slows the passage of moisture vapour. 

Windproof jacket worn over a synthetic insulated top in a bitterly cold wind

Windshirts

My favourite addition to the basic three layer system is a thin windproof or windshirt, the garment I wear more than any other. Except in heavy or continuous rain a windshirt provides all the protection needed and is far more breathable than a waterproof (if you only use your waterproof when it’s really needed to keep you dry it’ll last far longer too). For year round use a single skin windproof is much more versatile than any soft shell as insulation is minimal so the garment is rarely too warm. A windproof can be worn over a fleece and base layer in the cold and over the base layer alone in warmer weather. In rain a windshirt can be worn under a waterproof and will provide a little warmth and help keep any condensation away from inner insulating layers. Windshirts are very lightweight and very low in packed bulk and so a minimal burden to carry. They are usually made from lightweight nylon and polyester, often types of Pertex. 

  

Insulated tops

Synthetic insulated top as outer layer on a cold day

Garments insulated with synthetic fills like Primaloft are ideal for damp cold weather as they are windproof, breathable, warm when damp, water resistant and quick drying. I’ve worn the thinnest versions on cold stormy days and they haven’t been too warm even when I’ve had a light fleece or soft shell underneath. They can replace a fleece in milder weather too. Thicker synthetic garments are best worn during stops or in camp and as a back up in case of severe conditions. I much prefer one of these tops to a thick fleece, windproof or not, as they are much lighter, less bulky and warmer.

Down provides the best insulation for the weight and bulk of any material. Even the lightest tops are too warm for me to walk in unless it’s bitterly cold however. However down is excellent to wear in camp, at rest-stops and as an emergency back up. I like jackets that are big enough to wear over all my other layers so I don’t lose heat by having to take any garments off.

Any room for standard fleece?

Ordinary, breathable, non windproof fleece still has a place in a layer system of course. However if such fleece makes up your only mid layers then a waterproof shell has to be worn more often, reducing breathability. I still like the thinnest fleece tops, made from fabrics like Polartec 100, Polartec Powerstretch and Paramo Parameta S. One of these worn with a thin windproof gives the same protection as a soft shell whilst being much more versatile as you can wear each layer separately. In cold weather a soft shell can be worn over or even under a thin fleece. I’d much rather have this combination than a thicker fleece, again because of the versatility, so I don’t carry thick fleece even in cold weather. For extra warm wear an insulated top is a better choice, giving more warmth and better weather protection for less weight and bulk than thick fleece.

Waterproofs

Wearing a soft shell or a windproof reduces the need to wear a waterproof. It doesn’t mean you never need one though. I’ve been soaked in soft shells and windproofs and needed a waterproof just to keep warm. Much of the time your waterproof can be in your pack though. If you stick to the traditional approach and your waterproof is your only wind and waterproof layer note that light fabrics won’t last as long or provide as much protection as heavier ones.  

Waterproofs are for rain

The Heretics: Buffalo and Paramo

By now some readers may be thinking what about Buffalo and Paramo? Don’t they have a place? They do of course, but they don’t fit easily into more conventional layering systems. Buffalo Pertex/Pile garments, along with equivalents from Montane and other companies, really can replace several layers. Worn next to the skin Pertex/pile functions as base layer, warm layer and, in most conditions, outer layer. It’s not waterproof but it is comfortable when damp and dries fast. Breathability is good and it keeps out the wind. However the thick pile inner makes it very warm and even with good ventilation options I overheat in Pertex/pile in all but the coldest, stormiest weather. And when it’s the only garment you have it’s either on or off. However for those who feel the cold it can be a good choice. A second layer is still needed for rest stops, especially when the Pertex/pile is wet. This can be another Pertex/pile garment such as the Buffalo Belay Jacket, an insulated top or a lightweight waterproof. 

Protection from Paramo in a blizzard

 Paramo Directional Waterproof shell garments are much more versatile than either Pertex/pile or soft shell in my experience. They keep out the rain and the wind whilst being very breathable. The thin lining makes them warmer than other waterproofs too so they are not garments for warm temperatures, except for those who feel the cold. Overall a Paramo shell is roughly equivalent to a windproof top and a lightweight soft shell or fleece. For me that means a Paramo shell is comfortable in wet or windy weather when temperatures are below 10c. I often wear one between October and May. Sometimes a base layer is the only garment needed underneath though in blizzards, gale force winds and sub zero temperatures I wear a thin fleece or soft shell as well.

Putting It All Together

Layering for the cold

After trying various combinations of garments I’ve come to the conclusion that there is no one layer system that is better than others. For maximum versatility and comfort the old principle holds true however. Several thin layers are better than one thick one, especially for use in a wide range of conditions year round. New fabrics do make a difference as to how the layer system is used. Cover a non windproof fleece with a windproof shell or replace it with a soft shell and you will find you need to wear your waterproof jacket far less often and so only need a lightweight one. I’ve been doing this for many years, having always liked thin windproofs, but the choice in garments is much greater than in the past. I now often wear a windproof top over a soft shell instead of a fleece, which means I need to wear a waterproof even less. 

FIELD TESTS

January

Weather: northwest wind, light snow showers, cloudy, temperature -1°C

Activity: 12 kilometre walk up one peak with 1100 metres

          of ascent. 6.5 hours.

Garments: SmartWool Lightweight Zip T merino wool

          Patagonia R1 Flash Pullover – light fleece

          Mountain Equipment G2 Guide Windstopper Soft Shell

          Mountain Equipment Matrix Paclite/XCR Gore-Tex Jacket

          PHD Minimus down jacket

Notes: Set off wearing G2 Guide over base layer. After a hundred metres of ascent up a steep slope sheltered from the wind I was too hot even with the front and underarm zips open so I removed the soft shell. Only when I was on a high ridge and in the wind most of the time did I put it back on. On reaching the summit I was slightly damp under the G2. I cooled down very quickly so donned the down jacket while I had lunch. Removing this I descended wearing the G2, feeling slightly chilly while in the wind and then a bit too hot when out of it. Once down in the glen I replaced the G2 with the Flash pullover for the walk back to the car. This proved much more comfortable as the fleece was far more breathable than the soft shell and there was little wind. The G2 kept out the wind and shed the snow but didn’t breathe as well as I’d have liked.

Number of layers worn 4

Number of times clothing changed 5

August 

Weather: continuous rain, moderate wind, thunderstorm and torrential rain afternoon. Temperature at 800 metres 20°C.

Activity: 19km walk with some scrambling and 1500 metres of ascent over four summits.7 hours 40 minutes.

Garments: GoLite C-Thru polyester T-Shirt

          The North Face Apex 1 soft shell shirt

          Montane Lite-Speed Windshirt

          Montane Superfly eVent waterproof

          Helly Hansen Thin Air Primaloft Vest

Notes:    A warm, humid and very wet day following two previous very wet days. Streams burst their banks and paths were ribbons of water. Staying dry was impossible but wearing the waterproof kept me much warmer and more comfortable than any other garment would have done. Warm wet sweat is better than cold rain! I only wore the T-shirt underneath and had the hood up all day. After the first hour the T-shirt and my hair were wet with condensation. No other garments were worn as I didn’t stop for more than a few minutes and never felt cold.

Number of layers worn 2

Number of times clothing changed 0

         

July

Weather: Cloudy, rain morning, dry afternoon, breezy. Temperature 11°C at 900 metres.

Activity: 13km walk with 2000 metres of ascent over three summits. 9.5 hours.

Garments: SmartWool Aero merino wool T-Shirt

          Montane Aero Windshirt

          Mammut Cerro Torre Schoeller soft shell

          Montane Hydra-Lite waterproof

          Helly Hansen Thin Air Primaloft Vest

Notes:    I set off steeply upwards in just the Aero T-Shirt and soon warmed up. After a few hundred metres of ascent the rain and wind started so I put on the soft shell, which I then wore for the rest of the day. I was surprised that I only got slightly sweaty a few times and was mostly quite comfortable. The soft shell proved very breathable and not as warm as I suspected. It shed the rain and wind and was warm enough even when stationary so no other garments were needed. A hood would have improved it however. As it lacked one I wore a Paramo Cap.

Number of layers worn 2

Number of times clothing changed 1

May  (TGO Challenge)

Weather: Mostly cloudy, occasional sun. Rain on 6 days. Winds from 25-38 mph on summits on 9 days. Temperatures between 3 and 25°C.

Activity: 13 day backpack. 300km and 14,250 metres of ascent over 29 summits.

Garments: Icebreaker Skin Long Sleeve merino wool top

          Jack Wolfskin Gecko microfleece top

          Rab Photon Hoodie Primaloft jacket

          Montane Lite-Speed windproof jacket

          Montane Hydra-Lite waterproof jacket

Notes: On a long backpacking trip weight is important so garments were chosen on this basis as well as for performance and versatility. The wool top was worn all day every day. Most of the time the Lite-Speed windproof was worn over it. This shed light showers and kept off the wind. In heavy rain I got quite wet but as I never felt cold I never wore the waterproof. One wet afternoon I walked for an hour or so with the Photon Hoodie over the windproof. The Hoodie kept out the rain and proved very breathable. A few times I wore the microfleece top under the windproof, mostly on chilly mornings or cold windy summits. Overall this set of clothing was ideal for the conditions encountered.

FEBRUARY

Weather: Cloudy, dry, occasional sunshine, cold N wind. Temperature + 3°C in the glen, -1°C on the summits.

Activity: 13km walk with 850 metres of ascent over two summits. 5 hours 40 minutes.

Garments:  Berghaus Xstatic Powerdry Zip T

           Haglofs Speed Windstopper N2S Soft Shell

           The North Face BiLayer microfleece lined windproof

           Western Mountaineering Flight down jacket

           Rab Latok Alpine eVent waterproof

Notes: I wore the Haglofs soft shell over the base layer all day. It’s made of a thin version of Windstopper and has underarm zips. The air was dry and I only got slightly damp during the ascent. On the summits the Windstopper top wasn’t warm enough and I wore the BiLayer over it. The combination was excellent in the cold wind. The Haglofs top has a hood, which was very useful and meant I didn’t need to wear a hat.

Number of layers worn 3

Number of times clothing changed 2

JANUARY

Weather:  Cloudy, some sunshine. SW wind gusting to 35mph at 1000 metres. Temperature +6°C in the glen, -2°C at 1000 metres.

Activity: 20km walk and 715 metres of ascent over three summits. 7 hours.

Garments:  Berghaus Xstatic Powerdry Zip T

           Patagonia R1 Flash pullover – light fleece

           Mountain Equipment Microtherm Mountain Jacket

–   microfleece lined windproof

          GoLite Coal Polarguard insulated jacket

          Rab Latok Alpine eVent waterproof

Notes:     I wore the Microtherm jacket over the Patagonia pullover and the base layer all day. The combination was warm, breathable and comfortable. The Microtherm jacket has an excellent hood and pockets and is more designed as a full shell than most garments of this type. The Coal jacket was worn at stops.

Number of layers worn 3

Number of times clothing changed 2

NOVEMBER

Weather: drizzle turning to heavy rain. 40mph wind at 1000 metres. +3°C at 1000 metres.

Activity: 10km walk and 845 metres of ascent up one summit. 4 hours 45 minutes.

Garments:  Patagonia Lightweight Capilene Crew base layer

           Sprayway Lightspeed Powershield soft shell jacket

           Sprayway Primaloft Parka

           Montane Superfly eVent waterproof

Notes:     I set off in light drizzle wearing the soft shell over the base layer. Higher up the drizzle turned to rain and the wind became stronger and colder. The lightweight Lightspeed proved breathable and warm enough while I was climbing. It kept the wind driven rain out for a while but by the time I reached the summit it was wet inside and out and I was very damp. Some of the water had trickled down my neck as the Lightspeed lacks a hood. As soon as I stopped I felt cold so I put on the Primaloft Parka. I kept this on throughout the descent and stayed warm, if very wet. The Primaloft Parka was comfortable and didn’t lose loft when wet.

Number of layers worn 3

Number of times clothing changed 1

MARCH

Weather:   cloud, snow, sun, very windy at times, below

           freezing

Activity:  six day ski tour in the Norwegian mountains

Garments:  Icebreaker Skin Long Sleeve merino wool top

           Patagonia Flash Pullover – light fleece

           Paramo Aspira smock

           Rab Neutrino Endurance down jacket

Notes:     This was a stormy trip with snowfall and wind on five days. I wore the Paramo smock over the fleece and the merino wool throughout and kept warm and comfortable. This was an excellent combination. The Aspira smock has good ventilation options when required.