Waterproof or windproof jacket: the 10,000 mm water column threshold
You come back soaked from a hiking trip, even though your jacket was labelled “waterproof”. The problem is often confusion between a windbreaker and a fully waterproof jacket. A windbreaker can handle a few drops; a hardshell jacket with a membrane withstands a water column of 10,000 mm or more. At 20,000 mm of water column pressure, an Ultrashell® membrane blocks water even when you sit on a wet rock for several hours. Heat-sealed seams stop water seeping through where the fabric panels meet, unlike stitched seams.
Breathability follows the same principle. A membrane that releases 20,000 g/m²/24h lets vapour escape as quickly as sustained exertion in the mountains produces it. Below 10,000 g/m²/24h, condensation builds up inside and leaves you wet from within.
The Ultrashell® membrane: what each layer does
A hardshell jacket with an Ultrashell® membrane consists of three bonded elements: an abrasion-resistant face fabric, a waterproof-breathable microporous membrane and an inner lining that prevents the membrane from sticking to your skin.
The membrane itself is a sheet with pores 20,000 times smaller than a water droplet and 700 times larger than a vapour molecule. Liquid water cannot get through; vapour can escape. The water-repellent treatment on the face fabric completes the system: it makes water bead up on the surface instead of saturating the fabric and reducing breathability.
This water-repellent treatment wears off. It goes first in high-friction areas, particularly beneath backpack straps and on the shoulders. A machine wash followed by tumble-drying on a low heat reactivates it. If water still does not bead up after this, a technical water-repellent spray can extend its life.
Waterproof hiking jackets: CASCADE and COSMIQUES 2
For hiking, two ranges cover the most common needs: CASCADE for versatile outings in bad weather, and COSMIQUES 2 for more demanding use where greater mobility and lower weight matter.
CASCADE has fully heat-sealed seams, front pockets accessible beneath a backpack, and a hood adjustable at three points. Weight: 420 g for the men’s version, with a 2.5-layer Ultrashell® membrane. COSMIQUES 2 weighs 310 g in the men’s version and uses the same membrane, with a closer fit designed for climbing uphill.
Waterproof trousers: three things to check before you buy
Waterproof hiking trousers face different demands from a jacket. You need to be able to put them on and take them off over your shoes, withstand repeated rubbing against vegetation and rocks, and move your legs freely on steep climbs.
The height of the leg opening makes all the difference. Full-length zips on both sides let you put the trousers on without removing your hiking boots; a short zip means you have to undo the laces. The width at the knee determines whether you can bend your legs without the fabric pulling.
The water-repellent treatment on trousers wears off faster than on a jacket because the legs are constantly rubbing against things. After every extended outing in the rain, wash them to reactivate it.
HOGGAR 3 trousers: waterproof on and off the trail
HOGGAR 3 is the waterproof hardshell trousers in Cimalp’s hiking range. A 2.5-layer Ultrashell® membrane, heat-sealed seams at every join and a 75 cm full-length side zip for quick dressing. The pre-shaped articulated knee lets you climb without the fabric holding you back.
Layering: what you wear under your jacket makes all the difference
A hardshell jacket alone is not enough in cold weather. It blocks wind and rain, but it does not insulate. The midlayer, fleece or down depending on the temperature, is what retains warmth. Between 5 and 12°C in wind and rain, a 200 g/m² fleece under a hardshell keeps your shoulders warm without overheating during activity. Below 5°C, a lightweight down gilet replaces the fleece.
The base layer, worn directly against the skin, needs to move sweat towards the mid-layer. Cotton absorbs moisture and holds it against your skin. Merino or a technical synthetic does the opposite: it moves moisture vapour outwards. Wear cotton as a base layer in the rain and you will start to feel cold within ten minutes of stopping.
Care: two mistakes that undermine waterproofing
The first mistake is using fabric conditioner. It leaves a film on the fibres that clogs the membrane’s pores and neutralises the water-repellent treatment. Wash waterproof jackets in cold water with a technical detergent, without fabric conditioner.
The second mistake is laying the jacket flat to air-dry. A 20-minute tumble-dry cycle at 40°C reactivates the water-repellent treatment with heat. Skip this step and water stops beading, saturating the outer fabric. What looks like a loss of waterproofing is actually a loss of water repellency. The membrane remains intact, but its effectiveness drops by 30 to 40%.
Store the jacket unfolded or hanging up, never compressed at the bottom of a bag for weeks. Prolonged pressure permanently creases the membrane.
Frequently asked questions about rainwear
What is the difference between a 2-layer and a 3-layer membrane?
A 2.5-layer membrane bonds the membrane to the inside of the face fabric and has a partial protective coating. A 3-layer membrane bonds the membrane between the face fabric and an attached woven lining. The 3-layer construction is more durable and lighter at an equivalent weight; it costs more to manufacture. The 2.5-layer construction suits regular hiking, while the 3-layer construction is better for intensive use.
Can you wear waterproof trousers as a ski base layer?
Hardshell hiking trousers lack the seat and knee reinforcements needed for sliding on snow. They withstand rain and wind, but not the repeated abrasion of ski touring. For ski touring or mountaineering, choose trousers designed specifically for those activities, with Cordura reinforcements in high-wear areas.
How can you test your jacket’s waterproofing at home?
Spray the shoulder and chest with water. If droplets bead up and roll off without soaking in, the water-repellent treatment is working. If the fabric darkens and absorbs the water, wash the jacket and tumble-dry it for 20 minutes at 40°C before testing again.
