Technical outdoor jackets: waterproof, windproof and breathability explained

Modern technical outdoor jackets combine waterproof and windproof qualities with breathability, thanks to advanced materials and constructions. The key properties, from fully waterproof to water-repellent, windproof and breathable, are explained below, as well as the technologies that enable this performance, because does anyone really know the difference?

Waterproof vs water-repellent

A jacket is called waterproof if it keeps out precipitation completely, no matter how long or hard it rains. This performance level is usually indicated by the water column: the higher this value (in millimetres), the better the rain resistance. Technical outdoor jackets often offer 10,000 mm or more, while extreme expedition models reach 20,000-30,000 mm.

Water-repellent (also known as water-resistant) means that the outer fabric causes water to bead up. However, with prolonged exposure, moisture will eventually seep through. Such a material is fine in a short shower, but will leak if it gets soaking wet.

Therefore, advanced rain jackets combine a waterproof membrane with a durable, water-repellent DWR coating on the outer layer. This coating ensures that raindrops roll off the fabric without penetrating the fibres. An important detail: such DWR-wear decreases due to dirt, friction and washing, and must therefore be regularly re-impregnated to remain effective.

Windproofness

Protection from wind is just as crucial, as a harsh wind can quickly cool you down (windchill). A fully windproof jacket blocks the wind and prevents cold air from cooling the insulating layer under your clothing.

In practice, a truly waterproof hardshell is automatically windproof as well. Such membranes let virtually no air through. Softshells, on the other hand, are often wind-resistant. They block 80 to 95 percent of the wind, but are therefore not completely windproof.

Breathability

In addition to protection from the outside, a good outdoor jacket must also stay dry from the inside. The breathability of a jacket is the capacity of the material to wick away perspiration in the form of vapour. Anyone who moves intensively in a non-breathable rain jacket will inevitably become clammy inside.

Therefore, technical rain jackets use microporous membranes or coatings that allow water vapour to pass through, but not the larger water droplets. This is often expressed in:

• MVTR value (Moisture Vapour Transmission Rate) : how many grams of water vapour per m² can escape in 24 hours. A value of 10,000 g/m²/24h or more is seen as highly breathable.
• RET value (Resistance to Evaporative Heat Transfer) : the resistance the material offers to vapour permeability. The lower the number, the more breathable (RET < 6 = excellent, 6–13 = good).

Tenson’s own MPC™ laminate also works according to this principle, where rain beads off the surface while moisture from the body is transported outwards, allowing the garment to “breathe” during intensive activities.

For very intensive efforts, outdoor athletes often opt for a softshell instead of a hardshell. Such a jacket is usually only water-repellent, but has a much higher breathability, which prevents condensation.

Materials and technologies

There are two main ways to make a jacket both waterproof and breathable: via a separate membrane under the outer fabric (such as Gore-Tex®) or via a thin coating on the inside of the fabric. A microporous membrane is usually more durable, but both techniques provide a windproof, waterproof and breathable construction. In addition, with good rain jackets, all seams are taped (sealed with heat-sensitive tape) to prevent water from penetrating at those vulnerable points.

Furthermore, details such as waterproof zips, a well-fitting hood and ventilation zips under the arms provide extra protection and more wearing comfort. The end result is a functional outdoor jacket that is ready for all weather conditions, without compromising on comfort. Whether choosing a hardshell for maximum protection or a softshell for breathability during intensive activities: the right jacket depends on the situation of use.

This article was produced in partnership with Tenson. For more information on Tenson, visit the brand page.