Waterproofing and breathability

The importance of

Image by: @HH

Waterproofing and breathability

In winter sports, you are constantly exposed to the elements: snow, wind, cold, and sometimes even rain. Your clothing must protect you from these conditions, keeping you warm and dry. Waterproofing and breathability play a crucial role in this.

Waterproofing:

Waterproof clothing prevents moisture from the outside from penetrating your outfit. This is essential during long days on the slopes, where you frequently come into contact with snow. If your clothing is not waterproof, it becomes wet, causing your body to cool down quickly – a recipe for an uncomfortable and even dangerous situation.

Breathability:

On the other hand, your body generates heat and sweat during exertion. Without breathability, that moisture can accumulate in your clothing, leading to a clammy and cold feeling. Breathability allows perspiration to escape, so you stay dry and comfortable, even during intense descents.

The balance between being dry on the outside and inside:

The interplay between waterproofing and breathability is what makes technical ski and outdoor products so special. It ensures that you are optimally protected from the elements while keeping your body temperature regulated. This makes it not only important for comfort but also for your performance and safety on the slopes.

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What does that 20,000 mm actually mean?

You’ve probably seen it before: a waterproof rating like 10,000 mm, 20,000 mm, or even 28,000 mm on ski and outdoor products. But what do these numbers actually mean? The answer lies in the water column test.

The water column test: How is waterproofing measured?

Waterproofing is tested by placing a piece of fabric under a vertical tube that is gradually filled with water. The number in millimeters indicates the maximum height of the water column before the water begins to leak through the fabric.

  • 10,000 mm: Can withstand the pressure of 10 meters of water. This is suitable for light to moderate snow and rain.

  • 20,000 mm: Can withstand the pressure of 20 meters of water. Ideal for intense snow days and wet conditions.

  • 28,000 mm and higher: Extreme protection, suitable for the harshest conditions such as wet powder snow or rain during ski touring.

Note: Seams and zippers

Waterproofing is more than just the fabric. Also pay attention to:

  • Sealed seams: These prevent water from seeping in through the stitching.

  • Waterproof zippers: Important for pockets and ventilation openings.

A good waterproof product is a combination of a strong water column, sealed seams, and high-quality zippers.

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How is breathability measured?

Breathability is just as important as waterproofing, especially during intense activities like skiing and snowboarding. It determines how well a fabric can transport moisture in the form of sweat, keeping you dry and comfortable. But how is breathability actually measured?

MVTR: Moisture Vapor Transmission Rate

The most common way to measure breathability is through the MVTR (Moisture Vapor Transmission Rate). This value indicates how many grams of moisture are transported through a square meter of fabric in 24 hours. For example:

  • 10,000 g/m²/24h: Suitable for less intense activities.

  • 20,000 g/m²/24h: Ideal for skiers and snowboarders with moderate exertion.

  • 30,000 g/m²/24h or higher: Perfect for intense activities like ski touring or cross-country skiing.

The higher the MVTR, the better the fabric breathes.

RET value: Resistance to Evaporative Heat Transfer

Another method to measure breathability is the RET value (Resistance to Evaporative Heat Transfer). The lower the value, the better the fabric breathes.

  • RET < 6: Excellent breathability, suitable for intense exertion.

  • RET 6-13: Good breathability, ideal for active winter sports enthusiasts.

  • RET > 13: Moderate breathability, more suitable for light activities or very cold conditions.

How does it work?

Breathability is made possible by membranes such as Gore-Tex or Helly Tech Professional. These membranes have microscopic pores that are large enough to let water vapor (sweat) through but too small for water droplets. This keeps you dry on the inside, even when your outfit is fully waterproof.

Image by: @Peak Performance

Waterproof and breathable: how do they work together?

Waterproofing and breathability may seem contradictory, but in high-quality ski and outdoor products, they work together to keep you comfortable and protected. Here’s how it works:

The membrane:

The secret to both waterproof and breathable lies in the use of special membranes like Gore-Tex, Helly Tech Professional, or other technical materials. These membranes have millions of microscopic pores that:

  • Are too small for water droplets: This keeps rain and snow out.

  • Are large enough for water vapor: This allows sweat in the form of vapor to escape.

Thanks to these properties, your garments stay dry on the outside and inside, even during intense exertion.

The balance between waterproof and breathable

Improving waterproofing can sometimes come at the expense of breathability. For example, a very thick coating can keep water completely out, but it may also be less effective at wicking away sweat. That’s why the best products are designed with a careful balance: they provide enough protection against wet conditions without overheating you.

Example:

  • Gore-Tex Pro: Extremely waterproof (28,000 mm) and still breathable (25,000 g/m²/24h), ideal for off-piste adventures.

  • Helly Tech Performance: 20,000 mm waterproof and 15,000 g/m²/24h breathable, perfect for all-round winter sports enthusiasts.

Extra features for optimal performance

Many products combine waterproofing and breathability with additional features such as:

  • DWR coating (Durable Water Repellent): Ensures that water droplets bead off the fabric, improving breathability by preventing the outer fabric from becoming saturated.

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What should you consider when choosing ski equipment?

Choosing the right ski equipment starts with a good understanding of waterproofing and breathability. Depending on your activities and the conditions on the slopes, there are a few key factors to consider.

1. Activity and intensity

  • Recreational skiing: If you mainly stay on groomed slopes, a waterproof rating of 10,000-15,000 mm is often sufficient. A breathability of 10,000 g/m²/24h is comfortable for descents and breaks.

  • Off-piste and powder snow: Choose at least 20,000 mm waterproofing to withstand prolonged exposure to snow and moisture. A higher breathability (20,000 g/m²/24h or more) prevents overheating.

  • Ski touring or cross-country skiing: In this case, breathability is more important than extreme waterproofing. Look for products with a breathability of 25,000 g/m²/24h or higher, and a waterproof rating around 10,000-15,000 mm.

2. Climate and weather conditions

  • Dry cold: Opt for clothing with high insulation values and adequate breathability.

  • Wet snow or rain: Products with a waterproof rating of 20,000 mm or higher, combined with sealed seams and a strong DWR coating, are a must.

3. Specific details

  • Sealed seams: Check if the seams are fully sealed, especially in clothing with high waterproofing.

  • Ventilation zippers: Useful during intense activities for extra airflow.

     

  • Waterproof zippers: For pockets and ventilation openings that should not allow water to pass through.

Image by: @HH

Maintenance of waterproof clothing: How to keep it performing well

Waterproof clothing often loses some of its effectiveness over time, especially due to wear and dirt buildup. Fortunately, with the right maintenance, you can extend the lifespan and performance of your ski equipment. Here are a few tips:

1. Clean regularly, but gently

Dirt and sweat can reduce the breathability of your clothing. Therefore, wash your waterproof clothing regularly according to the instructions on the label. Use a mild detergent specifically designed for technical fabrics. Avoid fabric softener, as it can damage the membrane and DWR coating.  
Note! Do not wash too often. Excessive washing can wear out the materials more quickly.

2. Reactivating the DWR coating

The Durable Water Repellent (DWR) coating causes water to bead off your clothing. Over time, this layer can wear off, but you can restore it:

  • Place the clothing in the dryer on a low heat setting, if permitted. The heat reactivates the coating.

  • Use a special DWR spray or detergent to reapply the water-repellent layer.

Not all waterproof clothing can be tumble dried. Always check the label. For clothing that cannot be tumble dried, you can restore the DWR coating with a special spray or detergent.

3. Avoid excessive heat

Keep your clothing away from direct heat sources, such as radiators. These can damage the membrane. It’s better to air dry your clothing if the dryer is not recommended.

4. Check seams and zippers

Regularly inspect the sealed seams and waterproof zippers for wear. If you find any damage, have it repaired with a special repair product or by a professional.

5. Store your clothing properly

Make sure your ski gear is completely dry before storing it. Keep it in a cool, dry place to prevent mold and damage.

With proper maintenance, your waterproof clothing will not only last longer but also perform as it should – keeping you dry and comfortable, no matter the conditions.

Image by: @Peak Performance

Stay dry and comfortable with the right equipment

Waterproofing and breathability are essential for a comfortable and safe skiing experience. By understanding how these properties work and what to look for when choosing ski equipment, you can prepare yourself for all weather conditions.

Ready to upgrade your gear? Discover our extensive range of midlayers from top brands like Helly Hansen, Arc'teryx, Peak Performance, and Norrona. Visit our store or shop easily online and get advice from our winter sports experts.

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