How Do Waterproofs Work?
How Do Waterproof Jackets Work?
When it comes to outdoor adventures, staying dry is key to staying comfortable. Whether you’re hiking through a drizzle or caught in a downpour, a good waterproof jacket can make all the difference. But have you ever wondered how waterproofs actually work? What keeps the rain out while still allowing sweat to escape?
In this guide, we’ll break down the technology behind waterproof jackets, explain how they’re designed to be breathable, and offer tips on how to care for your gear so it lasts longer.
Check out our range of waterproof jackets here.
The Basics: What Makes a Jacket Waterproof?
A jacket’s ability to keep you dry comes down to two main factors: waterproof fabrics and water-repellent coatings.
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Waterproof Fabrics
The core of any waterproof jacket is a special fabric designed to block out water. These fabrics often have a waterproof membrane or laminate—a thin layer that’s either bonded to or sandwiched within the fabric. This membrane has tiny pores that are small enough to prevent water droplets from penetrating but large enough to allow water vapor (like sweat) to escape.Popular waterproof membranes include:
- GORE-TEX: A well-known waterproof membrane that offers excellent breathability.
- eVent: Known for its direct-venting technology, which enhances airflow and sweat evaporation.
- Proprietary Membranes: Many brands have their own waterproof technologies, like Patagonia's H2No or Columbia's Omni-Tech.
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Durable Water Repellent (DWR) Coating
Most waterproof jackets also have a DWR coating applied to the outer layer. This coating causes water to bead up and roll off the fabric, rather than soaking in. DWR doesn’t make the fabric waterproof on its own, but it helps prevent the outer layer from becoming saturated, which can reduce breathability and make the jacket feel colder and heavier.Over time, the DWR coating can wear off, especially if the jacket is exposed to dirt, oils, or frequent washing. Fortunately, you can reapply DWR treatments to restore water repellency. Check out our clothing care range to revitalize your waterproofs.
Waterproof vs. Water-Resistant: What’s the Difference?
Not all jackets marketed for rainy weather are truly waterproof. Here's the distinction:
- Waterproof: A waterproof jacket has a membrane or laminate that fully blocks water. These jackets are typically tested to withstand specific levels of water pressure, ensuring you stay dry even in heavy rain.
- Water-Resistant: Water-resistant jackets, on the other hand, may have a DWR coating but lack a waterproof membrane. They’re fine for light rain or drizzle but won’t keep you dry in a downpour.
If you’re planning serious outdoor adventures, a waterproof jacket is your best bet. Water-resistant jackets are more suitable for casual use or light showers.
How Does Breathability Work in Waterproof Jackets?
Breathability is what makes a waterproof jacket comfortable to wear, even during high-energy activities. Without it, you’d end up sweating inside the jacket, making you feel damp and clammy—defeating the purpose of staying dry!
So, how does a jacket keep rain out while letting sweat escape? It’s all about microporous membranes and moisture transfer:
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Microporous Membranes
Waterproof membranes like GORE-TEX and eVent contain microscopic pores that are smaller than water droplets but larger than water vapor molecules. This means that while raindrops can’t pass through, the moisture from your sweat can escape. -
Moisture Transfer
When you’re active, your body produces heat, which creates water vapor inside your jacket. The warmth from your body pushes this vapor toward the cooler outside air, helping it pass through the membrane. This process, known as moisture wicking, helps keep you dry from the inside out.
However, keep in mind that breathability has its limits. In very humid or cold conditions, breathability can decrease, as there’s less of a temperature difference to drive moisture out.
Waterproof Ratings: How to Measure Water Resistance
Waterproof jackets are often rated based on the hydrostatic head test, which measures how much water pressure the fabric can withstand before it leaks. Here’s what those numbers mean:
- 5,000mm – 10,000mm: Suitable for light rain or brief exposure to heavier rain. Good for general outdoor use.
- 10,000mm – 20,000mm: Provides solid waterproofing in heavy rain. Ideal for prolonged outdoor activities in wet weather.
- 20,000mm+: Extremely waterproof, suitable for intense, prolonged exposure to rain or snow, like mountain expeditions or extreme weather.
For most outdoor activities, a jacket rated between 10,000mm and 20,000mm should be more than sufficient.
Caring for Your Waterproof Jacket
Over time, dirt, sweat, and oils from your skin can clog the microporous membrane, reducing both waterproofing and breathability. Here are some care tips to keep your jacket performing at its best:
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Regular Washing
Yes, you should wash your waterproof jacket! Dirt and oils can build up on the fabric, affecting its performance. Use a mild, specialized detergent (no fabric softeners!) and follow the manufacturer’s washing instructions. -
Reapply DWR Coating
The DWR coating will wear off with time, but you can reapply it using a spray-on or wash-in product from our clothing care range. This will help your jacket continue to repel water effectively. -
Drying
After washing, air-dry the jacket or tumble-dry on low heat if the care label allows. Low heat can help reactivate the DWR coating, restoring its water-repellent properties. -
Store Properly
Store your jacket in a cool, dry place, away from direct sunlight, to avoid degrading the fabric and waterproof coating.
Choosing the Right Waterproof Jacket for Your Needs
When selecting a waterproof jacket, consider the following factors:
- Climate and Activity Level: If you’re doing high-intensity activities (like trail running or climbing) in wet conditions, opt for a highly breathable jacket with a lower hydrostatic head (around 10,000-15,000mm). For colder, more stationary activities, a jacket with higher waterproofing (20,000mm+) might be more suitable.
- Weight and Packability: Lightweight waterproof jackets are great for warmer weather or as emergency layers. For winter or cold conditions, a heavier, insulated waterproof jacket may be a better choice.
- Fit and Layering: Choose a jacket with enough room for layering underneath. A slightly looser fit allows you to add extra insulation when needed without sacrificing comfort or breathability.
Explore our full range of waterproof jackets to find the perfect fit for your adventures.
FAQs
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Can I use a waterproof jacket in snow?
Yes! Waterproof jackets are often windproof as well, making them suitable for snow. Just make sure it’s rated for cold conditions if you’ll be in freezing temperatures. -
What’s the difference between waterproof and water-repellent?
Waterproof means the jacket has a membrane that blocks water, while water-repellent typically refers to a DWR-treated surface that resists water but won’t keep you dry in heavy rain. -
How often should I reapply DWR coating?
It depends on usage, but typically every few months or after several washes. If water stops beading up on the surface, it’s time to reapply. -
Can I wear a waterproof jacket for high-energy activities?
Yes, but choose a highly breathable jacket. Look for one with good ventilation features, like pit zips, to help regulate body temperature. -
How do I restore my jacket’s breathability?
Wash it regularly with a mild detergent and reapply DWR coating when needed. This helps prevent dirt and oils from clogging the membrane.
A well-chosen waterproof jacket can be your best defense against wet, unpredictable weather, keeping you comfortable and dry so you can focus on enjoying the outdoors. With the right care, your waterproof gear will be ready for all your adventures.
Ready to stay dry? Browse our waterproof jacket collection now and don’t forget to check out our clothing care range to keep your gear in top shape!
