We all know the importance of waterproof and breathable rainwear for our outdoor adventures, but have you ever wondered how it actually works?
Obviously, the main reason we need rainwear is to stay dry, but it needs to ensure that sweat can escape while keeping the rain out or we’ll still end up a soggy mess.
That’s where waterproof and breathable rainwear comes to the rescue, allowing us to stay dry and comfortable no matter what Mother Nature throws our way. But how exactly do these high-tech fabrics manage to keep out the rain while still letting our skin breathe?
In this article, we’ll delve into the fascinating world of waterproof and breathable materials, exploring how they work, the science behind their construction, and the various factors influencing their performance.
Key Takeaways
- Waterproof and breathable rainwear is important for outdoor activities to stay dry and comfortable.
- PTFE is a popular micro-porous material for water vapor but not water droplets, and is used in Gore-Tex and other brands.
- Durable Water Repellent (DWR) coatings improve breathability by causing raindrops to bead up and roll off.
- The 3-layer system (baselayer, midlayer, and shell layer) is essential for proper breathability, and backpacks can be a barrier for rainwear performance.
History of waterproof clothing
Before we dive into the history of waterproof clothing, let’s take a moment to appreciate how far we’ve come. Older rainwear used to be heavy, stiff, and uncomfortable, leaving us clammy and damp on the inside.
Fortunately, the discovery of micro-porous materials revolutionized the industry, followed by hydrophobic coatings to repel water, providing us with lightweight, breathable, and effective solutions to stay dry and comfy outdoors.
The main reasons why we need it
You might wonder why waterproof and breathable gear is essential for your outdoor adventures, right? Well, it’s all about staying dry and comfortable while enjoying the great outdoors.
Waterproof materials, like those found in a layer laminate construction, provide excellent weather protection by keeping rain and snow out, while still allowing water vapor (i.e., sweat) to escape. This is crucial because our bodies generate heat and moisture during physical activity, and if that moisture can’t escape, it can lead to a clammy, uncomfortable feeling.
A good waterproof jacket, for example, will have a high level of water resistance combined with breathability performance, ensuring that you stay dry from both external elements and your own perspiration.
In addition to waterproof and breathable layers, most rainwear also features a durable water-repellent (DWR) finish. This treatment causes raindrops to bead up and roll off the surface of the fabric, preventing them from soaking in and compromising the breathability performance.
The combination of waterproof materials, breathability, and DWR treatment provides a level of weather protection that is unmatched by non-waterproof gear. Furthermore, the durability of these materials ensures that you can rely on your rainwear for many outdoor adventures to come.
So, whether you’re hiking, biking, or just out for a walk in the rain, investing in waterproof and breathable gear will give you the freedom to truly enjoy your time outdoors, no matter the weather conditions.
The Problem With Old Rainwear
Originally natural products like furs and skins of animals were used to keep the rain off. These were heavy and not entirely waterproof. However, with the advent of plastics and other materials, materials like PVC came to the fore.
While far more waterproof than skins and furs, PVC clothing often feels like you’re trapped in a stuffy, damp cocoon, unable to breathe, and soaked in your own sweat if you attempted anything strenuous.
This discomfort stemmed from the fact that traditional rainwear prioritized waterproofing over breathability, often using a double PVC layer construction that did a great job of keeping water out but left you feeling hot and clammy inside. In fact, studies have shown that a person’s sweat rate can increase by up to 30% when wearing non-breathable rainwear.
The lack of classic breathability, combined with the potential for body oils and dirt to clog up the waterproof membranes, made old rainwear a less-than-ideal option for outdoor enthusiasts seeking protection from the elements without sacrificing comfort.
Thankfully, the innovation of backcountry rainwear has come a long way since those days, with advances in microporous membrane and hydrophilic coating technologies that have revolutionized the basics of rainwear technology. The development of layer construction systems, such as 2-layer, 2.5-layer, and 3-layer systems, has allowed for more efficient water vapor transmission while maintaining waterproof capabilities.
The Discovery of Micro-Porous Materials
In the 1950s, Bill Gore left his job at DuPont to focus on exploring the potential of the polymer polytetrafluoroethylene (PTFE). However, it was his son, Bob Gore, who made a groundbreaking discovery in 1969.
By chance, while trying to make the membrane thinner, he found that PTFE could be stretched or “expanded,” creating tiny holes. These holes were big enough to let water vapor through, but not big enough to allow water droplets through. This discovery led to the birth of Gore-Tex.
Despite this breakthrough, it took another seven years for the microporous, water-repellent, and vapor-permeable material to be utilized in clothing fabrics. But, in 1976, the first Gore-Tex rain jacket was introduced to the market.
The discovery of micro-porous materials revolutionized the world of outdoor gear. These microporous membranes transformed gear from stuffy, damp cocoons to comfortable, breathable havens for adventurers.
Types of waterproof materials used in the construction of outdoor gear
In our exploration of waterproof and breathable materials, we’ll dive into the two main types, micro-porous membranes and hydrophobic coatings (DWR), and how they are used in conjunction to create the modern garments we wear out on the trails.
This all really started with Gore and the discovery of micro-porous materials like PTFE.
Microporous Membranes
So, what exactly is the microporous membrane? It’s a thin layer of material that is waterproof and breathable, allowing air and moisture to pass through while keeping us dry. These materials work by having microscopic pores that allow water vapor (sweat) to escape while keeping out larger water droplets (rain).
There are several types of membranes available, each with its own unique properties and benefits. Some are made from synthetic materials like Gore-Tex, while others use natural materials like eVent.
One of the most well-known and widely used waterproof and breathable rainwear materials is Gore-Tex. This remarkable material has set the standard for performance in layer rain jackets. It offers a combination of dedicated material layers that provide fair breathability, fair wind resistance, and a high level of protection from the elements.
At the core of Gore-Tex is a performance layer, made from expanded PTFE, which consists of billions of micro-pores that allow water vapor to pass through while keeping water droplets out. This layer is then bonded to other materials like polyester strands, creating a durable and effective barrier against wind and rain.
The result is a versatile and reliable choice for outdoor enthusiasts who need top-notch waterproof and breathable rainwear to keep them dry and comfortable in a wide range of conditions.
However, if the garment becomes waterlogged, called ‘wetting out,’ it reduces the garment’s breathability and lets water through, making it basically useless.
Luckily there have been developments in hydrophobic material and coatings.
What Do Hydrophobic & Hydrophilic Mean?
A hydrophile, or hydrophilic molecule, is one that adores water – it’s a true ‘water-lover’. On the flip side, a molecule that shuns water, repelling it, is labeled ‘hydrophobic’.
These labels, hydrophilic and hydrophobic, categorize molecules or substances based on their relationship with water.
How much a molecule or surface is attracted to water determines its ‘hydrophilicity’.
Hydrophobic Materials
The most well know hydrophobic treatments are Durable water repellent, or DWR, coatings added to fabrics to make them water-resistant or hydrophobic. DWR coatings are commonly used in conjunction with waterproof breathable fabrics such as Gore-Tex to prevent the outer layer of fabric from becoming saturated with water.
Their hydrophobic nature causes water to bead up and roll off the surface, rather than soak into the material and wet it out.
These coatings have less environmental impact than before, requiring both fewer harmful chemicals and less of them. These modern coatings create an extremely thin hydrophobic layer while ensuring the fabric is still very wearable.
Hydrophilic Materials
Hydrophilic materials work by actively attracting water molecules and transporting them through the material, allowing sweat to escape.
Rather than the microporous PTFE approach taken by Gore-Tex others have developed a combination of hydrophilic and hydrophobic materials. The hydrophobic molecules keep water from getting through the fabric, while the hydrophilic molecules enable the water vapor to escape to stop you from feeling sweaty.
Some great examples of hydrophilic materials include Dermizax, SympaTex, Pertex, and Vaude. They all offer high-performance rainwear options for various outdoor activities.
Comparison of Gore-Tex, PTFE and Dermizax, SympaTex, Pertex, Vaude
Brands like Dermizax, SympaTex, Pertex, and Vaude offer impressive alternatives to the more well-known Gore-Tex, providing exceptional waterproofing and breathability for your outdoor adventures.
These brands utilize innovative layer-and-layer designs, featuring an actual fabric layer combined with additional layers that ensure lightweight, waterproofing, and breathability.
An added bonus is that many of these brands use clever weight distribution, allowing shoulder straps and other components to be more comfortable while still providing excellent protection.
Furthermore, these materials are designed to work well with the oils in sweat, so you won’t have to worry about your rainwear losing its effectiveness due to a popular oil coating.
Let’s take a closer look at the different types of waterproof and breathable materials and their advantages and disadvantages in this handy table:
| Material Type | Advantages | Disadvantages |
|---|---|---|
| PTFE (e.g., Gore-Tex) | Highly durable, excellent breathability, recyclable | May contain harmful PFCs, expensive |
| Dermizax, SympaTex, Pertex, Vaude | 100% recyclable, PFC-free | Slightly less breathable than PTFE, may wear out faster |
| Hydrophilic materials | Efficient sweat transport, no harmful PFCs | Affected by temperature and humidity, may wear out faster |
| DWR coatings | Enhances breathability and water resistance | Some contain harmful PFCs, may need frequent reapplication |
As you can see, there are various materials and coatings used in the construction of waterproof and breathable rainwear, each with its own strengths and weaknesses. Ultimately, the ideal choice for you will depend on your specific needs, preferences, and commitment to environmental sustainability.
So, next time you’re shopping for waterproof and breathable rainwear, consider giving these brands a try – you might just discover your new favorite outdoor gear.
How it All Works Together
The secret of modern rainwear lies in its construction, which typically consists of a microporous and/or hydrophilic layer that blocks water droplets from entering, while still allowing the movement of sweat vapor to escape. This layer is often sandwiched between an outer shell that provides protection against the elements and a soft, comfortable innermost layer that sits next to your skin.
Some rainwear even features an additional mesh layer or isolation layer to help keep your body warm and maintain the breathability of the fabric. The result? A sophisticated system that keeps you dry from both external rain and internal sweat, allowing you to stay comfortable and focused on your outdoor adventures, no matter the weather.
The Construction of Breathable Rainwear
The evolving designs of waterproof and breathable rainwear rely on two main types of materials: the aforementioned micro-porous materials, and hydrophobic ones.
By using advanced technology and materials such as Gore-Tex membrane, manufacturers create rainwear that is both water-resistant and breathable, providing protection from rain while maintaining our body temperature and comfort.
There are several key components to waterproof and breathable rainwear that make it effective. These include:
- Outer fabric: This is the tougher outer material designed to protect fragile materials like PTFE and provide the first line of defense against the elements, so often treated with a Durable Water Repellent (DWR) coating to make rain bead up and roll off, preventing the fabric from becoming saturated.
- Waterproof membrane: A thin layer, usually bonded to the outer layer. Made from hydrophilic or micro-porous materials like PTFE, which allows water vapor to pass through but prevents water droplets from entering. This ensures the breathable fabrics remain dry while allowing sweat to escape.
- Inner lining: This layer, often made of soft and moisture-wicking materials, helps to transport sweat away from the skin, further enhancing the breathability and comfort of the rainwear.
Next comes the construction, where we combine the waterproof and breathable material with other layers to create a durable and functional piece of clothing. There are three common constructions to choose from:
- 2-layer system: A waterproof and breathable membrane or coating is applied to the outer fabric, creating a single layer for protection and comfort.
- 2.5-layer system: In addition to the 2-layer system, a protective, lightweight layer is added to the inside of the garment, providing extra durability without sacrificing breathability.
- 3-layer system: The waterproof and breathable membrane is sandwiched between a tough outer fabric and a comfortable inner lining, providing the best combination of durability, breathability, and protection.
Finally, a Durable Water Repellent (DWR) coating is applied to the outer fabric, enhancing the garment’s ability to repel water and maintain breathability.
Membranes vs Coatings
Layers and coatings are used by different manufacturers for their waterproofing. These can often achieve similar goals, but they are different.
Coatings are applied as a layer on another material. DWR coatings are a prime example of this as this coating makes the material it is applied to hydrophobic. However, there are materials that are themselves hydrophobic. In this case, we would describe this as a membrane
So when we talk about the way the layers are constructed below, we will mention the typical solution, but some manufacturers may use a membrane instead of a coating and vice versa.
As you can see, the process of creating waterproof and breathable rainwear is a delicate balance of materials, construction, and technology, all working together to perform in the great outdoors.
Conclusion
Waterproof and breathable rainwear utilizes advanced technologies and materials to provide protection against rain while allowing moisture to escape. By combining water-resistant fabrics, durable water repellent coatings, and breathable membranes, these garments ensure comfort and functionality in wet weather conditions.
Understanding the principles behind this technology can help individuals make informed decisions when selecting rainwear that suits their needs.
Matt Green, is an avid hiker and lover of the great outdoors. He is always planning his next big trip or hitting the trails for a solo hike.
He’s traveled extensively to many remote regions and has plenty of experience exploring various terrains, and stories to tell.