Is there a such thing as breathable and waterproof?

If you&#;ve ever found yourself trying to choose between two waterproof jackets and wondering what was meant by &#;tricot&#;, &#;DWR, or &#;water-resistant&#;, this article is for you. In this gear guide, I&#;m going to go into the technology used in waterproof fabrics and the things you might want to consider when choosing your next piece of rainwear. Just know that it&#;s going to get a little nerdy as this is the most technical article in a whole series on waterproof garments. If you are looking for something more general, like how to choose a rain jacket or an article explaining the differences between a soft shell and a hard shell, I have articles on those too.

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Waterproof vs water-resistant

To ensure proper protection in the conditions you expect to face, it&#;s important to know the difference between the three levels of water protection afforded by fabrics. To be clear, the industry has yet to develop a standardized system for rating the water resistance of fabrics, and what I have done here is use designations where there is the most consensus among brands. Thankfully, many manufacturers have performed a more or less standardized test, which makes it possible to make comparisons. In a hydrostatic head test, an open-ended cylinder is placed on top of a piece of fabric and slowly filled with water. Results are measured in how much water the material can be exposed to (in milimeters) before it begins to seep.

Water-resistant (0 to 1,500 mm)

&#;Water-resistant&#; means that a fabric is tightly woven or manufactured in such a way that it resists penetration by moisture. But that doesn&#;t mean much. A garment made from water-resistant fabric won&#;t keep you dry in much more than a misty morning fog or a little drizzle. This is the lowest level of protection against moisture. Water-resistant fabrics perform very poorly in hydrostatic head tests and usually aren&#;t even tested.

Water-repellent (1,500 to 5,000 mm)

Water-repellent fabrics have one up on water-resistant fabrics in that they have a durable water repellent (DWR) coating which causes water to bead and roll off a jacket instead of soaking through it. This slows the speed at which a jacket becomes saturated in sustained rain. Because they don&#;t have waterproof membranes, water-repellent fabrics are only good for keeping you dry in light rain and are not sufficient for rainwear.

Waterproof (over 5,000 mm)

A waterproof layer will protect you in moderately heavy to very heavy rain depending on its rating. In very wet conditions, a fabric rated to 10, 000 mm will keep you drier than one rated to 5,000 mm, but above 20, 000 mm there is little notable difference in performance. Garments deemed waterproof typically have a DWR-treated face fabric and a waterproof-breathable membrane. Beyond this, they also need to have sealed seams (taped or heat welded) to ensure that water doesn&#;t get through the seams.

Waterproof fabric construction

Before we can get into 2L, 2.5L and 3L fabrics, we need to understand what is meant by &#;DWR&#;, &#;face fabric&#; and &#;inner lining&#; &#; elements commonly incorporated into waterproof-breathable fabrics.

Durable waterproof repellent

Durable waterproof repellent (DWR) is the coating that causes water to bead up and roll off the outer layer (face fabric) rather than be absorbed. In most membrane fabrics, this hydrophobic function has no impact on waterproofness, but what it does do is help maintain breathability. A shell that has absorbed water and &#;wetted out&#; cannot breath, something that DWR helps prevent.

Face fabric

The outer layer or face fabric protects the waterproof membrane and provides a surface on which to apply DWR. Typically made from nylon or polyester, this layer can be thicker and more durable or thinner and lighter. Hard shells typically use 50 to 75-denier polyester while lighter rain shells are usually made with 20 or 30-denier nylon. The higher the denier number, the thicker the fabric.

Sealed seams

The problem with stitched seams is that they create thousands of tiny holes for water to get through. To make a garment properly waterproof, the seams have to be sealed. That can mean either taping up stitched seams or foregoing stitches altogether and heat-welding panels together instead. Soft shell jackets, even those with membranes, have unsealed seams, making them merely water-repellant.

Inner lining

After the face fabric and membrane, 3-layer fabrics have an inner tricot lining. The main purpose of this layer is to protect the membrane and prevent it from becoming clogged with dirt and oil, but it also adds a level of comfort and helps wick away sweat to prevent clamminess. The inner lining in 2-layer garments, on the other hand, is not bonded to the membrane and is considered a separate fabric.

2L, 2.5L and 3L fabrics

To help you stay dry, a fabric has to be both waterproof and breathable (allow water vapor to escape). It if isn&#;t breathable, perspiration will build up on the inside of the garment, and you will still feel wet. While 2-layer, 2.5-layer, and 3-layer fabrics are all waterproof, they differ in terms of breathability and durability.

2L fabrics

Traditionally, 2-layer shells have had a face fabric bonded to a waterproof-breathable membrane with a loose (typically mesh) protective liner hanging inside them. Although more affordable, these mesh-lined 2L garments are generally heavier, bulkier, and less comfortable than 2.5L and 3L equivalents. Enter Gore-Tex Paclite Plus. This innovative 2L fabric also features a face fabric laminated to a waterproof-breathable membrane, but then instead of adding an separate mesh lining (or protective coating as used in 2.5L fabrics), Gore-Tex has textured the inside of the membrane in such a way that it increases abrasion resistance and makes an additional protective layer unnecessary.

2.5L fabrics

Like 2L and 3L fabrics, 2.5L fabrics also have DWR-treated face fabric and a waterproof-breathable membrane. But instead of having a separate mesh lining like 2L fabrics or an inner layer bonded to the membrane like 3L fabrics, 2.5L fabrics have a thin protective coating (the 0.5 layer) painted onto the inside of the membrane. In the past, these coatings weren&#;t as good at absorbing and transmitting perspiration as a tricot lining, and many 2.5L shells left wearers feeling a bit clammy when they were worn next to skin. But recent developments in 2.5L fabric construction have helped improve the clammy factor, and some 2.5L shells are now almost as comfortable as 3L equivalents.

3L fabrics

In 3-layer fabrics the waterproof-breathable membrane is sandwiched between the face fabric and a protective inner lining. Again, the main purpose of this last layer is to prevent sweat and oils from clogging the microscopic holes in the membrane &#; something that would hinder breathability and make the wearer clammy with perspiration. It is this ability of the lining to prevent a membrane from becoming fouled that gives 3-layer fabrics an advantage over comparable 2.5 layer fabrics. The disadvantage of 3L fabrics is that they are slightly heavier than 2.5L fabrics (2L garments have a separate inner lining and can actually be heavier). As with 2L and 2.5L fabrics, the degree to which a 3L fabric is breathable depends on the type of waterproof-breathable membrane.  

Waterproof-breathable membranes

Making a garment waterproof isn&#;t difficult, but making it waterproof and breathable is. To overcome this challenge, gear manufacturers have all turned to the same solution, a waterproof-breathable membrane. The original ePTFE membrane was produced by Gore-Tex, a brand that dominated the market for decades. 60 years on, there are now  four different types of waterproof-breathable membranes and a dozen companies making them. This is what you need to know about the pros and cons of each.

Air-permeable membranes

Because they are porous, air-permeable membranes allow for the transmission of air and water vapor molecules, making them significantly more breathable than vapor-permeable membranes, which don&#;t allow air to pass through them. Given how important breathability is for preventing the build up of sweat during exercise, this type of membrane is often a better choice for physically intense activities.

ePTFE

Expanded polytetrafluoroethylene, or ePTFE for short, is the material that was first used in waterproof-breathable membranes. Because it doesn&#;t need to be as thick as polyurethane, it can be made thinner and more breathable than polyurethane film equivalents. The downside to ePTFE membranes is that they can become fouled more easily (impairing breathability) if exposed to oil and dirt and need to be washed regularly to ensure breathability and longevity. Products include Gore-Tex Pro and eVent, the two most expensive outdoor fabric brands on the market.

• Gore-Tex Pro
• eVent

Electrospun polyurethane

Because they are non-porous, regular PU film membranes (described under vapor-permeable membranes) are inherently less breathable than ePTFE membranes. To overcome this limitation and improve breathability, a few fabric manufacturers have started using electrospun polyurethane to make porous membranes. The result is a type of air-permeable membrane that is almost as breathable (or even as breathable) as ePTFE membranes and only slightly less waterproof. Fabrics include Polartec NeoShell, Outdoor Research AscentShell, and The North Face FutureLight.

• Polartec NeoShell
• Outdoor Research AscentShell
• The North Face FutureLight

Vapor-permeable membranes

Unlike air-permeable membranes, vapor-permeable membranes are non-porous, meaning that air cannot pass through them. To achieve breathability, vapor-permeable membranes allow the transmission of water vapor through molecular wicking. This makes them inherently less breathable than air-permeable membranes, although the degree to which they are less breathable varies significantly between the two types of vapor-permeable membrane.

ePTFE-PU

Unlike Gore-Tex Pro, which has an ePTFE-only membrane, regular Gore-Tex features an ePTFE membrane bonded to a thin PU film. The purpose of the latter is to help prevent oil and dirt from clogging the membrane, the achilles heel of true ePTFE membranes. The result is a membrane that is less breathable than ePTFE membranes but more breathable than PU membranes. This type of hybrid membrane also splits on the difference on resistance to fouling and sits between the two in terms of price. Achieving a happy middle ground in all aspects of performance, Gore-Tex is still the most popular of waterproof-breathable fabrics.

• Gore-Tex

Polyurethane film

Because they don&#;t incorporate any other membrane layers, PU film membranes have to be thicker to ensure the same level of waterproofness. Being thicker and entirely non-porous, these membranes are less breathable than other types of membrane, especially in humid conditions. But PU films also have their advantages: they are very durable and don&#;t become fouled by dirt and oil as easily as ePTFE membranes. And they are more affordable than any other type of membrane, making them a popular choice for proprietary fabrics like Patagonia H2No, Marmot NanoPro, and Columbia OmniShield.

• Patagonia H2No
• Marmot NanoPro
• Columbia OmniShield

Get more advice from this gearhead

You now have everything you need to know about waterproof-breathable fabric. But don&#;t stop here. If your next purchase is going to be some kind of waterproof jacket, I strongly recommend reading my guide on how to choose rainwear next. Or maybe you haven&#;t even decided between a soft shell or hard shell yet, in which case my guide to outdoor jackets might help you to make a decision. You&#;ll find all of these and more right here under GEAR in the Outdoor life category. Alternatively, sign up for my newsletter to get all the latest from Trail & Crag delivered straight to your inbox.

Whether you are hiking through a torrential downpour, skiing in the mountains, or navigating a rainy urban commute, having the right outerwear can make all the difference. Waterproof breathable fabric is the unsung hero in outerwear, offering protection from the elements while keeping you comfortable. In this comprehensive guide, we will delve into everything you need to know about waterproof breathable fabric, from its construction to care.

 

What is waterproof breathable fabric?

Waterproof breathable fabric is a specially engineerted textile designed to repel water while allowign moisture vapor (like sweat) to escape from inside, keeping you dry and comfortable in various weather conditions. This type of fabric is commonly used in outdoor clothing, including rain jackets, ski pants, hiking gear, and in various industrial and military applications.

 

 

 

What makes fabric waterproof?

A fabric's waterproof rating is determind by its ability to resist the penetration of water. This resistance is achieved through the combination of the outer shell material, DWR finish, and waterproof membrane. The key factor that make fabric waterproof include:

• DWR Coating: DWR causes water to bead up on the fabric's surface, preventing it from saturating the outer shell. Regular reapplication of DWR is essential to maintain this property.
• Waterproof Membrane: The waterproof membrane forms the primary barrier against water penetration.
• Taped Seams: Properly sealed seams prevent water from seeping through the stitched areas of the fabric. Untaped seams are a common point in waterproofing.
• Fabric Quality: The quality of the outer shell material can affect waterproofness. High-quality fabrics are often more durable and better at repelling water.

 

What is DWR (Durable Water Repellent)?

A durable water repellent (DWR) coating is a treatment applied to the outer shell of waterproof fabric. It works by reducing the surface tension of water droplets, causing them to bead up and roll off the fabric rather than being absorbed like when raindrops hit the finish on a car or a plant leaf. Over time, DWR treatments can wear off dur to regular wear, exposure to dirt and oils, and repeated washing. To maintain optimal performance, it is essential to regularly wash your outerwear and periodically reapply DWR using products specfically designed for this purpose.

 

 

 

How do waterproof membranes work?

 

Hydrophobic membranes

Hydrophobic membranes play a crucial role in the functionality of outerwear by providing waterproof and breathable properties. These membranes are typically made of polymers or synthetic materials with hydrophobic characteristics, meaning they repel water. When integrated into outerwear, these membranes function as a barrier that prevents external moisture, like rain or snow, from penetrating while allowing internal moisture, such as sweat vapor, to escape. The hydrophobic nature of these membranes ensures that water droplets bead up on the fabric's surface and slide off, rather than being absorbed. This dual-action mechanism maintains the wearer's comfort by keeping them dry from external elements and allowing their body heat and moisture to dissipate, resulting in a more breathable and comfortable outdoor experience. Additionally, advanced hydrophobic membranes often include microscopic pores that facilitate water vapor molecules' movement while blocking larger liquid water molecules, further enhancing the breathability and waterproofing of the outerwear.

 

Hydrophilic membranes

Hydrophilic membranes in outerwear function by utilizing a specialized material that exhibits inherently affinity for water. These membranes are typically integrated into the fabric layers of outdoor garments to provide waterproof and breathable properties. The hydrophilic membrane is engineered to have microscopic pores that are smaller than a water droplet but larger than water vapor molecules. When snow, rain, water, or any liquid contacts the outer surface of the garment, the hydrophilic membrane actively attracts and absorbs the water, preventing it from penetrating the inner layers.

Simultaneously, the moisture vapor produced by the body's perspiration is allowed to escape through these pores due to the difference in pressure and the membrane's hydrophilic nature, ensuring breathability. This combination of repelling external moisture while permitting internal moisture transfer helps keep the wearer dry and comfortable, making hydrophilic membranes a fundamental technology in waterproof and breathable outdoor apparel.

 

Waterproof breathable fabric construction

Waterproof breathable fabrics are produced with the construction of layers of fabric and membrane, fused together with heat and glue, creating a fabric laminate. The most common fabric laminates consist of the top fabric (the outer shell fabric), or face fabric, a membrane layer, and a backer (or liner) fabric. The number of layers in a fabric laminate creates the expectation for durability, breathability, and overall function of the laminate. The most common laminate types are:

• 2-layer laminates are the most basic construction, combining a face fabric with a membrane. These laminates are either paired with insulation and/or drop liner to protect the membrane layer from damage.
• 2.5-layer laminates are constructed the same as a 2-layer laminate, but the membrane is printed on to protect it from damage.
• 3-layer laminates are the most common construction found in high-performance waterproof apparel. In this construction, the membrane is sandwiched between a face fabric and a backer fabric, protecting it on both sides. 
• 4-layer laminates are most used in footwear. This construction method is the same as a 3-layer laminate but between the membrane and backer, a layer of foam or felt is inserted to provide added protection.

 

Waterproof garment components

When waterproof fabric laminates are constructed into garments, footwear, and accessories, different components are used to lock out moisture and help increase breathability. These components help reinforce any potential weak points, while still maintaining the intended structure and design:

Linghui Product Page

• Seam sealing or seam taping is used to reseal the holes that were created when seams were sewn together and ensure there are no pinholes in the garment where water can enter.
• Zippers and fasteners have dual purposes in waterproof garments. In addition to being used to construct outerwear that is easy to put on and take off, zippers and fasteners can also provide added waterproof protection. Of note, in heavier jackets or garments that have membranes with limited breathability, it is common to find zippers in the armpit area (aka "pit zips") that allow the user to quickly shed body heat.

 

Waterproofness and Breathability

Even if a garment is constructed using a waterproof membrane with a DWR-treated face fabric, the waterproof and breathability ratings can vary depending on the materials used and how the garment is constructed. By reviewing the waterproof and breathability ratings in waterproof outerwear and footwear, you can find the right piece for your favority activity, lifestyle, or region.

 

Waterproof Ratings

Waterproofness (or in industry terms water column) measures the level of water pressure that a fabric can withstand before water penetrates it. Waterproofness is measured in millimeters and is tested by putting a 1&#;x1&#; cylinder over a piece of fabric and filling it with water until the water leaks through. As the material withstands a greater amount of water presure, illustrating a greater water pressure, the measured water column increases.

 

Water column ratings give you a roadmap as to what garment works best in the conditions you face. If you need a waterproof jacket for protection as you go for a run outdoors, you don&#;t need as high of a waterproof rating as someone in more rainy conditions carrying a heavy backpack. The below chart can help you determine what level of waterproofness is the best match for your activities:

 

Water Column Rating (mm)

Waterproofness

Usable Conditions

5,000

Some resistance to moisture

Light rain, dry snow, no pressure

10,000

Withstand most downpours and heavy snowfall

Heavy rain and snowfall, light to no pressure

20,000

Waterproof in all conditions

Heavy rain and snowfall, medium to heavy amounts of pressure

30,000

Waterproof in all conditions

Heavy rain and snowfall, heavy amounts of pressure

 

 

Breathability Ratings

Much like how waterproofness keeps you comfortable and dry on the outside, breathability keeps you comfortable and dry on the inside of your garment. By selecting the appropriate level of breathability in your garment, you can help regulate your body&#;s temperature and help prevent overheating. Breathability is measured by the moisture vapor transfer rate, or MVTR. MVTR measures the rate in which moisture permeates through a fabric in grams/meter2 in a 24-hour period. The higher the MVTR is in a fabric, the more breathable the fabric is, helping you stay dry and comfortable.

 

Breathability Rating (g/m2)

Usable conditions

Ideal Activities

10,000

Cooler weather conditions, stationary activities

Snowsports, motorsports, fishing, hunting, lifestyle

20,000

Aerobic activities, all weather conditions

Backpacking, camping, climbing, hunting, snowsports

30,000

High-aerobic activities, warmer conditions

Cycling, trail running, cross country skiing

 

 

Waterproof fabric care

Technical outerwear benefits from regular washing to keep it performing at its best. Before washing, carefully review and follow the manufacturer&#;s care instructions. Most waterproof garments can be cleaned with the following instructions:

1. Secure all zippers and closures on your garment and loosen any elastics
2. Always wash technical garments separately
3. Do not overload the washing machine. Aim for half a load for proper washing.
4. Do not use regular laundry detergent. Use a detergent designed for technical waterproof fabrics. Follow the directions on the label. These can be easily found at outdoor shops or online. 
5. Tumble dry on low heat to rejuvenate the DWR finish
6. Do not use fabric softeners, bleach, or stain removal products and never dry clean your waterproof garments. This will damage the functionality of the fabric.
7. Do not use an iron to rejuvenate the DWR finish, an iron that is too hot can irreparably damage the fabric.

 

Shopping for waterproof gear

When you are looking for waterproof clothing and footwear, keep in mind what activities you plan on using it for, and what the weather conditions are typically like for the area. Pay attention to the item&#;s water column rating and breathability to ensure you are getting the right garment for your intended use. If you aren&#;t sure where to start, take a look at our brand partners to find some of the best breathable and waterproof garments, footwear and accessories on the market.

Contact us to discuss your requirements of Waterproof Breathable Membrane(in,vi,ru). Our experienced sales team can help you identify the options that best suit your needs.