The Ultimate Guide to Waterproof Breathable Fabrics

We don’t have the power to change the weather, but we can change what we wear to better adapt to the conditions. No matter if you are an avid cyclist, skier, or a weekend warrior in the outdoors, you need the right clothing that can protect you from rain, sleet and snow. However, not all waterproof clothing is the same—you want your garment to keep you dry both from the elements and from the perspiration from your body doing everyday activities. How can this be done? Enter: waterproof and breathable fabrics. If you have ever wondered how fabric can be waterproof and breathable, you’ve come to the right place.

 

Waterproof fabric construction

Waterproof fabrics are produced with the construction of layers of fabric and membrane, fused together with heat and glue, creating a fabric laminate. Fabric laminates consist of the top fabric, or face fabric, a membrane layer, additional insulation 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 laminate: comprised of face fabric and membrane. These laminates are either paired with insulation and/or drop liner to protect the membrane layer from damage
  • 2.5-layer laminate: similar to a 2-layer laminate, but has either a drop liner or a print on the membrane side to protect the membrane from damage
  • 3-layer laminate: consists of a face fabric, membrane, and backer fabric. 3-layer laminates are most common for high-performing rain shells 
  • 4-layer laminate: commonly used in footwear, the 4-layer laminate construction contains a face fabric and membrane, but has an extra layer of foam or felt

 

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:

  • Seam sealing/seam taping: waterproof garments will have the seams sealed with waterproof seam tape to lock out moisture at the edges of each fabric panel
  • Zippers/fasteners: Zippers and fasteners have dual purposes in waterproof garments. They serve the obvious purpose in the general construction of any jacket, but some zippers and fasteners also provide some level of waterproof protection. And for jackets with limited breathability, you might find zippers in the armpit area to quickly let out body heat and keep the wearer cool

 

What makes fabric waterproof?

For most waterproof breathable fabrics, there are two components that make it waterproof: the membrane and a durable water repellent (DWR) finish. When properly constructed, a garment with the right membrane technology and a face fabric with DWR treatment can offer maximum breathability while offering protection from the storm.

 

Waterproof membranes serve as a barrier from the elements and can offer protection against wind and rain. The membrane can be created using a variety of materials such as polytetrafluoroethylene (PTFE), polyurethane (PU), or even (TPE) sustainable materials such as castor beans. No matter their material composition, the membrane is designed to prevent wind and rain from penetrating the fabric, while allowing perspiration to escape through its microporous structure.

 

Durable water repellent, or DWR, are treatments applied to the fabric to prevent water from saturating the face fabric and prevents the exterior of the garment from becoming waterlogged and heavy (known as “wetting out”). When DWR is paired with a waterproof face fabric, it creates a waterproof barrier while still maintaining the breathability of the membrane.

 

Fabrics that are constructed with a waterproof membrane but do not have a DWR treatment can still offer protection from the wind along with offering water resistant properties, but without DWR it cannot prevent rain from soaking into the fabrics.

 

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 any activity.

 

Waterproof Ratings

Waterproofness (or water column) measures the level of water pressure that a fabric can withstand before water penetrates it. Waterproofness is generally 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 water column rating increases, it shows the material can withstand a greater amount of water pressure, giving a greater level of waterproofness.

 

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 transmission 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, keeping you more comfortable while wearing.

 

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. Generally speaking, most waterproof garments can be cleaned with the following instructions:

  1. Secure all zippers and closures on your garment, and loosen any elastics
  2. Machine wash warm (110°F / 40°C) with a high performance cleaner. If you use a conventional liquid laundry detergent, run a second rinse cycle to remove all traces of detergent from the fabric
  3. Tumble dry on low heat to rejuvenate the DWR finish
  4. Do not use fabric softeners, bleach, or stain removal products and never dry clean your waterproof garments
  5. Do not use an iron to rejuvenate the DWR finish, an iron that is too hot can irreparably damage the fabric

 

DWR care

Most waterproof garments have likely been treated with a factory-applied DWR finish. DWR finishes will degrade over time and will occasionally need to be replenished to keep performing at its best.

 

To test your garment’s DWR finish, lightly spray it with water. If the water is beading up and rolling off the fabric, your DWR is still protecting the garment from water. If the water droplets are absorbed or “wets out,” it’s time to revive the DWR finish. You can find DWR treatments made for high-performance garments that can be applied as a spray, or during the wash cycle. Follow all instructions when applying DWR treatments for maximum efficacy.

 

Shopping for waterproof clothing and footwear

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 stay comfortable in any weather condition. If you aren’t sure where to start, take a look at our brand partners to find some of the most breathable and waterproof garments, footwear and accessories available, or contact us for our recommendations in all-weather protection.