Waterproofing Technology Basics
When fabric gets wet, it loses its breathability, insulation, and flexibility—all things that affect your comfort on the slopes. Waterproofing technology is designed to prevent moisture from saturating outerwear fabric and keep your gear performing as intended.
Not all waterproofing technology is created equally. The secret to staying dry, warm, and comfortable on the mountain comes down to three distinct features.
1. DWR Treatment
When you watch water bead off your jacket rather than sink into the fabric, you’re witnessing durable water repellent (DWR) in action. DWR is a water-resistant coating that’s applied to outerwear fabrics to prevent garments from “wetting out”—a term that aptly describes what happens when your jacket soaks through and instantly loses its breathability and insulation properties.
In addition to repelling falling rain and snow, DWR is the first line of defense against moisture that’s applied with pressure. When you’re sitting on a lift, your entire body weight is pressing against the chair and pushing moisture into your ski pants and jacket. DWR is designed to stand up to this extreme pressure and prevent water from penetrating into the fibers of the fabric.
DWR is often applied to fabrics that have been specially designed or treated to be water-resistant. These fabrics are the specialty of industry-acclaimed brands like Gore-Tex, but the same technology is also available in non-branded forms.
2. Waterproof Membranes
If DWR is the first line of defense against moisture, waterproof membranes are the second string. Without this thin, plastic-like film, a garment may be water-resistant, but it won’t be truly waterproof.
Membranes are typically used in performance outerwear in three ways:
Together with DWR, this three-level membrane combination provides the highest degree of waterproofing possible for high-performance outerwear.
Although waterproof membranes are intended to keep you dry, some types are known to hinder breathability. If you find yourself zipping and unzipping your jacket as you break a sweat on the hill, then your outerwear membrane probably isn’t made of polytetrafluoroethylene (PTFE).
PTFE is the most advanced waterproof membrane on the market. Unlike its predecessors, PTFE is exceptionally thin, flexible, and porous. The pores are small enough to prevent liquid like melting snow, sleet, and rain from penetrating the membrane, but big enough to allow water vapor (i.e., sweat) to escape. Because PTFE doesn’t require additional lamination as an outer layer, it’s also exceptionally breathable, flexible, and light.
3. Seam Sealing
On a basic level, the more tiny holes that exist where the fabric has been sewn together, the more opportunities exist for moisture to pass through.
To eliminate this risk, garment seams can be reinforced with a sealant or seam tape. Oftentimes, only the critical seams (areas that are most vulnerable to moisture penetration) will be sealed. On a jacket, critical seams include the shoulder, armhold, and hood back yoke. For pants, critical seams usually refer to the knees, ankles, and rise.