Restoring Water-Repellency to your Waterproof/Breathable Outerwear

To maximize water-resistance and breathability, most waterproof/breathable outerwear layers come with DWR (durable water repellent) treatments on their outer surfaces. These DWR finishes cause water to bead up and roll off the garment, which keeps the fabric surface clear so that sweat and body heat can pass through from the inside. DWR treatments also keep fabric surfaces drier, which keeps outerwear layers lighter and warmer (less evaporative heat loss).

Over time, with regular laundering and exposure to the elements, DWR treatments can wear off. When this occurs, water may no longer bead on the surface of the outerwear fabric and the fabric may absorb some water. This doesn't mean that the waterproof/breathable barriers built into the layers (like Gore-Tex®, REI Elements and so on) are no longer working—most likely, they are. But it does mean that the outerwear layer will be heavier and may lead to faster heat loss.

Bringing Back your DWR

The best way to renew your DWR is to launder your waterproof/breathable outerwear according to the care instructions and iron it using a warm steam setting. This will restore the water beading protection on the outer surface as long as the original water-repellent treatment is present.

Unfortunately, there is no such thing as a permanent DWR treatment. Eventually, after extended wear and/or many washings, the original repellent finish will be depleted and you'll need to use a spray-on or wash-in water repellency treatment to treat the outer surface of the fabric. You may repeat this process as many times as needed.

A Case of Mistaken Identity

Problems caused by worn DWR coatings are often blamed on faulty waterproof/breathable fabrics. This is due to the fact that when DWR coatings wear off, waterproof/breathable layers may:

• Appear wet on the outside—since the outer fabric may absorb some water
• Feel heavier—again, due to water absorption
• Collect condensation on the inside—water on the fabric's surface can lower the temperature of the fabric through evaporative heat loss. This can cause warm, humid air inside the garment to condense on its inside surface so it feels wet—like it's leaking.

Before you consider replacing your rain jacket or rain pants, first try restoring your DWR or reapplying a spray-on or wash-in coating. Remember—just because the outer fabric becomes wet does not mean that water is passing through the waterproof/breathable membrane or coating inside your garment.