Tech Tips: My $350 coat leaks!

Here comes the storm… is your rain-jacket ready? Chief Lake from the John Muir Trail. copyright Colby J Brokvist

This happens all the time to expensive waterproof jackets, but no worries; the jacket is most likely fine. It just needs some love. Let’s begin with a little background regarding waterproof-breathable (W-B) fabrics. These products (such as Gore-tex) are a plastic layer or laminate embedded within the nylon fabric of your shell. Additionally, the outer layer of nylon the shell is treated with a Durable Water Repellant (DWR) coating to shed water off the nylon.

This outer DWR coating is the key to the “leaking” issue. If the DWR wears off the outer nylon, the nylon wets out. The W-B layer still prevents the water from soaking through to you. However, with the outer nylon saturated, the W-B cannot “breathe” properly because the moisture you are creating as you move cannot escape. So, any moisture you create becomes trapped inside your jacket and you become wet. This all gives the appearance that your jacket is leaking. After all, it’s wet on the outside and wet on the inside in the same places!

So, the issue is not that your jacket leaks, but that the DWR has worn off and the jacket cannot function properly. This is not a quality problem with your jacket.  As you use your jacket and stuff it in and out of your pack, the DWR coating is abraded and wears off. This is normal. Periodically, re-treat it with an after market spray such as Revivetech. The spray-on stuff is best (wash-in is the alternative). A simple spray once or twice a season will keep your jacket in good working order, with no more apparent “leaking problems”. Every other season or so, it’s also a good idea to throw your jacket in the dryer on medium heat. This will warm the W-B layer and it will “even out” the surface so that the jacket continues to breathe well.

A rainy day is no excuse to not have fun in the backcountry. So grab your rain-jacket and hit the trail!