Curious about how your rain gear keeps you dry?

In order to repel water, a garment must have some sort of a DWR on its surface. DWR or Durable Water Repellent is a treatment that is applied to most pants and jackets at the factory before you buy them. DWR helps your jacket repel water and keep you dry.

How does Durable Water Repellent Work?

Picture DWR as millions of tiny hairs standing straight on end. When a bead of water falls from the sky and lands on the hairs, it simply rolls off. When those hairs are exposed to smoke, sweat, dirt, and other residues, they lose their ability to stand up and the water no longer flows away from the fabric.

Water is actually attracted to dirt, so if you’ve got a dirty jacket, you’ve got a wet jacket.

Regularly washing your technical outwear in a specialized cleaner will remove dirt and grime, and help revive your DWR. Applying heat to the garment will also help those little hairs stand back up.If your DWR is still not working well, you might want to apply an aftermarket water repellent spray.

Using a specialized cleaner is important because normal laundry soaps can contain heavy residues, added fragrances, optical brighteners and fabric softeners. These things may make your cotton clothes smell and feel great, but they can negatively impact the performance of your DWR just like dirt will by leaving behind added residues. These cleaners can also clog your waterproof breathable membranes.

Maintaining your DWR will help your gear (and adventures) last longer.

Originally Published: Feb 20, 2014

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