DWR: what it is, why it fails, and how to restore it

A step-by-step guide to restoring the water-repellent finish on a waterproof jacket — what to wash it with, why heat matters, and when to reproof.

By GearScouting · 6 min read

DWR — durable water repellent — is the reason water beads on your jacket rather than soaking in. It's also the reason a perfectly functional waterproof jacket can start to feel like it's failing.

Most jackets that seem to have given up haven't. They need maintenance, and the whole process takes about an hour of attention spread over an evening.

What DWR actually is

DWR is a chemical finish applied to the outer face fabric — not the waterproof membrane, which is a separate layer underneath. As REI's guide explains, it coats individual fibres and alters the surface tension of the fabric so water forms tight beads and rolls off rather than spreading and soaking in.

When it's working, water hits the jacket and balls up. When it's degraded, water spreads and soaks into the face fabric — the fabric "wets out". The jacket looks and feels saturated even though the membrane beneath is usually still doing its job.

That saturated outer layer is what stops moisture escaping from inside, which is why failed DWR feels so much like a leak. If you're not sure which you're dealing with, our guide to telling condensation from a genuine leak covers the shower test that settles it.

Why DWR degrades

Abrasion. Pack straps, harnesses, rock and general use wear the coating off the areas taking the most friction — shoulders, upper back, anywhere a rucksack sits. Entirely normal.

Contamination. Body oils, sweat, sunscreen and dirt block the coating from working even when the chemistry is intact. A jacket can wet out without heavy use if it's been stored dirty.

Incorrect washing. Standard detergent leaves residue. Fabric softener is worse: it works by coating fibres with water-attracting chemicals, which is precisely the opposite of what DWR does. One wash with either can noticeably compromise performance.

The PFAS transition. The industry has moved away from PFAS-based DWR under EU regulation and environmental pressure. The replacements work well but are generally less durable, needing more frequent reproofing. If a newer jacket seems to need more attention than older kit you've owned, that's why — it isn't a defect.

How to restore DWR

Step 1 — Wash with a technical cleaner

Nikwax Tech Wash or Grangers Performance Wash. Close all zips and Velcro first. No standard detergent, no fabric softener, and run an empty rinse cycle first if your machine has recently had either in it.

Step 2 — Apply heat

Tumble dry on a gentle heat setting for around 20 minutes. Gore-Tex's own guidance is to wash and tumble dry before assuming the coating needs replacing — heat alone reactivates existing DWR in a good proportion of cases.

This step gets skipped constantly and it shouldn't be. It's often the whole fix.

If you don't have a tumble dryer, a warm iron on a low setting through a clean cloth or tea towel does the same job. Never iron the fabric directly.

Step 3 — Test

Sprinkle a few drops of water on the clean, dry face fabric. Beading and rolling off means you're done. Spreading and darkening means move to step 4.

Step 4 — Reproof, then heat again

Apply a wash-in or spray-on DWR product — Nikwax TX.Direct, Grangers Performance Repel or Storm are the common UK options — and cure with heat again. The heat bonds the treatment to the fibres, so skipping it wastes the product.

Use spray-on rather than wash-in for insulated jackets, where soaking the lining isn't what you want. Spray-on also lets you concentrate on the areas that actually need it, usually shoulders and forearms.

How often to reproof

The water bead test is the whole answer. When water stops beading in real use, run the sequence. For regular users that's typically once or twice a season, and more often for newer PFAS-free finishes.

Washing a technical shell more often, with the right product, keeps DWR working better than washing it rarely — the instinct to avoid washing a good jacket is backwards.

Frequently asked questions

How do I know if my jacket's DWR has failed?

Sprinkle water on the clean, dry face fabric. If it beads and rolls off, the DWR is working. If it spreads and darkens the fabric, it needs attention. Test on a clean jacket — dirt alone will cause wetting out.

Can I use normal washing powder on a waterproof jacket?

No. Standard detergent and fabric softener leave residues that actively damage DWR performance, and softener coats fibres with exactly the kind of water-attracting chemistry DWR is designed to prevent. Use a technical cleaner made for waterproof outerwear.

Does tumble drying damage a waterproof jacket?

No — on a gentle heat setting it's actively recommended, because heat reactivates the DWR coating. Check the care label, but gentle tumble drying is standard advice from Gore-Tex and most technical brands. A warm iron through a cloth works if you have no dryer.

What's the best DWR product for a waterproof jacket?

Nikwax TX.Direct and Grangers Performance Repel are the most widely available in the UK and both work well. TX.Direct comes in wash-in and spray-on versions; use spray-on for insulated jackets and anywhere you want to target specific areas. Always follow with heat.

How long does DWR last?

It depends on use, conditions and which chemistry the jacket uses. Newer PFAS-free treatments generally need more frequent attention than the older fluorocarbon formulas they replaced. There's no fixed interval — use the bead test rather than a calendar.

Can I restore DWR without a tumble dryer?

Yes. Iron the jacket on a low setting through a clean cloth or tea towel, which supplies the heat that cures the treatment. Never apply an iron directly to the face fabric, and check the care label first.

Sources

Gore-Tex: Restore DWR on Raingear · REI: Rainwear Care and DWR · Nikwax TX.Direct · Grangers Performance Repel · The Hiking Tribe: How to Restore DWR

Reproofing won't save a delaminated membrane. If a jacket has genuinely reached the end, our waterproof jacket spec table tracks current UK replacements and today's prices.

The waterproof jacket spec table · Watch a product · All field notes