Care & Repair
How to Restore DWR: Re-Waterproofing a Jacket That Wets Out
The most common "my jacket stopped being waterproof" complaint has nothing to do with the waterproof membrane. It's the invisible chemical coating on the face fabric — the DWR — wearing off. The good news: you can restore it at home for the price of a bottle of treatment, and the difference is dramatic.
What DWR actually does
Durable Water Repellent is a finish applied to the outer fabric that makes water bead up and roll off. It works by lowering the surface energy of the fibres so water can't spread and soak in. The membrane underneath (Gore-Tex and friends) is what actually blocks water — the DWR's job is to keep the face fabric from saturating.
When DWR fails, the face fabric absorbs water. The jacket feels wet and heavy, the fabric goes dark, and a cold clammy layer sits against the membrane. This is called wetting out. Crucially, the membrane is usually still fine — you're not leaking, but wet fabric kills breathability, so your own sweat condenses inside and you get wet anyway. From inside the jacket, wetting out and leaking feel identical, which is why so many working jackets get replaced for a fault they don't have.
The 10-second test
Sprinkle water on the shoulders and forearms — the high-wear zones:
- Beads roll off: DWR is healthy.
- Water sits in flat blotches and the fabric darkens: DWR is dead. Restore it.
- Water comes through to the inside on a clean, undamaged jacket: now you're looking at membrane damage or blown seam tape — that's a repair (or warranty) case, not a DWR case.
Step 1: wash the jacket first
Dirt, sweat and skin oils mask DWR and attract water. Half of "dead" DWR revives after nothing more than a proper wash.
- Zip everything up, open all pocket flaps, empty the pockets.
- Wash at 30 °C (86 °F) on a gentle cycle with a technical cleaner (Nikwax Tech Wash, Grangers Performance Wash) — never fabric softener, never bio detergent with additives; both leave residues that attract water.
- Rinse twice. Detergent residue is the enemy.
- Re-test with the sprinkle test. If it beads now, you're done.
If your machine has had years of fabric softener through it, run an empty hot cycle first — softener residue in the drawer and drum transfers straight onto technical fabric.
Step 2: reactivate with heat
DWR is heat-activated. After washing, tumble dry on low for 20 minutes, or iron on low with a tea towel between iron and jacket. Check the care label first — nearly all membrane jackets tolerate low tumble drying, and manufacturers actually recommend it. Many "worn out" coatings come back to life from heat alone.
This is the step people skip, and it's why "I washed it and it still wets out" is such a common complaint. Air-drying a shell on a hanger cleans it but never reactivates the coating. If you own a membrane jacket and no tumble dryer, a cool iron through a tea towel does the same job in ten minutes.
Step 3: reapply
If washing and heat didn't bring the beading back, the coating is genuinely depleted:
| Method | Best for | Notes |
|---|---|---|
| Wash-in (Nikwax TX.Direct, Grangers Repel) | Jackets without down/fleece lining | Even coverage, easiest; treats the whole garment including the inside, which slightly reduces breathability |
| Spray-on (TX.Direct Spray, Repel Spray) | Lined jackets, insulated parkas, targeting wear zones | Apply to clean, damp fabric, wipe off excess, concentrate on shoulders/cuffs/hood |
For an insulated parka or anything with a soft lining, always choose spray-on — wash-in products coat the insulation and lining where you don't want them.
Spray technique matters: hold the bottle 10–15 cm from the fabric, spray in overlapping passes until the surface is evenly wet, give the shoulders, hood, cuffs and the pack-strap zones a second pass, then wipe off anything sitting on the surface with a damp cloth after a couple of minutes. Excess product doesn't add protection — it dries into sticky patches that attract dirt. A 300 ml bottle treats one to two jackets.
After treatment, heat-activate again (low tumble dry) unless the product says otherwise. Grangers products are generally heat-activated; most Nikwax products cure at room temperature — read the bottle, not the internet.
Mistakes that kill DWR faster
- Fabric softener and dryer sheets. Both coat fibres with hydrophilic residue. One softener wash can undo a fresh treatment.
- Washing a shell twice a year. Counter-intuitively, not washing is the bigger sin — accumulated oils and dirt abrade and mask the coating. A dirty jacket wets out sooner.
- Leaving it wet in a bag or the car boot. Prolonged damp encourages the face fabric to saturate and, over time, attacks seam tape adhesive.
- Treating over dirt. DWR applied to an unwashed jacket bonds to the grime, not the fabric, and washes off with it.
How often
There's no calendar answer — it's wear-driven. Pack straps, seatbelts and washing all grind DWR off. Daily-wear jackets typically need retreatment once or twice a season; occasional-use shells can go years. Re-run the sprinkle test whenever the jacket starts feeling heavier in rain. A fresh aftermarket treatment doesn't last as long as the factory finish, which is baked on under industrial heat and pressure — expect weeks-to-months of wear rather than years, and plan to top up the high-wear zones.
A note on the chemistry
The industry has moved away from long-chain fluorocarbon (PFAS/"C8") coatings — first to shorter-chain C6, and now increasingly to fluorocarbon-free chemistry, pushed along by tightening regulation in the EU and several US states. The honest trade-off: modern PFC-free DWR (Nikwax has always been PFC-free; Grangers, Gore, Patagonia and others have converted their lines) beads slightly less aggressively against oils and needs reapplying a bit more often — in exchange for not being a persistent pollutant that turns up in drinking water. Gore has gone further and replaced the PTFE membrane itself with an expanded polyethylene (ePE) version in much of its range. Buy the PFC-free bottle; retreat a little more often; nothing else changes.
When it's not the DWR
Two failures that no bottle will fix:
- Peeling seam tape. Look inside the jacket along the shoulder and hood seams. Lifting or flaking tape means water gets in at the stitching. Repair shops can re-tape; many brands do it under warranty.
- Membrane delamination. The inside of a 2.5-layer shell flaking, bubbling or peeling in sheets means the laminate itself has failed — typically after many years or after storage damp. That jacket is done as rainwear; retire it to windbreaker duty.
FAQ
Can I restore DWR on a down jacket? Yes — spray-on only, applied to the shell fabric, and dry it thoroughly with dryer balls afterwards. Never wash-in on anything insulated.
Does DWR treatment make a non-waterproof jacket waterproof? No. It makes fabric shed light rain for a while. A softshell or fleece with fresh DWR resists drizzle; it will never survive an hour of steady rain, because there's no membrane behind it.
Can I use the same bottle on gloves, trousers and pack? Spray-on products work on any technical outer fabric. Leather (glove palms, boot uppers) needs its own dedicated treatment — standard DWR sprays do nothing useful for it.
Is the supermarket "waterproofing spray" fine? Generic silicone sprays repel water but can clog the pores of a breathable membrane and often aren't wash-durable. On a €300 shell, use a product designed for membrane garments — the €12 difference is not where to save.
The one-line answer
Wash it, heat it, test it — and only then buy the bottle. Most wet-out jackets are dirty, not broken.
