How to Reproof a Rain Jacket

All technical outdoor fabrics are finished with a DWR (durable water repellent) treatment on the outer face. That treatment causes rain to bead into discrete droplets that roll off the surface rather than spreading into the weave. When it works correctly, the shell sheds water within seconds and your base layers stay dry. After repeated wash cycles, or after sustained exposure to abrasion and body oils at the cuffs, shoulders, and collar, the DWR breaks down unevenly and the jacket starts to wet out: the face fabric absorbs water, the garment feels heavy and cold, and the membrane's breathability collapses because trapped moisture has nowhere to go.

This is not a membrane failure. The waterproof membrane underneath is still intact in the majority of cases. Wetting out is a surface treatment issue, and the fix is to restore that surface treatment with Stormproof. Done correctly it takes about 20 minutes and costs a fraction of a new jacket. A technical mid-layer or hardshell that is reproofed every four to six washes will maintain its water-shedding performance across many seasons.

What You'll Need

• Stormproof DWR reproofing spray
• Technical garment wash (Nikwax, Grangers, or similar)
• Washing machine or hand-wash basin
• Tumble dryer on low heat, or an iron and pressing cloth

How To Do It

1. Wash the jacket with a technical cleaner first

Wash the jacket according to its care label, using a technical garment cleaner rather than standard household detergent. Standard detergent contains surfactants that strip DWR treatment from the fabric and leave residues that prevent new treatment from bonding properly. A technical wash removes dirt and body oils without affecting the fabric surface chemistry.

2. Apply Stormproof to the damp jacket

While the jacket is still damp from the wash, lay it flat and spray Stormproof evenly across all exterior panels. Hold the can approximately 15cm from the fabric surface. Work systematically by panel (front left, front right, each sleeve, the back) rather than at random, to ensure complete coverage. Applying to a clean damp surface ensures even coverage before the fabric fully dries.

3. Work the treatment into high-wear areas

Smooth the treatment across the fabric with a clean cloth, paying extra attention to the shoulders, elbows, cuffs, collar, and the area where a pack hip belt rides across the lower back and front hem. These zones wear the DWR fastest through friction and are always the first to wet out. A second light pass with the spray over these areas before smoothing is worthwhile.

4. Wipe zips and seam tape

Run a dry cloth over all zips, zip baffles, and visible seam tape before the treatment sets. Stormproof on metal zip teeth does not cause any harm but the residue can feel tacky on zip pulls before it cures. Wiping now takes 30 seconds and avoids any stiffness in the zips later.

5. Heat activate the treatment

Heat helps the DWR treatment bond durably to the face fabric fibres. Without it, the treatment will not bond durably to the fibres and will wear off far sooner than expected. Put the jacket in a tumble dryer on a low heat setting for 20 minutes, or iron it through a pressing cloth on a medium heat setting, working slowly across each panel. Do not apply the iron directly to the fabric or use high heat, which can damage membranes and delaminate seam tape.

Timing: 20 minutes low-heat tumble dry, or iron through a pressing cloth

6. Test beading before use

Hold the jacket under a running tap or spray it with water from a bottle. Reproofing has worked when water forms distinct beads that roll off the surface immediately rather than spreading into the weave and darkening the fabric. If beading is patchy (some areas shedding, others wetting out) apply a second light coat of Stormproof to the wet-out areas only and heat activate again.

Prevention Tip

Do not wash a technical jacket in standard household detergent. Use a technical wash every two to three cycles and a reproofing treatment every four to six washes to keep the DWR functional. A jacket that is never reproofed will need replacement sooner than one that is properly maintained. The reproofing cycle is the single most cost-effective maintenance step for any waterproof garment.

Common Questions

How do I tell the difference between a DWR failure and a broken membrane?

Wetting out (water spreading into and darkening the face fabric) is always a DWR surface issue first, not a membrane failure. Reproof and test before assuming the membrane is broken. A broken membrane causes something different: internal condensation and wet base layers even when the outer shell is dry and still beading water. If you reproof and the jacket still soaks you from the inside in wet weather, the membrane or seam tape may be at end of life.

Can I use Stormproof on softshells and fleece-backed shells?

Yes. Stormproof works on woven technical fabrics including softshells, fleece-backed membranes, hardshells, and waterproof trousers. The application process is the same. On fleece-backed softshells, spray the exterior woven face only and avoid saturating the fleece backing, which does not need treatment and takes longer to dry if it gets wet.

How often should I reproof my jacket?

Reproof when you notice water spreading into the face fabric rather than beading off. For a jacket in regular use this may be several times a season; for occasional use, once a year is often enough. If you notice water spreading into the face fabric after two or three washes since the last reproofing, that jacket may have heavily contaminated fabric from body oils and needs a more thorough clean before the next treatment cycle. Some fabrics simply deplete DWR faster than others, particularly lightweight fabrics with a finer weave.

Does reproofing affect the breathability of a Gore-Tex membrane?

Reproofing the face fabric actually restores breathability rather than reducing it. When the face fabric wets out, it acts as a saturated barrier that blocks vapour transmission through the membrane beneath it. Restoring DWR allows the face fabric to shed water rather than holding it, which means the membrane can move vapour outward again. A jacket that has been wetted out for a full day in rain will feel far more breathable the first time you use it after reproofing.