Why Waterproofs Quietly Give Up

A jacket that kept you dry on a soaking Welsh ridge two winters ago can start leaking without any obvious hole. Two things usually fail, and they fail separately. The first is the durable water repellent finish — the DWR — on the outer fabric. That finish makes rain bead and roll off. When it wears away, the face fabric wets out, goes dark and clammy, and the garment feels damp even though nothing has got through yet. The second is the waterproof membrane underneath, which can be damaged by tears, abrasion, ground-in dirt, or the oils and salts from your own skin.

There is also a common false alarm. If the fabric wets out, the membrane stops breathing, so your own sweat condenses inside and you blame the jacket for leaking. Cleaning and reproofing often cures what feels like a serious failure. Before you write anything off, give it a proper wash and a fresh dose of proofing.

Washing Is Maintenance, Not Damage

Many hillwalkers avoid washing shells for fear of ruining them. The opposite is true. Dirt, sweat, sunscreen and body oils clog the fabric and membrane, and they actively degrade the DWR. A dirty jacket performs worse than a clean one.

• Check the care label first, then use a non-biological detergent with no softener, no bleach and no added fragrance. Fabric conditioner is the enemy — it leaves a waxy film that kills repellency.
• Wash on a gentle cycle at 30°C (some makers allow 40°C), with a low spin. Zip up all zips, fasten Velcro, loosen drawcords and empty every pocket.
• Use a dedicated technical wash if your jacket is heavily soiled, or a small amount of pure soap. Never a standard biological powder.
• Rinse twice if your machine allows it. Residue stops the reproofer bonding.

Do not dry clean a shell unless the label explicitly permits it — the solvents can strip finishes and seam tapes. If you have a front-loading machine with no central agitator, so much the better.

Reproofing the Outer Fabric

DWR is a consumable, not a permanent feature. Expect to reproof a hard-wearing jacket roughly once a season, more often if you walk in abrasive terrain with a pack rubbing your shoulders.

You have two main choices. A wash-in reproofer is applied in the machine and treats the whole garment evenly, which suits a jacket or trousers that are uniformly tired. A spray-on reproofer gives you more control and is better for a jacket with a lined interior, since you are treating only the outside. Spray outdoors or in a well-ventilated space, paying extra attention to shoulders, hood, cuffs and the fronts of the legs.

Here is the step most people miss: heat reactivates the finish. After washing, tumble dry on a low setting for around 20 minutes, or warm the garment with a cool iron through a thin cloth. Many spray instructions only fully cure once warmed. Always follow the label, and never iron a laminated membrane directly.

Patching Tears and Worn Seams

Small damage becomes large damage fast. A nick from a barbed wire fence will open under tension on the next windy summit.

• Clean and dry the area thoroughly, then degrease with a little alcohol if the fabric is shiny.
• For pinprick holes, a dab of flexible seam sealant or clear adhesive on both sides is enough. Let it cure fully — usually overnight.
• For anything larger, use a peel-and-stick repair patch with rounded corners to stop it lifting. On a big rip, patch inside and out, sandwiching the damaged fabric.
• Do not stitch through the membrane if you can avoid it. Needle holes leak. If you must sew, seal the seam afterwards.
• Re-tape or reseal lifting seam tape before it peels further. Catch it early and it is a five-minute job.

Delamination — where the membrane separates from the face fabric — is harder to fix. Small bubbles can be stabilised with a patch. Widespread bubbling usually means the jacket has reached the end of its life and is better retired to garden duties.

Storage, Packing and Everyday Habits

How you treat a jacket between trips matters as much as how you treat it on the hill.

• Never store a shell damp or compressed. Hang it on a wide hanger in a dry, cool, dark place.
• Keep waterproofs away from campfire sparks, hot stoves and car heaters. A single ember hole is permanent.
• When packing, fold rather than stuff. Sharp objects — trekking pole tips, crampons, a stove — should never share a compartment with a shell.
• Wash out salt and mud after coastal or peaty walks; both are abrasive.
• Carry a small repair kit on multi-day trips: a couple of patches, a tube of sealant and a needle and thread for emergencies.

With a wash once or twice a season, a fresh proofing and prompt attention to damage, a good shell will keep you dry for years rather than months. That is money saved, and far more importantly, a warm and comfortable day out when the weather turns nasty on the tops.