Why Even a Good Shell Starts Leaking

There is a moment every hillwalker knows. You are halfway up a Munro, the cloud has dropped, the rain has settled in for the day, and the jacket that kept you dry last winter suddenly feels clammy and cold against your back. You are not imagining it, and your jacket is not finished. In almost every case, the fabric is perfectly sound and what has failed is its surface finish.

Waterproof shells work on a two-part system. The membrane underneath stops liquid water getting in while still letting vapour out. On top of that sits a durable water repellent finish, usually shortened to DWR, which makes rain bead up and roll off rather than soaking into the face fabric. When the DWR wears out, the outer layer wets out, the membrane is smothered by a film of cold water, and breathability collapses. The jacket still keeps rain out, but you get soaked from the inside instead.

The good news is that this is a maintenance problem, not a replacement problem. A careful clean, a fresh reproof and a few small repairs will bring most shells back to near-new performance, saving you a serious amount of money.

Start With a Proper Wash

Dirt, sweat, sun cream and body oils are the quiet killers of waterproof clothing. They clog the tiny pores of the membrane and physically mask the DWR, so no amount of reproofing will work on a filthy jacket. You must clean first, always.

Use a technical cleaner designed for waterproof fabrics, or a pure liquid soap with no additives. The important things to avoid are biological washing powders, fabric softener and anything with bleach, all of which will strip or damage the finish. Do up all the zips and Velcro, empty the pockets, and loosen any mud with a soft brush around the cuffs, hem and shoulders.

• Wash on a gentle cycle at around 30°C with a low spin.
• Use roughly half the detergent you think you need, and run an extra rinse if your machine allows it.
• Never dry clean a technical shell, and never use an iron directly on the fabric.
• Wash your jacket two or three times a season if you walk regularly, and more often if it is visibly grubby.

Reactivating and Reapplying the DWR

Before you reach for a bottle of reproofer, try heat. Many DWR finishes are simply dormant rather than dead, and warmth brings them back to life. After washing, tumble dry the jacket on a low, gentle setting for twenty to thirty minutes. If the label forbids tumble drying, a warm iron through a clean cotton cloth on the lowest setting can achieve the same thing. Check the beading under a running tap: if water still soaks in rather than running off, it is time to reproof.

You have two main choices. Wash-in reproofers treat the whole garment evenly and are quick, but they can leave the inside of the jacket slightly less breathable, and they do nothing for the lining. Spray-on reproofers let you target the shoulders, hood and sleeves where rain actually lands, and they keep the interior clean. Many people use a spray for best results, hanging the damp jacket up and working in thin, even coats from around 20cm away.

Whichever you choose, apply it to a clean, damp jacket, then tumble dry or gently warm the garment again to cure the finish. Let it hang in a warm room for a day before you trust it in anger.

Patching Holes, Snags and Worn Cuffs

Small damage is normal on rocky ground. A snagged sleeve or a spark hole from a stove does not mean the jacket is done, but it does need dealing with before the membrane tears further.

• Small nicks and thorn holes: use a self-adhesive repair patch cut to size with rounded corners, pressed firmly onto a clean, dry surface. Keep a couple in your pack for mid-walk fixes.
• Larger tears: clean the area with alcohol, then use a flexible polyurethane seam sealant or a heat-applied patch. Follow the curing time properly; a rushed repair will peel off in the first downpour.
• Worn cuffs and hems: these often just need reproofing, but if the fabric has gone thin and fuzzy, a patch on the inside will stop it spreading.
• Delaminated seam tape: if tape is lifting inside the jacket, press it back with a warm iron through cloth, or seal the seam with a thin bead of flexible sealant.

Zips, Hoods and the Small Stuff

Zips are the most common point of failure on an otherwise healthy jacket. Grit and salt clog the teeth, and a sticky zip gets forced until it breaks. Clean the teeth with an old toothbrush and warm soapy water, then lubricate lightly with a silicone or zip-specific wax. Never use oil, which attracts dirt.

Check the hood adjustment cords, the cord locks and the Velcro cuff tabs. Replacing a frayed drawcord costs pennies and takes minutes. If a cord lock has cracked, swap it out before a windy day on a ridge turns your hood into a flapping sail.

Building a Simple Care Routine

Look after your shell and it will look after you for years. Rinse it after muddy days, wash it properly every few trips, reproof when beading stops, and repair small damage before it grows. Hang it on a wide hanger rather than cramming it into a stuff sack for months, and store it somewhere dry and out of direct sun.

Do this and you can head out into a wet Welsh valley or a breezy Scottish ridge knowing your jacket is doing its job. That quiet confidence is worth far more than a new jacket, and it costs a fraction of the price.