Wash, reproof, repeat

Leaking, or wetting out?

When the outside of your overtrousers darkens and goes soggy in rain, and your legs feel cold and damp, it's easy to assume they've failed. Usually what has happened is that the DWR (durable water repellent) coating has worn or clogged with dirt, so the face fabric soaks up water. The membrane underneath is probably still waterproof, but a wet outer layer chills you, stops the fabric breathing, and lets your own sweat condense on the inside. It feels exactly like a leak.

A real leak usually shows up in one place: a lifting seam tape, a worn-through knee or seat, a puncture, or a failed zip. If the dampness is spread out and the outside is wetting out, wash and reproof first.

Step by step: washing

1. Read the care label first. It overrides anything here.
2. Empty pockets, close all zips and poppers, and loosen drawcords.
3. Clean the drawer. Residue from ordinary detergent and fabric softener undoes the work, so run a rinse or wipe out the dispenser.
4. Use a technical cleaner made for waterproof clothing, or a small amount of mild non-bio liquid if the maker allows. Never use fabric softener, and avoid powders, which can leave residue.
5. Wash at the temperature on the label, usually a gentle synthetic cycle, with an extra rinse.

Step by step: reproofing

After washing, test by sprinkling water on the knees and seat. If it beads, you may only need to reactivate the existing DWR with gentle heat (below). If it soaks in, reproof.

• Wash-in reproofer: added in a second wash cycle. Easy and gives even coverage, but it coats the inside as well as the outside, which some makers say can slightly reduce breathability of lined trousers.
• Spray-on reproofer: applied to the outside of clean, damp trousers. Lets you target the areas that wear fastest (seat, knees, lower legs) and keeps the inside untreated. Generally the better option for breathable trousers.

If your trousers have a PFC-free finish, choose a PFC-free reproofer. See PFC-free treatments.

Heat reactivation

Many DWR finishes (and many reproofers) work better after gentle heat. If the care label allows it, tumble dry on a low setting, or iron on a low setting with a cloth between the iron and the fabric. If the label says no tumble drying, just line dry. Never dry PVC or PU coated trousers on a radiator, stove or in a hot dryer.

How often?

Wash when they're visibly dirty, smell, or start to wet out, and don't be afraid to do it: dirt and body oils do more harm than washing. Heavily used trousers (daily dog walks, commuting, farm use) might need washing every few weeks; occasional hill trousers perhaps a couple of times a year. Reproof when washing and heat alone no longer make water bead.

Repairs

• Small holes and tears: clean the area and apply an adhesive repair patch designed for waterproof fabric, rounded at the corners so it doesn't peel.
• Lifting seam tape: can sometimes be re-bonded with a seam sealer; bigger failures are worth taking to a specialist repairer.
• Sticky or failed zips: clean grit out of the teeth; some zip sliders can be replaced by a repairer rather than binning the trousers.

Storage

Make sure overtrousers are completely dry before you put them away. Store them loosely hung or folded, rather than compressed in a stuff sack for months, which can crease and stress the membrane and seam tape. Keep them out of direct sunlight and away from heat.