Rain Jacket

Rain jackets, and the difference between shedding water and stopping it

A rain jacket is the layer that decides whether a wet day is bearable, and the range here covers breathable shells, three-in-one systems with a zip-in liner, fleece-lined versions, short cuts and unisex fits in nylon and coated fabrics. All of them keep rain off to some degree. What separates them is how long for, and how much sweat they let out while doing it.

What makes a jacket waterproof rather than shower-resistant?

Three things, and the fabric is only the first. A membrane or coating stops water passing through the cloth. Taped seams cover the needle holes left by stitching, which is where an untaped jacket leaks first regardless of how good the fabric is. A storm flap or a coated zip closes the last opening. A jacket with a treated face fabric but plain seams holds off a shower and wets through in sustained rain. If the priority is a wind and drizzle layer rather than a sealed shell, a softshell jacket answers a different question altogether.

Why do you get wet inside a waterproof jacket?

Because you are producing water as fast as the jacket is blocking it. A working body puts out vapour, and a membrane can only pass so much of it per hour before condensation forms on the inside. That is what people mistake for a leak. Walking slower, opening the front zip and using pit zips move more air than any fabric can. Breathability is a rate rather than a switch, and no shell keeps up with a hard climb.

Which rain jacket fittings should be checked?

• Hood adjustment: a hood with a rear volume adjuster and a stiffened peak turns with the head instead of blocking the view sideways.
• Cuff closure: hook-and-loop cuffs seal over a glove; elasticated cuffs are simpler and wick water up the sleeve when you reach up.
• Hem drawcord: it stops the jacket lifting in wind, which is how rain reaches the back.
• Pocket height: pockets set above a rucksack hip belt stay usable with a pack on. Set low, they are sealed shut all day.

What is a three-in-one jacket for?

It is a shell with an insulating layer that zips inside, so one purchase covers three conditions: shell alone in mild rain, liner alone as a mid-layer indoors and out, and both together in cold and wet. The compromise is fit, since the shell has to be cut roomy enough to take the liner and therefore hangs loose without it. Women's cuts of the same idea sit in rain jacket women. Single-layer shells across the wider waterproof jacket range trade that versatility for a closer fit and less packed bulk.

How do you keep one working?

Wash it. A shell that has stopped beading is usually dirty rather than worn out: body oils, sun cream and grime hold water against the face fabric and stop it shedding. Use a technical wash rather than detergent, skip fabric softener entirely, and reproof when beading no longer returns after washing. Many finishes are revived by gentle heat, so check the care label before putting it anywhere near a tumble dryer. Hang it to dry rather than storing it packed and damp.