How to wash a ski jacket, and why not washing it is worse

The advice everyone repeats is backwards

Somebody in every family says washing a ski jacket ruins the waterproofing. It is the most persistent bad advice in skiing and the opposite of the truth.

A waterproof jacket has two separate systems. The membrane or coating on the inside is what actually stops water passing through, and it is not affected by washing at all. The outside of the face fabric carries a durable water repellent finish, a surface treatment that makes water bead and roll off. That finish is defeated by body oils, sunscreen, sweat, hair product and plain dirt, all of which accumulate exactly where the finish lives.

When a dirty jacket stops beading, the face fabric soaks up water instead of shedding it. The membrane is still keeping you dry, but the wet outer layer feels cold and clammy and kills breathability, so it feels exactly like a failed jacket. That is what “wetting out” means, and washing is the cure, not the cause.

Jackets and snow pants, step by step

1. Empty every pocket and close every zip. Open zips and Velcro chew face fabric in a drum. Close the main zip, the pit zips, the pocket zips and the thigh vents, and fasten every hook-and-loop tab.
2. Loosen the drawcords at the hem and hood so water can move through.
3. Wash alone or with one other similar garment. Overloading is the most common reason detergent residue is left behind.
4. Use a technical wash made for waterproof garments, or a small amount of plain liquid detergent. Not powder, which leaves residue in seams, and nothing that advertises softening, conditioning or brightening.
5. Warm cycle, gentle, then an extra rinse. The extra rinse is the step that separates a jacket that beads afterwards from one that does not.
6. Dry warm, then heat it. Tumble on low for twenty minutes if the care label permits, or hang it dry and then press it with a warm iron through a thin cloth. Heat is what re-orients the repellent finish so it works again.

Three things that do permanent damage

• Fabric softener. It works by depositing a thin film across fibers. On a waterproof shell that film is a water-attracting layer sitting exactly where you need a water-repelling one, and on merino it clogs the fiber and destroys both wicking and odor resistance. There is no garment in a ski bag that benefits from it.
• Bleach and stain removers. They attack membranes, taped seams and elastic, and there is no way to keep them off the parts you did not aim at.
• Dry cleaning, unless the label says so. The solvents strip the repellent finish and can attack seam tape.

What each garment actually needs

Insulated jackets have one extra rule

A synthetic-insulated jacket, which is what most family ski jackets are, must be dried thoroughly all the way through or the insulation stays matted and insulates worse. Low tumble drying with a couple of dryer balls breaks the clumps up. Down is a longer job and a different one; if you own a down layer for the evening, wash it with a down-specific product and expect a long dry cycle.

Three-in-one systems come apart, and they should: the inner and the shell are separate garments with separate needs, and washing them zipped together is how the liner never gets properly rinsed.

Merino: gentler than you think, and not as delicate as you fear

Modern merino base layers and socks are machine washable and they do not need washing as often as cotton, because wool resists odor rather than absorbing it. Two rules cover almost everything: cool water on a gentle cycle, and no heat when drying. Heat is what felts wool fibers together and shrinks a base layer by two sizes in one cycle.

Socks are the exception to the frequency rule, because they are against skin all day inside a boot. Wash them after every wear, inside out, and dry them low or flat. Why one thin pair beats two thick ones is on the socks page, and it is the most useful counterintuitive thing on this site.

Does this apply to inexpensive outerwear too?

Yes, with one adjustment. Budget insulated jackets and pants often use a polyurethane coating rather than a laminated membrane, and coatings are more sensitive to heat and to harsh detergent than laminates are. Wash cooler, skip the tumble dryer, and hang them. The repellent finish is still a surface treatment and still responds to a clean wash and gentle warmth.

This matters more than it sounds, because the outerwear most families own is exactly this kind. What a waterproof rating in millimeters actually means explains the difference between the two constructions, and shell against insulated covers which one you should have bought in the first place.

The realistic schedule

• Mid-season, once: jacket and pants, when beading fades.
• End of season, always: everything, before storage. A jacket stored dirty spends eight months with oils soaking into the face fabric. The rest of the storage list is here.
• Every trip: socks and base layers, in the sink if necessary.
• Never on a schedule: gloves. Spot clean, air dry, and only wash them if the maker publishes instructions for it.