How to waterproof your ski clothing?

Your ski outfit does not need regular cleaning. The fabrics used on winter sports clothing are generally breathable, preventing perspiration inside your ski jacket or pants.
Subsequently, occasionally washing it is sufficient, preserving the clothing's waterproofing.

Whether machine-washed or by hand, washing your technical clothing must be done depending on the fabric and the water-repellent treatment applied to it. 
The same goes for drying: It is essential for down or feather-filled jackets, and will be an added bonus for restoring your ski clothing's water-repellent properties.

If you keep using and washing it, your ski outfit will lose its waterproof and water-repellent properties. You will quickly notice the moisture penetrating the fabric.
To find out when to re-waterproof or restore the water-repellency of your ski outfit, do the water drop test. Put a drop of water on to your ski jacket or pants:
   ▪️ if the water drop perfectly runs off the membrane, your outfit is still water-repellent;
   ▪️ if the water drop permeates the fabric, it is time to reapply a water-repellent treatment to restore the waterproofing wanted.

The most practical solution for quickly and effectively re-waterproofing is the wash-in waterproofer. You can be certain the product is evenly distributed all over your outfit: ski jacket and pants.

Wash-in waterproofer is used just like an ordinary washing powder: put a bit of the product into your washing machine and select the standard wash cycle. Then put your clothes to air dry or on a low temperature cycle in your spin dryer.

By doing this, your outfit will be both cleaned and waterproof again without losing its breathable properties.

There are several ways to restore the water repellency of your Gore-Tex type membranes without using a product, but just with the help of heat: 

After washing your ski equipment or for simply restoring the missing waterproof effect, a spin in the dryer does the job perfectly.
Firstly, turn your ski jacket or pants inside out because the water repellent-treatment is on the inner lining. Then, select a delicate spin cycle at a maximum of 60°C. If your clothes are still damp after the drying cycle, leave them to air dry.

If you don't have a spin dryer, the ironing technique is just as effective for restoring your ski outfit's water-repellency.

If you have washed your outfit, leave it to air dry.Once dry, place your membrane flat with a towel over it before ironing all of it. Continue doing this over the whole surface of the fabric to be re-waterproofed.

Both these solutions are effective when the water repellent treatment is still active on your membrane. . You will eventually have to restore it completely.
Check your clothing's waterproofing after it is restored by using the water drop method again.

Several water-repellent or waterproofing sprays and products are available that are applied directly to the membrane of your ski jacket or pants.An option that lets you target the parts of your gear that need an additional coating: seams, damaged parts, etc.

Use a spray or dampen a sponge with a product and apply uniformly all over the ski anorak or pants. Pay particular attention to the clothes' seams to prevent water and moisture from permeating. Lastly, leave to air dry in a dry and ventilated place.. For the re-waterproofing to be effective, leave 2 to 3 days before putting your outfit back on.