The Gore-Tex membrane is the standard when it comes to breathable, windproof and waterproof membranes. The membrane consists of an extremely thin layer of stretched ePTFE, a material that is naturally waterproof. This layer is affixed to the outer layer of fabric of your raincoat, for example, or to the lining of your hiking shoes.

How can it be so completely watertight and breathe at the same time? This special membrane contains 1.4 billion pores per square centimetre. These pores are 20,000 times smaller than a water droplet and 700 times larger than a water vapour molecule. So, water from the outside cannot get in, but condensation (your evaporating sweat) can easily get out!

Basically, the membrane lasts as long as the clothing it is incorporated into or on. However, it is important to properly maintain the water-repellent layer—after a while, it will need refurbishment.

Drying or ironing your clothing after washing it, for example, will reactivate its capacity to repel water. Once that no longer works, you can always rely on the maintenance products from Nikwax or Grangers to help you out. Do you have Gore-Tex shoes? Then, to maintain them properly, fill them with lukewarm water. This will dissolve all the salt crystals that accumulate from your sweat, effectively clearing the pores of the membrane.

Yes, you can. But it is important that you do so correctly and with the correct products. Machine wash at a maximum of 40 degrees and use a small amount of liquid detergent. Do not use washing powder, fabric softeners, stain removers or bleach. 

Dry your Gore-Tex clothing on the washing line or in the dryer at a moderate temperature. As soon as it is dry, put it in the dryer for another 20 minutes to reactivate the water-repellent DWR layer. If you don't have a dryer, you can also reactivate the layer by ironing the clothing on a low setting.

When drying or ironing no longer work, it is time to apply a new, durable, waterproof layer. You can do this with maintenance products from Grangers or Nikwax , for example.

A shoe that is frequently exposed to a lot of water and dirt will eventually lose its breathability and capacity to repel water. That is why it is wise, after a few hikes, to treat your hiking shoes, both inside and out, with the maintenance products from Grangers or Nikwax.

For Gore-Tex shoes, in particular, it is important to also maintain the inside of the shoes. Bacteria and salt crystals from your sweat can create unpleasant odours and affect ventilation. So, when maintaining your shoes, be sure to fill them with lukewarm water. This dissolves the salt crystals and opens up the pores of the membrane once again!