How do you wash and care for your waterproof running jackets etc? It is vital that you do not wash your technical waterproof running jacket in normal detergent as this can strip off the DWR (durable water repellent) hydrophobic coating, which allows the water to bead up and run off. Clothes with a DWR coating should ONLY be washed in a soap solution, as detergents can strip out the DWR coating. Soap solution is the cheapest option however you can also use one of the specialist products such as "Tech Wash" from Nikwax or Grangers "Performance Wash"
However if you have previously washed your jacket in detergent and thus removed its DWR, or if you notice it is not quite as waterproof as it once was then it is time to reproof it with Nikwax "TX Direct" or Grangers "Clothing Repel" or similar, to replenish the DWR. Be sure to wash your jacket beforehand in a non detergent wash (soap solution) to remove any worn in dirt, grease or detergent before proceeding with reproofing.
Do not confuse the DWR with Gore Tex. Gore Tex is a membrane bonded to the inside of the jacket that adds additional waterproofing. Many brands will incorporate the two technologies to give you the best waterproofing.
The DWR coating encourages the water to run off and stops the fabric from "wetting out" which would reduce the breathability of the Gore Tex / Per Tex layer below by blocking the micro pores that allow these types of materials to breath.