Waterproofing trousers

[Earthwormjim]

I have a pair of The Gore Fusion SO Trousers which are great at keeping out the wind but are not that good at keeping the rain out.

Is it possible to add a waterproofing product to these (the liquids you put in the washing machine) or will this affect windproofing / breathability?

 

[festival]

Both the wash in and spray on products normally revive the breathability.
Although they are known as waterproofing they are more like water repellent, how long that lasts I am not sure.

 

[bridgy]

Nikwax TX Direct can be used as a wash-in waterproofing for Gore-Tex products without affecting breathability - it's specifically designed for Gore-Tex and other breathable waterproof clothing.