My winter roadie jacket is a windproof front and sleeves, breathable back effort, a bit like a Gore Phantom. Its not actually Gore Windstopper, but something similar.

I've been noticing this winter that its distinctly less warm than I remember it being and having just tried blowing through different bits of it, some areas (sleeves especially and upper torso) have negligible resistance.

I reckon its into its 5th winter now, been washed a good few times (although far from every ride). Does windproofing degrade over time? I'm guessing the windproof bit is a membrane between the outer and the fleecy inner, and there's no way of re-proofing it, like there (theoretically) is with waterproofs?

Thanks.