After about ten miles in today’s rain I discovered a waterproof rating of 30000mm head is not as much as I thought, my PACE 3×3 wetted out………shortly followed by the Sealskin Gloves (which were cold when wet and a load of poop). The Altura Attack long trousers took another couple of miles before they too couldn’t keep the rain out.
A tiny bit under 30 miles done in that sort of rain conditions leads me to come to the conclusion the only true waterproof cycling jacket is made of seam sealed clear PVC and I may well have ended up drier than wearing breathable modern fabris 😆
So what waterproof for biblical rain STW?

Dry suit

IME everything gets wet if it rains enough.

No such thing as a waterproof – they all have a hole at the top and bottom and on the arms. That’s where the water gets in, not through the fabric!

Strangely enough my neck area and front of shoulders was dry on my base layer, the rest was wring if out wet 😆
Just wish I had my merino base layer on for a bit more warmth……

warm and wet is the way to go.
north face apex soft shell, with a tight base layers.

even warm when sodden through, and i love to steam in it.

If it’s wetted out then it’s just the DWR finish which has been overcome – the membrane (with the 30,000 rating) hasn’t. Moisture inside likely to be sweat as the membrane can’t breath with a saturated face fabric. PVC would be worse funnily enough.

Re-activate the DWR with a quick tumble-dry (if manufacturer allows it) or cool iron it. Should fix it. If not a re-proofer will do the same thing.

Try pressure washing a roof in the piddling rain. If the 1500psi 18ltr/min washer spray back from the roof hasn’t wet it, the rain down your back will.
Helly Hansen ‘offshore’ rated suit, still soaked through under it by the end.
Every radiator in the house has some sort of clothing or rope access kit on it ATM!

Now from my readings since being soaked earlier, that’s where we as the punters are all wrong, the 30000mm head fabric can allow moisture through once wetted out and under heavy rain conditions….talking event fabric by the way…..I ceratinly hadn’t sweated as much on my body as water that had come through the arms etc. for what it’s worth it was not washed after the last damp but not dirty ride but ride before that had been washed and reproofed and tumble dried as per washing instructions.
Just proves there is no such thing as a waterproof waterproof!

My usual deeply unfashionable answer.

Cycling cape and proper mudguards. Add a pair of Pertex/waterproof trousers and you’re just about bulletproof.

Worked for our ancestors ever since the 1880s.

I looked at a cape earlier too and thought now there’s a beneath able functional if you’re going slow enough bit of bike wear. 😆

As for Sealskinz gloves (and Endura Deluge) – they are waterproof 100%. You can wash a bike/windows/dishes in them and they will not get wet inside (tested!). As long as there is no water ingress through the top! 😆 So if your jacket gives up (the sleeves are almost always first…) you’ll feel that almost instantly in your gloves…

Some time ago I discovered how much sweat evaporates from the body – and that was on a 2°C 5 miles commute! I wore merino base layer, thermal jersey (not wind/waterproof at all!) and lightweight gillet with windproof front (mesh on the back). So very breathable set up. I commute with a Deuter rucksack, which has that mesh frame, so there is always a gap between my back and the rucksack. That day it was quite cloudy, so I put a waterproof cover on the Deuter (it’s a rucksack cover, so no breathable fabric). After I got to work and took the rucksack off I discovered that the inside of the cover was absolutely wet! And I’m not talking “damp”, but properly soaked. And it was on a dry, chilly day, on short distance. And it was quite away from my body – so if similar stuff happens on the insides of our waterproof jackets, then I’m tempted to believe that it’s mainly the perspiration that makes us soaked wet on rainy day…

30000mm is 43psi – it’ll let water through above that pressure, but not below unless the membrane has been breached, or the tape has failed.

Wetting out the face fabric doesn’t have any effect on how waterproof the membrane is, but it does ruin its breathability. It also allows the membrane to conduct heat from you due to the cold wet face fabric on the other side of the membrane. This can lead to you feeling like it’s leaked when it hasn’t – it’s just cold sweat.

If it’s a 3 layer fabric with a trico liner, then any small breach in the membrane will give the impression that the entire fabric is leaking as the trick liner will quickly wick the moisture across the entire surface area.