Waterproofs

This may sound really quite a stupid things to ask, but, and I understand that I may be one among many, I just have to look at a waterproof jacket when I am out fellwalking and I start to get all sweaty.

Today I think I really discovered that for me waterproofs serve better when considered as a windproof shell.

I started off at the foot of Cat Bells and it was really quite blustery and showery with a temperature of about 5'c so I decided to put on my Bergen jacket. Underneath it I was wearing an Odlo base layer with a Powerstretch top. I decided however to leave putting on the trousers because of my tendency to run hot. it wasn't long before the showers had me wet through, but I wasn't cold until I had gained a fair bit of height, at which point I put my Bergen trousers on. It wasn't long before my legs warmed up, almost seeming to dry in fact.

My intention for the day was to complete the Dale Head Horseshoe but with the inclement weather just managed High Spy. Anyway, I got back to the car and removed my waterproofs to see that inside they were saturated, yet with the garments I had underneath, remarkably, I felt bone dry.

I think, though I may be wrong, if the truth be told, when working hard whilst wearing a waterproof jacket or trousers we will all see those garments overwhelmed with perspiration. I consider now though that if we look at what we're wearing underneath more carefully, it's less of an issue if one at all.

Is that common knowledge or a load of twaddle?

Damian

Do you work for Paramo?

I should have mentioned that once up on to Maiden Moor the spindrift stung a little - well, quite a lot actually.

Given 5'c continuously with blustery showers I would have to agree you, but with the temperature dropping most likely to a minus figure (without winchill), I would have thought, even for me, the Powerstretch top a must.

What do you think?

Damian

OutdoorsMagic Editor | jon@outdoorsmagic.com 

Thanks for that guys and gals.

I have to say that the Powerstretch top I have is the Rab PS Zip Top and a bit of a awkward top to get on and off if wearing something underneath. It's the reason why I've just purchased a Powerstretch jacket to make layering a little easier. That said, it was pretty grim yesterday and don't think I'd have looked forward to removing the waterproof jacket for a moment!

Once down from the fells I was still very surprised by how dry I felt under the base layer I had on and really proved to me how effective some modern materials are at wicking away moisture, despite the inside of the jacket being very damp.

Once overwhelmed with condensation on the inside of your jacket does it continue to breath? Or does that layer of moisture provide a barrier to any vapour? 

Damian

Damian Kimmins 2 wrote (see)

Once overwhelmed with condensation on the inside of your jacket does it continue to breath? Or does that layer of moisture provide a barrier to any vapour? 

What's the point of waterproofs?  Despite it being obvious it's to keep you dry, it's actually to keep you as comfortable as reasonably possible and the most important aspect of that by a long, long way is keeping you warm enough.  Because if you don't keep warm enough that can get far worse than uncomfortable, it can get to hypothermia.

Waterproofs don't insulate, but they do let your insulation layers work much better.  If you get wet through with cold rain at this time of year you can get very, very cold, very very quickly and if you do then it can be incredibly hard to warm back up.  Though it rarely gets dangerous it can do, and even if it doesn't it's utterly miserable.  Far worse than stewing in your own juices. Insulation is primarily about air-trapping.  It can't trap air so well when it's soakin, partly because there's less air space and partly because water conducts heat much better than still air.

Lots of sweat isn't that much fun, but it's better than being freezing.  People have been using waterproofs for a long time before they were breathable.  Breathable makes a good thing better, but keeping you from being soaked by cold water (as opposed to dampened by warm water) is the primary point because once you do then being warm enough can be a major issue.

And those of us older to remember completely non-breathable waterproofs know that the modern ones, while far from perfect, are lots more fun to be in than their predecessors!

Pete.

Damian Kimmins 2 wrote (see)

It's the reason why I've just purchased a Powerstretch jacket to make layering a little easier. That said, it was pretty grim yesterday and don't think I'd have looked forward to removing the waterproof jacket for a moment!

Like Moonlight Shadow said, don't take off the waterproof and put a midlayer on. Put an overlayer (like this or this) on top of the waterproof jacket. Synthetic insulation is light and packs down small and doesn't mind the wet.

That was kinda my point Peter.

I suspect that whatever waterproof I am wearing I will overwhelm it and consequently, unless anything better comes out, look at it as more of an insulating layer. I will however, like some have suggested, look to think more carefully about what I wear underneath.

Do you think they'll come a point at which waterproofs manufacturers will cease their efforts to look for the ultimate in breathability? It has to be a given that the more breathable a garment is, the less windproof it is. Is that right? Will we see a windproof soft-shell becoming a mid-layer?

Damian

Ben Turner wrote (see)

Damian Kimmins 2 wrote (see)

It's the reason why I've just purchased a Powerstretch jacket to make layering a little easier. That said, it was pretty grim yesterday and don't think I'd have looked forward to removing the waterproof jacket for a moment!

Like Moonlight Shadow said, don't take off the waterproof and put a midlayer on. Put an overlayer (like this or this) on top of the waterproof jacket. Synthetic insulation is light and packs down small and doesn't mind the wet.

Yes, sorry, I didn't understand that point.

Surely though as much as a waterproof is limited in terms of breathability, it is limited in transfering the heat from an insulating layer above it or indeed allowing the insulator to do anything?

Damian

Damian Kimmins 2 wrote (see)

I suspect that whatever waterproof I am wearing I will overwhelm it and consequently, unless anything better comes out, look at it as more of an insulating layer. I will however, like some have suggested, look to think more carefully about what I wear underneath.

Do you think they'll come a point at which waterproofs manufacturers will cease their efforts to look for the ultimate in breathability? It has to be a given that the more breathable a garment is, the less windproof it is. Is that right? Will we see a windproof soft-shell becoming a mid-layer?

Damian

Don't think of it as an insulator, think of it as a windshell. It will reduce heat loss via venting, but you will still lose plenty of heat by convection from the shell surface. To keep warm, you still need some sort of insulating layer underneath. If you're set on being totally anti-waterproof, ditch the hard shell and get a pertex windproof instead; it'll be a fraction of the weight and quicker to dry.

I would absolutely not want a windproof mid in a 3-layer outfit; when I'm hot, I want to be able to easily vent by undoing or removing the shell and letting the trapped hot air in the mid just blow away. As far as I'm concerned, only my outer layer (and overlayered insulation) need be windproof.

Damian Kimmins 2 wrote (see)

Surely though as much as a waterproof is limited in terms of breathability, it is limited in transfering the heat from an insulating layer above it or indeed allowing the insulator to do anything?

Putting an insulating layer over a shell will keep you warm, because heat will be trapped between the shell and the outer layer of the insulation. Insulation keeps you warm by reducing heat loss, not by generating heat itself! There's no heat being transferred in, and even if there were a thin shell couldn't possibly block it. Try sticking the shell on and standing by a fire or radiator, or under a duvet, for example.

Peter's pretty much said it all.

Any breathable waterproof can get overwhelmed but you will still be a heck of a lot more comfortable with it on than off (unless the weather is really warm).

Synthetic insulation is light and packs down small and doesn't mind the wet.

Up to a point, Lord Copper.  The insulation fibre itself isn't particularly affected, but the wetter the whole system gets the less air it can trap and the more you'll lose from heat conduction by the water.

So a dry Primaloft jacket will keep you warmer than a wet one.  But it is the case that a very wet Primaloft jacket will do a lot more of usethan a very wet down one.

Do you think they'll come a point at which waterproofs manufacturers will cease their efforts to look for the ultimate in breathability? It has to be a given that the more breathable a garment is, the less windproof it is. Is that right?

Again, up to a point...  you can be very usefully windproof but still nowhere near waterproof, as tight-woven fabrics like Pertex demonstrate.  And even within the Pertex range you've got different gauges, some of which are more windproof than others, but even the less windproof are still very windproof for most practical outdoor purposes.

look at it as more of an insulating layer

But it isn't.  It stops your insulating layers losing effectiveness through getting soaked, but if it's not actually raining and it causes your insulating layers to get soaked from within you can actually be scoring an own goal.  It's not typically one you'll notice until you stop, but when you do you can get colder quicker.

The main insulator is static air.  If it's all wet then the way water conducts heat much more readily than static air compromises the insulation.  Penetrating wind takes away the "static" bit, and also compromises the insulation.

Surely though as much as a waterproof is limited in terms of breathability, it is limited in transfering the heat from an insulating layer above it or indeed allowing the insulator to do anything?

Insulating layers stop heat travelling through them.  They don't particularly trap heat in themselves or transfer heat to other layers, the point is that the heat is trapped in you (where it's coming from) because it can't easily move out.  A close-in insulation layer will typically work better as your body heat will heat up everything between it and the effective insulator, but a further-out one will still work.  Loft insulation makes a house warmer.  You'd be warmer yourself wearing that insulation up close, but it wouldn't be as convenient...

Pete.

Peter Clinch wrote (see)

Synthetic insulation is light and packs down small and doesn't mind the wet.

Up to a point, Lord Copper.  The insulation fibre itself isn't particularly affected, but the wetter the whole system gets the less air it can trap and the more you'll lose from heat conduction by the water.

Indeed, but many people only use these tops for short periods when stopped. For that use the insulation is unlikely to get really wet.

And there is nothing to stop you wearing these layers under your shell if you really found yourself in conditions when the benefits of doing so outweighed the disadvantages of removing your shell.

some have reached a point where a waterproof will only be worn when you are getting wetter i.e. water in is greater than water out. in between they wear a windproof which has far superior breathability to a waterproof (paramo and their ilk excepted).

there comes a point when you decide you are wet enough and put on a waterproof. a windproof (or something wind resistant) can be very effective in showery weather as the gap between showers allows you to dry out.

i don't run hot but i do get hot walking up hills and hence will sweat a lot more. getting rid of that sweat is more important to me than keeping rain outside everything.