windshirt over rain shell= enhanced waterproofing?

[Wim Depondt]

Here is the case: I have a lightweight eVent rain shell(OMM Cypher smock) and a lightweight pertex-type windshirt (el cheapo Decathlon Helium).
I have had exceptional cases whereby my rain shell failed miserably, most probably caused by failing DWR after some days of heavy rain.

My thesis is that this DWR coating will be more protected if I would systematically start wearing my windshirt – which I treat with DWR – over my rain shell? The thesis beiing that my rainshell itself will take less hydrostatic head, even with the windshirt wetting out.

But I am not an expert. Quid does my thesis make any sense?

Wim

[Todd T]

If all you've got is DWR, it's not a rain shell. DWR != WP.

[Hiking Malto]

You effectively have two wind shirts. And no I don't think doubling them up will help much.

[Steve K]

Nope. While the windshell will initially keep rain off your shell, once it starts to wet out it will negate the DWR on the rain jacket. DWR works best when it is allowed to bead the water off the jacket, but pressing water against the fabric will overcome the DWR and cause your jacket face fabric to wet out, resulting in poor breathability and internal condensation. It would be better to focus your energies on renewing the DWR on your jacket.

[Bryce]

There is no such thing as waterproof. If you have a truly waterproof jacket (think, thick, heavy vinyl, yellow jacket you had as a kid), then the rain stays out, but as your exert yourself, you sweat and you get wet from the inside. My best experiences have been with Frogg Toggs/Dri Ducks types of clothing. They breathe extremely well, are cheap, and are light. I want something that allows great breathability such that if I sweat it passes through, and if I get a little moisture in through the rain, then the body heat I am generating powers out participation. The goal for my rain gear is to keep me warm, not necessarily dry. GL!

[Marko Botsaris]

I'm thinking the contact alone between the wind shirt and the eVent pretty much ruins the waterproofing. Once you have condensed water sticking between the layers the event will probably immediately begin to wick from those points. After that things only get worse.

[steven franchuk]

The Cypher smock is an Event jacket with a hydrostatic head of 40,000mm. Water will not get through this jacket event if the DWR coating fails completely.

The wind shirt is just water repellent with a hydrostatic head close to zero. The windshirt will not increase the hydrostatic head of the Cypher smock so wearing both will not be of any real benefit.

The only down side of the DWR failing on the Cypher smock is that you own sweat will have a harder time getting through the fabric. However once the rain stops the outer fabric layer of the rain jacket starts to dry breathability of the jacket will return. The DWR is just a water repellent coating it is not a waterproof coating.

Your best course of action is to properly clean your rain jacket. Follow the manufacturer's directions when cleaning it. Do not expose the jacket to fabric softeners. Fabric softeners will severely damage the DWR coating. If the DWR coating is not restored after cleaning re apply it using a wash in or spray on DWR.

[Wim Depondt]

Thanks everyone.

About the DWR on the Cypher Smock: I do clean & reproof it very regulary. And yes, it has never leaked before. But if the DWR fails, the jacket will wet out (not the same as leaking), and as a byproduct stops breathing. In my experience, DWR will fail on longer, wet trips (trips of 3 weeks or more). Hence my question about 'layering' with a windshirt (whereby I am now convinced it would normally not be a good idea).

Wim

[Daniel Fish]

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[Dale Wambaugh]

Keep your windshirt dry if you can. It's not rain gear and is proably the first thing you will reach for if and when the rain quits.

I would l look for a new jacket. Be careful about cleaning it.

Look for rain shells with good ventilation features: pit zips, back cowl vents, big pocket openings with mesh linings, and snaps or seperate Velcro tabs on the front storm flap. That last items allows you to close the front of the jacket with the zipper open and venting through the gaps in the snaps or Velcro. A jacket with those features won't weigh 7oz. Too bad. Suck it up and put up with the extra weight for the features, or get wet— or maybe I should say wetter.

Or try a poncho

The Northwest Coast Native Americans delt with it by wearing capes of shredded cedar bark, probably the original breathable rain gear. Not much of a fashion statement, but interesting to think about. Maybe we need some sort of "shingled" rain gear. Imagine a Cuben jacket with four courses of overlapping Cuben fabric, bar tacked every three inches or so. A pull-over would be easier to make I think. The shoulders, upper chest and sleeves could be one piece to eliminate a top seam. Of call it a gill jacket.

An hour long thunder shower followed by glorious shafts of sunlight and warmth is a completely different thing than three days of drizzle at 50F and no direct sun. Even your brain gets soggy! There isn't a free lunch on that. Having a spare dry base layer is one way to deal with it.

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