7mesh_Guardian Jacket water beads.jpg
Presented by 7Mesh

2-Minute Expert: How Gore-Tex Works

Words Pete Roggeman
Photos Brian Goldstone / 7Mesh
Date Jan 24, 2020
Reading time
Presented By
7mesh logo

2-Minute Expert is a new feature on NSMB that distills technology and other concepts into short, easily digestible chunks.


Warranty departments at outerwear companies all have customers complaining that their fancy waterproof/breathable (w/b) jacket no longer works. It wets out on the outside, and bathes them with sweat on the inside. "Don't worry," the customer always says, "I've never washed it".

The irony? Not washing them is why they're not working.

Everyone's heard of Gore-Tex. Virtually no one really knows how it works - or how to make it work best for them.

Every time we test a high-end riding jacket - which will, more often than not, use Gore-Tex as its waterproof/breathable membrane - there will be commenters stuck in two camps: the first will extol the virtues of their Gore-Tex equipped jacket and how well it's worked for them for years. The second group will rail about the cost, the risk of ripping it in a crash, and the fact that their jacket no longer works like it did when it was new.

F19_7mesh_GuardianJacket_M_Riding_Moss-1.jpg

In short, one group gets it because they're the RTFM type (read the flippin' manual) and one group doesn't. In defense of that second group, yes, a jacket costing 3-, 4-, or 500 dollars is a big investment some may not be willing or able to make. However, the more you understand about how Gore-Tex works, and how to maintain it so that it keeps working the way it did when it was new, the more you'll realize that your waterproof jacket (pants, shorts, etc) will repay that investment many times over the years if you take care of it. Oh, and for those worried about ripping their jacket in a crash, any outerwear brand worth its sweaty salt will repair a damaged garment for a very reasonable cost - if not for free.

I spent some time chatting with Ian Martin, VP of Product for 7Mesh, who ran me through the fundamentals of Gore-Tex function and maintenance. What I learned was both useful and interesting.

Gore Tex 3 layer tech graphic

You've probably seen diagrams like this before to explain how Gore-Tex functions, but there's a little more to it than meets the eye.

How Gore-Tex Works

The basic premise of any waterproof/breathable (w/b) membrane is that, despite differences in structure or material, they are all designed to allow vapour to pass through them - but not water. Three key factors dictate the efficacy of your w/b garment's performance:

1 - Pressure Differential

Waterproof/Breathable membranes need an environment where warmth creates pressure on the inside of the garment that will push water (in a vapour state) to the outside where it condenses once it collides with cooler air. Anything that minimizes or reverses this pressure differential will decrease the membrane's effectiveness. This includes loose areas where the fabric is further from your body - the area under your arms, for example. Those larger spaces increase the pressure required to push vapour to the inner edge of the garment so it can be transported to the outside. Best case scenario, Martin says, is a next-to-skin fitting garment with gaskets. Vents are actually not useful as far as membrane performance, because they introduce cooler air to the inside environment and decrease the pressure differential. But this is also where theory and practicality collide, because we also know that vents are essential for high output activities. There are times when you're just going to generate too much heat and sweat vapour for the membrane to handle. When that happens, you need to use the vents in order to control your comfort. However, knowing how that impacts your garment's ability to function might impact how long you leave those vents open. The sooner you close them, or reduce the opening, the more you allow Gore-Tex to get back to doing its job to regulate your temperature.

At this point I was starting to understand just how important a garment's fit is in relation to the membrane's performance. It was also clear - yet again - just how important it is to get layering just right.

2 - Water Must Bead on the Outside

You know how water beads up and rolls off a new jacket? That's not Gore-Tex at work - that's DWR (Durable Water Repellent) - which is a protective layer applied to the outside of w/b garments. We all think its purpose is to keep water out, but it is also there to help keep sweat vapour moving to the outside. If your jacket has 'wetted out' meaning the outer surface is becoming saturated, that water is cooling and condensing the vapour before it can move through the membrane - leaving water on the inside and making you wet, uncomfortable, and maybe thinking about whether your jacket needs some warranty love. This is where maintenance comes in, but we'll get to that in a bit.

3 - Membrane Must not Change as it is Used

Gore-Tex is essentially extruded Teflon, which helps explain why water won't stick to it. Some w/b membranes have similar properties, while others are derived from polyurethane. Advantage: they allow designers to build stretch into a garment. Disadvantage: P/U-based membranes don't work well over time because water causes the polyurethane to swell, which reduces the size of the pores. Result: the more you sweat, the less they breathe. There are several reasons why 7Mesh chooses to use Gore-Tex for all of their w/b garments, and it's beyond the scope of this article to go into all of them, but the key reason is that 7Mesh feels that Gore-Tex is the best membrane choice for long-term use in a high output scenario like cycling.

F19_7mesh_GuardianJacket_M_Riding_Moss-6.jpg

Maintaining your Gore-Tex Garment

Getting back to helping frustrated Gore-Tex customer service reps worldwide, there was an old maintenance adage that said "wash it lots, dry it hot". Essentially still true, with a few caveats. Here, then, is how to care for your Gore-Tex jacket (and other w/b membrane garments).

  1. You should be washing your Gore-Tex* pieces...a lot. Oils in your sweat, dirt, smoke from campfires...it all can clog up the membrane's pores as well as interfere with the DWR's ability to work. Machine wash on a warm cycle. Use a small amount of liquid detergent (or even better, a specific cleaning product like Granger's). No powder detergent, fabric softeners, conditioners, or bleach.
  2. Tumble dry on low - this will reactivate the DWR treatment on your outer fabric. If you don't have a dryer, use an iron on a warm setting with a towel between the iron and your garment. *Do not skip this step*. Eventually that coating will need to be restored. When drying/ironing no longer reactivates your DWR treatment, apply a new water-repellent treatment to the garment’s outer fabric. Once again, use products like Granger's or Nikwax.
  3. Do this often. Once a year at least, depending on how much you use your garment. For mountain biking, where mud is an issue, that should be more like 2-4 times per year. If you get grease or oil on your jacket or shorts, use a grease-cutting dish soap like Dawn or Sunlight with a toothbrush before you wash it in the machine. From personal experience, this works even on stubborn grease stains, but requires some tenacity. Mare sure you rinse well prior to machine washing to ensure that no soap remains.

*Gore-Tex and other w/b membranes all have similar maintenance procedures, but to be safe, always check the instructions for your garment.

If you're more of a video learner, this short clip from Gore-Tex illustrates the procedure.

F19_7mesh_GuardianJacket_M_Details-5.jpg

More Resources on Gore-Tex maintenance

Here's 7Mesh's page on Gore-Tex maintenance.

And here's our most recent 7Mesh Guardian jacket review.

Related Stories

Trending on NSMB

Comments

asf
+1 Endur-Bro
asf  - Jan. 24, 2020, 7:16 a.m.

Timely. I have a Guardian jacket on the way. $200 at REI Outlet, couldn’t pass it up.

Reply

pete@nsmb.com
+1 andyf
Pete Roggeman  - Jan. 24, 2020, 1:35 p.m.

That is a crazy good deal. Nice grab!

Reply

Endur-Bro
0
Endur-Bro  - Jan. 24, 2020, 2:31 p.m.

I picked up the Guardian from 7Mesh on Black Friday sale. Charcoal Grey colour. 

Every time I’ve worn that jacket so far I’ve taken a digger. 😹Was worried about the Gore Alpha material but it’s held up so far without issue. 🤞🏽

I also have a black Revelation jacket for road riding also bought on sale  😹

Reply

pete@nsmb.com
0
Pete Roggeman  - Jan. 25, 2020, 8:58 a.m.

The outer material is tough. They'll also repair it if you happen to tear it.

I didn't include this in the article but 7Mesh is also experimenting with a pilot program that'll allow you to bring your jacket in to certain retailers and they'll clean it and restore its DWR for you.

Reply

Vincent66
0
Vincent66  - Jan. 27, 2020, 7:47 p.m.

I grabbed an ACRE Meridian for 50%-off as well last summer ; best jacket I ever had.

Reply

Vincent66
0
Vincent66  - Jan. 27, 2020, 7:47 p.m.

This comment has been removed.

slyfink
0
slyfink  - Jan. 24, 2020, 7:35 a.m.

2 things I think you missed in your write-up (but are in the article) - that were news to me: 

1. rinse twice and don't spin too fast (to avoid creasing). 

2. drying and re-activating the DWR are actually separate steps. Hang or use low heat to dry. Once it's dry, tumble dry for 20 minutes to re-activate the DWR. 

Thanks for the article, it's a good reminder. As a winter commuter in eastern Canada, the road spray, grime and salt can get really get into the fabric. I was worried washing too often would wear out the clothes too quickly. I used to aim for once a month. But I'll probably up that now. As a bonus, I find a clean jacket "pops" more than when it's covered in grime and dull. 

Now I just need to find a way to minimize the nano-particles of plastic that wind up in the ocean from all this washing...

Reply

AJ_Barlas
+1 Windbot Pete Roggeman satn
AJ Barlas  - Jan. 24, 2020, 8:15 a.m.

That’s an interesting addition on the dry then reactivate the DWR. It maybe explains why my efforts have brought only marginal improvements, and they’ve been short-lived at that.

Reply

pete@nsmb.com
0
Pete Roggeman  - Jan. 25, 2020, 8:56 a.m.

Thanks for the additions. This '2-minute expert' already had a suggested reading time of 4 minutes, so I had to keep it pared down. It was also primarily about how Gore-Tex works, and secondarily about care. Caring for Gore-Tex is pretty much its own 2-minute expert as well.

Reply

DanL
0
DanL  - Jan. 25, 2020, 10:25 a.m.

Yes! It's always dissonant when the manufacturer care says dry on low, but nikwax say tumble dry high.

Reply

sanesh-iyer
+1 AJ Barlas
Sanesh Iyer  - Jan. 24, 2020, 8:29 a.m.

Not sure about the dry and reactivate. Arcteryx says spray on when wet.

Protip, turn your garment inside out when drying. Keep the spray on the jacket and off your dryer. That simple step made my reapplication work way better with less mess.

Reply

pete@nsmb.com
0
Pete Roggeman  - Jan. 24, 2020, 1:37 p.m.

Good tip about turning it inside out!

Reply

Vikb
+3 Jerry Willows Pete Roggeman rvoi
Vik Banerjee  - Jan. 24, 2020, 9:29 a.m.

I worked in outdoor retail for a spell. Talking to customers about waterproof breathable fabrics was one of the least fun part of my job.

Reply

cedrico
+1 Pete Roggeman
cedrico  - Jan. 24, 2020, 10:12 a.m.

Wow, this is informative.

Reply

Endur-Bro
0
Endur-Bro  - Jan. 24, 2020, 2:39 p.m.

I never buy the 2 Pak of NikWax out west treatment. 

Always buy the detergent solo and buy the spray on repellent rather than the wash-in version. Like someone said above; extra rinse cycle on the cleaner is key. Then I hang the garment; use the spray on the outer fabric. Using a damp paper towel or rag to ensure even coating and wipe excessive. After it’s hung for a while and absorbed I’ll turn them inside out and tumble dry them on lower heat.

Reply

Hollytron
+2 Velocipedestrian Pete Roggeman
Hollytron  - Jan. 24, 2020, 8:15 p.m.

I have heard that due to atmospheric pressure none of the membranes work well under 1000ft/300m of elevation. 

Is this clown college info? 

The guy who said this was a bit of a clown.

Reply

pete@nsmb.com
0
Pete Roggeman  - Jan. 25, 2020, 8:53 a.m.

I've never heard 'clown college' but that's awesome. I've also never heard of atmospheric pressure affecting a membrane. The dude who said it should be tarred, feathered, and banished to live above 1000 ft in a remote area only accessible by like-minded idiots.

Reply

Hollytron
+2 Pete Roggeman Timer twk Windbot
Hollytron  - Jan. 25, 2020, 10:23 a.m.

Must be an American institution,  some of our finest public self-servants are alumni.

Reply

sanesh-iyer
0
Sanesh Iyer  - Jan. 25, 2020, 11:18 a.m.

I mean... since relative humidity gradient is what allows these to work... It doesn't make much sense for pressure to have an effect. Could someone go ride a bike with a humidy sensor inside their jackets please? Fund me. I'll build it.

Reply

tanadog
0
tanadog  - Jan. 26, 2020, 5:20 p.m.

I spent 15 years selling for a brand manufacturing Gore_tex garments...GoreTex doesn't work well when the outside humidity is high (see below comment about altitude), they talk about pressure differential but really its about "Humidity" differential across the membrane. This is why it's great in continental climates and in cold conditions...low external humidity. In wet temperate climates (like UK, PNW) it has its challenges. Experience suggests that polyurethane membranes work better here, to a point. The real point here is that a GoreTex membrane is only as good as it's DWR, which is kinda stupid really. As soon as the jacket gets dirty of abraded the DWR is compromised, luckily this is usually in areas that aren't required for "Breathability"....hence the move to the new Shakedry jackets where the membrane is exposed and the DWR is applied directly to the membrane, not a face fabric...but its not durable. You can't have it all

Reply

Timer
0
Timer  - Jan. 27, 2020, 9:45 a.m.

I was always wondering about this. If water cannot be allowed to touch the membrane, why even have a membrane?

Or is gore tex pure theory and manufacturers assume that the membrane will have to stop the water and therefore isn't breathable anyway?

Reply

brian
0
Brian Goldstone  - Jan. 29, 2020, 10:09 a.m.

Water can touch the membrane, the new Shakedry fabric as the membrane exposed but it's more susceptible to damage without a face fabric.

wfo922
+1 Pete Roggeman
Wfo922  - Jan. 25, 2020, 6:57 a.m.

thank you nsmb

Reply

cooperquinn
+3 Pete Roggeman DanL Deniz Merdano
Cooper Quinn  - Jan. 25, 2020, 11:11 a.m.

A friend at Dead Bird says a big part of their customer service is basically shouting "DIRTY GEAR DOESN'T WORK" into the phone a la Jim Carrey in Liar, Liar.

Reply

khai
0
khai  - Jan. 25, 2020, 10:09 p.m.

Any idea why no powdered detergents?  Reading the labels and manufacturer's websites for various waterproof/breathable garments they all seem to stress that some detergents (especially those with fabric softeners, etc) are bad as they'll clog up the pores - but I'd think that a gentle/natural cleaner such as Nellies would do well?  It's powder, but it doesn't have any weird stuff in it...  (I use Nellies for almost everything, but do try to keep a stock of Granger's on hand for my Gore/DWR kit)

Reply

pete@nsmb.com
0
Pete Roggeman  - Jan. 26, 2020, 9:47 a.m.

Remember that as a manufacturer selling expensive jackets, you're trying to do everything you can to keep people from messing up their investment - people who, in general, don't know a thing about how to maintain them. So, to cover your ass, you write 'no powder detergents' rather than listing which ones are ok, or which ingredients are bad. Generally speaking, a consumer that's gone to the length of reading the manual has already invested more care and effort into maintenance than 95% of the customer base. It's the same as having to write that hot stove elements can cause burns if touched.

Reply

tanadog
0
tanadog  - Jan. 26, 2020, 5:21 p.m.

because they leave residues that clog the DWR, more rinsing helps but soaps are better

Reply

velocipedestrian
0
Velocipedestrian  - Jan. 26, 2020, 3:15 p.m.

Thanks for the reminder, I've just washed, patched and ironed my riding jacket.

It's easy to forget when the summer arrives.

Reply

Please log in to leave a comment.