Imagine being out hiking and seeing those big black rains clouds approaching and rushing to put your wet weather gear on? You might see another hiker walk past with the ‘Gore-Tex’ logo on, looking warm and dry. Have you ever wondered what is Gore Tex and Why Do You Need It?
We’re here to help guide you through an introduction to Gore Tex material and why you might well want to invest in one of these jackets for next time you’re out on the trails. The satisfying feeling of being warm and dry in a rainstorm can sometimes be replaced by a sinking feeling when you realize your so-called waterproof coat is leaking.
If you visit any outdoor store or even take a look online, then you might feel a little bit overwhelmed by the sheer amount of choice out there. Before you rush into a purchase that’s not quite right for you, think about making a list of the things that would be high up on your list for a new jacket.
But I’ve had my waterproof jacket for 15 years….
If you’ve got an old waterproof coat stashed away in the back of your wardrobe, you might be tempted to pack it in the bottom of your rucksack when you head out on the trails. Just be aware that the technology behind waterproofing fabrics has come a long way in the last few years.
By choosing a high performance material such as Gore-Tex for your outdoor gear, it leaves you free to focus on what you’re doing – be it navigating a tricky section of mountain pass or cycling to work, without worrying about feeling cold and uncomfortable.
You’ve probably heard of Gore-Tex and seen the name embroidered on people’s coats, but you might not know exactly what it is or why you need it! Read on to find out a bit more about this fantastic fabric.
A brief history of Gore-Tex
Gore-Tex was invented in 1969 by Wilbert and Robert Gore. Their discovery involved heating and then stretching polytetrafluroethylene, or PTFE. This formed expanded polytetrafluroethylene which formed a versatile product with many microscopic pores throughout the surface.
The expanded PTFE is what forms the breathable yet waterproof membrane also known as Gore-Tex. This membrane is sandwiched between other layers of fabric to form rainwear. Interestingly, PTFE is also trademarked under the name Teflon, which most of us know is used in non-stick pans.
Gore-Tex is not only used in rainwear, but has many other applications too. It is used in a variety of medical devices including synthetic ligaments, sutures and grafts.
But how can a fabric be waterproof and breathable?
It’s all to do with the microscopic properties of the Gore-Tex membrane. The Gore-Tex membrane has around 9 billion pore per square inch. Under a microscope, these look like tiny, irregular holes. Importantly, these pores are minuscule in size – around 1/20,000 of the size of a drop of water.
This means, that you guessed it – water cannot penetrate the membrane. This means that your Gore-Tex jacket will prevent any water from seeping in whilst it’s raining. Importantly though, the water molecules from sweat are much, much smaller than a raindrop. This means that they can easily pass through the membrane to the outside, which is how we stay warm and dry!
If you do any other reading around this subject, you might see the words waterproof/breathable pop up a lot. Here we can shorten this to WP/BR. Many different WP/BR fabrics are available however, Gore-Tex was one of the first on the market.
A little More Detail about Gore-Tex
The two main components of Gore-Tex are a membrane and a laminate. The Gore-Tex membrane is breathable, waterproof and windproof. This is what sets it apart from a cheaper jacket which may be waterproof but not windproof or breathable.
Let’s take a look at those features in a little bit more detail:
Many articles of clothing claim to be windproof but they aren’t actually. In strong winds you will feel chilled, because the wind replaces the layer of warm air that had already formed between you and your clothes.
All Gore-Tex clothing completely prevents any wind from passing through, thereby keeping you both warm and dry.
The breathability of Gore-Tex clothing is what really sets it apart from many of its competitors. Lots of waterproof clothing will also trap sweat inside, so although you may not be wet from rain, you will find that your clothes are soaked in sweat instead.
Gore-Tex is different in that it allows sweat to pass through the fabric which keeps you dry inside.
Gore-Tex is different to many other waterproofed fabrics in that the durability of the product doesn’t degrade over time. All Gore-Tex clothing is subjected to a wide range of tests designed to ensure that they can protect you in even the most severe weather events.
Wet clothing can quickly make you feel cold so if you’re out in inclement weather for any period of time, the best waterproof clothing is important. Now you know what the Gore-Tex membrane itself is, let’s take a look at how this technology is incorporated into your rainwear.
To be able to use Gore-Tex technology in clothing, footwear and gloves, first the membrane needs to be sealed between a lining and outer fabric. Once this has taken place, the material is called the Gore-Tex laminate. If you imagine a sandwich, with the two layers of bread being the outer and inner fabric layers, the Gore-Tex membrane is the sandwich filling.
Type of constructions
Gore-Tex clothing is available in a number of different finishes which together provide a wide range of flexible uses:
2-layer construction is designed with a variety of different outdoor pursuits. Here, the Gore-Tex membrane is only attached to the outer fabric. This leaves a separate inner lining which allows for both a wide range of uses and comfort. Jackets and pants made of this 2-layer construction are ideal to combine with an insulating layer to increase warmth when necessary.
3-layer construction bonds
3-layer construction bonds the Gore-Tex membrane to both the outer and inner fabric. An advantage of this method of construction is that because the layers are all bonded together, there is less chance of wear and tear.
It’s a little bit different in that here, the Gore-Tex membrane is attached to a lightweight fabric, which is then allowed to ‘float’ between the inner and outer fabric layers.
This option is best suited to items with more of a fashion application because there is less need for sealed seams so designers have more creative freedom without the need to worry about the number or variety of seams.
LTD construction provides a balance between long-lasting waterproof protection and comfort, by combining soft, high-performance textiles with special linings.
Seams are important too…
A fabric can be as waterproof, windproof and breathable as you like, but if the seams where different pieces of fabric have been sewn together are not protected, then no matter how high quality the garment is, it will still not be waterproof. Any Gore-Tex product also has Gore-Tex tape over every single seam. This provides the same waterproof protection across any stitches and seams.
Different types for different jobs
Gore-Tex technology has evolved over the years, with refinements being made to the membrane and laminates. There are three main types of Gore-Tex rain jackets available at the time of writing:
- Gore-Tex products are designed to be affordable enough to use every day. They combine a WP/BR membrane as well as full wind protection. Suitable for a wide range of activities
- Gore-Tex Pro products are created with extreme conditions in mind and are also designed to reduce the build-up of sweat. Pro products are idea for mountain guides, off-piste skiers and others who demand high performing outerwear which is durable and built to last.
- Gore-Tex Active is designed for fast-paced aerobic outdoor activities such as trail running and cross-country skiing due to the use of Gore-Tex’s most breathable fabric. Lightweight and soft, Active products allow you to concentrate on your performance instead of your clothing.
Not just for jackets
As well as rain jackets, you can also find Gore-Tex in rain pants, footwear and gloves. This means that if you’re a serious hiker, cyclist or general outdoor enthusiast you can kit yourself out with a whole set of outdoor gear which you know will protect you when the elements take a turn for the worst.
Durable Water Repellent helps too
If you’ve ever seen a Gore-Tex garment close up when it’s been raining, you’ll probably have noticed that the water just rolls off the surface in small beads, rather than soaking into the fabric. This is because of the fact that the fabric is treated with something called DWR, or Durable Water Repellent.
The DWR is separate from the Gore-Tex membrane but also has a very important role to play in keeping you dry. The DWR coats the outermost layer of the fabric, and is designed to prevent this outer layer of fabric from becoming saturated.
If the fabric of your waterproof jacket becomes soaked in water, the result is that the fabric becomes very heavy and also you will most likely feel damp. Importantly, the DWR coating does not affect the breathability of your coat in any way.
One thing you do need to be careful of is if your coat gets dirty or the fabric is abraded or scraped on rocks, the DWR coating will be affected. Washing your rain gear too frequently can also affect the DWR finish so this isn’t always recommended. Check the care label inside your garment for the manufacturer’s recommendations.
Any DWR coating requires cleaning and renewing each season (or more frequently, depending on the amount of use) to maintain optimal performance. A great way to check the quality of the DWR coating is to test it before you head out on the trails.
Simply sprinkle or spray some water over your gear and watch to see if it forms small beads and easily rolls off. It does? Great, then that means your DWR coating is in great shape. Check our our article on the benefits of Gore-Tex spray to learn more.
If instead of rolling off, the water simply sits on the fabric then it’s definitely time to refresh that DWR coating.
This can be achieved using a spray to refresh the coating or adding special products when washing your gear. Heat is usually required to ‘set’ the new DWR coating in place, so that involves either tumble drying or ironing your gear.
Again, always check the manufacturer’s guidelines to see what they recommend. As a general rule, Gore-Tex recommends using a warm steam iron to set the new DWR finish in place.
Maintaining your Microclimate
Gore-Tex helps regulate your microclimate – which is basically the air closet to your body. It is this microclimate that keeps you at a comfortable temperature – usually around 90oF and 30% humidity is the ideal. Gore-Tex helps achieve the ideal microclimate in three different ways:
Whilst there’s no way that we can control the weather – we can adjust and adapt the microclimate around our bodies by which clothes we wear. This helps you to stay warm and dry at a temperature that you’re comfortable with.
Our bodies are constantly adapting to the environment around us in order to keep you at the optimum temperature. We sweat when we’re too hot and shiver when we’re too cold. To help your body achieve this, it’s important to think about the clothes you wear.
If you wear clothes that offer breathability combined with wind and waterproof qualities then you’re giving your body the best possible chance to help you maintain that delicate balance of being neither too hot nor too cold.
Your outdoor gear provides a vital layer between your body and the elements. It needs to work hard to protect you from sun, wind and rain. By layering up items you’re more likely to be able to fine-tune everything so that you are warm and dry at all times.
Gore-Tex technology is used by a wide range of different manufacturers so you’re sure to find something to fit your budget. Your rain jacket is an essential bit of kit: there’s no nicer feeling than being warm and snug whilst it’s raining. You’ll want to invest in the best possible equipment that your budget will allow.
To complete your gear, check out our piece on how to choose the best Gore-Tex hiking shoes for more protection.
If you’ve got any hints or tips on where to find great rain gear, or how you look after yours to make sure it lasts for more than one season, be sure to let us know in the comments section.