Waterproof Jacket Buying Guide

By Mark Roberts

There’s just one problem with the outdoors. Often it’s wet. Usually when we don’t want it to be. It's the reason why a decent waterproof jacket is probably your most important item of outdoor clothing.

But choosing which one to buy can be the most complicated buying decision you have to make. The world of waterproof jackets is a confusing combination of technical jargon and more branded fabrics than you can shake a very large and unwieldy stick at. This guide is designed to answer every question you might need to ask yourself when choosing a waterproof jacket:

How To Choose A Waterproof Jacket

  1. What am I going to use it for?
  2. How waterproof does it need to be?
  3. How breathable does it need to be
  4.  Do I need a 2, 2.5 or 3 layer waterproof?
  5.  What is a DWR and do I need to think about it?
  6.  How durable does it need to be?
  7.  Are weight and pack size important to me?
  8.  Will it be comfortable for what I need it for?
  9.  What other features do I need?

Confused by waterproof jacket technology!

What Am I Going To Use It for?

Deciding what you’re going to use your waterproof jacket for is your first step to narrowing down the options. You might need a waterproof jacket for very specific activities like winter mountaineering or trail running, or maybe you just want one jacket that will cover as many activities as possible. A jacket of all trades…

Waterproof jackets will generally fit into one of three categories depending on their features and what type of performance they prioritise: lightweight, flexible and packable jackets for high intensity activities; highly durable and fully featured for harsh mountain conditions; and all-rounders that strike a balance between the two.

Testing jacket waterproofing in the Peak District!

How Waterproof Should My Jacket Be?

For prolonged periods of heavy rain, your jacket should have a hydrostatic head of at least 10,000mm (you may see this listed as 10K). Hydrostatic head (HH) is the industry standard for waterproofing. Essentially, the higher the HH rating, the longer your waterproof will keep out the rain.

It’s also a measure of how much water pressure your waterproof can withstand. Heavy rucksack straps, stretching and kneeling increases the water pressure on your jacket. Because of this, waterproof jackets and waterproof trousers need a higher HH than tent flysheets which benefit from being stretched under tension.

1,500 – The agreed industry standard at which a fabric is considered ‘waterproof’. Real world conditions are another matter though!

5,000 – The rating often used for ski jackets and salopettes, enough to keep out snow and light showers. Our 0Hiro Primaloft® insulated jacket and Cirrus smock use 5K and 8K membranes respectively for extra shower resistance.

10,000 – Very good performance, enough for extended periods of heavy rain. This is the lowest rating we use for our waterproof jackets. Our Argonaut and Atalanta jackets both use a 10K waterproof membrane.

20,000 – Excellent performance, sufficiently waterproof for all day rain, wearing with heavy packs and strong winds. Our Gravitas, Balance, Fortitude and Pulsar jackets and Parallax and Nautilus trousers all have 20K performance.

30,000 – The highest performing fabrics for the very worst conditions. Reliably waterproof even in serious mountain conditions and storm-force winds. The Definition is our only waterproof jacket with a 30K rating.

Waterproof, shower-proof, water-resistant… what’s the difference?!

Waterproof: Any jacket listed as ‘waterproof’ will have a waterproof membrane and taped seams. Unsurprisingly, poking lots of holes in a jacket with a needle tends to let the water in!

Showerproof: This term is usually used for jackets with a membrane but no taped seams. Showerproof jackets will keep out light rain and short showers, but sustained rainfall will eventually seep through at the seams.

Water-resistant: Many windproof fabrics and softshells are listed as ‘water-resistant’. This means they’ve been treated with a water repellent (DWR) to brush off light showers, giving you a bit more time untill you have to put your waterproofs on.

Walking in the Balance multi-activity waterproof

How breathable should my waterproof jacket be?

The higher the intensity of your activity, the more breathable your jacket needs to be. Your body naturally produces sweat and moisture vapour to maintain an even temperature. If your jacket isn’t breathable enough, this moisture can’t escape, making you cold and clammy (think about every time you’ve ever worn a cheap plastic poncho). As well as being uncomfortable, getting cold and damp can be dangerous in mountain environments.

We measure breathability by something called Moisture Vapour Transmission Rate (MVTR) which is counted in grams per square metre per day (g/m²/24hrs).. You will often see MVTR listed as the second number after HH, e.g. 30K/20K. As a rough guide:

5,000 – Good breathability, enough for more stationary activities. (0Hiro)

10,000 – Very good, breathable enough for moderate activity like walking, gentle bike rides and paddle sports. (Argonaut, Atalanta)

20,000 – Excellent breathability, ideal for strenuous hillwalking, mountaineering, mountain biking and running. (Balance, Fortitude, Definition and Pulsar jackets, Parallax and Nautilus trousers)

30,000 – Exceptionally breathable. The highest performing fabrics for high intensity running and riding on steep terrain. (Gravitas)

Definition 3-layer waterproof jacket

Do I need a 2 Layer, 2.5 Layer or 3 Layer Waterproof?

Generally speaking, the higher the number of layers the more reliably waterproof the construction is as the waterproof membrane (the important bit) has more protection. Breathable waterproof fabrics are actually sandwich of multiple layers bonded together.

2 Layer: A face fabric and membrane, usually protected by a separate mesh or nylon fabric. This is a heavier and less reliable construction for waterproof jackets so we don't use 2-layer fabrics for any of our waterproofs.

2.5 Layer: A face fabric and membrane with a printed backer for protection. 2.5 Layer fabrics are usually light, flexible and extremely packable. Our Argonaut, Atalanta and Pulsar jackets and Parallax trousers use this construction.

3 Layer: A face fabric, membrane and backer fabric with the most reliable membrane protection. Our Gravitas, Balance, Fortitude and Definition jackets and Nautilus trousers all use this construction. The Gravitas is one of the lightest 3-layer waterproofs available.

Fortitude Waterproof Jacket with PFC-Free DWR

What Is A DWR And Do I Need To Think About It?

All waterproof jackets use a durable water repellent (DWR) treatment to stop the fabric from absorbing water and ‘wetting out’. Historically, these treatments contained chemicals called fluorocarbons (or PFCs) which have been found to build up in the environment with a number of harmful effects. Because of this, we’ve been moving all of our waterproofs to completely PFC-free DWRs. These new treatments require a bit more care (washing and reproofing) but we think it’s worth it to reduce our environmental impact.

Walking in the rain on the Isle of Arran in waterproofs

How Durable Does My Waterproof Need To Be?

If you’re only using your waterproof for low level walking, running and road cycling, durability probably isn’t your primary concern. But activities like hillwalking (where scrambling may be involved), mountain biking and even gravel cycling (lots of thorny hedgerows!) require more durable fabrics. Climbing and mountaineering waterproofs need to be particularly hardwearing to survive sharp climbing gear, heavy packs and repeated abrasions from rocks.

It can be hard to compare waterproofs for durability as there so many different factors which can affect how hardwearing a fabric is. For instance, our Balance waterproof is extremely tear resistant due to the fabric’s high levels of stretch, and the Definition is more abrasion resistant because it uses a ‘plain weave’ fabric that’s less easy to catch. That said, there are several things you can look out for as a rough guide.

Weight: Heavier jackets generally use more durable face fabrics and backer fabrics.

Denier: This is the thickness of the yarns used to make the fabric. Face fabrics with a higher denier number will often be harder wearing. For example, our Gravitas running waterproof uses 7 denier (D) nylon, whereas the Fortitude hillwalking waterproof uses 70D nylon.

Material: Ripstop fabrics have a grid of higher denier yarns woven through them which stop long tears from developing. Our Definition uses Nylon 6,6, a ‘high tenacity’ material that is more tear and abrasion resistant than regular nylon.

Running in the ultralight Gravitas waterproof in Snowdonia

Are Weight And Pack Size Important To Me?

For running and road cycling, you probably want a waterproof that’s as light and packable as possible, fitting neatly into running packs and jersey pockets without slowing you down. You will need a more durable waterproof for hillwalking and multi-day backpacks but may still prefer a lighter jacket that doesn’t add lots of weight or take up too much pack space – particularly in summer.

Will It Be Comfortable For What I Need It For?

You may also want to think about the fabric and the type of fit and cut that will be comfortable for your chosen activities.

Fabric

Lightweight, flexible fabrics are more comfortable for running and moving fast. Stretch fabrics give you greater freedom of movement for climbing, scrambling and leaning over handlebars. More rigid fabrics offer a greater feeling of protection in high winds.

Fit

Think about how many layers you’re likely to wear underneath. ‘Regular Fit’ jackets will give you more space for winter layers, while ‘Slim Fit’ jackets are usually designed to be worn over just a base layer or thin fleece.

Cut

A longer cut offers greater protection but more ‘active’ cuts are less restrictive for high strides and climbing moves. Mountaineering jackets are usually designed to allow you to raise your arms without your jacket riding up. If you’re likely to wear your jacket for cycling, make sure it has a drop hem that covers your bum and that the sleeves are long enough when you reach forward.

Walking in the Balance stretch waterproof in Devon

What Other Features Do I Need?

Pockets

Do you need pockets? Probably. Pockets are always useful. Fill them with trail mix, bits of cord, magic rings... But what size do they need to be? Do you need pockets big enough to fit a map or chunky winter gloves? Can you access them above a harness if you’re likely to use your jacket for mountaineering?

Hood

Make sure it’s a good fit and has adjustors that cinch it in close to your head. A wired/stiffened peak improves visibility and protection in strong winds. If you’re likely to wear your jacket for climbing or mountaineering, make sure your waterproof has a ‘helmet compatible’ hood that fits your climbing helmet.

Zips

Water-resistant zips (like YKK Aquaguard®) will keep your pockets drier (although we’d still use a dry bag for electronics in a downpour). Make sure the main zip has a storm flap (this will either be a Velcro flap on the outside or a thin strip of fabric behind the zip). Two-way zips are useful for wearing with a climbing harness so you can belay easily.

Vents

Vents allow you to dump excess heat and sweat when you’re overpowering your jacket. Usually these will be ‘pit zips’ under the arms but mesh pockets can also double up as vents in lightweight jackets. The Definition uses side vents which are easier to get to when wearing a harness.

Putting a map in the pocket of the Fortitude hillwalking waterproof in Devon

The Best Jacket Is The One You Look After

Whatever jacket you choose, look after it! That doesn’t mean bringing it cups of tea in bed or tucking it in at night. Just make sure you wash it regularly and reproof it once or twice a year. The fanciest waterproof jacket in the world won’t be very effective if it’s covered in a year’s worth of mud, dirt and skin oils... Here’s why caring for your waterproof is important and how to reproof it.

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