Waterproofing is measured in millimetres called a hydrostatic head which indicates the amount water pressure can a jacket withstand before it leaks.
For British standards, over 1500mm is legally ‘waterproof’, however on a standard jacket suitable for use whilst climbing, 2000 to 2500mm is an average hydrostatic head.
Waterproofing or Water repellency is created via either:
Coatings (for water repellency):
Fabrics are sprayed with a PU (Polyurethane) coating before being made into a jacket. Waterproofing is sprayed on the inside of the jacket and the seams then sealed.
DWR- Water repellency (DWR - Durable Water Repellent) is on the outside to form an impenetrable seal from the elements.
Membranes (for breathability and water resistance):
Membranes can be used to make a garment both breathable and waterproof.
Expanded PTFE or Polytetrafluoroethylene is used to make a garment waterproof.
GORE-Tex and E-Vent are examples of membranes utilising PTFE membranes.
Close woven fabrics: (for water repellency):
Fabrics woven together closely form a barrier against water and moisture droplets.
Known as close knit fibres, these do not need to be coated with an additional layer, so are highly breathable.
However, these are classed as water resistant, and not water proof, meaning that although these close knit fibres do not actively repel water, they can keep the bulk of the rain off.
Fitting a Climbing Jacket
Put the jacket on in store, or check as much information as possible about your jacket online. For fitting, online, see our size guides next to each product and measuere yourself for the best fit.
Lift your arms in a diamond shape, to check if the sleeves are as long as they need to be, and if the arms are articulated. The cuffs shouldn’t flop backwards, but should have the capability to be pushed back if you need to vent heat. If you’re buying online, check the measurements of the chest and body as well as the arms.
How short is it? Many mountain jackets are sold in a shorter length called an 'active fit'. However if you want to use a harness, a longer fitting jacket allows you to get to your gear when your arms are above your head. Even though you need longer lengths, a close fit is essential so your mountain jacket doesn't interfere with your movement.
Check the zips. Are they long enough, and do they run without snagging? Are they protected with a waterproof covering or are they exposed? If they are exposed, are the zips waterproof? (You may need to check the label for this.)
Try on the hood. Is the hood broad enough for a helmet? Can you wear it with a hat and does it obscure your vision? Check for toggles or Velcro areas that can conceal your lips and chin from cold.
Where is the venting? Are there pit zips, mesh areas of zips of the arms of the jacket?
Check the pockets. Do they suit your needs? There’s no point I a set of hand warming pockets too high up for you to comfortably put your hands in if your 5 inches taller than the model the jacket was based on. Stash pocket access is common and is one of the few pockets a mountain jacket has. Because you are likely to be wearing a harness and a rucksack, these are usually placed high up so the pocket can be reached even with your gear on.
Does it feel nice? Check the fabric. Is it stiff or flexible? Will it feel good out in the cold?
- How is the collar? Hiigh cut collars are important in mountain jackets because they minimise the amount of cold air that can reach inside the jacket, and prevent drips from overhanging rocks making contact with your skin.
- Is it too tight or too heavy? Imagine hauling it off and carrying it around when the sun comes out. If it feels like a deadweight, keep looking.
- What is it made of? Mountain jackets ususally incorporate coated membranes to provide both abrasion resistance as well as breathability. Typically man made synthetics are used to offer high levels of
protection against rocks, whilst also providing a suitable fabric to
enhance moisture management as you produce sweat whilst climbing.
The truth is there isn’t one perfect jacket. Your friend might be comfortable with 1000g of jacket comprising all manner of pockets, reinforced areas and top end breathability and waterproofing, whereas you may feel the fit and comfort from a lighter, less advanced jacket does the job for you.
Choose the jacket for your own specific needs.
- Sleeves of mountain jackets should be flexible and easy to roll up.
- Your hood should be able to be tucked out of the way when not in use.
- Pit zips are common, and are standard with many jackets but the best solution is a deep chest zip, or a full length zip for venting on the move.
- They can be open and shut as you walk, and with the correct midlayer beneath, you won’t suffer from cold.