Shell clothing

Shell clothing is usually the outermost layer of protection from the weather (excluding a belay jacket or other warm over layers). It is usually a waterproof and windproof layer, but not always.

Below are the main types of shell clothing as I see them:

Membranes or hard shell

The term membrane is used to describe a garment with a Gore-tex, event or equivalent membrane in it, allowing sweat to escape, whilst preventing rain from getting in. Hard shell describes the generic name given to fully waterproof membrane jackets and trousers (Although some membrane soft-shells can be fully waterproof), but also includes fabrics which have a moisture vapour permeable coating applied to them, again allowing sweat to escape but still being waterproof from the outside.

These 'hard shells' are typically used in a layering system over a baselayer and midlayer(s) (depending on the weather). Below are some of the advantages of hard shell style garments:

• They're waterproof (Although it may seem obvious, hard shells are very waterproof so that you are extremely unlikely to get wet from the outside)
• They're windproof (Almost all waterproof hard shell are windproof)
• They're quickdrying (Because no water can enter from the outside the fabrics dry extremely quickly)

Hard shells offer excellent protection from rain and wind. However, this level of protection does come with some drawbacks:

• They're expensive (A typical good quality hard shell will cost ~ £160 - £300)
• Breathability is limited (Although a good membrane hard shell does breathe, they can be clamy and condensation almost definatly will form on the inside of the jacket if you're sweating lots)
• Water trapped on the inside does not escape easily (When sweat condenses on the inside of the jacket it prevents further sweat from escaping, leaving you wet and damp on the inside)
• They do degrade (Through time the outer fabric will lose its water repellency and although products can be used to revive this it doesn't restore it fully)
• Delamination (The fabric itself can delaminate through time)
• Relatively short guarantee (Most waterproofs garments are guaranteed for up to a year after purchase)

Paramo

Paramo use a different system, called Nikwax Analogy. The Paramo waterproof system uses two layers of fabric; the outer, a durable, windproof and water resistant fabric, and then the liner, which pushes moisture away from the wearer. Precipitation can penetrate through the outer fabric but once it reaches the 'pump' liner it is pushed away from the body at a suffciently fast enough rate to keep the wearer dry. However, it is not a membrane like Gore-tex or event, so if you submerge the fabric (e.g. by sitting in a puddle) then water can come through.

This has the advantage of being able to allow water vapour to escape, but also pushes liquid water (i.e. sweat) away from the body. This means that even if you are drenched in sweat, then it will eventually be pushed to the outside.

This is probably the best waterproof fabric I have ever used. However, it is the design of the garments that cause problems, please see the detailed review of the Paramo Velez Adventure.

For further ideas and advice see 'The 3 Fs'.