Waterproof Jackets

Membrane-Technology

Jackets that are made waterproof using Membrane Technology, most notably Gore-Tex and eVent, are generally more expensive but the price reflects quality. The way in which membrane technology works is by using a membrane layer which has millions of pores (holes) which are too small for water droplets to fit through but at the same time are large enough for water vapor to be able to escape so liquid water is repelled and vapor is allowed to leave - this is what makes a jacket waterproof and breathable. This membrane is then bonded to a face fabric and turned into a waterproof jacket.

Coated-Technology

Waterproof jackets constructed from Coated technology are all based around a PU (poly urethane) coating, they are generally less expensive but again price reflects quality. The different levels of waterproofness and breathability are adjusted simply by the thickness of the coating and this will also determine the durability, breathability and waterproofness, this is measured in 'mm' of Hydrostatic Head so the higher the number the more waterproof the jacket is.

Hoods

Whether a waterproof jacket has a fold away hood which fold away into the collar of the jacket so looking much more tidy when not in use or on the other hand you have a fixed hood which can be tidied up using a velcro tab but generally you'd have it unfurled all the time. The bonus of a fixed hood is that it gives you a better field of vision as it'll move when you move, fixed hoods can come as hemet compatible too which means that they will fit and grip to a climbing helmet to prevent snow or rain from going down your neck.

Pockets

Pockets are also a key element to any waterproof jacket and they come in many different shapes and sizes and on different parts of the jacket so to accommodate backpack straps or harnesses depending on your activity. One thing to remember is that external pocket zips sometimes are not guaranteed to be waterproof but to be water resistant, so carry any not so water resistant items on the inside! Some jackets may come with A4 size Napoleon chest pockets so you can keep maps and all sorts close by without having to get into a backpack all the time while others may just come with standard pockets to keep your hands out of the cold and the rain.

Zips

Another important aspect of buying a waterproof jacket is to have a look at the zips, not just the centre zip but the pocket zips, some jackets may have pit zips too. The zips are important on a waterproof jacket as they represent the weak spot between you and the weather. Generally there are 2 different types of zips and they come on the shape of YKK and RIRI.

YKK are the most common of the two and are water resistant, YKK zips use a combination of interlocking teeth and a PU coated strip which come together to form a barrier against the weather. RIRI zips are waterproof and are used on more technical items due to their low weight and performance in challenging conditions. RIRI zips use a system of meshed plastic teeth which come together and form a hydrostatic seal making them 100% waterproof. Waterproof jackets which have YKK zips will use storm flaps to make sure that any moisture that does get through the zip does not make contact with your body whereas jackets with RIRI zip have no use for a storm flap.