Choosing your waterproof jacket
When battling the elements, an effective waterproof jacket suited to your outdoor activity is essential. Whether for hiking, trail or any other outdoor pursuit, the key features to look for are waterproofness and breathability. Here is our guide to choosing the right waterproof jacket.
Key criteria for choosing your waterproof jacket
To help you choose a waterproof jacket suited to your activity, here are a few criteria to consider:
- the waterproofing rating
- the breathability rating
- the sport activity
- the membrane construction
Waterproof jackets must be distinguished from so-called water-repellent ones. The latter are not 100% waterproof. Their fabric will shed light rain or light snow but will not hold up against heavy downpours. The same applies to the seams, which are not sealed.
Waterproofing and breathability ratings of a membrane
It is important to look at the waterproofing and breathability ratings of a waterproof jacket in order to effectively face rain or snow.
To begin with, the waterproofness of a membrane is expressed in millimetres and refers to its ability to prevent water from penetrating. Outdoor enthusiasts are thus protected from rain or snow. When a garment indicates a waterproofness rating of 10,000 mm, this means it can withstand a column of water 10,000 mm (or 10 metres) high before water seeps through.
When it comes to breathability, expressed in MVP for "Moisture Vapour Permeability", this is a fabric's ability to allow water vapour to pass through — in other words, to wick away perspiration during physical effort so you don't end up completely soaked under your jacket.
To summarise, these 2 ratings help outdoor enthusiasts compare membranes and determine which is more waterproof and more breathable. The higher these 2 figures, the more waterproof and breathable the garment.
Read a more detailed article on this topic.
Choosing your jacket according to your activity
There is another factor to consider when choosing your waterproof jacket: is the construction 2.5-layer or 3-layer? This difference lies in the textile design.
3-layer construction: greater durability
For 3-layer construction, the waterproof-breathable membrane forms the central layer, around which 2 further layers of textile are added to protect it. This makes it more abrasion-resistant and therefore more durable. To illustrate: the layers are stacked as follows — textile / membrane / textile. The only drawback is that this makes the garment slightly heavier and bulkier.
2.5-layer construction: greater lightness
Conversely, 2.5-layer construction means the inner textile layer is much thinner, saving weight across the whole garment. This is notably the case with jackets used in trail running. The only downside is that these are slightly less resistant (construction layout: thin film / membrane / textile).
At Cimalp, all hiking jackets are 3-layer for greater durability and performance. The 2.5-layer construction is found primarily in running with trail jackets, to ensure lightness and packability.
The 3-layer principle in hiking
Regarding the term "3 layers", it should not be confused with the 3-layer principle often adopted by hikers. To stay warm and dry during physical activity — particularly hiking — the layering technique is very commonly recommended, in the following order: a first breathable layer to wick away perspiration, a thermal layer for warmth, and a waterproof jacket to protect against the elements.
Looking for a jacket for hiking? Check out our pick of the best waterproof hiking jackets.
Cimalp's Ultrashell®
In the outdoor market, a membrane rated 10,000 mm / 10,000 MVP is generally considered a reliable benchmark for effective waterproofing and breathability.
However, at Cimalp, the brand's R&D team conducted studies over several years to improve comfort for outdoor enthusiasts. The French brand developed its own membrane delivering greater waterproofness and breathability. The Drôme-based SME subsequently patented the ULTRASHELL®, a membrane with the following ratings: 20,000 mm / 80,000 MVP.
The ULTRASHELL is today one of the best membranes available on the market. Initially designed for waterproof hiking jackets such as the Advanced, Cimalp's ULTRASHELL® is now found across a range of the brand's products: hiking overtrousers, trail jackets, as well as waterproof trail and hiking shoes.
And since then, Cimalp has also developed the Aerodry, a breathability optimisation system. Progress continues!
More details on waterproof jackets in video! Our ambassador and expert Florian Olivier, a mountain guide, explains everything.
Finally, make sure you preserve the waterproof and breathable properties of your membrane by caring for your garments properly: Tips for caring for your waterproof jacket
