Choosing the waterproof jacket that best suits your needs is essential. This Waterproof Jacket guide outlines waterproof ratings, important features such as breathability and technical terms to help you find the right jacket for your next adventure.
Your choice is likely to be influenced by price, fit, personal taste and where and when you plan to wear the jacket. Understanding a jacket’s waterproof capabilities will help you make an informed decision about which jacket is appropriate for the conditions you’re likely to use it in.
Waterproof Jacket Ratings
How waterproof a jacket is will depend on its waterproof rating. The higher a jacket’s waterproof rating, the longer the fabric will remain waterproof for.
|0 – 1,500mm||Water resistant / snowproof||Dry conditions or very light rain|
|1,500mm – 5,000mm||Waterproof||Light to average rain|
|5,000mm – 10,000mm||Very Waterproof||Moderate to heavy rain|
|10,000mm- 20,000mm||Highly Waterproof||Heavy rain|
Jackets with a rating of 1,500mm to 2,000mm are suitable for everyday use, whether it be around town or walking the dog. These jackets may also be suitable for walkers or hikers who aren’t likely to get caught out in heavy, sustained rain.
A rating of 5,000-10,000mm is suitable for just about all weather conditions but equally at home in lesser ones, great for walking the dog or a serious trek in bad conditions. These higher rated jackets will also be breathable.
For extremely wet conditions a jacket of 10,000mm or above will offer the most protection.
Mountain Warehouse stock a wide variety of different waterproof jackets from lightweight and packable to extreme 10,000mm tested jackets.
How Is Waterproofing Measured?
Waterproofness is tested in the factory to ensure the product meets the British Standard (which must be more than 1,500mm). Waterproof ratings are measured in millimetres using a Hydrostatic Head test.
In a Hydrostatic Head test, the fabric is pulled tight under a 1 inch diameter sealed tube of water. This is then observed over 24 hours to ascertain how many millimetres of water the fabric can withstand before it soaks through. The level at which water starts to come through the fabric is the hydrostatic head, which is measured in mm. See the below video for more information.
What Makes a Jacket Waterproof?
Essentially there are two kinds of ‘waterproof’ jacket- water resistant, sometimes referred to as showerproof, and fully waterproof. Water resistant jackets are treated with a waterproof coating while fully waterproof jackets are made with a waterproof membrane and taped, or sealed, seams.
The fabric used for water resistant jackets will be treated with a Durable Water Repellency coating (DWR), or a similar water repellent coating. You can tell a jacket has been treated with a water repellent coating as water will bead up on the surface of the fabric and run off.
The biggest advantage of water resistant jackets is price, they tend to be more affordable than fully waterproof styles. However, they will usually be less durable and may need reproofing more regularly than other waterproof jackets. If you need to reproof your waterproof jacket, check out our How to Reproof a Waterproof Jacket Guide.
A waterproof Membrane is a lining which is found in waterproof jackets. IsoDry is a waterproof membrane unique to Mountain Warehouse which allows perspiration to pass through one side but not the other, so moisture is wicked away from the body but rain will not enter. Check out our IsoDry guide to find out more about IsoDry Fabrics.
Waterproof jackets will be treated with a water repellent coating as well as having a waterproof membrane bonded to the outer fabric.
A jacket can be treated with a waterproof coating and have a waterproof membrane but not be fully waterproof. For a jacket to be 100% waterproof it will also need to have taped seams. Taped seams are heat sealed seams that stop water coming through the stitching. It is particularly important to choose a jacket with taped seams if you will be in heavy, prolonged rain.
Types and Styles of Waterproof Jacket
Two Layer Waterproof Jackets
Two Layer Waterproof Jackets are the most common type of Waterproof Jacket. A two layer jacket combines an outer shell that is fully waterproof with an inner lining layer (membrane) of mesh, polyester taffeta or both. The inner lining layer prevents the deterioration of the waterproof lining by acting as a barrier to corrosion by the wearer’s movements and sweat.
Three Layer Waterproof Jackets
Three Layer Waterproof jackets are suitable for for just about all weather conditions, including torrential rain. Three layer Waterproof jackets contain an external waterproof fabric layer, an internal waterproof and breathable membrane and an additional bonded protective lining. These 3 layers are bonded together to make a technically efficient 1 layer lightweight jacket.
3 in 1 Waterproof Jackets
Not to be confused with a three layer jacket, a 3 in 1 waterproof jacket consists of a waterproof outer-shell with a detachable inner fleece, softshell or padded jacket. A 3 in 1 jacket is a versatile option for all year round and ideal for changeable weather conditions.
A packaway (Pakka) jacket is a lightweight waterproof jacket that can easily be packed away in its own waterproof pouch. Packaway jackets are an ideal ‘just in case’ jacket for those who want something lightweight which can be stored in their rucksack.
Breathable Waterproof Jackets
The ability of a jacket to allow perspiration to escape is as important as not letting water in, especially if you will be doing anything energetic. If a waterproof jacket is not breathable, sweat will be unable to escape, making the wearer feel damp. It’s common for people to feel as though their waterproof has ‘leaked’ when in fact it’s perspiration from inside they are feeling.
In addition to a breathable membrane, other features such as pit zips and mesh lined pockets can contribute to a jackets breathability.
Most waterproof jackets will be cut differently for men and women, often you will find that womens jackets have shorter arms and a more tailored fit. As a women if you prefer a looser fitting jacket you may opt for a mens jacket. However, it is worth remembering it has not been cut for a female shape so may have wider shoulders and narrower hips.
When trying on waterproof jackets always take into account the layers you will need to fit underneath. You need to be able to move your arms and shoulders especially if you are likely to be wearing a backpack or doing an activity, such as hiking, where freedom of movement will be important.
Make sure the cuffs of the jacket are long enough to cover the top of your hand to help stop rain entering and soaking your arms.
The length of the jacket is also an important consideration. Always make sure the jacket is long enough to cover your lower back even when you lift your arms up. Shorter length waterproof jackets will often have a longer back so there won’t be a gap between your trousers and the jacket should it ride up. This is especially important for cyclists who will be bending forward a lot!