When you’re buying rainwear, you're going to get bombarded with technical jargon explaining all kinds of functions and capabilities that a jacket comes featured with. “ Waterproof ” and “Breathable” are two such words that are actually of the utmost importance when it comes to finding the best rain jackets to suit your purposes.
However, when a rain jacket is advertised as being waterproof and breathable, what exactly does that mean? Many waterproof fabrics are treated with a durable water repellent ( DWR for short), which can keep you dry in light to moderate rain showers by repelling water. Breathability, on the other hand, is the extent to which the inner fabric extracts moisture from the interior and pushes it out to the exterior.
How are these two factors related? In order to answer that, we’ll need to take a look at what’s going on inside the fabric. Rain jackets are constructed using a layering method in order to provide a certain degree of water-repellency and breathability.
There are 3 types of layering construction found in most waterproof shell jackets: 2-Layer, 2.5-Layer, and 3-Layer Construction . Most of these jackets will feature a DWR treated exterior shell fabric to help keep the outer fabric hydrophobic . The second, or middle layer, is the breathable layer or membrane. The third and innermost layer is where all of the technical differences can be found.
This is the most common waterproof/breathable layer construction method. In this process, a laminate or membrane is applied to the face fabric, with nothing attached to the interior. A semi-loose hanging layer is added to provide protection (usually mesh or other such porous fabric). This option tends to be less expensive but adds a little weight to the jacket.
Outerwear featuring a 2.5-layer construction look aesthetically similar to those that feature a 3-layer design (with the exception that it may feel slightly lighter). Jackets that feature a 2.5-layer construction will generally have a similar external shell as a 2-Layer jacket, but also feature a thin polyurethane laminate or coating on the inside. This laminate/coating acts as a barrier to help protect the layer against sweat, dirt, or other oils that could clog the pores, which would affect the breathability. Because this “layer” is not really a true layer, it's considered a “half layer”, hence why it's called 2.5.
A 2.5-layer construction method offers breathability close to that found in 3-layer jackets, although the fabric may feel a bit “clammy” to a consumer. Why is this? Interestingly, the innermost layer doesn't do as good of a job at wicking away moisture, leaving the inside feeling somewhat humid and damp. Again, since 2.5-layer jackets are considered to be lighter than the other layering methods, they are not quite as durable. Therefore, they must be cleaned more frequently to maintain their breathability.
3-layer construction features the highest performance and best quality layering that is possible. This type of construction features a laminated external DWR fabric as the first layer. The fabric is then bonded to a waterproof/breathable membrane in the middle, the second layer. A polyurethane (PU) film or lining covers the second layer, which acts as a shield. The directive of this third layer is to keep sweat and oils from congesting pores in the waterproof-breathable layer.
The overall lifespan of a jacket is increased when the third layer effectively inhibits the second layer from making contact with your skin. How does this work?
As this third layer keeps dirt, oil, and grime at bay, the pores of the waterproof membrane are protected from clogging, thus maintaining better breathability between washings.
|Weight||Midweight||Ultralight to lightweight||Lightweight|
Whether it’s an urban jaunt or a mountain climbing holiday, the best rain jacket is one that features one of these three construction methods. Picking the right raincoat with this information is bound to keep you comfortable and dry no matter what the day has in store.