Waterproofing and water repellent properties: what is the difference?
What is the waterproofing of a garment and why it should not be confused with the water repellent properties? Let's look at the difference right away, in order to avoid getting in a muddle!
The water repellent property of a fabric is simply its capacity to make water run off its surface, without absorbing it. Conversely, the waterproofing of a fabric is its capacity to prevent water (rain, snow, dew or humidity) from getting inside a product.
Whether we are talking about a water-repellent or waterproof product, it is characterised by a "chemical" treatment applied to the component of the product. As you now know, a water-repellent fabric has the ability to make water "bead" on the surface. The more the water runs off the surface without soaking into the fabric, the more it is waterproof. Consequently, the garment does not soak up water and stays lightweight. This is due to treatment on the outside of the component.
A waterproof fabric is a water-repellent component to which extra protection has been added. This is what prevents water from getting inside the garment, even if water should stagnate or be sprayed on the fabric (e.g. backpack). This is achieved by treating the outside of the fabric, but also by waterproofing it from the inside. There are two different types: the coating and the membrane.