Waterproof vs Water-repellent: A guide to rainwear
Whether you're facing heavy rain, light showers, or drizzly conditions, choosing the right outerwear is essential. There are significant differences between waterproof and water-repellent materials, and knowing the pros and cons of each will help you select the right jacket and pants for your needs. Stay dry and prepared for anything nature throws your way as we explore the world of outdoor clothing and its protective capabilities.
| Water-repellent | Waterproof | |
|---|---|---|
| Light and short rain showers, moderate snow. | Heavy and prolonged rain showers and wet snow. | |
| DWR treatment | ✓ | ✓ |
| Waterproof membrane | Occationally* | ✓ |
| Fully taped seams | X | ✓ |
| Water-resistant zippers | X | ✓ |
*While some garments feature waterproof membranes that provide wind protection and extra resistance against water pressure, such as sitting in the snow, we do not classify them as waterproof due to the lack of fully taped seams and water-resistant zippers.
But to make a garment waterproof, you also need to consider other weak points where water could seep through, such as the seams and zippers.
What does water-repellent mean?
A water-repellent fabric has a higher level of water protection than water-resistant, but still not waterproof. It refers to a material's ability to resist absorption or shed water droplets upon contact. Water-repellent fabrics are treated with DWR (Durable Water Repellent) to create a surface that repels water, causing it to bead up and roll off rather than being absorbed. Wax is also a popular water-repellent treatment for some materials in outdoor gear, like cotton canvas.
Adding a water-repellent treatment to your clothing can give them a higher level of protection against rain. Still, water will eventually penetrate in heavy rain or during prolonged exposure to water. Over time and with heavy use, the water-repellent treatment must be reapplied to maintain its effectiveness.
Read more: What is DWR (Durable Water Repellent)?
What does waterproof mean?
A waterproof material has a high level of water protection. The two main ways to make a material waterproof are a membrane or a coating. Most outdoor clothing designed for intense activities is constructed with a membrane.
A membrane is a technical barrier that allows water vapor from inside the garment to escape while preventing water droplets from entering. Clothing made with waterproof membranes offers good breathability while providing excellent water protection.
But to make a garment waterproof, you also need to consider other weak points where water could seep through, such as the seams and zippers.
Fully taped seams
The waterproofness of the material is weakened in the seams, where the needle makes tiny holes in the membrane where water can leak through. This means all seams in waterproof clothing are weak points that must be reinforced with waterproof tape to prevent leaks.
Water-resistant zippers
Zippers are another weak point where water can leak through the stitching and the zipper teeth. Therefore, always look for water-resistant zippers to avoid leakage.
How are waterproof fabrics with membranes constructed?
Breathable, waterproof materials are made of an outer fabric, a waterproof membrane laminated on the inside and often a third material as an inner lining for comfort.
There are different types of membranes, but they all prevent water from penetrating the garment while allowing water vapor inside the garment to escape. This clever design ensures you stay comfortable and dry, even in wet conditions, without feeling sweaty or uncomfortable inside your clothing.
The waterproof membrane is fragile, and any rips or tears will compromise its water protection. To add durability, the membrane is laminated on the inside of a more durable fabric that acts as an outer layer. The outer layer is often a tightly woven material treated with DWR to prevent water from soaking through the outer fabric and affecting the garment's breathability.
The inside of the membrane also needs to be protected to prevent it from being damaged. This can be done with a loose inner liner, a protective coating, or a bonded inner layer. The different construction types are often called 2, 2.5, or 3 layers.
2 layers (2L)
In this design, the waterproof membrane is bonded to the inside of the outer fabric. The inner lining is separate, which provides a comfortable feel against the skin.
2.5 layers (2.5L)
This type has a waterproof membrane laminated to the inside of the outer fabric. But instead of a loose inner lining, it has a protective coating sprayed or printed on the inside. This protects the membrane from abrasion and provides a lighter, more packable garment.
3 layers (3L)
Here, the outer fabric, waterproof membrane, and inner lining are tightly bonded together as one fabric. This design offers superior durability and protection.
What is a waterproof rating?
A standard called the Hydrostatic Head (HH) measures a material's waterproofness. The waterproof rating indicates how much water pressure the membrane can withstand before water penetrates and is expressed in millimeters (mm).
In the past, this type of test was done by pouring water into a column and measuring how much pressure the fabric could withstand before it leaked. Therefore, it is common to refer to the water column as another name for the rating. Nowadays, the tests are automated, and the measured values can differ significantly depending on how quickly you increase the pressure. We use the Japanese standard, JIS L 1092, when testing the waterproofness of our materials.
The higher the waterproof rating, the more waterproof the material. The construction of the garment, weather conditions, and use also affect waterproofness.
Waterproof rating < 10 000 mm
Withstands light rain, moderate snow, and light pressure.
Waterproof rating 10 000 - 15 000 mm
Whitstands moderate rain, average snow, and light pressure.
Waterproof rating 15 000 - 20 000 mm
Whitstands long-lasting and heavy rain, wet snow, and some pressure.
Waterproof rating 20 000 mm +
Withstands continuous and heavy rain, wet snow, and high pressure.
The importance of breathability
It’s often when the breathability is compromised that you feel like your waterproof clothing has soaked through. Without breathability, warm and moist air inside your clothing can not escape, making you feel damp and clammy.
The breathability can be compromised when the outer fabric of your clothing is saturated with water since it prevents water vapor from escaping through the weave. The DWR treatment on the outer fabric makes the water bead up and roll off, thus extending the time it takes for the material to get saturated.
The more active you are, the more moist air you have to vent, and the membrane’s breathability might not be able to keep up. That is why you should look for ventilation zippers in your waterproof garments. They allow you to vent hot and moist air during high-intensive activities quickly.
Breathability is measured in a lab and indicates a material’s ability to release body moisture. It is measured in g/m²/24h, i.e. the amount of water, measured in grams, a square meter of fabric can release in a day. The higher the breathability rating, the more breathable the material is.
| Breathability rating | Activity levels |
|---|---|
| 5,000 – 10,000 g/m² | 5,000 – 10,000 g/m² Low-intensity activities like walking and light downhill skiing. |
| 10,000 – 15,000 g/m² | Medium-intensity activities like hiking or skiing. |
| 15,000 – 20,000 g/m² + | High-intensity activities like running or going uphill. |
What should you choose?
What level of water protection and breathability you should choose depends on the weather, climate, activity, and intensity level. Choosing the right balance between these factors can help you regulate your body temperature and help keep you dry and comfortable.
