Difference Between Waterproof and Water-Repellent: Guide to Rainproof Fabrics
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What is the difference between waterproof and water-repellent? And in which situations are the different fabrics more suitable?
These terms are often confused, but they are not synonyms. They describe different levels of protection, achieved through different technologies. Knowing how to distinguish them is essential for sailors, water sports enthusiasts, and outdoor athletes — but also for anyone looking for versatile garments to wear in everyday life.
With autumn bringing the first rains and more unstable weather, understanding these differences becomes even more important.
A waterproof garment provides complete protection: it doesn’t let water in, even during heavy rain or under pressure from wind or shoulder straps.
This level of protection is achieved through:
The 'water column test' (or hydrostatic pressure test) measures the maximum height of a water column (in millimeters) that the fabric can withstand before droplets start to penetrate. The higher the value is, the more waterproof the garment results.
From 1,000 mm upwards a fabric is considered slightly waterproof, while the best outdoor jackets exceed 10,000 mm and can even reach 20,000 mm.
A water-repellent fabric keeps water out thanks to a surface treatment such as DWR (Durable Water Repellent). In practice, droplets don’t penetrate the fabric but instead bead up and slide off.
To be considered water-repellent, a garment must offer:
Overall, water-repellent clothing is ideal for both sports and everyday use, especially in changeable weather.
The treatment can wear off with washing and use. To check if a garment is still water-repellent:
The DWR treatment is present both in waterproof and water-repellent products, but it tends to degrade over time. However, it can be renewed with specific products that help preserve the garment’s technical features.
In water sports such as sailing, choosing the right fabric is crucial. Here are some examples of outfits depending on the situation:
Knowing these technical differences helps you choose the right garment for the right occasion, avoiding the risk of being caught unprepared.
With the arrival of autumn, rainy-day gear becomes more important than ever. SLAM offers a range of rainproof products that combine technology and versatility, providing protection at sea, in sports, and in everyday life.
Waterproof jackets are essential for races and challenging weather, but also for anyone who wants reliable protection in daily life.
The Foil Hooded Jacket is made of multilayer technical fabric, both waterproof and breathable. With its essential design, it’s perfect at sea or in the city.
For those looking for a shell for regattas or intense outdoor activities, the Foil Spray Top is the right choice. This waterproof shell is designed to guarantee protection and freedom of movement in tough conditions: strong wind, spray, and heavy rain.
When the first rain arrives and temperatures fluctuate, it’s often hard to know what to wear.
For mid-season, water-repellent clothing offers the perfect balance of lightness and protection. An outfit combining a technical hoodie and water-repellent pants is a smart choice for a casual look that provides comfort and easy layering.
Not just jackets: accessories also make a difference on rainy days or in humid environments. Examples include:
Understanding the difference between waterproof and water repellent, and the role of water-resistant fabrics, means being ready for any occasion.
At sea, while traveling, or in the city, rainproof clothing is indispensable — especially when the change of season brings unpredictable weather.
1. What is the difference between waterproof and water-repellent? A waterproof garment completely blocks water, even in heavy rain. A water-repellent garment repels water on the surface but only resists light or moderate rain.
2. How is waterproofness measured? The “water column test” measures hydrostatic pressure. In other words, it tests how much water pressure a material can withstand before penetration occurs. The result is expressed in millimeters (mm) and indicates the height of the water column the fabric can resist before leaks start.
From 1,000 mm the fabric is considered slightly waterproof. At 10,000 mm it has excellent waterproofing, while above 20,000 mm it offers protection even in extreme conditions.
3. Does water repellency last forever? No, frequent washing and wear can reduce its effectiveness. Specific sprays are available to renew the treatment.
4. Which waterproof and water-repellent garments are best for sailing or water sports? It's essential to choose products with fabrics featuring membranes, a waterproof rating above 10,000 mm, and taped seams.