A 20,000mm waterproof rating signifies that a material can withstand the equivalent of 20,000 millimeters of water pressure before it begins to leak. This level of waterproofing is considered excellent and suitable for demanding outdoor activities in heavy rain or snow.
Understanding Waterproof Ratings: What Does 20,000mm Really Mean?
When you’re looking at outdoor gear, especially jackets, pants, or tents, you’ll often see a "waterproof rating" expressed in millimeters (mm). But what does a 20,000mm waterproof rating actually translate to in real-world terms? It’s a crucial piece of information for anyone venturing outdoors, as it directly impacts how dry you’ll stay when the weather turns.
Essentially, this rating comes from a standardized test. Manufacturers take a piece of fabric and place it under a column of water. The height of that column, measured in millimeters, before water starts to seep through is the fabric’s waterproof rating. So, a 20,000mm rating means the material can hold back a column of water 20,000 millimeters (or about 65.6 feet) tall.
How is Waterproofing Measured? The Hydrostatic Head Test
The hydrostatic head test is the industry standard for determining a fabric’s waterproofness. It’s a straightforward, yet effective, method. A cylindrical tube is placed over a sample of the fabric. Water is then gradually poured into the tube, increasing the pressure on the fabric.
The test continues until the first drop of water appears on the underside of the fabric. The measurement of the water column at that exact moment is the fabric’s hydrostatic head rating. A higher number indicates superior waterproofing.
What Can You Expect from Gear with a 20,000mm Rating?
Gear boasting a 20,000mm waterproof rating offers a high level of protection. This means it can handle substantial downpours, prolonged exposure to rain, and even being sat on or rubbed against rough surfaces without leaking.
This rating is generally considered excellent for serious outdoor enthusiasts. It’s more than sufficient for activities like:
- Hiking and trekking in wet conditions.
- Skiing and snowboarding where snow and moisture are prevalent.
- Camping in unpredictable weather.
- Cycling during rainy commutes.
You can expect your gear to keep you dry and comfortable even when facing challenging weather. This level of performance is often found in premium outdoor apparel.
Beyond the Numbers: Breathability and Durability
While a 20,000mm rating is impressive for waterproofing, it’s not the only factor to consider. Breathability is equally important, especially during strenuous activities. A highly waterproof material that doesn’t allow moisture vapor (sweat) to escape can leave you feeling clammy and uncomfortable.
Look for a good balance. Many fabrics with high waterproof ratings also offer excellent breathability, often measured in grams per square meter per 24 hours (g/m²/24hr). A common pairing for a 20,000mm rating might be a breathability rating of 15,000g or higher.
Durability is another key consideration. How well will the fabric hold up to abrasion and wear and tear? Higher denier fabrics (a measure of fiber thickness) generally indicate greater durability. A 20,000mm waterproof rating on a robust fabric will provide long-lasting protection.
Comparing Waterproof Ratings: Where Does 20,000mm Stand?
To put a 20,000mm rating into perspective, let’s compare it to other common levels:
| Waterproof Rating (mm) | Level of Protection | Best For |
|---|---|---|
| 0-5,000 | Light protection; suitable for brief showers | Casual wear, light drizzle |
| 5,000-10,000 | Moderate protection; good for everyday rain and light snow | General outdoor activities, light rain showers |
| 10,000-15,000 | Good protection; handles moderate to heavy rain and snow | Hiking, camping, skiing in moderate conditions |
| 15,000-20,000+ | Excellent protection; withstands heavy rain and snow | Demanding outdoor pursuits, prolonged exposure to wet weather, extreme conditions |
| 20,000+ | Superior protection; for extreme and prolonged wetness | Mountaineering, expeditions, severe weather adventures |
As you can see, a 20,000mm waterproof rating places gear in the upper echelon of waterproof performance. It signifies a product designed to keep you dry in serious weather.
Maintaining Your Gear for Optimal Waterproof Performance
To ensure your gear continues to offer that 20,000mm waterproof protection, proper care is essential. Over time, dirt, oils, and residues can clog the fabric’s pores and degrade its waterproof coatings.
Regular cleaning, following the manufacturer’s instructions, is key. Most waterproof garments can be machine washed on a gentle cycle with a mild detergent. Avoid fabric softeners and bleach, as they can damage the waterproof membranes.
Re-waterproofing treatments, often available as sprays or washes, can also help maintain the fabric’s ability to repel water. These treatments replenish the Durable Water Repellent (DWR) finish that causes water to bead up and roll off the surface.
When to Consider a 20,000mm Waterproof Rating
Choosing gear with a 20,000mm waterproof rating is a smart investment if you frequently engage in activities where staying dry is paramount. If you’re tired of getting soaked on your adventures, upgrading to gear with this level of waterproofing can make a significant difference.
Consider your typical outdoor environment and the intensity of your activities. For most hikers, campers, and skiers who face regular rain or snow, this rating offers a fantastic balance of protection and performance. It’s a reliable indicator that the gear is built to withstand challenging conditions.
### What is a good waterproof rating for a jacket?
A good waterproof rating for a jacket depends on its intended use. For everyday wear and light rain, 5,000-10,000mm is usually sufficient. However, for serious outdoor activities in heavy rain or snow, a rating of 15,000mm to 20,000mm or higher is recommended for excellent protection.
### How waterproof is 10,000mm?
A 10,000mm waterproof rating means the fabric can withstand moderate to heavy rain and snow. It’s a solid choice for many outdoor activities like