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Waterproof Jacket Ratings Explained: Stop Wasting Money on the Wrong Gear
- by Mike Johnson
British Standards require waterproof jackets to have at least a 1,500mm waterproof rating. The ratings can range from 1,500mm to 20,000mm, which makes choosing the right gear challenging.
Light rain needs jackets rated up to 2,000mm, and heavy downpours demand ratings above 10,000mm. Understanding waterproof ratings is a vital part of buying outdoor gear. These numbers determine whether you stay dry or get soaked.
Let us guide you through waterproof levels and their significance to your outdoor activities. You will learn about testing methods, rating interpretations, and the best way to pick a jacket that meets your needs.
Basic Waterproof Technology
Modern waterproof jackets use sophisticated membrane technology that keeps you dry. Each square inch packs nine billion microscopic pores, which are 20,000 times smaller than a water droplet. We designed this remarkable engineering to let sweat vapour escape while blocking rain.
How waterproofing works
Membrane technology and surface treatments work together to create waterproofing. The membrane measures just 0.01mm and acts like a one-way philtre. Manufacturers bond these membranes to protective layers to create what they call a waterproof laminate. Your microclimate stays regulated through this construction, which works harder as you increase your activity level.
Different coating types
You'll find these main coating constructions in waterproof jackets:
- Two-Layer Construction: Combines a waterproof outer shell with an inner protective mesh or polyester taffeta
- 2.5-Layer Design: Adds a thin polyurethane coating to protect breathability
- Three-Layer System: Incorporates an external DWR layer, waterproof membrane, and protective inner lining to maximise durability.
Manufacturers enhance protection by applying a Durable water-repellent (DWR) coating to the outer fabric. This makes water bead up and roll off instead of soaking through. DWR coating plays a vital role in the jacket's breathability because a saturated outer fabric can substantially reduce moisture transfer.
These coatings' effectiveness depends on their construction and application method. Microporous membranes create tiny channels for water vapour while blocking liquid water. Non-porous membranes work differently - they absorb and wick moisture away from your body.
Rating Systems Explained
You need to know how manufacturers test their fabrics to understand waterproof ratings. The testing process uses advanced lab equipment and standard procedures that ensure consistent results.
Hydrostatic head testing
Scientists measure a fabric's resistance to water pressure through the hydrostatic head test. They place the fabric under a sealed tube of water and slowly increase the pressure until water seeps through. The waterproof rating shows the pressure at which water breaks through, measured in millimetres. A 10,000mm rating means the fabric can hold up against a 10-metre water column before it starts leaking.
Breathability measurements
Two main methods help measure breathability. The first one, Moisture Vapour Transmission Rate (MVTR), shows how much water vapour moves through one square metre of fabric in 24 hours. A higher MVTR rating means better breathability. The second method, Resistance to Evaporative Transfer (RET), measures how well moisture escapes through the fabric. A lower RET value points to better breathability.
Industry standards
British Standards say a jacket needs at least a 1,500mm rating to be called waterproof. In spite of that, practical use ratings usually fall into these groups:
- 5,000-10,000mm: Works well in light rain and average snow conditions
- 10,000-15,000mm: Good for moderate rain and regular outdoor activities
- 15,000-20,000mm: Perfect for heavy rain and long outdoor exposure
- Above 20,000mm: Top protection for extreme weather conditions
We see breathability ratings follow a similar pattern, with 20,000g/m²/24hr showing premium performance. More importantly, RET values between 0-6 show excellent breathability, while 7-13 show good performance.
Essential Jacket Features
Three significant features make a jacket truly effective against rain beyond just waterproof ratings. Let's get into these elements that work together and keep you dry.
Seam sealing
The way seams are constructed determines how well a waterproof jacket works. The highest-rated fabric becomes useless if the seams aren't sealed properly. Manufacturers create an impenetrable barrier against water by using heat-sealed tape along the stitching points.
You'll find two main ways to protect seams. The first uses waterproof tape on every seam throughout the jacket - these are fully taped seams. The second focuses on high-exposure areas like shoulders, neck, and chest - known as critically taped seams. Fully taped seams give you better protection in heavy, long-lasting rain.
Hood design
A good hood can make the heaviest downpour feel manageable. Today's hoods come with several smart features:
- Stiffened or wired peaks that protect your eyes and keep their shape
- Volume adjusters that make the hood follow your head's movement
- Helmet compatibility that works with climbing or cycling gear
The hood's success depends on how well it seals around your face while letting you see and move freely.
Zip protection
Waterproof jackets use two main methods to protect zips. The first method uses hydro-seal zips - rubber mechanisms that seal themselves when closed. Storm baffles make up the second method - protective flaps covering the zip.
Both approaches work well in different ways. Hydro-seal zips give you a lighter, less bulky option, while storm baffles last longer. Some jackets also include pit zips under the arms to control temperature. This helps you stay comfortable without letting water in.
Choosing the Right Rating
Your outdoor activities and local weather patterns will determine the right waterproof rating you need. Different weather conditions just need varying levels of protection, so learning about your needs is vital to make an informed choice.
Light rain protection
A jacket with a rating between 5,000mm and 10,000mm will give you enough protection for occasional outdoor activities or light showers. These jackets work great for everyday use - walking the dog or running errands. The ratings protect you well during brief rain exposure but might not hold up in sustained downpours.
A 5,000mm rated jacket works best if you:
- Take regular breaks during outdoor activities
- Spend time outdoors in cold but clear conditions
- Need simple protection for brief showers
Heavy downpour needs
You should pick jackets rated 15,000mm or above for serious weather protection. These higher-rated jackets become essential if you explore remote areas where the weather shifts quickly. A 20,000mm rating will give you maximum protection if you stay outdoors for long periods or carry heavy loads.
Your location and activity level make this choice even more important. To name just one example, see regions with frequent heavy rainfall - a jacket rated between 16,000mm to 20,000mm resists sustained precipitation effectively. Higher-rated jackets usually come with fully waterproof taped seams and protected zips.
A jacket rated above 10,000mm will protect you reliably during activities with long wet-weather exposure or when you carry equipment. This rating helps anyone who needs consistent performance in challenging weather and gives peace of mind during extended outdoor adventures.
Top Waterproof Jacket Picks: Stay Dry No Matter What
Now that you know how waterproof ratings work and what features matter... let’s talk about jackets that actually deliver.
Not all waterproof jackets are built the same. Some protect against a drizzle but fail under heavy rain. Others are built like tanks but lack breathability, leaving you sweating inside. That’s why choosing the right waterproof jacket for your needs is key.
Here are three top-performing waterproof jackets that strike the perfect balance between waterproofing, breathability, durability, and comfort.
Price: £32.00
If you’re working in tough conditions, this jacket is built to handle it. With an 8,000mm waterproof rating, it can handle moderate to heavy rain, and its CORDURA® reinforced shoulders and elbows add serious durability.
How it fits into waterproof tech:
- 3-layer bonded fabric enhances waterproofing and breathability
- Seamless shoulders & inner storm flap prevent water from seeping through weak points
- Reflective piping makes sure you stay visible in low-light conditions
- Adjustable shockcord hem lets you customise the fit
Note: This jacket is perfect for outdoor workers, tradesmen, and anyone working in unpredictable weather who needs durability without sacrificing comfort.
2. PW3 Winter Hi-Vis 3 in 1 Waterproof Jacket (PW365) – Waterproofing + Warmth + Versatility
Price: £59.78
This 3-in-1 jacket is a waterproof shell, an insulated fleece, and a hi-vis work jacket all rolled into one. With a 15,000mm waterproof rating, it handles heavy rain with ease. The removable fleece gives you adaptability, so you stay comfortable no matter the season.
How it fits into waterproof tech:
- EN 343 Class 3 waterproof protection for long-term exposure to rain
- Taped seams and storm flaps ensure complete water resistance
- Hi-Vis Class 3 certified for maximum safety in low-visibility conditions
- Multiple zip pockets, detachable hood, and adjustable cuffs for full functionality
Note: If you need a jacket that keeps you visible, warm, and protected from the elements, this is it. Perfect for construction workers, site managers, or anyone working in challenging weather conditions.
3. Snickers Allround Waterproof Softshell Jacket (1205) – Lightweight & Flexible for Active Work
Price: £59.58
Some waterproof jackets feel like wearing a tent - bulky, restrictive, and uncomfortable. This one? Not at all. Made from windproof softshell fabric, it offers lightweight waterproof protection without sacrificing mobility.
How it fits into waterproof tech:
- Windproof and water-resistant softshell - great for light to moderate rain
- Breathable material keeps you from overheating
- Adjustable hem and cuffs let you personalise the fit
- Large front and back panels - perfect for adding custom branding
Note: If you need freedom to move while staying dry, this is the jacket for you. Ideal for tradesmen, warehouse workers, or anyone looking for a breathable, water-resistant layer.
Conclusion
Waterproof jacket ratings knowledge helps you make smart decisions about outdoor gear purchases. British Standards set 1,500mm as the minimum requirement, yet your specific needs might just need higher protection levels.
Protection between 5,000mm and 10,000mm works well for casual outdoor activities in light rain. Serious adventurers should look for jackets rated 15,000mm or above. Note that successful waterproofing combines three essential elements: appropriate rating levels, quality construction features, and proper maintenance.
The best waterproof jacket ended up balancing protection level with your intended use. Your typical weather conditions and outdoor activities should guide your choice rather than automatically selecting the highest-rated option. This practical approach will give you reliable protection without overspending on unnecessary features.
Frequently asked questions.
What waterproof rating should I look for in a jacket?
For light rain and everyday use, a rating between 5,000mm and 10,000mm is sufficient. However, for heavy downpours or extended outdoor activities, opt for jackets rated 15,000mm or above. Those facing extreme weather conditions should consider ratings of 20,000mm or higher.
Are jackets with a 3,000mm rating considered waterproof?
While a 3,000mm rating offers some water resistance, it may not provide adequate protection in sustained wet conditions. For reliable waterproofing in most field conditions, look for ratings above 3,000mm. However, lower ratings might be acceptable if you prioritise lighter materials and understand the trade-offs.
How effective is a jacket with a 10,000mm waterproof rating?
A 10,000mm rating provides good entry-level protection suitable for light to moderate rain. These jackets perform well in dry or mildly damp conditions but may struggle in heavy, prolonged downpours. They're ideal for casual outdoor activities or short exposures to wet weather.
What features should I consider besides the waterproof rating?
In addition to the waterproof rating, pay attention to seam sealing (fully or critically taped), hood design (with adjustable features), and zip protection (hydro-seal or storm baffles). These elements work together with the fabric's waterproof rating to ensure overall effectiveness against rain.
How does breathability factor into waterproof jacket selection?
Breathability is crucial for comfort during active outdoor pursuits. Look for jackets with high Moisture Vapour Transmission Rate (MVTR) ratings or low Resistance to Evaporative Transfer (RET) values. A breathability rating of 20,000g/m²/24hr is considered premium performance, ensuring you stay dry from both rain and perspiration.
