Waterproof Ratings Explained: How Waterproof Clothing Really Works

Understanding Waterproof Ratings

A 10,000 mm waterproof jacket sounds impressive. A 20,000 mm jacket sounds even better. But what do those numbers actually mean, and how much waterproofing do you really need?

Waterproof ratings are useful when comparing wet weather clothing, but they are only one part of the picture. Fabric construction, seams, zips, breathability, garment condition and water repellent treatments all affect how dry and comfortable a jacket feels outdoors.

This guide explains waterproof ratings, breathability and Durable Water Repellency, along with why waterproof clothing can start feeling damp and what you can do about it.

What does a waterproof rating mean?

A waterproof rating measures how much water pressure a fabric can withstand before water begins to pass through it. The rating is normally expressed in millimetres, such as:

• 5,000 mm
• 10,000 mm
• 15,000 mm
• 20,000 mm
• 30,000 mm

In general, a higher number means the fabric can withstand greater water pressure. However, a waterproof rating does not tell you everything about how a complete garment will perform. The quality of its seams, zips, hood, cuffs and outer water repellent finish also matters.

How are waterproof ratings tested?

Waterproof ratings are commonly measured using a hydrostatic head test.

During the test, a section of fabric is placed beneath a column of water. The water pressure is gradually increased until moisture begins to pass through the material.

The height of the water column at that point becomes the fabric's waterproof rating.

For example, a fabric with a 10,000 mm rating has been tested to withstand the pressure created by a 10 metre column of water under the relevant test conditions.

This does not mean you could place the jacket under 10 metres of water. It is a laboratory measurement used to compare how fabrics respond to water pressure.

Waterproof ratings chart

The following ranges provide a general guide to how waterproof fabrics may perform.

Waterproof rating	General protection	Common uses
Under 5,000 mm	Limited protection	Brief showers, casual wear and sheltered conditions
5,000 to 10,000 mm	Light to moderate protection	Everyday rainwear and short outdoor activities
10,000 to 15,000 mm	Good protection	Day hikes, regular outdoor use and moderate rain
15,000 to 20,000 mm	High protection	Bushwalking, hunting and prolonged wet conditions
Over 20,000 mm	Very high protection	Alpine environments, exposed terrain and severe weather

These ranges are a starting point rather than a guarantee. Different manufacturers may use different test methods, and a garment's design and condition will influence its real world performance.

Is 10,000 mm waterproof enough?

A 10,000 mm waterproof rating may be enough for everyday rain, shorter walks and moderate outdoor conditions. It may be less suitable for prolonged exposure to heavy rain, particularly when pressure is applied to the fabric. Pressure can come from:

• Pack shoulder straps
• A hip belt
• Kneeling on wet ground
• Sitting on a wet surface
• Strong wind driving rain against the garment

Someone walking around town has different requirements from someone spending several days in exposed Australian alpine country, rainforest or remote bush.

For regular bushwalking, hunting or work in sustained rain, a higher waterproof rating may offer more reliable protection. Garment construction and condition should still be considered alongside the number.

Is 20,000 mm fully waterproof?

A 20,000 mm fabric offers a high level of resistance to water pressure, but no rating makes a garment completely immune to every form of moisture. Water may still enter through:

• Damaged or poorly sealed seams
• Open or unprotected zips
• Loose cuffs
• An exposed neckline
• A poorly adjusted hood
• Tears, punctures or worn areas

Moisture can also build up inside a jacket through sweat and condensation. This may make the wearer feel wet even when rain has not passed through the waterproof membrane.

Waterproof versus water resistant

The terms waterproof and water resistant are often used interchangeably, but they do not mean the same thing.

Water resistant clothing

Water resistant clothing provides limited protection from moisture. It may handle a brief shower or light drizzle but is not normally designed for prolonged rain. Many softshell jackets and casual outer layers are water resistant rather than fully waterproof.

Waterproof clothing

Waterproof clothing uses a membrane, coating or fabric construction designed to prevent water from passing through the material. For a garment to provide reliable rain protection, its seams and openings must also be properly constructed and protected. A waterproof fabric alone does not automatically make the entire garment waterproof.

What is a breathability rating?

Breathability describes how effectively moisture vapour can escape from inside a garment. When you walk, climb, hunt, ski or work outdoors, your body produces heat and sweat. A breathable waterproof jacket allows some of that moisture vapour to move through the fabric while helping prevent rain from entering. One common breathability measurement is expressed in grams per square metre over 24 hours, such as:

• 5,000 g/m²
• 10,000 g/m²
• 20,000 g/m²

A higher number generally indicates that more moisture vapour can pass through the fabric under the test conditions. Some manufacturers use an RET rating instead. With RET measurements, a lower number generally indicates greater breathability. As with waterproof ratings, laboratory results do not always predict exactly how a garment will feel in changing outdoor conditions.

Waterproof ratings versus breathability ratings

Waterproofing and breathability perform different jobs. The waterproof membrane helps resist rain from the outside. Breathability allows moisture vapour created by the body to escape from the inside.

A highly waterproof jacket with poor breathability may keep rain out but feel hot and clammy during strenuous activity. A highly breathable jacket may feel more comfortable while moving, but it still needs sufficient waterproofing for the conditions.

The right balance depends on how and where the garment will be used. Someone standing in cold, heavy rain may prioritise maximum protection. Someone moving quickly through humid or steep terrain may place greater importance on breathability and ventilation.

How Australian conditions affect waterproof clothing

Australia's climate varies significantly, so the same waterproof jacket may perform differently depending on where and when it is used.

Humid and tropical conditions

In warm, humid environments, sweat may not evaporate efficiently. Even a breathable jacket can feel damp inside when moisture production exceeds the fabric's ability to release vapour. Ventilation, lightweight layers and an appropriate activity level can be just as important as the jacket's breathability rating.

Alpine and cold weather conditions

Australian alpine areas can bring cold rain, snow, high winds and rapidly changing weather. Higher waterproof ratings, sealed seams, secure cuffs and an adjustable hood may provide more dependable protection in these conditions.

Coastal and exposed environments

Wind-driven rain can place greater pressure on waterproof fabric and force water towards seams, zips and garment openings. A secure fit and good garment construction become especially important in exposed areas.

Bushwalking with a pack

Pack straps and hip belts press against the fabric, increasing water pressure and wearing down the outer water repellent finish. The shoulders, upper back and waist are often the first areas to stop beading effectively.

Why seams, zips and garment design matter

Waterproof ratings normally relate to the fabric rather than the complete garment. Even a highly rated fabric can perform poorly if water enters through another part of the jacket.

Seams

The stitching used to join fabric panels creates small holes. Waterproof garments commonly use seam tape or another sealing method to prevent water from passing through these areas. Older seam tape may lift or separate, creating a potential leak.

Zips

Standard zips are not automatically waterproof. Wet weather clothing may use water-resistant zips, storm flaps or protective covers to reduce water entry.

Hoods

A well-designed hood should protect the face and move with the wearer's head. Adjustment cords, a shaped peak and a secure fit can make a significant difference in wind-driven rain.

Cuffs and hems

Adjustable cuffs and hems help prevent water from being driven into sleeves or underneath the jacket.

Fit

A jacket that is too tight may place additional pressure on the fabric and restrict airflow. A jacket that is too loose may allow rain to enter through openings or flap excessively in strong wind.

What is DWR?

DWR stands for Durable Water Repellency. It is the treatment on the outside of waterproof clothing that causes water to bead and roll off the surface.

DWR is not the same thing as the waterproof membrane. The membrane sits within the fabric construction and provides the main barrier against water passing through the garment. The DWR treatment protects the outer face fabric from becoming saturated.

When the DWR is working correctly, rain should form droplets on the surface rather than immediately spreading into dark, soaked patches.

What is wetting out?

Wetting out occurs when the outer fabric begins absorbing water instead of repelling it. The waterproof membrane may still be preventing rain from passing directly through the garment, but the saturated outer fabric can create several problems. The jacket may:

• Feel heavier
• Feel colder
• Take longer to dry
• Become less breathable
• Feel damp or clammy inside

Once the outside is saturated, moisture vapour from sweat has more difficulty escaping. Condensation may then collect inside the jacket, creating the impression that it is leaking.

Why has my waterproof jacket stopped beading?

Water repellency can decline through regular use. Common causes include:

• Dirt
• Body oils
• Sunscreen
• Smoke
• Food residue
• Incorrect washing products
• Abrasion from pack straps
• General wear

These contaminants can interfere with the water repellent finish and cause the outer fabric to attract or absorb water. This does not always mean the waterproof membrane has failed. The garment may simply need to be cleaned correctly or have its DWR restored.

Does a wet looking jacket mean it is leaking?

Not necessarily. If the outside of a jacket darkens and becomes saturated, it is probably wetting out. The waterproof membrane beneath the outer fabric may still be intact.

A leaking jacket allows water to pass through from outside. A jacket that is wetting out may instead feel damp inside because breathability has declined and condensation is building up.

Look at where and when the moisture appears. Moisture concentrated around a damaged seam, tear or zip may indicate a leak. General dampness during strenuous activity may be sweat or condensation.

Why does my waterproof jacket feel wet inside?

There are several possible causes.

Sweat and condensation

A waterproof jacket cannot prevent the body from producing moisture. During physical activity, sweat vapour may build up faster than it can escape. Warm, humid and still conditions can make this more noticeable. Opening ventilation zips, adjusting layers and slowing your pace may help manage moisture.

Wetting out

When the face fabric becomes saturated, the garment becomes less breathable. Sweat is then more likely to collect inside.

Dirt and contamination

Oils, dirt and detergent residue can affect water repellency and breathability.

Damaged seams or fabric

A localised damp patch may indicate worn seam tape, a puncture or physical damage.

Membrane failure

Waterproof membranes can eventually deteriorate, particularly when garments are old, heavily worn or stored incorrectly. Cleaning and reproofing can restore water repellency, but they cannot repair a delaminated or badly damaged membrane.

Does washing ruin waterproof clothing?

Washing waterproof clothing correctly does not ruin it. In fact, cleaning can help restore its performance.

Dirt, oils and other contaminants can reduce water repellency and breathability. Removing them allows the fabric and existing DWR to work more effectively. Problems may arise when unsuitable products are used.

Ordinary household detergents can leave residues that attract water. Fabric softeners may also interfere with technical fabrics and water repellent finishes. Always check the garment's care label before washing. For waterproof clothing, use a specialist cleaner such as Nikwax Tech Wash® rather than standard laundry detergent.

How to test whether a jacket needs reproofing

A simple water test can help you assess the condition of the outer fabric.

Step 1: Inspect the garment

Check for tears, worn fabric, damaged zips and lifting seam tape. Reproofing will not repair physical damage.

Step 2: Clean the jacket

Wash it according to the care label using an appropriate technical cleaner.

Cleaning alone may remove the contamination that was preventing water from beading.

Step 3: Test the surface

Once the jacket is clean, apply water to several areas of the outer fabric.

Pay particular attention to high wear areas such as:

• Shoulders
• Upper back
• Cuffs
• Hood
• Elbows
• Areas beneath pack straps

Step 4: Look for beading

If the water forms rounded droplets and rolls away, the DWR is functioning.

If it spreads out, darkens the fabric or soaks in, the garment may need reproofing.

Can you restore a waterproof jacket?

Many waterproof jackets can be restored, provided the membrane and garment construction remain in good condition.

The first step is cleaning.

Nikwax Tech Wash® is designed to clean wet weather clothing without leaving the water attracting residues associated with ordinary detergents. Cleaning may revive existing water repellency if it has been masked by dirt or oils.

If water still fails to bead after cleaning, the garment may need to be reproofed with Nikwax TX.Direct®.

TX.Direct® adds Durable Water Repellency to wet weather clothing and helps maintain its breathability.

It is available in Wash In and Spray On formats.

Five common waterproofing mistakes

Reproofing can restore the water repellency of waterproof clothing, but the treatment needs to be applied correctly.

1. Reproofing dirty clothing

Dirt, body oils and other contaminants can prevent a waterproofing treatment from bonding evenly with the outer fabric.

Always clean the garment first with a suitable technical cleaner such as Nikwax Tech Wash®. Once clean, test whether water repellency has returned before deciding whether reproofing is necessary.

2. Using ordinary laundry detergent

Standard detergents may leave water-attracting residues behind. These residues can interfere with the garment's Durable Water Repellency and cause the outer fabric to wet out more quickly.

Use a specialist cleaner designed for waterproof and breathable clothing.

3. Reproofing damaged gear instead of repairing it

A waterproofing treatment cannot repair torn fabric, failed seam tape, damaged zips or a delaminating membrane.

Inspect the garment before treatment. Repair physical damage where possible and replace gear that has suffered extensive membrane failure.

4. Applying the wrong amount of product

Using too little product may leave parts of the garment untreated. Applying too much can lead to uneven coverage or unnecessary residue.

Follow the application and dosage instructions on the product label, taking the garment size and treatment method into account.

5. Waiting until the jacket is completely saturated

Do not wait until every shower leaves the jacket soaked through.

Test the garment regularly by applying water to the outer fabric. If cleaning no longer restores water beading, it is time to reproof the garment.

TX.Direct® Wash In versus Spray On

Both products are designed to restore water repellency, but they are applied differently.

TX.Direct® Wash In

TX.Direct® Wash In can be applied in a washing machine or by hand.

It is a convenient choice when the entire garment requires treatment. It provides an even application across the clothing, including areas that may be difficult to reach with a spray.

TX.Direct® Spray On

TX.Direct® Spray On is applied directly to the outside of the garment.

It is useful when:

• Only the outer fabric should be treated
• The garment has a moisture wicking lining
• High wear areas require additional attention
• A washing machine is not available
• A more targeted application is preferred

Always follow the garment care label and product directions.

How often should waterproof clothing be reproofed?

There is no single schedule that suits every garment.

How often clothing needs reproofing depends on:

• How frequently it is worn
• The conditions in which it is used
• Abrasion from packs or equipment
• How often it is washed
• How it is stored
• Whether water still beads on the surface

Reproof waterproof clothing when cleaning no longer restores its ability to repel water.

The water beading test is generally more useful than relying on a fixed number of months or washes.

Can an old waterproof jacket be made waterproof again?

It depends on what has caused the loss of performance. Cleaning and reproofing may help when:

• The outer fabric is dirty
• The DWR has worn away
• Water is no longer beading
• The jacket feels clammy because the face fabric is saturated

Aftercare products cannot fully restore a jacket when:

• The membrane is delaminating
• Seam tape has extensively detached
• The fabric is badly worn
• There are significant tears or punctures
• The internal coating is breaking down

Inspect the garment carefully before deciding whether to clean, reproof, repair or replace it.

How to look after waterproof clothing

Good care helps wet weather gear perform for longer.

• Follow the garment's care label.
• Clean the garment before it becomes heavily contaminated.
• Use a specialist cleaner rather than ordinary detergent.
• Do not use fabric softener.
• Check water beading after cleaning.
• Reproof the garment when cleaning alone no longer restores repellency.
• Repair small areas of physical damage promptly.
• Store the garment clean and completely dry.

Which waterproof rating is best?

There is no single waterproof rating that is best for every person or activity. Consider:

• How long you will be exposed to rain
• How heavy the rain is likely to be
• Whether conditions will be windy
• Whether you will carry a pack
• How physically active you will be
• Whether you will kneel or sit on wet surfaces
• How important garment weight and packability are
• Whether the seams and zips are properly protected
• Whether you will be travelling through humid, alpine or exposed conditions

A higher waterproof rating may provide greater resistance to sustained rain and pressure, but the garment still needs appropriate breathability, fit, construction and maintenance.

The best waterproof clothing is the clothing suited to your conditions and kept in working order.

Frequently asked questions

What does a 10,000 mm waterproof rating mean?

It means the fabric resisted the pressure produced by a 10 metre column of water under the relevant laboratory test before water began passing through it.

Is 10,000 mm waterproof enough for bushwalking?

It may be sufficient for day hikes and moderate rain. For prolonged exposure, heavy packs, exposed terrain or severe weather, a higher rating may provide more dependable protection.

Is 20,000 mm better than 10,000 mm?

A 20,000 mm fabric can generally withstand more water pressure than a 10,000 mm fabric. That does not automatically make the complete garment better. Breathability, seams, zips, fit, weight and condition must also be considered.

What does 20K waterproofing mean?

A 20K rating is another way of writing 20,000 mm. It indicates that the fabric has been tested to withstand the pressure of a 20 metre water column under the relevant test conditions.

What is the difference between DWR and waterproofing?

A waterproof membrane helps stop water from passing through the fabric. DWR is the water repellent finish on the outer surface that causes rain to bead and roll away.

Why is rain no longer beading on my jacket?

The outer fabric may be dirty, or its DWR may have worn away. Clean the garment with a suitable technical cleaner. If water still does not bead after cleaning, apply a compatible waterproofing treatment.

Can normal detergent be used on a waterproof jacket?

Standard detergent may leave residues that attract water and interfere with water repellency. A specialist technical cleaner is a safer option for waterproof clothing.

Does reproofing repair a waterproof membrane?

No. Reproofing restores water repellency to the outer fabric. It cannot repair a torn, delaminated or deteriorated waterproof membrane.

Should a waterproof jacket be cleaned before reproofing?

Yes. Dirt and oils can prevent a waterproofing treatment from working effectively. Clean the garment first, then test whether water repellency has returned before applying a reproofer.

Is wash-in or spray-on waterproofing better?

Neither is universally better. Wash-in treatment is convenient for even, all-over coverage. Spray-on treatment is useful for garments with wicking linings, targeted applications and high wear areas.

Keep your waterproof clothing working

Waterproof ratings help explain how fabrics respond to water pressure, but the number on the label is only the beginning. A reliable waterproof jacket also needs good construction, appropriate breathability and a functioning water repellent finish.

When rain stops beading, do not immediately assume the jacket has failed. Cleaning away dirt and oils may revive its performance. If cleaning is no longer enough, restoring the DWR can help the outer fabric repel rain and keep the garment breathing effectively. Clean waterproof clothing with Nikwax Tech Wash®. When reproofing is required, restore water repellency with TX.Direct® Wash In or TX.Direct® Spray On. Proper care helps outdoor clothing perform better, last longer and keep doing the job it was made for.