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How to wash and reproof waterproof trousers: A complete guide

By: Andrew Forrest - December 2024

Waterproof trousers before and after washing and proofing

Our guide provides clear steps on how to wash and reproof your waterproof trousers or pants to maintain their performance.

Table of contents 

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Keeping your waterproof trousers in top condition ensures they stay effective against rain, wind, and mud. Often, all your waterproof trousers need is a proper cleaning to restore their waterproof properties, but how do you do that?

What to do before cleaning your waterproof trousers

  • Check the care label: Most waterproof trousers come with a care label attached, either on the trousers themselves or on a piece of card attached to the trousers when you buy them. Ensure you keep this card for future reference. Read the care instructions on your trousers to ensure proper cleaning and avoid damaging the fabric.
  • Shake off dirt from the trousers: Shake or gently brush the trousers to remove loose dirt and debris.
  • Close zippers and Velcro on the trousers: Fasten all zips, Velcro straps, studs or any other closure types on the trousers to prevent snags during washing.
  • Inspect for damage: Check for tears or worn-out areas. Repair these before washing to prevent further damage.
  • Clean the detergent compartment: If you are machine washing rather than hand washing, ensure the washing machine's detergent compartment is clean before use.

What cleaning products to use on waterproof trousers

Specialist detergents: Use non-detergent cleaners specially designed for waterproof fabrics, such as Granger's Performance Wash or Nikwax Tech Wash. These help maintain the durable water repellent (DWR) treatment on waterproof garments, which is crucial to ensure water beads and runs off, preserving the garment's performance. Dirt in the garment's 'pores' can greatly reduce the material's waterproof properties.

Avoid regular detergents/washing powders: Ordinary laundry detergents can damage the waterproof coating and leave residues that reduce breathability, so DO NOT use them.

How to wash waterproof trousers

Washing by machine: Using the detergent compartment

1 - Prepare the washing machine

  • Clean the detergent drawer to remove any leftover detergent. My washing machine's drawer pulls out so I can wash it in the sink. It is amazing how much detergent builds up in, around, and below the drawer. While the drawer is out, you can clean underneath it. The drawer pulls out differently on different brands of washing machines, so check your manual or watch a YouTube video on removing your particular one.

    Washing machine drawer before cleaning out all previous remaining detergent and conditioner

    Washing machine drawer before cleaning out all previous remaining detergent and conditioner

    Cleaned washing machine drawer ready for us to wash the waterproof trousers

    Cleaned washing machine drawer ready for us to wash the waterproof trousers

  • Run a hot wash cycle with no detergent to remove residual substances from previous washes. It may seem a bit of a waste to run an empty wash, but I find it does make a difference in how well the specialist detergent and reproofer work.
  • Set the machine to the correct cycle and follow the manufacturer's washing instructions. If you do not have any instructions, use a gentle cycle with cold or lukewarm water.

2 - Wash the trousers

  • Place the waterproof trousers in the machine with a small amount of specialist detergents, such as Granger's Performance Wash or Nikwax Tech Wash. The instructions on the detergent will show how much to add.
  • Avoid overloading the machine to allow proper rinsing. Use a gentle spin setting to help preserve the integrity of the fabric in line with manufacturers' care guides.

3 - Rinse thoroughly

  • Select an extra rinse cycle to ensure all cleaning agents are removed.

Washing by hand

1 - Fill a basin or large bucket/trug

2 - Gently agitate

  • I generally leave my waterproof trousers in the basin, submerged in water and detergent, for about 5-10 minutes, and then gently rub the fabric with my hand to remove the dirt.

3 - Rinse

  • Discard the dirty water and rinse under running water until no soap remains.

How to dry waterproof trousers

Air dry

Hang the trousers in a well-ventilated area, avoiding direct sunlight.

Use a dryer if allowed

If the care label on your waterproof trousers or pants permits, tumble dry on low heat. This can help reactivate the waterproof coating.

Putting the waterproof trousers and jacket in the tumble dryer to dry on a gentle heat

Putting the waterproof trousers and jacket in the tumble dryer to dry on a gentle heat

All the above cleaning techniques for waterproof trousers generally apply to all waterproof gear and especially waterproof jackets, but whatever you are washing, ALWAYS read the manufacturers' care guidelines first.

Properly washing and reproofing waterproof jacket trousers is essential to maintain their effectiveness and longevity.

How to reproof waterproof trousers

What reproofing products to use

Wash-in treatments:

Wash-in treatments are my preferred way of reproofing, and I find they work better than spray products. Add these to the washing machine for full garment coverage. The ones I generally use and find are the best are Granger's Clothing Repel and Nikwax TX Direct.

Spray-on products:

These are ideal for targeting specific areas if you want to do only part of the trousers or the areas that wear the most. I generally use Granger's Performance Repel Plus and Nikwax TX Direct Spray-on Waterproofer.

Steps to reproof: Restoring durable water-repellent

Clean first

Always reproof after washing to ensure the fabric is free of dirt and residues. This step is essential to ensure the proofing works its best.

Apply the product

  • For wash-in: Follow the product's instructions for the correct amount and pour it directly into the detergent drawer of your washing machine. Run the recommended cycle setting as per the manufacturer's care guide.
  • For spray-on: Evenly mist the outer surface while the trousers are damp, focussing on areas more prone to wear. Remove any excess with a clean cloth.

Dry to activate

Heat often helps activate waterproofing. If the manufacturer's care guide permits, use a dryer on low heat or air dry thoroughly.

How to wash and reproof your waterproof trousers at the same time

Rather than washing and then reproofing your waterproof trousers, you can buy specialist cleaners/proofers that do the job in one go. Do you remember the old Vidal Sassoon's 'Wash and Go' ads on TV? Why take two bottles into the shower? Well, these products work in the same way and do both jobs simultaneously.

The product I've found best for this is Granger's Wash + Repel. If the care instructions allow you to use a washing machine, add 100ml to the drawer and wash following the recommended cycle. If you are washing more than one garment at once, add 50ml extra for each additional garment. I tend never to wash/proof more than two items at once, so they have space to wash properly.

Then dry as above. Grangers recommends that you do that if your product can be tumbled dried as per the manufacturer's care instructions. They say that all Grangers protection products are effective when air-dried. However, they recommend applying a small amount of heat, such as a tumble or hair dryer, for optimum durability.

How often to wash and reproof

Washing: I generally clean my waterproof trousers after heavy use or when visibly dirty. It's crucial to wash them regularly and follow care labels to maintain their effectiveness and prolong their lifespan.

Dirty waterproof trousers that no longer bead when soaked in water

Dirty waterproof trousers that no longer bead when soaked in water

Reproofing: I generally reproof every 3–4 washes or when water stops beading on the surface of the trousers. You can usually tell when you are wearing them if they need reproofing.

Washed and reproofed waterproof trousers that now bead and repel water again

Washed and reproofed waterproof trousers that now bead and repel water again

What not to do when washing and proofing waterproof trousers

  • Do not use fabric softeners: These contain chemicals that can clog the pores in the trousers' waterproof membrane.
  • Do not use high heat: Excessive heat can damage the fabric of the trousers.
  • Do not skip rinsing: Residual soap can compromise waterproofing.
  • Do not use ordinary washing detergent: An ordinary detergent will clean your trousers but strip them of their waterproofing properties. You MUST use a specialist cleaning product.


Always read the manufacturers' care labels. Washing waterproof jackets and trousers is crucial for ensuring the waterproofing is effectively restored, and the garment remains in optimal condition. Proper care and maintenance of waterproof gear, including using specialised cleaners and periodic reproofing, are essential to ensure optimal performance and longevity and maintain your trousers' durable water repellency (DWR).

Field repairs and maintenance for waterproof trousers

When you're out on your walk or hike, it's essential to know how to perform basic repairs and maintenance on your waterproof trousers to ensure they continue to perform optimally. Here are some tips to help you keep your waterproof trousers in good condition:

  • Regular Cleaning: Gently brush your waterproof trousers with a soft-bristle brush to remove dirt and debris. You probably won't have one on your walk, but keep one handy in the car for when you return.
  • Repairing tears and holes: If you notice any tears or holes, use a patch kit or waterproof repair tape to fix them promptly. This prevents further damage and maintains the trousers' waterproof capabilities.

    Iron-on tapes are available, but I use and recommend McNett Tenacious Tape Fabric and Seam Repair, assuming you have no iron on your walk(!). I also have a small roll of waterproof gaffer tape in my first aid kit.
  • Inspect zips and seams: Regularly check your trousers' zips and seams for signs of wear and tear. Repair or replace them as needed to ensure the trousers remain fully functional.

Professional repair options for damaged waterproof clothing

Professional repair options are available if your waterproof clothing is damaged beyond self-repair or if you're uncomfortable performing repairs yourself. Here are some options to consider:

  • Contact the manufacturer:
    Many manufacturers offer repair services for their waterproof clothing products. Check your warranty or contact the manufacturer's customer service department to see if they provide repair services.
  • Local outdoor gear repair shops:
    Many outdoor gear repair shops offer waterproof clothing repair services. They may be able to fix tears, replace zips, or reproof your trousers.
  • Online repair services:
    Several online repair services specialise in waterproof clothing repair. They may offer mail-in repair services or online tutorials to help you repair your gear.
  • Professional seamstresses or tailors:
    If you have a local sewist or tailor specialising in outdoor gear repair, they may be able to fix your waterproof clothing.

Storage of your waterproof trousers

Store your waterproof trousers in a cool, dry place.

Avoid cramming them into tight spaces to maintain the fabric's integrity.

Summary

Washing and reproofing your waterproof trousers doesn't have to be complicated. Using the right products and techniques can extend their lifespan and keep them performing like new. Follow this guide to ensure your trousers are ready to face any weather.

Start caring for your waterproof trousers today to stay dry and comfortable tomorrow!

Happy, dry walking. 😊

December 2024