5 Ways for How to Waterproof a Backpack

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Ever been out on a hike or a backpacking trip only to find yourself tramping through the rain and your gear wet and soggy? I have definitely been there before and have learned how important is it is to learn how to waterproof a backpack and have a plan to stay dry out in the backcountry.

Waterproofing your backpack not only keeps your gear dry but also extends the lifespan of your backpack. In this guide I am going to teach you how to waterproof your pack, other waterproofing techniques, and how to care for and maintain your backpack.

Key Takeaways

  • waterproofing technique for your backpack
  • Maximize protection with seam sealers, pack liners, rain covers & custom-fitted bag covers.
  • Maintain water resistance through regular cleaning & re-waterproofing plus safe storage & handling tips

Choosing the Right Waterproofing Technique

Understanding the various methods of waterproofing your backpack is the first step towards ensuring your gear stays dry. Your specific needs and the nature of your outdoor activities will largely dictate the technique you choose.

Are you a light rain hiker or an all-weather adventurer? Choosing the appropriate method can significantly impact the dryness of your gear.

The most common waterproofing techniques include using a water repellent spray, a seam sealer, and a durable pack liner. Each method has distinct benefits and drawbacks and understanding them is key to choosing the best solution for your backpack.

Water Repellent Spray & Seam Sealant-No added weight
-Easy application process
– will require reapplication over time
– not best for heavy rain
External Pack Cover-Protection in rainy conditions
– Not the best in high windy conditions
– Adds a little weight to your pack
Internal Pack Liner-Protects the items inside the liner from rainy conditions
– Does not protect anything in the exterior pockets
Dry sacks & Zip Lock bags– Protects items in the sacks or bags
– cheap
– helpful for organizing
– Only protects what’s in the sack or bag
– adds weight
– sometimes makes packing too complicated
Waterproof Backpack– Convenient
– May still have to seam seal sewn areas.
– Usually very expensive
– Sometimes heavier.
– Ultralight options, most will be made up of Dyneema Composite Fabric (DCF)

Using Nikwax Waterproofing spray

How to apply Water Repellent Spray and Seam Sealant

Water repellent sprays, offer a simple and cost-effective solution to increase your backpack’s water resistance. They form an invisible layer over the fabric, repelling water and keeping your gear dry. Waterproof spray is particularly suitable for light rain conditions.

Waterproof a Backpack using Waterproofing Spray

  1. First, you will prep the backpack by using a cleaner I recommend using Nikwax Solarwash it works well for cleaning gear that spend a lot of time in the sun and will add extra layer of protection from UV.
  2. After cleaning the backpack next, you will wipe off any excess cleaner.
  3. While the backpack is still damp use the waterproofing spray, I recommend using Nikwax Solarproof. This will add UV and waterproofing protection to your backpack which helps to extend longevity and adds a water-resistant layer for wet conditions.

Despite their effectiveness, these sprays might need regular reapplication to sustain their water resistance. Over time, the repellent of the spray can lessen, especially with regular exposure to the elements. So, remember to reapply the spray as needed to keep your backpack water-resistant.

Seam Grip + WP sealer

Utilizing a Seam Sealer for Extra Protection

After waterproofing your backpack, I recommend sealing the seams in your backpack, seam sealers offer an additional layer of protection. It’s common for water to seep through seams and zippers especially in heavy rain. Applying a seam sealer can help prevent this, making your backpack more resistant to water.

  1. First, pick a seam sealer I recommend using Seam Grip- WP from GearAid, I have used this on a lot of gear repairs especially when seam sealing tents and it works well.
  2. After finding a seam sealer, open and use a application brush or attach on brush.
  3. Depending on your backpack and ease you can seam seal the backpack inside out or from the exterior. Or you could do both. For packs that are built more like a sack with a roll top like the Hyper Lite Mountain Gear Southwest 55L, it is usually better to turn inside out. Traditional backpacks are usually easier seam sealed from the outside.
  4. After, you have seam sealed the seams let the backpack cure overnight.

While seam sealers provide excellent protection, they do require careful application. Applying the sealer to all seams is vital, since overlooking even a small section can let water in. It’s also important to allow the sealer to dry fully before using the backpack to ensure its effectiveness.

Using a Internal Pack Liner

Another effective method to waterproof a backpack is the use of pack liners. They provide a protective layer inside your pack, preventing water from reaching your gear. They’re particularly useful for heavy rain conditions or when crossing rivers, as they can keep your stuff dry even if your backpack gets fully submerged.

Pack liners, also known as backpack liners, come in various types, from budget-friendly plastic bags to high-quality liners. While they’re a reliable method of waterproofing, they can be pricier, and you’ll need to consider the size and type of your gear when choosing a pack liner.

If looking for a cheap option, I recommend using a compactor trash bag. I used a cheap 40-gallon compactor bag and a pack cover during my backpacking trip in Point Reyes National Seashore and it worked quite well protecting my gear from the wet conditions.

Use an External Pack Rain Cover

Despite the effectiveness of internal waterproofing techniques, external protection methods can also be a reliable and effective method as well. One external method is the use of rain covers. They provide an additional layer of protection, keeping water from seeping into your backpack.

However, rain covers may not be the best option for all weather conditions. In heavy rain or high winds, they can become less effective as water can get through any exposed gaps. If using a pack rain cover, I recommend combining it with other waterproofing methods like an internal pack liner to maximize protection out in the rain.

When choosing a rain cover, look for the following features:

  • Durable materials like ripstop nylon that can withstand harsh weather conditions
  • A snug fit for your backpack
  • Secure attachment methods to prevent it from getting blown away in high winds

Some awesome pack covers I have used are REI’s Duck Back pack cover and some cheaper ones like this one

Dry sacks from Outdoor Products

Internal Dry Storage: Dry Bags and Zip Lock Bags

While external shields protect your backpack from external elements, internal dry systems shield your gear internally. Other methods beside using a pack liner are dry bags and zip lock bags. These items can be incredibly effective in keeping your things dry and while organized.

Dry bags like ones from Outdoor Products and zip lock bags are essentially waterproof bags that you can put inside your backpack. They keep your gear dry and can work well for sleeping bags, electronic devices, and clothing.

Dry bags serve more than just keeping your gear dry; they also assist in purposeful packing. By using different sizes or colors of dry bags, you can organize your gear based on type, use, or need. This makes it easier to find what you’re looking for and keeps your gear protected and organized.

DCF material is waterproof and lightweight

Waterproof Backpacks

If a comprehensive solution is what you seek, a waterproof backpack may be the solution. Waterproof backpacks are designed to withstand wet conditions without requiring additional waterproofing techniques.

It’s worth mentioning that not all backpacks branded as ‘waterproof’ fulfill this claim. Some are simply water-resistant, which means they can withstand light rain but may not hold up in a downpour.

Dyneema composite fabric (DCF) is becoming a super popular fabric that is ultralight and entirely waterproof. A lot of ultralight backpacks these days are made up of DCF in which will be able to provide waterproof protection at a fraction of the weight but a high cost. Hyperlite Mountain Gear makes some of the best lightweight DCF backpacks like the Southwest 55 pack.

Strategies for Packing & Compartmentalization

Compartmentalization revolves around organization. By dividing your gear into different compartments or bags, you can easily locate things when you need them and keep your gear safe and dry. This can be particularly useful in a downpour when you don’t want to expose all your gear to the elements just to find one item.

You can use smaller dry bags, zip lock bags, or even trash compactor bags for compartmentalization. Just remember to keep similar items together and consider the frequency of use when deciding where to store items.

Preventive Measures and Care for Your Backpack

Now that you’ve acquired the knowledge to waterproof your backpack, understanding its maintenance becomes important. Proper care and preventive measures can significantly extend the lifespan of your backpack and maintain its water resistance.

The longevity of your backpack is a result of regular cleaning and re-waterproofing, safe handling, and appropriate storage. Remember, a well-maintained backpack not only lasts longer, but it also provides reliable performance during your outdoor adventures.

Cleaning a backpack with Nikwax Solarwash

Regular Cleaning and Re-Waterproofing

Keeping your backpack clean is an integral part of maintenance. Dirt and grime can wear down the waterproof coating over time, so regular cleaning can help maintain the water resistance of your backpack. However, it’s essential to clean your backpack correctly to avoid damaging the material or the waterproof coating.

You may need to re-waterproof your backpack after cleaning it. Over time, the waterproof coating can wear off, especially in high-wear areas. Using a waterproofing spray or a wash-in waterproofing product can help restore the water resistance of your backpack.

Safe Storage and Handling Tips

The lifespan of your backpack can also be extended through safe storage and handling. Avoid overpacking your backpack as this can strain the seams and potentially allow water to penetrate. Also, be careful to avoid sharp objects or rough surfaces that can damage the material or the waterproof coating.

Store your unused backpack in a dry, cool location away from direct sunlight. UV rays can damage the material over time and reduce the effectiveness of the waterproof coating. Also, make sure your backpack is completely dry before storing it to prevent mold and mildew growth.

Frequently Asked Questions

Can you make a backpack water-resistant?

You can make your backpack water-resistant with the help of waterproof sprays available on the market. Follow instructions specific to the spray for the best results and remember that it won’t make your backpack 100% waterproof.

What’s the difference between a waterproof and a water-resistant backpack?

Water-resistant backpacks can handle light rain or splashes, while waterproof backpacks provide complete protection against water, no matter how heavy the rain or if the backpack is submerged.

How often should I re-waterproof my backpack?

Re-waterproof your backpack when you notice the waterproofing is wearing off or when water starts to seep through. This will ensure it is always protected from water and in good condition.

How can I clean my waterproof backpack without damaging it?

I recommend using a cleaning solution like Solarwash from Nikwax. Avoiding hard scrubbing to preserve the waterproof coating. Allow your backpack to air dry once done.


Remember there are multiple ways to make a backpack waterproof whether you use pack liners, external pack covers, dry bags or zip lock bags, waterproofing sprays, or just go with a waterproof backpack. There are a lot of options for how to waterproof a backpack and keep your gear dry.

If you have any questions leave us a comment down below or if you think we missed something let us know. Thank you and hike more and worry less!

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