A waterproof backpack is a luxury that many backpackers lust for, but what does it really buy you? Most of the people that own waterproof backpacks still line the inside of their pack with a garbage bag or pack their gear in waterproof stuff sacks.
What is a waterproof backpack anyway?
When you or I use the word waterproof, we usually think it means “100% impervious” to penetration by water. But many companies take liberties when they say their packs are waterproof. More often than not, some parts are waterproof and some parts are not.
For instance, there are basically two parts to a backpack:
- The main “pack bag” that holds all the stuff you might want to keep dry, and
- The shoulder straps, hip belt, external pockets, and compression straps.
While it is possible to buy a backpack with a waterproof pack bag, it’s virtually impossible to get one where the external pockets, the shoulder straps, the hip belt, and the compression straps are impervious to water. Most mesh-covered shoulder straps and hip belts will absorb water in the rain and make you wet when you put them on.
So as a matter of definition, a waterproof backpack will have a waterproof pack bag and not leak, but its suspension and external pockets, straps, etc. are unlikely to be waterproof as well.
Dry Pack Bags
Backpacks and daypacks with 100% waterproof pack bags are usually classified as Dry Backpacks. They’re mainly designed for use by rafters, pack rafters, canoeists, urban cyclists, but they’re not the most comfortable things to backpack with for any distance because their shoulder straps and hip belts, if they even have them, aren’t up to snuff.
Here are a few examples:
- Granite Gear Voyageur Portage Pack (80L)
- Sealine Black Canyon Dry Pack (65L)
- Sea-to-Summit Hydraulic Dry Pack (65L)
One exception is the ULA Epic which is basically an external frame backpack used to carry a high-capacity rolltop dry bag. It is designed for long-distance backpacking because it has a good suspension system.
Backpacks with Waterproof Pack Bags
If you just want a regular internal frame or frameless backpack with a highly waterproof pack bag, here are the three things you should look for when choosing between the options available.
- Waterproof materials including Dyneema Composite Fabric (DCF), X-Pac, ECOPAK, and Liteskin, the higher the denier (fabric weight) the better for abrasion resistance.
- Taped, not bound seams (although you can seam-seal bound seams to make them waterproof.)
- Roll-top closures.
1. Waterproof Materials
The use of waterproof materials like DCF, X-Pac, ECOPAK, and Liteskin doesn’t make a backpack waterproof but it’s a start: the way the seams are constructed is an issue too, as we discuss below. DCF, X-Pac, ECOPAK, Liteskin have a waterproof film sandwiched between abrasion resistance fabrics like polyester which prevents water from soaking through.
Here are some of the popular, but small, backpack manufacturers that use these fabrics:
- Zpacks: DCF
- Hyperlite Mountain Gear: DCF
- Mountain Laurel Designs: ECOPAK
- Superior Wilderness Designs: ECOPAK
- Waymark Gear: ECOPAK
- Atom Packs: ECOPAK, X-Pac
- Seek Outside: X-Pac
- ULA: X-Pac
Pack bag fabrics like Robic, Dyneema Gridstop, and the High Tenacity Nylon used by larger, more mainstream, pack manufacturers aren’t waterproof.
2. Taped vs Bound Seams
Most DCF backpacks from Zpacks and Hyperlite Mountain Gear have taped seams, like tents, which prevent water from seeping through the needle holes used to join different pieces of material together or to attach the shoulder straps, hip belt, external pockets, and compression straps to the pack bag.
However, packs made with X-Pac, ECOPAK, and Liteskin by companies like Superior Wilderness Designs, Waymark, and Seek Outside have bound seams (with visible needle holes), where the cut edges of the pack bag fabric are enclosed by another piece of fabric to keep them from fraying.
While bound seams are pretty tight, they can leak after use or submersion. You can seam seal them fairly easily, however, by turning a backpack inside out and brushing seam sealer over the needle holes. It’s a pain in the ass, but it’s a way for you to turn a water-resistant pack bag into a waterproof one.
3. Roll-top Closure
Roll-top closures are a must-have instead of top lids and extension collars because they prevent leaks if they’re made with a waterproof fabric and seam-sealed.
How is having a waterproof pack bag different?
How does owning a backpack with a waterproof pack bag change the way you use it? The answer is not much.
I’ve owned packs with pack bags made with every one of the waterproof fabrics listed above: DCF, X-Pac, ECOPAK, and Liteskin, and I still line all of them with a plastic bag and pack my moisture-sensitive gear inside waterproof stuff sacks the same way I do when I use backpacks that aren’t waterproof. The reason I like backpacks made with these materials is that they’re generally lighter weight and tougher than backpacks made with nylon and its variants. If I need more water protection for the bound seams, it comes from the plastic bag I use to line my pack.
The only time I’ve ever felt that I needed a truly waterproof pack bag is for packrafting. But even then a waterproof pack liner or drybag is usually enough to keep the contents of any backpack dry.Editor's note: If you’re thinking about buying gear that we’ve reviewed or recommend on SectionHiker, you can help support us in the process. Just click on any of the seller links above, and if you make a purchase, we may (but not always) receive a small percentage of the transaction. The cost of the product is the same to you but this helps us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides. Thanks and we appreciate your support!