Dry Bags & Waterproof Packing: Keep Your Kit Dry in Any Rain

Why do backpacks leak?

Most pack fabrics are coated and fairly water-resistant when new, so it is tempting to call a pack "waterproof". In steady rain it is not, for four reasons:

• Seams and zips: every stitch is a hole. Factory seam tape is rare in packs, and zips – even coated ones – let water creep through under pressure.
• Wicking straps and webbing: wet shoulder straps, compression straps and haul loops soak up water and carry it into the pack where they are sewn in.
• The back panel: rain running down your jacket pools between your back and the pack and soaks the padding. A rain cover cannot stop this, because the back has to stay open.
• Ageing coatings and canvas: polyurethane coatings wear and flake after years of use; waxed canvas sheds a shower but soaks up water once the wax wears thin.

Add water from inside – a leaking bottle, a wet tarp packed on top of a sleeping bag, condensation – and the bottom of an unlined pack is where everything ends up. The fix is not a more expensive pack but a waterproof layer inside it.

Pack liner vs rain cover vs dry bags: an honest comparison

There are three tools, and they do different jobs. Our backpack guide calls the liner the most important of the three – here is why, with the downsides of each.

Which combination is best?

For most bushcraft trips the answer is a liner plus two or three dry bags for the items that must never get wet – sleeping bag, dry clothes and electronics. The liner does the heavy lifting; the dry bags are a second barrier and keep the kit organised, so you can open the pack in rain and take out one thing without exposing the rest.

A rain cover is a useful extra rather than the plan. It earns its place on long rainy days and with canvas packs, which would otherwise soak up a kilogram or more of water, and it keeps mud off when the pack stands on the ground. In dense brush or strong wind, many people leave it at home. A long poncho that covers the pack does a similar job – see rain gear: jackets, ponchos and gaiters.

How to close a roll top dry bag correctly

A roll top dry bag seals by folding: the stiffened strip at the top is rolled down on itself until water would have to travel around several tight turns to get in. That only works if the closure is done properly. The rule most manufacturers and outdoor guides give – and the one our rain camping guide uses – is at least three tight turns, then clip.

Five habits that keep a roll top dry

• Do not overfill. Choose a bag with room for the roll – roughly a hand's width of empty fabric above the contents.
• Keep the closure clean. Sand, pine needles and grit in the fold create gaps and wear the coating.
• Closure up or inwards. In the pack, the rolled end faces up or towards the middle, never down into the bottom where water collects.
• Splash-proof is not submersible. Most roll tops shed rain and splashes reliably and survive a short dunking; few are made for long submersion. Treat "waterproof" claims with caution and protect a phone with a second bag.
• Check the buckle. A cracked buckle lets the roll open – carry a spare as part of your field repair kit.

Dry bag materials, sizes and weights

Dry bags differ mainly in fabric. Lighter fabrics save grams but tear more easily; heavy coated fabrics are tough but add weight quickly once you carry several bags. All values below are typical ranges, not product data.

Which sizes do you need?

Buy bags for the items you will put in them, not as a matching set. Typical sizes for a bushcraft kit:

Tapered or oval bags fill a pack better than round ones, and several small bags pack more flexibly than one big bag. Pack volume itself – and how many litres your kit needs – is covered in the backpack volume table and the Kit Builder. If weight is a concern, add your bags to the pack weight calculator: five heavy bags can weigh as much as a small tarp.

A colour-coding system for dry bags

Coloured bags turn a pack into a cupboard with labelled drawers. You reach in with a headlamp, see orange and know it is the sleeping bag, without emptying the pack in the rain. Any system works as long as it is the same on every trip and everyone in the group knows it. One that is easy to remember:

Colour coding also helps in groups: the shared first aid and fire kits are always red and always in the same pocket, so anyone can find them in an emergency. Our first aid kit guide recommends exactly that – a clearly marked, waterproof pouch at the top of the pack.

What must stay dry – and what can get wet

Not everything needs a dry bag. A pot, a saw or a tent peg does not care about rain. Concentrate your waterproofing on the items whose failure turns an uncomfortable night into a dangerous one.

What can travel without a dry bag: cookware, the saw and knife (sheathed), tent pegs, water bottles, cord and the tarp itself – the tarp is going to get wet anyway, so it rides on top of the closed liner where you can reach it first. Keep tinder separate from food and fuel, and never put a fuel canister in the same bag as the sleeping bag.

Compression and squeezing out the air

Air trapped in a closed dry bag takes up space and turns the bag into a balloon that will not fit into the pack. Before the final roll, kneel or press on the bag to push the air out, then roll. With a compression dry bag, close the roll top first, then pull the straps evenly – the air escapes through a one-way valve in the base.

• Compress for the walk, not for storage. Sleeping bags and puffy jackets recover their loft when unpacked at camp; stored compressed for months, the fill loses springiness. At home they belong loose in a large sack – see sleeping bag care and storage.
• Do not over-compress in winter. A hard, tiny sleeping-bag package looks efficient but strains seams and fill; compress to fit the space, not to the limit.
• Use the air on water. On canoe trips, a little air left inside a closed bag adds some buoyancy, which helps recover kit after a capsize. It is no substitute for a buoyancy aid.
• Soft bags fill gaps. Slightly under-compressed clothing bags mould around the hard items and stop the load from shifting, as our packing order recommends.

Waterproof packing in your backpack, step by step

Waterproof packing follows the same order as normal packing – it just adds a liner and a few bags. Keeping it consistent with the backpack guide means the pack carries well and stays dry.

A few details make the difference in real rain. Fold the closed liner top down beside the load rather than leaving it standing up under the lid, where rain runs in. Keep the first aid kit, headlamp, map and fire kit in the lid or hip-belt pockets – in small dry or zip bags – so you never need to open the liner during the day. Water bottles live in the side pockets, outside the liner; a leaking bottle inside soaks everything.

On a rainy approach, keep the pack closed and the shell on. Camping in the rain shows the rest of the routine: tarp up first, then unpack under the roof, one bag at a time.

The wet and dry clothes routine

The best dry bag in the world does not help if you put wet clothes into it. On a multi-day trip in rain, the system is simple and strict:

• Dry set: base layer, socks, hat and – in cold weather – a warm layer, sealed in a dry bag at home. It comes out only when you are under the finished roof for the night.
• Wet set: the clothes you walk in. In the morning you put them back on, damp and cold, and they warm up within minutes of walking. Unpleasant, but it keeps the dry set dry.
• Wet bag: a separate stuff sack or the outer pocket for wet shell, towel and socks – outside the liner, never inside a dry bag with dry things.

When you break camp in the rain, pack the sleeping bag and dry set first while the tarp still gives shelter, and pack the wet tarp last, in its own bag on top of the liner. Hanging and venting wet clothes is covered in clothing in the rain, and choosing shells that keep you as dry as possible in rain gear. The layers themselves are explained in bushcraft clothing.

Packing for river crossings, canoes and boats

Near water, waterproof packing is not about rain any more but about a possible dunking. Before you wade, everything that must stay dry should already be in closed bags inside the closed liner: the phone, GPS and power bank in a dry bag high in the pack, where you can reach it on the far bank. Open the hip belt and chest strap so you can get out of the pack quickly if you fall – the full procedure, including when not to cross at all, is in crossing a river safely.

On canoe and kayak trips, heavier PVC or TPU dry bags and waterproof barrels take the place of a backpack. Secure bags to the boat with a short strap or clip so nothing floats away after a capsize, but keep lines short and tidy so they cannot tangle a swimmer. Keep a small bag with phone, a warm layer and a snack within reach of your seat. Ferro rod and lighter belong on your person or in a sealed pocket, as the fire kit guide suggests.

Water trips also mean refilling and treating water from rivers and lakes – see refilling water on the trail – and, on the coast, salt spray and sand that wear closures quickly. Rinse roll tops and buckles in fresh water after a coastal or coastal camping trip.

DIY alternatives: bin bags, rubble sacks and zip bags

You do not need to buy anything to start packing waterproof. A thick bin bag or a builder's rubble sack makes a good pack liner, and resealable freezer bags protect small items. The trade-off is durability: thin bags tear on the corner of a pot or a sharp stick, so choose heavy-duty bags and replace them when they show holes. Closing a plastic liner works best with the gooseneck:

Single-use plastic is not ideal, but a heavy bag that you reuse for many trips is a good bargain. Take every scrap and wrapper home again, in line with Leave No Trace. More money-saving ideas are in surplus and DIY gear.

Care, leak testing and repair

Dry bags fail slowly: a pinhole from a pine needle, a worn corner, a peeling seam. Check them before the season and after rough trips.

Wash dirty bags by hand with lukewarm water and a mild soap; never in the washing machine or the dryer. Store them loose and dry, out of direct sunlight, which ages coatings. Tape, round patches and a spare buckle belong in your field repair kit, and the fabric repair steps there work for dry bags too.

Waterproof packing on a budget

Waterproof packing is one of the cheapest upgrades in bushcraft. In order of value:

1. A heavy-duty liner – a rubble sack or a dedicated pack liner. This alone keeps most kits dry.
2. One good dry bag for the sleeping bag – the item you can least afford to get wet.
3. Zip bags for phone, documents, first aid dressings and tinder.
4. Two or three light dry bags in different colours for the dry set, food and electronics.
5. A rain cover or poncho – useful for canvas packs and long wet spells, but last on the list.

Second-hand dry bags are fine if they pass the light and bubble tests. The budget gear guide explains what to buy first across the whole kit, and the bushcraft kit list shows where waterproofing fits in. New to all of this? Start with bushcraft for beginners and keep the glossary entry on dry bags at hand for the terms.