This post may contain affiliate links.

How to Keep Your Backpacking Gear Dry with Trash Compactor Bags

Line your Backpack with a Trash Compactor Bag
Line your Backpack with a Trash Compactor Bag

The first thing I do when I pack my backpack is to line the inside with a thick trash compactor garbage bag, like the kind you can buy in a supermarket. These plastic bags are very tough, last a long time, and are an excellent defense against rain and wet ground. I’ve been using this technique to keep my gear dry for years in all kinds of horrific weather, both for three-season and winter hiking and backpacking.

Waterproof Backpacks

Most backpacks are not waterproof – even ones made with waterproof fabrics like Dyneema DCF and Xpac. That’s because the stitching used to sew them together creates many tiny holes in the fabric that leak water unless the manufacturer seals them with seam tape or you touch them up with seam sealer. While you can buy a waterproof backpack, such as the Exped Torrent 50 or the ULA Epic, they’re usually 1-step up from rafting dry-bags and not as comfortable or functional as a regular 3 season backpack.

That’s where a trash compactor bag comes in. If the fabric of your backpack is reasonably waterproof, any water that leaks in at the seams will be stopped by the trash compactor bag before it gets to your gear. You can even pack your gear loose without stuff sacks and it will keep dry. You’ll get a lot more gear into a backpack by packing it loose like this, if space is an issue.

Using a trash compactor bag as a backpack liner also means that you can use regular stuff sacks instead of waterproof roll-top ones to pack your gear. This can save you a lot of money since waterproof stuff sacks have a limited life span before they fall apart – 2 years for me.

Backpack Rain Covers

Backpack rain covers are primarily designed to prevent the fabric of your backpack from soaking up water when it rains, a holdover from the days when packs were make out fabrics that were not waterproof, but they do a piss poor job of keeping the gear inside your backpack dry. Internal condensation, leaky seams, and poor fit are all contributing factors and a lot of hikers don’t even bother with them.

The Best Backpack Liners

I’ve experimented with many different backpack liners over the years ranging from black plastic garbage bags to the ultralight plastic backpack liners that Gossamer Gear sells. But when it comes to convenience and longevity, a trash compactor bag lasts the longest and is very easy to repair with duct tape if it’s punctured or torn. The white color also makes it a lot easier to see the contents of your backpack and they cost less than $1 per bag.

Sometimes the best backpacking gear isn’t backpacking gear at all.

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.


  1. I always pack one of these – either for the purpose mentioned or sitting on wet ground or wearing if it gets really cold and/or wet. A cheap, light way to cover a lot of issues.

  2. Been going this route for years. Simple, effective, inexpensive.

  3. I hiked the entire AT with 2 compactor bags. I only switched them out because I could, not because I needed to. This is the best system to keep gear dry. Hands down. My gear was never wet INSIDE my pack. Also works good to section off wet/dry sections in your pack. It doesn’t feel right to pack my bag anymore without one of these. Lifetime supply of these bags is about $7.

  4. I used trash compactor bags for a while, now I’m using turkey roasting bags. Smaller, lighter, totally transparent, I use just one for my sleeping bag, most everything else in my pack can stand getting damp.

  5. This is the best info I’ve found on the subject of trash compactor bags being used as pack liners. I had been using the XXX-large ziploc bags but these may be a lighter and more durable option. Great!

  6. Compactor bags are heavy duty and made to have trashed mashed under pressure whereas garbage bags, even the “heavy duty” type, not nearly as rugged or durable,

  7. I have used a TC bag for canyoneering. Many swims with my backpack on, and completely dry inside. Just secured by tying. Also held air for flotation (I had a CCF pad, too).

    • No more than a good soaking rain. Most river crossings on hiking trails are less dramatic than they sound. Unless you try to cross during a flood. The same it’s just best to wait for the water level to drop.

  8. Bought 30 HDX brand at Home Depot for $10. 2.5 mil, 18 gallon, unscented.

  9. Compactor bags are thicker than a standard bin liner being from 2.0 mil to 2.5 mil thick (53-63.5µm) and are even more robust because they are meant as liners for a kitchen compactor. Yes, they’re available in Europe (look for 18-gallon compactor bags). At night cover your backpack with a 3 mil contractor clean-up bag – they’re virtually bomb proof.

  10. Probably a stupid question, but what do you do to close the bag? Twist tie? Fold it a few times?

  11. Are these TC bags the correct size to use for the ‘bucket’ toilet when car camping? It must be cheaper than the ‘bucket’ recommended brand.

  12. I did a little web searching for bags so that I could get out of doing any real work today.

    Home Depot carries HDX (formerly Husky brand), unscented, 30 in a box, for about ten bucks. I’m going to get a box and line all the backpacks I have, which is too many! I do have different size packs I use for different conditions (weather, length of hike, whether or not I have to carry gear for others, etc.) and the grandkiddos use them as well.

    I succeeded in today’s avoid work expedition. Now I have to figure out how to elude productive labor tomorrow!

    • bought a box of them 2 yrs ago. got 28 left. (I only use 2 packs)

    • I use those from Home Depot, too. I go through them a little faster than others might because I use two at a time. One for sleeping gear at the bottom of my pack, the other for the rest of my gear in the top. One of them becomes night time storage in my tent and the other I use to inflate my sleeping pad.

  13. Philip,

    I tend to think there are a lot of ways to keep gear dry inside the bag. My preference are freezer bags but also use other options. My question is that for those of us that use older backpacks and occasionally rain covers comments about treating backpacks to not absorb moisture and weight similar to DRW treatments? Again less concerned about contents and more about a heavy bag. Presently hiking with osprey variants of 52 litres and 37 litreswhich are winter purpose bags but fit my frame well

    • I’ve never tried it, but I don’t think adding waterproofing treatment on a regular nylon backpack would work well. 1. It is a big area, so the chemicals would get expensive. 2. A backpack is a complicated shape with lots of seams, reducing the effectiveness of waterproofing. I would, however, consider applying a DWR to a backpack cover, if it is old. Some hikers complain their covers tear off in a high wind or from snagging on branches, but I’ve never had those problems with the cover secured carefully. Personally, I rarely use a cover unless I expect lots of rain. I use the thick plastic bags sold by Gossamer Gear — sized to fit inside a backpack better than garbage bags do.

  14. Your Amazon link goes to plastic lined paper bags which are useless for this purpose… My bad for trusting w/o checking but didn’t realize until they arrived -_-

  15. Any specific and or brand or thickness you recommend? For a 60 liter ultralight pack such as the Gregory Optic 58 what size compactor bag is best?l


    • I think trash compactors bags only come in one size.

    • It doesn’t need to hold everything, just what needs to be kept dry. In my case, it is just my clothes and sleeping bag. Put that stuff in the bag and roll the plastic bag down. The other can just go on top of that. So outside the compactor bag, but inside your backpack.

  16. So what is the best method of closing the bag … twist tie, drawstring or tie-able flaps? I’m thinking drawstring because I would probably lose the twist tie and it would be easyist to open and close. :-)

    • The bags are fairly large size and completely lined my GG Crown 60. On my section hike, I kept my sleeping bag, extra clothing, electronics, personal and first aid kit in the compactor bag and rolled the top. I had another waterproof bag with layers to be used during the day and packed that on top of the compactor bag in my backpack to hold it all down and the trash compactor bag kept everything inside dry through several days of rain.

  17. Timothy Dannenhoffer

    I might have made a mistake spending well over $150 on dry sacks and dry stuff sacks. Expensive AND not too resilient / abrasion resistant? Not happy.

    • Depends what you bought. They’re certainly not completely waterproof, but they do make good organizational aids when packing. Although I know some frugal types who just use ziploc bags to the same effect.

Leave a Reply

Your email address will not be published. Required fields are marked *

Captcha loading...