Recycling is an essential part of decreasing our waste, and lowering our impact of the planet. It plays a role in our daily lives, and it is crucial to make sure that we recycle correctly…otherwise our efforts and time have been wasted. One of the most common questions people ask when they start recycling is if they can recycle wet cardboard. Wet cardboard is a common issue, especially for homes wit curbside recycling, businesses that deal with shipping and receiving goods, or even busy millennials that have a tendency to forget about their packages outside for a couple of days. But is it possible to recycle wet cardboard?
The answer is not super straightforward, but generally, the answer is no, you shouldn’t recycle wet cardboard. Wet cardboard is still cardboard, but the water changes its ability to be recycled and reused. When cardboard gets wet, it loses its structural integrity, and the fibers that hold it together start to break down. As a result, wet cardboard is more challenging to recycle, can cause issues with the recycling facility’s machines, and it can even contaminate other recyclable materials. And….everything is just a little bit more gross when wet.
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Understanding Cardboard Types and Their Recyclability
When it comes to cardboard recycling, it’s important to understand there are different types of cardboard, and how that affects their recyclability. Cardboard is a type of paper product that is commonly used for packaging and shipping, so I’m sure we are all familiar with it. It is made from a combination of wood pulp and recycled paper fibers. One simple trick to differentiate between the types of cardboard is to feel it. I know you know what I mean, there’s regular cardboard and then the cardboard that feels plastic-y.
The two main types of cardboard are corrugated cardboard and paperboard. Corrugated cardboard is the thick, ridged material that is commonly used for shipping boxes, while paperboard is the thinner, flat material used for cereal boxes and other consumer goods. I have a shit ton of corrugated cardboard that we’ve been accumulating in our garage since 2020. I’m 100% not joking; we have a full section of our garage devoted to cardboard at home.
Both corrugated cardboard and paperboard can be recycled, but there are some differences in their recyclability. Corrugated cardboard is the most commonly recycled type of cardboard, as it is easy to process and has a high recovery rate. In fact, in 2021 the recycling rate for old corrugated containers (OCC) – you know these as cardboard boxes – was…an impressive 91.4%.
On the other hand, paperboard can be more difficult to recycle due to its coatings and laminations, the plastic-y feeling. Coated cardboard, which is used for products like frozen food boxes and drink cartons (like oat milk cartons), can also be recycled, but it requires a more specialized process. The coating must be removed before the cardboard can be recycled, which can be a difficult and expensive.
It’s important to note that wet cardboard can still be recycled, contrary to popular belief, but it’s not accepted all all recycling facilities. While wet cardboard is more difficult to handle, and weighs more during transport, it can still be processed and recycled. The important thing is to ensure that wet cardboard is separated from other materials to prevent further contamination.
Why Wet Cardboard is a Problem for Recycling
Wet cardboard can be a big no-no for the recycling process in several ways. It can contaminate other recyclables, clog the recycling machinery, and reduces the overall recycling rate. It is important to keep cardboard dry before putting it in the recycling bin to avoid these problems.
Being wet means it tends to mold pretty quickly, and mold is a contaminant in recycling. Mold can spread to other dry recyclables fairly quickly. Water does have a tendency to just keep spreading to everything it touches, thus feeding the mold. And maybe one moldy piece of cardboard isn’t too bad…but when it keeps spreading and contaminating other recyclables like the cereal boxes and the other dry cardboard, then the whole batch could possibly end up in the landfill instead of being utilized again.
Secondly, wet cardboard can clog the recycling machinery, which can be a big problem for the recycling center. Wet cardboard can stick together and form clumps that can clog up the machinery, causing delays and damage. Workers at the recycling center may have to spend hours cleaning the convert belt or other machinery if it gets clogged with wet cardboard, whereas dry cardboard runs smoothly like butter through the machines.
Another thought is that wet cardboard is heavier than its dry counterpart. So transportation and fuel efficiency come into play when attempting to recycle wet cardboard. And finally, wet cardboard can reduce overall recyclability of paper particles it’s made of. Once it’s wet and has dried, it manipulates the fibers (as a result, the paper or cardboard will become brittle). If too much wet cardboard is mixed with other recyclables, it can reduce the quality of the recycled material, making it less valuable and less likely to be used again. This can lead to a lower recycling rate and more waste in landfills.
Alternative Uses for Wet Cardboard
Okay, so wet cardboard cannot easily be recycled. My brain takes that information and translates it to wet cardboard shouldn’t be recycled. The easiest way is to do this is to separate your recyclables to prevent it from getting wet; we have two recycling “totes:” one for cans and plastics and one for cardboard, paperboard, and other papers. We used to keep it all in one bin until we would drop it off at the recycling center, but the aluminum cans and plastic milk containers (the Boyfriend’s milk since I make my own oat milk) would be rinsed and just thrown in the bin all willy-nilly. And then all the paper and cardboard in the bin magically just gets wet from the micro-drips of water on the plastic containers. So, we found some alternative uses for wet cardboard to keep our overall waste production low.
Compost Wet Cardboard
Wet cardboard is 100% compostable. It is high in carbon, which helps balance the materials in the compost. Since most of what we add to our compost is nitrogen-rich kitchen scraps, the carbon in the wet cardboard helps to create the perfect environment to help the compost thrive. We simply tear the cardboard into small pieces and add it to our compost pile.
Sometimes the Boyfriend and I are on-top of our adulting game and shred our wet cardboard, but other times I just throw whole wet boxes on top of the pile and keep going about my day. I just did this today with some boxes that we had left in the driveway after our fencing project. It has rained, snowed, and rained some more since we’ve finished the project, but the boxes were just sitting in our driveway collecting water.
So I threw them on our compost pile...in whatever shape they were in (some falling apart, some still resembling boxes)…and then put some garden waste and kitchen scraps on top. Voila. Done. One of the easiest ways to use wet cardboard.
Whatever you have the time and mental-capacity for, I’m sure your compost will appreciate it all. It will break down over time, especially since we keep adding all of our garden and kitchen scraps to it, and will eventually turn into nutrient-rich soil that can be used in our garden.
Composing is also a great way to utilize the pizza boxes or other cardboard soiled with grease and/or food waste.
Reuse Wet Cardboard
Wet cardboard can be used for a variety of other things around the house, especially if you let it dry. For example, you can use it as a temporary mat to wipe your feet on when you come inside on a rainy day, or a mud-carpet for your dogs as they come flying in through the door. You can also use it to protect floors or furniture when you are painting or doing other messy projects.
The two ways we most often re-use wet cardboard outside of just chucking it into the compost bin, are as a weed barrier in our no-dig garden, and as shims for literally everything. About 50% of our whole home square footage is below grade concrete floors that are all designed to drain to the lowest point of the floor. So….pantry and root cellar shelving ends up needing shimmed so that our canned goods actually stay on the shelves. Wet cardboard that has dried is more malleable than the original corrugated cardboard, so I fold it over it on itself and I have an instant shim. It’s not perfect, and it won’t last forever, but it will last (hopefully) until we level all the floors and finish these areas of our home.
Mulch Wet Cardboard
Wet cardboard can also be used to create your no-dig garden, or as a mulch around your plants. Simply lay it down on the ground around your plants to help retain moisture and suppress weeds. Ever leave a cardboard box on your lawn too long (no, just me?), and when you pick it up the soil is still so moist in the middle of summer with no rain for weeks? It’s amazing how well cardboard can suppress weeds, maintain moisture, and withstand the elements. Over time, the cardboard will break down and add organic matter to the soil.
Or if you’re wanting to start a garden, you could lay down a thick layer or two of cardboard (wet or dry, it doesn’t matter) and then top it with some nutrient rich compost. The cardboard breaks down to allow the roots to grow through, and you’ll watch your garden thrive. Since we have the main layout of our garden already created, we are going back through and adding pathways by laying wet cardboard and topping with a super heavy layer of wood chips. Let me tell you, it looks absolutely beautiful in our berry patch.
Dispose of Wet Cardboard
If you have no other use for your wet cardboard (and I promise you can find one!), you can dispose of it in your regular trash.
While wet cardboard cannot always be recycled, there are still ways to reduce your waste and give it a second life.
Role of Recycling in Environmental Conservation
Recycling is an important aspect of environmental conservation. It helps to reduce the amount of waste that ends up in landfills and reduces the need to cut down trees for new paper products. By recycling, we can conserve natural resources and reduce the impact of waste on the environment. Globally, the cardboard box is one of the most recycled items.
When we recycle, we reduce the amount of waste that ends up in landfills. Landfills take up a lot of space and can have a negative impact on the environment. They can release harmful gases into the air and contaminate the soil and water. Recycling 1 ton of cardboard eliminates 9 cubic yards of landfill space. By recycling, we can reduce the amount of space needed for landfills and reduce their impact on the environment.
Cardboard together with paper make up about 41% of solid waste streams each year. In the United States, an average household throws away more than 9000 pieces of cardboard every year, and that includes a portion of the 17 billion cardboard tubes are thrown in trash globally. We’ve limited the amount of cardboard tubes in our house with our switch to a bidet instead of toilet paper.
In the United States alone, 544,000 trees could be saved every year if each household replaced one roll of 70-sheet virgin fiber paper towels with a roll of 100% recycled paper towels. It’s that incredibly easy.
Recycling also helps to conserve trees. Trees are an important natural resource, and cutting them down for paper products can have a negative impact on the environment. By recycling paper products, we can reduce the need to cut down trees and conserve natural resources. For example, recycling one ton of cardboard can save up to 17 trees and 700 gallons of water.
In addition to conserving natural resources, recycling can also save a massive amount of energy. It generally takes less energy to recycle materials than it does to manufacture and produce new ones. Recycled cardboard equates to saving 24% of the energy required to make a new cardboard. And recycling one ton of cardboard equates to saving 390 kWh of energy, 46 gallons of oil, and 50% decrease in sulfur-dioxide production from making cardboard from virgin materials.
How to Properly Recycle Cardboard
Preparing any cardboard you receive for recycling is really easy. It’s not as difficult as recycling plastic is, which is why cardboard is one of the most recycled materials. The less confusing our part in the recycling stream, the more gets recycled.
Check Your Recycling Program Guidelines
Different recycling programs may have different guidelines for preparing cardboard. Some programs may require you to separate corrugated cardboard from paperboard, while others may accept both types. Check with your local recycling program to make sure you’re following the correct guidelines.
Remove Tape and Labels
Before recycling your cardboard boxes, make sure any excessive tape or labels are removed from the cardboard. These materials can get stuck in the recycling converter belt system and cause problems. Most local recycling facilities will allow some tape and/or labels on your cardboard, but anything that seems excessive should be removed. You can use a box cutter or scissors to remove the tape or labels. My word to the wise, is to ALWAYS remove the shipping label from your recyclables. Maybe this is just my latent anxiety, but I remove and shred all of my address labels; I don’t need that information floating about anywhere.
Flatten Your Boxes
To save space in your recycling bin and make it easier to transport, it’s important to flatten your cardboard boxes. Simply break down the boxes along the creases and fold them flat. Breaking down your boxes will also save space in your bin if you are the one who takes your recycling to the facility, instead of curbside pickup. This will also make it easier for the recycling sorting machine to handle them.
Prevent Contaminants
You can prevent contamination and your cardboard from getting wet by separating your recyclables. This helps to keep anything that may be wet, even just from you rinsing it, apart from the cardboard you are trying to recycle. Make sure you compost your food-soiled boxes. If they are in with your regular cardboard recycling, this could contaminate and lead to all of your cardboard being trashed.
Get Recycled
Once you’ve prepared your cardboard, it’s time to get it to your local recycling center. This can be done by placing it in your curbside pickup, or you can drop off your recycling like we do. Make sure to place your cardboard in a clean and dry bin, and avoid contaminating it with other materials that can’t be recycled so the entire batch isn’t wasted.
Final Thoughts on Wet Cardboard Recycling
After three years of lazy-girl gardening and composting, I feel like I’m the wet cardboard pro. While it can’t be recycled easily, I’ve never felt the need to recycle it because there is just so much we can use it for around the garden. It’s the perfect start to start or expand your no-dig garden. It can help create amazing pathways as you build your outdoor oasis, or even mulch around those newly planted trees, herbs, and veggies. Otherwise, use it as much-needed brown-waste in your compost bin.
Recycling is super important to the sustainability of our planet. But it can be soooo fucking confusing, especially with every local center having different guidance. The best thing you can do is to check with your local recycling facilities on what they do accept, keep your recycling separated (and dry), and if you end up with wet cardboard, now you have a couple alternative uses for it.
