Over my many years of composting, I’ve tried nearly every way of making it. From an open heap in my backyard to expensive dual-bin devices with cranks and gears. At the end of the day, a pallet compost bin has become my method of choice. A bonus – the pallets are free.

It’s also one of the simplest, easiest, and cheapest methods for making plenty of compost. Ten years later and counting, I’ve been so satisfied with everything about it, I have no plans of using anything else.

Building a composting bin using pallets is an incredibly easy project and a great use for these common items. While you could make a simple, single bin system, I don’t recommend it. To make compost in a way that actually allows you to keep finished compost separate from new inputs, you need at least two sections.

I suggest you make a 3-bin system if you have the room. It only requires seven pallets (versus three pallets in a single bin system), and it makes a world of difference to the efficiency of what you can make and use.

In a 3-bin system, use the first section for your initial contribution. Continue to add new ingredients until the bin is nearly full.

Then, move to the middle section and start filling that bin with the newest ingredients. Continue to add inputs to this section until it is nearly full.

Finally, use the third bin just as you used the first two bins. The logic is that by having three separate sections, you always have compost in different stages of decomposition: new, in-process, or finished.

Once the third bin is full, the first (original) bin should have broken down and is now ready to use as finished compost. Once that’s used up, the middle bin should now be ready, etc.

Important Considerations to Keep in Mind Before Diving into this Project

  • Some pallets are treated with potent pesticides. Be sure to choose pallets that have not been chemically treated. The most common treatment methods for pests and pathogens are either heat-treating (marked on the pallet with “HT”) or fumigation, using Methyl Bromide (marked MB). Stick with heat-treated or new virgin wood if you can find it.
  • Pallets come in different sizes. While assembling your compost bin with mismatched pallet sizes will work, for this system, it’s preferable that they’re all the same size. It makes for a better looking finished product and helps during assembly.
  • Choose a rot-resistant wood. Pallets are made from different types of wood. For a compost bin, try to find pallets made from rot resistant hardwood, such as oak or cedar. Pine, although easy to find, is not as strong, nor does not stand up to the elements as long.  For strength and durability, you ‘ll want hardwood.

My compost bins are made from 4’x4’ untreated, virgin hardwood pallets. Despite constant moisture and exposure to the elements, they last for years.

This is my current 3-bin pallet composting bin. This workhorse has been cranking out year-round compost for over 6-years. It’s still holding up very well despite the untreated hardwood being in constant contact with moisture.

How to Make a 3-Section Compost Bin Using Free Shipping Pallets

Assembly is straightforward and intuitive. All you need are seven pallets, all-weather deck screws (3-inch length is ideal) and a drill with the appropriate bit.

Assemble your bin where you plan on leaving it, preferably on a level surface. The seven pallets are used as follows: one for each outer wall, two for the dividers to separate the bins, and three across the back.

  1. Using several screws, attach one pallet that will serve as an outer sidewall to another pallet that will be part of the back side of the bin.
  2. Next, add one of the inner pallets that will serve as a divider for each section. Secure it against the first back pallet with several screws. Be sure to offset this inner pallet when securing it to the backside. You’ll need this extra surface space to attach the next middle, back pallet section to the divider.
  3. Now add the next pallet to make up the middle section of the backside. Secure it to the diving pallet you added in the previous step (using the offset space mentioned in step 2). With the remaining four pallets, work your way across for the next two sections in this same manner.

Pro Tip: Consider grabbing an extra pallet to use just for additional parts. I removed the slats from it to place in between other slats of my finished bins wherever I wanted to close some of the gaps. It’s a smart and simple fix to help keep more of your precious compost in place.

One of the best things you can do to protect your compost from slipping between the spaces between slats is to grab an extra pallet to use for spare parts. I used the slats from it to fill the gaps where needed. I strongly suggest this!

The Options. Although unnecessary, in my first version, I liked the idea of having a cover over the bin that would hold my finished compost. My improvised solution consisted of a cut-to-fit sheet of corrugated plastic screwed to a wooden frame made of 2×2 pine.

If you do this, I suggest you find a way to make the top movable since, over time, each section will house finished compost. You should know I no longer do this. Unless the cover is reinforced, the weight of accumulated rain or snow will cause the cover to sag. Plus, it’s really not necessary.

Also, I strongly suggest adding a long treated 2×4 across the backside and securing it to the back panels. The extra stability it provides is a simple and inexpensive option to reinforce the entire system.