How to Build a Compost Bin

Composting lawn and garden waste is a great way to obtain organic material for your garden while reducing the environmentally negative aspects of trucking yard waste to the landfill. This DIY compost bin is easy to build and made from pressure treated wood so it will last for many years to come. It has a removable top along with a hinged door on one end for easy access when filling the bin and removing compost.

While you can make your compost bin any size desired, the one we built was 2’ wide by 3’ long by 30” high. Pressure treated 4” x 4” posts were used for the corners and 5/4” by 6” treated lumber for the sides and top. Be sure to leave gaps between the boards to allow for air to circulate in the bin. Here’s how to go about building a compost bin for your garden.


  • Tape measure and pencil
  • Square
  • Safety glasses and ear plugs
  • Level
  • Circular saw
  • Drill/driver
  • Drill and screwdriver bits
  • Post hole digger


  • 2 – 4” x 4” x 8’ pressure treated pine
  • 9 – 5/4” x 6” x 8’ pressure treated pine
  • 1 – pair hinges
  • 1 – screen door latch or barrel bolt
  • Corrosion resistant deck screws

Cutting List:

  • Corner Posts: 2 – 3½” x 3½” x 42”
  • Top Boards: 4 – 1” x 5½” x 38”
  • Top Cleats: 2 – 1” x 2” x 22”
  • Side Boards: 10 – 1” x 5½” x 36”
  • End Boards: 10 – 1” x 5½” x 24”
  • Door Cleats: 2 – 1” x 2” x 17½”

Building Note:

Pressure treated wood is often slightly thicker and wider than standard dimension lumber and may require minor adjustments to the lengths on the cutting list.

Building the Compost Bin

Start by cutting the posts square and to length.

Next, cut the side, end, and top boards square and to length.

Attach a side board flush with the end and edges of two of the posts using screws. Check to see that the board is square with the posts.

Position each of the other four side boards, using 5/8” spacer blocks, and attach them to the posts with screws. Repeat this process to assemble the other side.

Dig four holes with a post hole digger for the corner posts.

Set the side units in the holes so the outside of the boards are 2’ apart at each end. Check to be sure the sides are level and plumb, then loosely fill the holes with dirt.

Screw the top end boards to the posts, positioning them flush with the top of the post and aligned with the outside of the sides. Use the spacer blocks to position the remaining boards on the back end of the compost bin, and attach them with screws.

Rip the cleats from a piece of leftover 5/4” lumber and screw three of the end boards together to form the door. Use the spacer blocks to position the boards the correct distance apart.

Attach the hinges to the door and mount the door on the end board of the compost bin. Attach the bottom end board below the door using a screen door latch or barrel bolt to hold it closed. Pack down the dirt in the holes.

Assemble the top of the bin by screwing the top boards to cleats so that the outside boards are spaced 24” apart with an even gap between each of the other boards.

Finally, fill the compost bin with leaves, grass clippings, and other lawn and garden waste. The amount of time it takes to turn the waste into compost will vary depending on the materials used, the outside temperature, and the humidity. To speed up decomposition, turn the pile with a pitch fork from time to time and keep the mix damp by wetting it down if it dries out. Remove the compost from the door on the end of the bin when it is ready.

Further Information


  1. One thing I didn’t realize was how much we were going to use our compost bins. A set of three is recommended but we only have space for two. After doing some projects we had a lot of pallets to get rid of so we used them to make the bins. We throw in kitchen scraps, leaves, and grass. It fills up quick but the process deflates the material after a while… I think that everyone should have one!

    • Hi Barb,
      We positioned it so the gate latch could be use to hold the door on the bin open. Other suggestions include using spring loaded hinges (like those for a screen door) or cutting a 1×2 the length of the height of the door and hinging it inside the door at the bottom to one side so it swings down and props it up when you open the door. Good luck with your project!

    • Hi Roger,
      You definitely don’t want to use creosote or penta treated lumber to build a compost bin. While a rot resistant wood (like redwood, cypress, or cedar) would be best, the newer pressure treated wood that uses ACQ (alkaline copper quat) or CA-B (copper azole) hasn’t been shown to cause a problem with leaching into the soil, and should be okay to use. Avoid using the older arsenic based CCA (chromated copper arsenate) pressure treated wood, which was taken off the market for most consumer uses in 2004. Good luck with your project!

  2. I have a question, I an old wood box that is not made with treated wood. It’s been in storage for years and I am wondering what I would have to do to it to make a compost bin. Such as, do i need to remove the bottom and should i drill holes in the sides ?


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