I build compost bins like this from old fence pickets and scrap cedar. They work great, however, I created an updated design that may interest you.
These compost bins are easy to build and work great. The design includes:
- An easy mechanism for turning the pile.
- A lid to keep animals out.
Construction
Each layer of the bin is a square as shown. The layers stack, one on top of the other, to form the bin. Most of our bins are made from old 6 foot fence boards, so each side is a little under 3 feet long. That length allowed us to get two sides out of each board. To make the layers nest properly, it is important to make all the sides of all the layers exactly the same length.
The sides of each layer are screwed to a corner block. The corner block length and location is the key to the nesting layers.
The length of the corner block is the height of the side board plus the gap you want between the layers. If the side board is 5.5" wide and you want a 2" gap between the layers, then the corner block would be 7.5" long.
Note that the sides come just to the edge of the corner block. The two sides just barely touch at the corner. That configuration does two things. First, it means that all the sides can be exactly the same length and the layer will be a square. Second, it allows some play in the layer. On its own, the layer will wrack badly, but when the bin is entirely together, it is quite sturdy. The wracking allows some “wiggle room” when getting the layers to nest.
The corner block is offset from the the top of the layer to allow for nesting. The exact overlap doesn’t matter that much, but the overlap should be consistent among all the levels. A good rule of thumb is to attach the corner block to the bottom 2/3 of the side board.
The sides are attached to the corner posts with screws. I have tried using deck screws from a home center, but they split the end of the boards too easily, even if I drilled a pilot hole. What works best are #8, round washer head, No-Co-Rode screws from McFeely’s.
Once you have built a few layers, attach hardware cloth to one layer and use it as the top layer. The hardware cloth keeps animals from digging in the pile. You can also try to use the top layer to sift the compost. I’ve had mixed results trying to do that. Mostly the hardware cloth clogs too easily.
Turning the Pile
Turning the compost pile using these bins is easy. You just transfer one layer at a time as you re-build the bin right next to the one you are turning. Here’s a photo sequence:
