I finally finished my compost bins over the weekend. I decided to build a triple-bin (turning bin) system, each approximately one cubic meter (3’x3’x3′.)
The bins are constructed entirely of cedar (renewable, weather resistant, and generally termite resistant), using cedar fence panels and 2x4s. The lids are made from cedar 2×2 deck-railing slats, covered in a square, wire mesh (to keep the birds and squirrels out.) The bins are held together with cedar-rated Deck Mate screws, which I had left-over from another project. (It’s pointless to use nice, weather resistant wood if you’re just going to join it with cheap, rust-prone fasteners. Spend the extra money on rust-free nails/screws/staples so you don’t end up with rust stains running from every joint.)
For those new to three-bin compost systems, here’s how they work:
- New compost materials are put into the bin on the left. (You can still turn materials in this bin like normal.)
- Part-way through the composting process, you shovel-out the materials in the left bin and move them into the center bin. (This provides opportunity to fully flip/aerate the pile.)
- When done, shovel the center bin’s pile into the right bin. The right bin stores ready-to-use compost.
- Once you have a cycle going, you can have a new pile starting, while still having a steady stream of available compost.
It’s hard to tell in the picture above (by design), but the front of each bin opens for easy access. The doors are held on with a simple gate latch:
The screen lids lay on top of each bin, resting on simple guides made from exposed screws. The mesh is attached using staples:
Using cedar raised the materials cost a bit, but the extra durability should be worth it in the long run. All said and done, the materials were a bit over $100 for the whole unit (which is still significantly cheaper then buying a pre-made bin this size.)
For more on composting, see: