How big should a compost bin be?

Each bin should be approximately 3x3x3 feet (27 cubic feet). This volume retains heat well for active composting.

Can I use pressure-treated wood for a compost bin?

It's best to avoid pressure-treated lumber for compost bins since the chemicals can leach into the compost. Use naturally rot-resistant cedar, redwood, or cypress.

How long does it take to make compost?

With proper management (turning, moisture, green/brown balance), compost can be ready in 2-3 months. Passive composting takes 6-12 months.

How to Build a Compost Bin: Complete DIY Guide | Lumberama

beginner

3-5 hours

$75 - $250

How to Build a Compost Bin (2026)

Prepared by Lumberama's Building Projects Team

|Last updated May 26, 2026|Sources & methodology

A wooden compost bin turns kitchen scraps and yard waste into rich garden soil amendment. A three-bin system lets you manage compost at different stages of decomposition simultaneously. This beginner project uses simple butt-joint construction with slatted sides for airflow — a critical element for efficient composting.

Key Takeaways

A wooden compost bin turns kitchen scraps and yard waste into rich garden soil amendment.
A three-bin system lets you manage compost at different stages of decomposition simultaneously.
This beginner project uses simple butt-joint construction with slatted sides for airflow — a critical element for efficient composting.
Gaps between the slats are essential for airflow — compost needs oxygen to decompose properly.
The three-bin system lets you fill one, turn into the second, and harvest finished compost from the third.

Tools Needed

Drill/driver, circular saw, tape measure, speed square, level, safety glasses

Materials List

2x4 cedar or PT posts, 1x6 cedar boards (for slats), exterior wood screws, galvanized hinges, hook-and-eye latches, optional hardware cloth for the base

Recommended Species

Western Red Cedar, Redwood, Cypress (avoid pressure-treated lumber where it contacts compost)

Recommended Sizes

2x4x8 posts (cut to 4 feet), 1x6x8 slat boards (cut to 3 feet)

Pro Tips

Gaps between the slats are essential for airflow — compost needs oxygen to decompose properly. The three-bin system lets you fill one, turn into the second, and harvest finished compost from the third. Place the bin on bare soil to let earthworms and microbes access the compost. Line the sides with hardware cloth if rodents are a concern.