Having a garden with fresh veggies in the summer is one of the most enjoyable delights there is. Taking your urban garden to the next level with a compost bin is a great way to enhance your growing opportunities.

Here we explain how to build a pressure-treated compost bin for your yard that is both functional and eye appealing.

Design and features overview

A 30 x 30-inch box is a manageable size for a family in the city. Consider incorporating dual access with a top-mounted lid and bottom trap door. These would open out, allowing you to mix and pull the compost that is ready for use. Your box also needs to breathe, so having space between the wood slats is important. The box will require a strong frame to hold the weight of the compost, as well as a finished shell to make it look polished. Horizontal slats give the box a more modern look. Add finishing trim to the bottom to make it look more grounded.

Box plans and cut list

Make a set of construction drawings with dimensioned plans that include the top and side views of the box frame and box shell. For the box frame, use 2 x 4-inch brown pressure-treated lumber. The shell can be built with 1 x 6-inch brown pressure-treated fence boards with squared corners. The trim is 1¼ x 6-inch brown pressure-treated deck boards with a bullnose edge.

Once you know your lumber and box dimensions, you can create a cut list. This is a list of all the cuts you need to make to create each side of the box. This cut list will eliminate the need to do math when you are ready to construct the box.

Putting the puzzle together

Stay organized by measuring the pieces, labelling them, cutting them and stacking them according to the side each piece belongs to. Once you have all the pieces cut from your cut list, start assembling the box. Cut the frame pieces first, then assemble the frame and then measure the frame to confirm the shell piece dimensions. The pieces should go together exactly as outlined in your plan. Build each side individually and then assemble each side together to create the box. Measure and cut the lid and doors once the frame is completed to ensure they fit. 

Install the moving parts

The hinges need to be installed to ensure the lid and trap doors are working properly. Keep in mind that the shell will be installed over top of the hinges, so extra room needs to be left to ensure the doors function properly.

Dress up the box

Add horizontal slats with a 3/4-inch space between each board. Ensure the boards are level. Each corner is mitered at a 45-degree angle to provide a clean, finished look. The slats are installed with a brad nail directly to the frame. When installing the slats over the trap door, make sure not to nail the door shut and to only nail the slats to the door itself.

The finishing touches

Add latches to each side of the box to hold the trap door closed. Install handles to the lid and trap door. Finish off the look of the box with a bottom trim, also with mitered corners.

Reminders

When working with pressure-treated lumber, you must seal every cut that you make.  Purchase a sealant that is the correct colour – either green or brown, depending on your wood choice.

Find the perfect location in your yard for your compost box and sit back and let Mother Nature do the rest. 

Building Material List