What you’ll build
Six 27½″ 1x4 slats per side fit between 32″ 4x4 posts. Build the two side panels flat, stand them up, then add the back and front slats. The whole bin takes two 8-foot 4x4s and eight 8-foot 1x4s.
Shopping list
Buy these boards. The list fits every cut onto standard lengths and leaves ⅛″ for each saw cut and ¼″ for trimming board ends.
| Lumber | Length | Qty |
|---|---|---|
| 4x4 | 8 ft | 2 |
| 1x4 | 8 ft | 8 |
Cut list
Every part, grouped so you can cut matching pieces together. Sizes are actual dimensions (a 1x4 is ¾″ × 3½″). Check them against your own boards before cutting.
| Part | Lumber | Section | Length | Qty | End cut |
|---|---|---|---|---|---|
| Slat | 1x4 | ¾″ × 3 ½″ | 27 ½″ | 24 | Square |
| Post | 4x4 | 3 ½″ × 3 ½″ | 32″ | 4 | Square |
Tools
- Tape measure
- Pencil
- Speed square
- Eye & ear protection
- Drill
- Miter saw
- Clamps
- Sander
Step-by-step instructions
Assemble the Left Side Panel
Lay the front and back left 4x4 posts parallel on a flat work surface. Position the six 27 1/2-inch left wall slats between the posts from bottom to top, keeping slat outer faces flush with the post exterior faces. Clamp the assembly firmly to hold alignment.
Assemble the Right Side Panel
Lay the front and back right 4x4 posts flat on your work surface. Arrange the six 27 1/2-inch right wall slats across the inner post faces to mirror the left side tier spacing. Align all exterior faces flush and clamp the panel square.
Connect the Back Wall Slats
Stand both side panels upright and parallel, separated by 27 1/2 inches. Fit the six rear slats between the rear posts from the bottom tier upward, aligning each slat flush with the side tiers. Clamp the rear slats tight against the posts, keeping the three-sided frame square.
Install the Front Wall Slats
Position the six 27 1/2-inch front wall slats between the two front posts, working from bottom tier to top. Align slat faces flush with the front post exterior faces and matching side tier heights. Check that all four corners remain plumb and square.
The posts sit on the ground, so use ground-contact-rated or naturally rot-resistant lumber for them and exterior-rated screws for the slats.
Change the size or design
This plan is one of the projects in the TimberLab app’s catalog. In the app you can turn the model in 3D, follow the assembly steps one part at a time, and ask for changes in plain words, such as “make it 6 inches shorter” or “add a shelf”. The cut list and shopping list update to match the new design.
Questions about this plan
How much lumber do I need to build this slatted compost bin?
The shopping list calls for 2 × 4x4 at 8 ft; 8 × 1x4 at 8 ft. It groups every cut onto standard board lengths and leaves room for saw cuts and trimming the board ends.
How big is the finished slatted compost bin?
It is 34 ½″ wide, 32″ tall, and 34 ½″ deep.
What tools do I need?
You need a tape measure, pencil, speed square, eye & ear protection, drill, miter saw, clamps, sander.
Can I change the size of this slatted compost bin?
Yes. Open the slatted compost bin in the TimberLab app and describe the change in plain words, such as “make it 6 inches shorter”. The 3D model, cut list, and shopping list update together.
