Compost Bin - Low Cost, Easy, and Modular




Introduction: Compost Bin - Low Cost, Easy, and Modular

This design is based on an evolving design for composting my grandfather came up with. Throughout his life he tried various strategies for composting, and different bins to go with them. Some used lathe and 2x4s, others used cedar dimensional lumber; some had removable braces, or entire sides. This design is an evolution of what I can recall of his compost bins.

The key principle here is for each side to be removable, allowing you to leave the compost heap on the ground, and move the bin. Once the bin is moved, you can either let it sit and do its thing, or you can transfer it back into the bin in the new location, thus aerating and mixing the material. You could also remove just one side, allowing you to more easily scoop or turn the compost.

Lets get started!

Step 1: Materials and Tools

I used pressure treated lumber, but you could use cedar
Fence Pickets - 10 @ $1.55 ea
1 x 4 x 8 - 4 @ $3.37
1 1/4" Construction Screws @ $7.94

Circular Saw (a.k.a. Skill Saw)
Cordless Drill
Tape Measure
Square (Carpenters/Construction)

Total Dollars:
Lumber - $29
Lumber + Hardware - $37

Step 2: Plans

See the attached image for the plans.

Its important to make the cross lap cuts "big enough". The dimensions marked in the drawing are 0.75" wide by 1.75" deep, but thats exactly half of the board size, so you'll want to "eat the line" when you make the cuts to allow for some wiggle room. In my opinion, its okay to make this cross lap joint a bit loose, since you'll want to be able to take the sides off easily, even if the wood is wet or swollen.

I originally wrote these plans for a 6' 1x4 for the cross bars, but it turns out they are only available in 8' lengths anyway. When I did mine, I actually broke two of the cross lap end pieces when chiseling out the joint. My original dimensions also were just barely too small to assemble the bin with the crossbars on the outside. For those reasons, I've utilized more than 6' of the 1x4 in these plans, but left my original dimensions in the plans, denoted with (Alt).

Step 3: Cuts

Cut the fence pickets in half, so you have 20 sections at 3' each. You could dog-ear the lower half boards to match the upper ones. I didn't, because I don't have a miter saw.

Cut the 1x4's to length. See the drawing on the previous step. If you wanted to use a 6' board instead of an 8' board, read the previous step and adjust appropriately.

Cut the cross-lap joint. I did 4 boards at a time by clamping them together, marking the width, and set my circular saw to the right depth. A table saw with a sled would be better here, but again, my only saw is a circular saw at the moment :)

Clean out the cross-lap joints. You can use a chisel to clean out the bottom side, but be careful to not break off the end of the board!

Step 4: Assembly

Refer to the Plans step for detailed measurements. Use your square (carpenters or construction) to make sure the pickets are square to the crossbars.

Be sure to assemble two panels with the cross-lap joint up, and two with it down.

Once you have all four panels assembled, you can put the puzzle together!

Step 5: Compost!

Once your compost bin is set up, its time to compost!

Fill the bottom of the bin with sticks and branches to keep the compost off the ground. This helps regulate moisture, and promote aeration.
Follow the "brown layer, green layer" recipe.
Turn your compost heap monthly with a shovel or potato fork.

I don't have any compost started yet! Check back in a few months for an update.



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    14 Discussions

    I want and plan to build this ASAP but I got confused by the comments. What's the upshot, guys? Untreated wood? What exactly is "the New" treated wood? And the hinges would be better than the slots? I'm a 67 yr old woman, on my own, so I need easy! I think the lumber store can make the cuts I need and I'm thinking the removable pin hinges, but can you help me out with lumber choices?

    2 replies

    I don't think the lumberyard would be able to make the crosslap joint cuts for you, so you should try using door hinges. Cedar is probably a better choice overall, if its available for a reasonable price. I'm letting my treated bin sit in the rain for a few weeks to get most chemical leaking out of the way.

    Thank you for the quick response! I'm going to Home Depot right now to get something appropriate for my high desert climate. Rain is pretty much not a problem here! Instead I have to remember daily watering to keep the pile moist at all! Again, thank you for your assistance.

    I would recommend NOT using pressure treated lumber for composite bins. The chemicals will give the decaying process problems. Also for structural strength, I would put the vertical slats inside the braces, then any pressure will push them tighter to the braces not off of the braces.

    2 replies

    I agree on both fronts.

    The plans drawing I posted should allow you to assemble the bin with the slats on the inside. My initial measurements were just a tad off, so I had to put it on the inside. You bring up a good point on the outward pressure. Maybe I will adjust mine...


    2 years ago

    Might you consider changing the notch joints? They may not stand the test of time. One option would be to use hinges with removable pins. And use large, loose-fitting common nails in place of the hinge pins. Unfortunately, this increases the hardware costs.

    2 replies

    Yes! I actually did consider that, but decided not to due to cost, and the precision alignment that would be required - at may get more difficult to keep aligned over time with weathering.

    I would encourage you to try it though!

    Good point on the alignment vs. weathering!

    You must check what kind of pressure treatment is on the wood. Some can kill your compost.

    2 replies

    Yes, the new process is safe enough to eat off of. Even with CCA treatment, the arsenic leakage into the soil is negligible. However, there is some controversy over creating CCA compost bins. I would encourage using Cedar, but I was on a tight budget this time around (just buying my first house...)
    This was an interesting read: