Compost Barrel




Introduction: Compost Barrel

I like to recycle my pots of soil after the growing season. I have been using a plastic trash can to store and compost my potting soil, but it does not allow me to rotate the mix as I add organic material (leaves, grass clippings, etc.). I have seen several compost barrels on the Instructables site and wanted to make my own.

So ... here is my version.

Step 1: Concept

My project started off with an idea of what I wanted - a barrel to make it easier for me to compost and recycle my potting soil. But I wanted to use the materials I had on hand. I had a barrel, but it did not have a top or lid. I had lots of spare lumber. The only item I did not have were the rollers. I also wanted to not put any additional holes in my barrel. One was because I did not  have any hinges to make a side hatch to access my barrel and I did not have the original top to cap off the end. I also wanted no side hatch or hole, because I might decide to recycle the barrel and turn it into a rain barrel later. So I came up with my current design.

List of Materials:

1/4 inch plywood
2x4 pressure treated timber of various lengths
4 small casters
wood screws

Tools Needed/Used:

Drill (for screwing and drilling pilot holes)
Phillips head screw driver
Saw (I had a table saw but any saw to cut wood with will work)

Total Cost of Project:

$8.50 for the casters - all other material was on hand or salvaged.

Step 2: Make a Top

For the top, I used a scrap piece of 1/4 inch plywood. I placed the barrel on top of the plywood and traced the outline. I then used a jigsaw to cut it out.

My next step was to cut out some square blocks to act as spacers and allow the top to stay centered on the barrel. Because the edge or rim of the lip on the barrel extends out, I could not place the blocks flush against the top. I placed the block on the center of one of four 'corners'. I then measured from the corner of the block to the edge of the top. The distance of the rim was 1 5/8 inches, so this was the distance I measured from the corner of the block to the edge of the top. I did this for each block placed at the other three (3) corners. Once this was done, I put the top on with the blocks down or 'inside' the barrel. (Note: I nailed the blocks in as I did not have screws long enough to secure them. The nails were 1/8 inch longer and stuck out, so I bent them so as not to snag on anything).

Step 3: Build the Frame

The frame is fairly simple - just a rectangle to place the rollers and keep the barrel stable while turning it on the rollers.

I did not measure the lengths - the width was about 3/4 the width of the barrel. The length was slightly longer than the barrel itself. The actual lengths were dictated by the 2x4's I had on hand. These were nailed together to form the frame. (NOTE: I used treated 2x4's as I had these on hand. Also, since it was going to stay outside, the treated wood would last longer).

I was worried the frame would not stay together, so I cut some braces and screwed these into the corners. I cut these braces from scrap left over from the 1/4 inch plywood used to make the top.

Step 4: Place the Rollers

To roll the barrel on its frame, I needed four (4) casters - I found these at Home Depot. I placed the barrel on the frame and 'eye balled' their placement. I wanted to put the casters on either side of the two ridges on the barrel to help keep the barrel centered and prevent it from slipping when rolled.

I used wood screws to secure the casters. This way, I could easily remove them if I needed to make adjustments to their placement.

Step 5: Project Comments

As in any project, there are unforeseen things which come up.

First, I ended up making the frame a bit longer than I intended. But then, I did not measure anything (except by eye). However, I thought overall the frame came out okay. I did put in some diagonal braces in the corners to help keep everything square as well as to keep the frame together. Since I did not have screws long enough to use in the frame itself, I had to use nails. Because of this, I added the braces in which I was able to use the screws I had on hand.

Second, since the frame was longer than I expected, I added the short 2x4 at the end as a 'stop' for the barrel. This is to prevent the barrel from sliding off the end as it is being rotated.

I have noticed I placed my rollers too close together. Once I have the barrel running with a load of soil, I may separate them to balance the load. These are screwed in so it will be easy to move them.

As for my top, I plan to use bungee cord to secure it and keep it closed.

Step 6: Completed Barrel

Here is my completed barrel. I think it turned out all right, considering I did very little measuring and everything was built 'by eye'.

This project took longer to collect the materials and write up these instructions than it did to actually make. But then, I imagine a lot of folks will find that to be true.

I hope this inspires you to make your own composting barrel.

Step 7: Project Updates

Well, my barrel works, but not exactly like I had hoped.

My bungee cords are not quite long enough, so I am going to get some longer ones. This will make it easier to take to top on & off.

When I rotate the barrel, it is hard to roll and unstable. So, I will move the casters farther out. Also, the organic material slides and does not 'tumble'. To fix this, I will add some baffles into the sides to help toss things around. I know this will put holes in the barrel to secure the baffles, but that's okay.

Once I have made my changes, I will let you know how they worked out.

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    8 months ago

    I made a smaller version. Love the simplicity of the casters.


    9 years ago on Introduction

    I like this idea. I have a pickle barrel but no lid, and never knew what to do with the thing. Now that I need a rolling composter, I'll make the lid and all of the other parts. I'll use wider casters so as not to indent the barrel when it's getting heavy. Thanks for sharing. =)


    11 years ago on Introduction

    If you place at random some holes and the through the holes 2,3, and 4" bolts with washers and nuts on the inside fror additional strength, these will help as extra drag to help break up compost while spinning. Also I used an old pair of inline skates cut in half, so where you have one wheel I have 2 (8 total) these help to lend stablity and have 2 contact points in each corner. I am working on a new version, trying several different ways to make it people powered. Everyone has motors, but I like the idea of a hi ratio hand crank or a bike pedal system.. any ideas?


    12 years ago on Introduction

    I really like your idea of using casters. This is the first time I have seen this. I was thinking of building a composter today and you have done a great job! Thanks for the great ible, and let us know how your casters work out. I will be trying larger ones as I have them laying around.


    Reply 12 years ago on Introduction

    The larger casters should work better than what I used. But, remember to spread them farther apart than I did. I still have to change that on my original design. Also, you will need to put something inside to help turn the material. That is the other item I still have to add. I have seen folks use nails and/or screws stuck into the sides. I was thinking of something else, but not sure. Once I have mad the changes I will post and let folks know how it works out.


    12 years ago on Introduction

    Used potting soil does not need to be run through the composting process - it will actually slow down composting of the organic materials. If you only have a couple of houseplant pots to deal with, throwing that into the compost pile won't be a problem, but if you have a lot of container plants, it's better to run the compost pile separately and just put the used soil in a big bin, then mix it with compost as you refill the containers.


    Reply 12 years ago on Introduction

    Thanks for the tip - I had not thought about that. I have been doing things the other way as you suggested, but I wanted something easier to turn my mixture with. Hence my barrel.