How to Build your own Compost Bin

Have you ever thought of building your own compost bin? Well, hopefully now I've sown the seed.

In this post, we go through all the major steps involved so you can see if it's right for you.

Building a compost bin is a fairly simple project that anyone could attempt themselves with a minimal amount of tools.

Lots of the same skills you learn making a compost bin can be used to tackle larger projects as you get more confident.

Building your own compost bin gives you the freedom to make it any size and style you want.

Let's face it if you cock up when making your compost bin it is probably the best time to do it! It's not the end of the world.

Then when you do attempt something more extravagant you will have more experience.

Essential Tools and Equipment

You will need a tape measure and pencil but relatively few power tools in order to build yourself a compost bin.

You can use either a handsaw or a circular saw. If you were only making one compost bin then a handsaw would get your job done!

But, If you feel confident and you are looking to speed through the process then I would definitely recommend a circular saw and speed square.

This is a winning combination and it is how I performed all my cuts. It dramatically increased the speed of the operation and left me with perfectly straight cuts.

Best Timber to Use

If you don't have any wood lying around that you could use, 6"x1" (150mm x 22mm) Treated Timber is really useful stuff, it's a great choice for building your compost bins or raised beds.

The 6"x1" provides a decent amount of cover per board. You will only need 6 boards one on top of the other and you have built your compost bin up to 3ft (900mm) high.

Pricing Up

We paid £5.20 for a 14ft (3.6m) length of 6"x1". This was from a timber wholesaler in the north of the UK so prices might vary depending on your area, but it's just to give you an idea.

This is not the total cost of the compost bins as we used some of the 6x1 to make some raised beds in our allotment Greenhouse.

A 3ft x 3ft x 3ft Compost bin will only cost around £40 for the materials, as you can get a good few boards cut from a 14ft (4.2m) length of timber.

You can buy 6"x1" boards in standard lengths, usually, these are - 8ft (2.4mm), 10ft (3.0m) 12ft (3.2m), 14ft (4.2m) and 16ft (4.8m), but check with your local timber merchant first.

We managed to get 4 boards @ 3ft long boards cut from our 14ft lengths to form the sides of our compost bin.

Making the frames

It can often be difficult to determine how big your compost bin needs to be which is why It can be useful to make one frame up. Cut it to the desired height and length you are thinking of and see how it looks.

You can maneuver it into its final position then once you are happy with its proportions you can make the other frames up. You don't want to build up all 3 frames just to realize you made them the wrong size.

If you want the compost bin to be smaller you can always cut more off. Then once you are happy you can proceed to making all the frames.

Once you have determined the length of your planter you can cut the 6"x1" boards to size. Once you have determined the height of your planter you can cut the 3"x2" vertical corner pieces to length.

Checking For squareness

Once you have screwed your frame together with one screw in each corner, you will then need to check that it is square. Both these readings on the tape measure should be exactly the same!

To do this you need to measure diagonally from corner to corner, then repeat the process from the opposite corner to corner. This is shown in the picture bellow

You will need to shimmy the frame around until both diagonal readings on the tape measure are exactly the same, this is how we know that the frame is perfectly square. Then add an extra screw in all 4 corners.

Spacing the 6"x1" Rails

You can use off-cuts of timber to make some spacers, these will go in between the 6"x1" rails and help you to space them up evenly.

We have used a 1"(25mm) Spacer because that is the thickness of the timber we have been using. It also gives us a decent amount of airflow around the compost bin.

Screwing on the 6"x1" Rails

When screwing on your 6"x1" rails, place your screws diagonally away from each other, this helps prevent movement in the frame.

Don't go too close to the edges of the timber with your screws and angle them inwards slightly to reduce the chances of the wood splitting.

I always recommend piloting holes whenever your can!

Assembling Your Frames

Once you have made all your frames you can lay them out ready for assembly.

The two frames on either side of the compost bin are exact mirror images of each other. They have a grove at the front that enables you to slide the boards in as the compost pile increases.

The back panel has two boards fixed in the middle to create another grove, this will allow boards to be slid in to separate the two halves of the compost bin.