Turning Trash into Treasure: How to Build a DIY Pallet Compost Bin

It’s my neighbor’s fault I have a pallet compost bin.

I was wandering down to the bottom of the garden to check the progress of my untidy compost heap (and believe me, heap was the operative word) when I saw her slotting together some wood.

A quick inquiry revealed she had bought some slatted compost bins. They were incredibly easy to put together and looked quite attractive too.

Needless to say, I wanted to do things the hard way. Doubly hard, actually. But don’t worry, if you want to make your own wooden compost bin from pallets, I’ll tell you the easy way too.

(Do note this tutorial is for composting larger amounts of waste. If you want to compost smaller amounts, see our tutorials on building a DIY trash bin composter and a worm bin composter. They are free or cheap to make, simple to build and take less than 30 minutes!)

Pros and cons of pallet compost bins

But first things first. Before you invest the effort into making a pallet bin, you need to decide if it’s worth if for you.

Pros

• It’s fun if you like making things.
• Their size and capacity make them excellent for hot composting.
• Slatted edges mean oxygen can get in.
• Cheap! All you need to purchase are screws, hinges and corner brackets.

Cons

• Open-slotted sides mean insulation is lacking, and they don’t do so well in winter unless you insulate them.
• Their sheer size means they are not suitable for smaller gardens with less material to compost. In that case, you would be better off with a slatted bin or a closed bin system.
• Pallet bins can be heavy – ideally, you need two people to collect them, and a decent sized vehicle to put them on.
• They can look unsightly (but see below for a tip on this.)

Still interested? Then read on.

What type of pallets do you need to make a DIY compost bin?

Ideally, you’ll want to find pallets that are roughly the same size.

Then you’ll want to look for certain markings on the pallet. Pallets come with stamps on them which indicate if they are safe to use.

Look out for the marks IPPC or EPAL, as well as HT, which indicates that it has been heat treated, or KD, which means it has been kiln-dried. (These are sometimes combined into KD-HT.) You can read more about pallet marking on Universal Pallets.

Caution: Do not use palettes with the letters MB on them. MB stands for methyl bromid, which is a toxic chemical used as a pesticide. These are illegal in the UK, US and Europe but there are still some around and may be still used in other countries.

You can often find pallets at larger shops or at warehouses, and they are usually either free or very cheap. If not, you can buy them online.

Which is best: Three sided or four-side pallet bin?

You can choose to make either a four-sided pallet bin or a three-sided pallet bin. A three-sided pallet bin offers continual easy access, and you don’t have to faff around with a gate every time you bring a wheelbarrow of waste to the compost bin.

However, I personally prefer a four-sided pallet bin. As the compost heap grows, a fourth side helps keep the structure and allows you to build the compost heap up several feet above the top of the pallet. And as I mention below, you can always leave the gate off in the early stages of the compost heap, giving you the best of both worlds.

How to make pallet bins

The hard(er) way to make pallet bins

(I say harder – it’s still not very hard.)

I started off by getting some palettes. I’m fortunate that we seem to have an endless supply of pallets at work. I dragged my teenage son away from his computer and drove down to the yard at work. The palettes were a bit big for my car, but fitted neatly into the company pool car.

After a bit more sweating (and a lot of complaining from my son!) I had the palettes at the bottom of the garden.

The process from then on was fairly simple.

What you need:

• 3 or 4 palettes, depending on the design you choose
• Spade
• Drill
• Corner Brackets
• Screws
• Drill (a screwdriver is also handy)
• Hinge (optional)
• Latch (optional)
• Saw (optional)

Steps:

1. Level off the ground where you are going to make the pallet bin. If you have a large garden, I’d recommend you choose an area with a lot of space, as this gives you the option to enlarge into a 2 or 3-pallet bin system in the future. Ideally, you’ll place the pallet bin on earth or soil rather than concrete, although this is not essential.

2. Prop up the first pallet. (It’s handy to have a child or friend to help you do this.) I started with the side but you could also start off with the back.

3. Put the second pallet at a 90-degree angle to the first, so that you are forming two sides of a box. It’s helpful to tie them together with string at this point, so they are held together while you add the hinges. (Especially useful if you are doing this alone.

4. Attach the sides together with three corner brackets. (You can use more if you want.)

To do this: Place the corner brackets where you want them. Mark them with a pen or a nail. Remove the brackets and drill a hole into them. Replace the corner bracket over the holes, and use the drill or a screwdriver to insert the screws.

5. Repeat the process with the third pallet to form three sides of a box.

6. Optional stage: I then went on to attach a fourth pallet with a hinge. This was a little bit trickier. I first shortened the pallet by sawing a section off. I then propped up the pallet on a piece of wood. That’s because (especially on the sloping ground) the pallet door would otherwise drag along the soil. Finally, I attached the pallet gate to the side of the pallet with the hinges.

(I did think of attaching a latch but by that stage, I’d had enough. A bungee rope turned out to work nearly as well.)

I thought I had finished at that stage, but due to the influence of my wife, I eventually ended up painting them too.

Do you really need a gate on your pallet bin?

No. In fact, months later a gale blew the gate off. (Don’t make the same mistake I did and leave your gate open.)

I currently leave the gate on the pallet off on the first in my series of three-bin pallet compost system until it gets about half full. I then reattach the gate with a string until the bin is ready for turning into the next bin.

The other two still retain their gates, which is great as you are not constantly opening and shutting them.

Second: The easier way to build pallet bins

Can’t be bothered to mess around with hinges and corner brackets? Then just get strong string or wire and tie the pallets together. I don’t think they look quite as nice as mine (and it may not be quite as strong) but it’s a viable solution for the gardener short of time.

Optional extra stage

You can further strengthen your pallet bin by hammering stakes in between the gaps of the pallet. This will make it super strong. I didn’t personally do this step, but it might be advisable if you are using string or wire to hold your pallets together.

Improving your pallet bin

Insulating your pallet bin

Side insulation

As mentioned earlier, your bin will have gaps in the sides. While this is great for improving airflow, it does mean the pile will be cooler. This may not be a problem in the middle of summer, but this will slow things down in winter.

Some people insulate their bins with wool. But a quicker solution, and one I have used, is simply to put cardboard around the edges.

Cardboard is a great insulator, and it also has the advantage of stopping bits of compost leachate from leaking out of the sides. The cardboard will eventually away, but when it’s on the outside of the compost this can take a surprisingly long time.

I’ve since tried straw, which is a better insulator again.

Covering the top

It’s also well worth covering the top of the compost bin, especially in winter.

This helps insulate the compost, prevents weed seeds from getting into the compost, and stops it from getting too wet when it is raining, and too dry when it is sunny. There are several different options.

Carpet: Great for keeping the compost warm in winter. You can easily find unused carpets at the local dump.
Black plastic: This is great when it’s sunny, as it absorbs the heat. In the winter it keeps rain off but is not as good as carpet for insulation.
Straw: A thick level of straw will help keep the inside dry.
Cardboard: Several layers of cardboard will help insulate the compost, and will eventually rot away and can be incorporated into a future compost pile.

If you use carpet or polythene, it’s worth adding some sticks below it, as this will ensure there is more air trapped beneath.

Don’t worry too much. I left one compost heap open just before heavy rain, and assumed it would be sodden inside. But when I turned it, I found the heat generated had dried the inside out and I needed to add water to the inside of the compost.

With a mature heap, you can also put plants in it. This year I grew tomatoes, courgette and mangetout in my second compost bin, and right now I have green manure in the third one.

While plants may use a little bit of the nutrients up, they can also reassure you that the compost is safe and ready to use, and can be dug back into the compost heap when you are finished with them.

Wiring your compost bin

Another way to stop compost from leaking out is to add wire around your compost bin.

This helps keep the compost bin tidy, but it doesn’t have the warming effect of cardboard.

It’s unlikely to keep mice/rats away unless you also wire the bottom, as they can easily burrow under the bottom or, in the case of mice, squeeze through the holes in the wire.

Painting/treating your pallet bin

I think it’s well worth treating or painting your bin.

The paint helps preserve the wood, so it should last longer, and painted bins also look much nicer than rough old pallets. I’ve only painted mine on the outside, but in hindsight, I would have been better off painting them on the inside before I filled them up.

FAQs

Read more

How to Make A DIY Trash Bin Composter (With Passive Aeration)
Which Compost Bin is Right For You?