02 Mar How to build a composting toilet in 5 simple steps
Got an off-grid outdoor place to host on Campanyon but don’t know how to deal with the lack of plumbing? Here’s a safe and sustainable solution. I’s called a composting toilet. These things make a daily visit to the restroom better and cleaner than you can image, because they don’t waste water nor leave a foul smell. Here’s how to build a composting toilet in 5 simple steps.
What you need to build a dry toilet
Building a dry toilet doesn’t require constructing experience, but it does take some consideration. Some might find the idea of pooping in a bucket offensive, so this design keeps said bucket out of sight. Here’s what you need to make your own inoffensive composting toilet.
- Two hinges
- Steel screws
- Plywood plates
- Wooden planks for legs
- Toilet lid with bolts
- Bag or bucket and scoop for sawdust
- 20L bucket
- Sawdust (or other composting medium)
Finally, you’ll need a few basic tools. A saw, chisel, hammer, and screwdriver will do. Having a jigsaw and power drill will make the job a little easier and much less time-consuming.
How to build a composting toilet
Follow these 5 steps to build your own dry toilet.
1 Make a plywood top
Start by marking out the outline of the bucket on a squarish plate of plywood you’ll be using as a top cover. Leave an extra 20-30 centimeters of space between the circular outline and one end of the plate to later fit hinges on. Then use a chisel and hammer to carve out the outline to exactly fit the bucket. (Alternatively, use a jigsaw for much less manual labor.) The better the fit, the less chance of spillage when using the dry toilet.
2 Add a Toilet Seat
Take your plywood top and fit a toilet lid over the hole. On the side with extra length, use a pencil to mark the bolt holes that secure the seat. Then take a screwdriver and hammer (or power drill) to gently drill two holes that are just big enough for the bolts to fit through. Any bigger and the toilet seat will wiggle.
3 Construct legs
Now that you effectively have a pot to poop in, let’s give it a frame for toilet-goers to sit on. Construct the frame by making L-shaped legs out of wooden planks and screws. Note that the legs need to be the same height as the bucket so that both the legs and the pot rest firmly on the ground.
Secure the two rear legs under the corners of the plywood cover with screws. Don’t screw the front legs onto the plywood top because the front part of the cover will become a trapdoor.
4 Cover the frame
With two rear legs securely in place and the other two freestanding in position under the toilet cover, mark the outlines for four plywood tops to cover the structure and form a closed box. Once sawn, screw the plywood plates onto the legs. With the front legs secured too, your dry toilet is almost done.
5 Build a trapdoor
Lastly, saw through the width of the top cover’s rear end. Screw two hinges over the gap to create a trapdoor. This way, you can take out the humanure bucket when it’s full and empty its odorless contents for further composting.
The right composting material
With your composting toilet ready for action, the one crucial missing piece is the composting material. You can pick a composting medium based on what you have available, as long as it’s carbon-rich and has a fine texture so that it covers human droppings well.
The material needs to be absorbent but still porous enough to let air through. Too thick material won’t compost well. On the other hand, a too fine composting material won’t control odor. Sawdust is a tried and tested composting method––but don’t use any with chemically treated wood.
How to use a composting toilet
Before the first use, fill the bucket with a layer of about 10 centimeters of sawdust or other composting material. Place the composting material in a bag or bucket together with a scoop next to the dry toilet. Each time after usage, cover your droppings with a scoop of sawdust. Use just enough composting material to cover and not more. Once the bucket is full, take it out and empty it into a larger bin for further composting.
A composting toilet takes both solid and liquid waste. Toilet paper goes in too, but nothing more. Always keep the lid close in between uses and no smell should arise. If it does, you’re either not using enough composting medium or the material you’re using does not contain the smell.
Is humanure compost safe to use?
Composting turns everything to soil. This process happens at temperatures high enough to kill nearly any pathogen humans excrete. When humanure is composted well, it should leave nothing but fertile and odorless soil––but that’s in a year’s time and if all goes according to plan.
If you’re not an expert composter, we recommend using the compost from your composting toilet only for non-edible plants and fruit trees.
Now that you know how to build a composting toilet, all that’s left is making a regular deposit. And while the basics of composting humanure are a piece of chocolate cake, you would do good reading more about the composting process before putting yours to use in the vegetable garden.