How to Build a DIY Urine Diverting Composting Toilet?

Urine diverting composting toilets can reduce household water consumption by up to 30% and improve nutrient recycling.

This sustainable solution is gaining popularity for its environmental benefits and practical use, especially in off-grid or tiny home settings.

In this guide, we’ll walk you through the steps to build your own urine diverting composting toilet, providing a detailed and straightforward answer to the question: How to build a DIY urine diverting composting toilet?

Materials needed

Before you start building your DIY urine diverting composting toilet, gather the following materials:

• 5-gallon bucket as the primary container for solid waste.
• Plastic urine diverter to separate urine from solid waste.
• Straw or sawdust as a cover material to reduce odor and aid composting.
• Garden hose to channel urine into a separate container.
• Plumbing hardware that connects the urine diverter to the garden hose.
• Cotter pins and zip ties to secure components in place.
• Caulk and rubber washer to Seal and prevent leaks.
• Screws and knob for attaching parts securely.
• Wooden box or alternative support structure to support the toilet seat and bucket.

Each of these materials plays a critical role in the construction and function of your composting toilet.

Preparing the components

Cutting the hole for plumbing hardware

1. Mark the spot: Identify where you’ll cut the hole in the side of the 5-gallon bucket for the plumbing hardware. The hole should be located near the bottom of the bucket to allow urine to flow out effectively.
2. Cut the hole: Use a drill with a hole saw attachment to cut a hole that fits your plumbing hardware snugly. Ensure the hole is clean and smooth to avoid leaks.
3. Install rubber washer: Place a rubber washer around the hole inside the bucket to ensure a tight seal when you insert the plumbing hardware.

Preparing the urine diverter

1. Purchased diverter: If you have a plastic urine diverter, ensure it’s the correct size to fit inside your bucket. Check for any manufacturer instructions for installation.
2. DIY diverter: To save money, you can make your own urine diverter:
   • Cut the bottom: Take a second plastic bucket and cut off about an inch from the bottom.
   • Split the bottom: Cut the bottom into two semi-circular pieces.
   • Connect pieces: Use a cotter pin and rubber washer to connect the pieces, creating a slight V-shape.
   • Drill holes: Drill holes in the sides of the bucket where the urine diverter will be attached.
   • Attach diverter: Use zip ties and screws to secure the diverter inside the bucket at a slight angle, ensuring urine flows towards the plumbing hardware.
   • Seal diverter: Apply caulk around the edges of the diverter to seal any gaps and prevent leaks.

Assembling the toilet

Attaching the plumbing hardware

1. Insert plumbing hardware: Insert the plumbing hardware through the hole in the bucket. The hardware should extend inside the bucket, allowing urine to flow out through the garden hose.
2. Secure hardware: Use screws and a rubber washer to secure the plumbing hardware in place. Tighten the screws to ensure a leak-proof seal.
3. Check for leaks: Before proceeding, pour a small amount of water into the bucket to test for leaks around the plumbing hardware. Tighten screws or add more caulk if necessary.

Installing the urine diverter

1. Position diverter: Place the urine diverter inside the bucket, ensuring it directs urine toward the plumbing hardware.
2. Secure diverter: Drill additional holes if needed and use zip ties and screws to attach the diverter securely. Make sure it’s stable and positioned at the correct angle.
3. Seal diverter: Apply a generous amount of caulk around the edges of the diverter to seal any gaps and ensure no leaks. Let the caulk dry according to the manufacturer’s instructions before using the toilet.

Final assembly

Attaching the garden hose

1. Connect hose: Securely attach one end of the garden hose to the plumbing hardware. Use clamps if necessary to ensure a tight fit.
2. Direct hose: Route the other end of the garden hose to a urine-holding container, which can be a separate tank or jug designed to handle liquid waste.

Installing the toilet seat

1. Prepare seat: Choose a plastic toilet seat that fits well on your bucket. Ensure the seat has a lid to cover the waste when not in use.
2. Secure seat: Attach the toilet seat to a supporting structure, such as a wooden box, which can house the bucket and provide stability. The wooden box should have a hole cut out on top to fit the bucket snugly.

Creating a supporting structure

1. Wooden box method: Construct a wooden box with a hole on top to fit the toilet seat and bucket. The box should be tall enough to accommodate the bucket and provide a comfortable height for sitting.
2. Alternative methods: You can also build a frame or attach the toilet directly to a stable surface inside your home. Ensure the structure is stable and secure to prevent tipping.

Using the composting toilet

1. Using correctly: Always sit on the seat to ensure urine is diverted properly.
2. Separate waste: Keep urine separate from solid waste to prevent odor and enhance composting.
3. Add cover material: After each use, cover solid waste with straw or sawdust to reduce odor and facilitate composting.

Maintenance and cleaning

Emptying the waste bucket

1. Monitor level: Check the waste bucket regularly and empty it when it’s about 2/3 full.
2. Transfer waste: Move the contents to a larger compost bin to continue the composting process.

Proper composting

1. Curing Compost: Allow the compost to cure in a bin for at least a year, ensuring it reaches high temperatures to kill pathogens.
2. Using Compost: Once fully composted, the material can be safely used as fertilizer in your garden.

Cleaning tips

1. Regular cleaning: Clean the toilet regularly with vinegar to prevent odors and maintain hygiene.
2. Avoid water: Do not pour water into the toilet to avoid making the compost too damp.

Final thoughts: DIY urine diverting composting toilet

Congratulations! You’ve successfully built a DIY urine diverting composting toilet that is both eco-friendly and efficient. Not only does this project contribute to sustainable living by reducing water usage and recycling nutrients, but it also provides a practical solution for off-grid and tiny home settings. With your new composting toilet, you’ll enjoy the benefits of a low-maintenance, odor-free, and environmentally responsible waste management system.

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