The plumbing rough-in happens before the floor goes down (preferably), which is easier and cheaper to do. It starts with the 'waste water' pipes. During the process I got to thinking about how to make best reuse of water before it went down the sewer.
There are three types of reused water that I will have on site. Greywater (laundry and bathroom), dark greywater (kitchen) and blackwater (toilet).
- Greywater is ideal to use in subsurface irrigation systems, but there is a lot to consider when designing these types of systems. By ensuring that we don't put any nasties into the water in the first place we know that anything that we reuse wont be damaging to the environment, or us.
- Kitchen water (dark greywater) is not ideal for sub-surface irrigation as it contains food particles, fats and soaps that can block pipes and clog the soil. This water can be filtered through a wormfarm to produce a rich liquid fertiliser.
- Blackwater goes directly to the sewer. A composting toilet is a great solution to the 'poo problem', turning 'waste' into a rich fertiliser. I'm interested in exploring this option further. I've often said that "Humanity's greatest contribution to the planet is our shit, we just need to learn how to deal with it." Joseph Jenkins has written a lot about humanure. I got the book recently for my birthday, and am looking forward to finding the time to read it.
All of the hot water pipe are insulated, which means less heat loss and less water sent down the sink while you wait for it to heat up. The water will be heated using 3 methods. Solar, wood fired and gas boosted. More about that later...
Laundry greywater pipe (in background) with kitchen dark greywater in foreground running on a separate line. The kitchen pipe runs outside the building so that water can be diverted to a possible future wormfarm, or straight to the sewer.
Laundry and bathroom greywater run on higher line (middle of photo) than kitchen and (possible future) toilet line (diagonal), keeping greywater separate from dark greywater and blackwater
Greywater diverter (left) that diverts bath and laundry water to either the sewer or a sub-surface irrigation system (not yet installed). All internal water lines run at 19mm (3/4 inch) to allow for better flow rates using a gravity fed system. All hot water pipes are insulated (see left of photo).
19mm (3/4 inch) insulated pipework for woodfired stove wetback. Minimum lift to solar is 1 in 10, so that air pockets don't form in line. Air pockets can cause pressure to build up and vibrations in the line, reducing effectiveness of system.