Tiny House Plumbing

Tiny House Plumbing

Plumbing is probably one of the scariest parts of any build, especially when you have zero construction experience (like me). I’ll take you through my Tiny House plumbing, but keep in mind that there are several ways to do this depending on your preferences.

One thing to note before we get started: my set up is simple. I only have one shower and one sink. I do not have a washing machine, dishwasher or bathroom sink. My toilet is a waterless compost toilet.  My system is set up to be on-grid or off-grid and to be water conscious.

Alright, are you ready? Let’s dive into Tiny House plumbing!

To understand this article, you’ll need to learn the following terms: off-grid, on-grid, fresh water, greywater, and black water. Don’t worry, I’ve defined them all below.

“Off-Grid” VS. “On-Grid”

What do these terms mean? Off-grid means that you are NOT connected to city water and that your system is self-contained. You might be off-grid when dry camping or parked on a  piece of land without city connections. On-grid is when you are connected to city water, such as in an RV park.

I have both off-grid and on-grid options in my tiny house, which I recommend for flexibility in parking. Of course, if you will always have a city water connection, having an off-grid system is not necessary.

First, let’s discuss fresh water for both off-grid and on-grid. 

Fresh water is the water you use for drinking, cooking, showering, toilet, washing dishes, etc. 

My “Off-Grid” fresh water system

First, let’s talk about my off-grid fresh water system. For water storage, I fill a 46-gallon water tank, which is secured under my kitchen counter. I fill this tank by connecting an RV drinking hose (or carrying jugs of water) to my water inlet.


The average American uses between 80 -100 gallons of water a day, so it’s good I am not “average.” I use about 10 gallons of water a day. When I am off-grid, I fill my tank every 4 days.

My Water Inlet

Now that we’ve gotten water into the house, how does it work?

To heat the water, I have a tankless propane water heater, which is extremely efficient. Read more about it here. For off-grid water pressure, I use a water pump. The water pump runs on 12V and the water heater requires 12V to spark and to protect itself from freezing. My house is wired for 110, so I have a 12V converter to run these appliances. These elements can easily be powered by a gas generator or solar power when off-grid.


 

Our 12V Converter

My “On-Grid” fresh water system

When I am “on-grid” (connected to city water) I simply connect my RV drinking hose to the supplied spigot and there’s no need to use my water tank or pump. In the winter, I need to use a heated hose and insulated spigot. More on Tiny House winterization here.

Once the city water pressure was so strong it actually broke my inlet! Since then I’ve replaced my inlet’s plastic fittings with brass ones, and I’ve purchased a pressure regulator.

The plumbing choice for tiny homes is PEX. It’s DIY friendly and lightweight. You will need the PEX piping,  crimping tool, brass elbows and fittings to do the jump yourself.


As a note, I also use a low-flow shower head to conserve water. I have not found this to be a problem when washing my hair. I’ll also mention that the water pump I initially bought (pictured below) can be a bit loud. I ended up replacing it with this more expensive and quieter water pump. Both work fine, but if you want the quieter version, go with the one I just mentioned.

Water pump

Greywater is the water that drains out of sinks and showers

Greywater is not necessarily waste. I use biodegradable products for my soaps, shampoo, conditioner, lotions, etc. My greywater consists of these soaps, my body oils, and food products diluted with fresh water. If I had my own land, I would create a drainage system to use my greywater for irrigating my garden, similar to Art’s tiny house system. It’s a great way to recycle!


When I’m off-grid, I use a portable greywater tank. If I’m on-grid, usually at a campground, I connect to the sewer system with an RV sewer hose.

grey water tank

Portable greywater tank

As with fresh water tanks, greywater tanks come in all shapes and sizes. Mine is only 15 gallons, so I have to dump it once a day. I’m actually glad it’s small because I can empty it myself (it weighs almost 100 pounds when full).

How to dispose of greywater when Off-grid

Where I dump my greywater really depends on my location. If I’m on at a national park, I dump it at the allocated dump stations. Dump stations are also sometimes available at rest stops. If I’m in a residential neighborhood, I dump my greywater in the nearest sewer drain or I ask my host if I can use it to water their grass. If it’s raining outside, that’s a good time to dump! Any smelly food product is easily washed away by the rain. Consider it this way, most people wash their cars in their driveway. The soaps they are using have chemicals that are substantially more harmful than my greywater.

*As a note, dumping greywater is not legal everywhere. Research your location and use your best judgement. 

Drain

Greywater drain and portable tank

Black Water is the waste water from a toilet

I don’t have this because I use a composting toiletNo, it doesn’t stink. Read my full review.

I did plumb a fresh water line for a possible flush toilet addition in the future (in case I sell my house one day). You can see that above my toilet in the below photo.

toilet thgj

Nature’s Head composting toilet

Dumping black water

This is a very unenjoyable process. You will need to install a black water tank on your tiny house, and then pay to have it pumped out or drive it to a dump station and do it yourself. You can also bypass your black water tank and connect to the sewer via an RV sewer hose. 

Guess how you know when it’s time to dump? Smell….

I’m told that the average full time RVer has to dump their black water every two weeks. I dump the solids in my composting toilet every 3-4 months. I don’t have much more to say about black water because I don’t have it. My suggestion is to go waterless with a compost toilet. 



YOUR TURN: How did you handle Tiny House Plumbing?

Follow:
Share:

65 Comments

  1. Grace
    June 1, 2017 / 2:48 pm

    What do you do with your gray water tank when on the road? Do you just throw it in the back of the truck or do you have it secured to the bottom of the trailer somehow?

      • snu
        June 25, 2017 / 6:02 pm

        Hello there,
        thank you deepbottomheartedly for sharing the details of your plumbing set-up!! so much appreciated (me also noo building experience:D). You say, that when you are on grid you connect a hose to a supplied spigot – would that be a different inlet than for the H2O-tank or is there a different way how you skirt your tank and pump when on the grid?
        also, i am wondering how you fill the tank when carrying water – do you use a funnel?
        <3

      • June 27, 2017 / 10:38 am

        There is a different inlet hole for the tank and simply connecting to city power. If look at the photo of the inlet, you will see two holes – one for the tank and one for bypassing the tank/pump and simply using city water and pressure. You can fill the tank by connecting to a hose or carrying jugs with a funnel. Hope this is helpful.

  2. raphaelberrios
    May 10, 2017 / 8:50 pm

    Although it relates more to your electrical system, how did you wire the 12v converter? It looks as though you have run standard romex to the AC supply end of the converter. Is that just running to a breaker in your AC panel? I am in the process of trying to set up a similar system and having trouble finding information on how to safely get it all wired. Thanks

    • May 12, 2017 / 9:34 am

      I’m sorry, but I don’t really remember. Also, Guillaume did this, with maybe some help from our electrician. I think it’s pretty straight forward, but I can’t answer this question.

  3. February 16, 2017 / 8:45 am

    Where did you get your tub? I’m looking for something similar.

Leave a Reply