How to water a tiny house

Where’s the water going to come from and what plumbing setup options exist for tiny living? No plumbing is obviously the simplest and easiest option but not quite everyone is ready to live without running water. For those who prefer the convenience of constant supply and constant pressure, hooking into municipal water supplies is very common with tiny homes. The plumbing, water heater and fixtures can all be set up just like any other residence.

If off-grid living is a goal with the tiny structure, then a ground well can be dug or rainwater collection to a freshwater tank can be used. Either of these setups will usually require a pump and pressure tank as part of the setup, along with the appropriate level of filtration for the source. Freshwater tanks come in all sizes and can be very creatively located. From between floor joists to a loft tank with a gravity feed, many tanks will fit under the cabinet.

Tanks do take up space so if water storage is a needed for the build, give it plenty of thought during the design and layout phase. Most tanks are plastic and relatively light, but when traveling with a full tank the weight may become a concern. About rainwater collection, a tiny house has a tiny roof and therefore a tiny water catchment area. In some areas with lower average rainfalls, a tiny house dweller may need to manually refill the tanks or cistern during dry spells. Water is heavy, so ideas like this must be addressed before the build begins.

 A hybrid system is recommended. A hybrid water system combines having a tank and pump with the ability to hook into city pressure. This gives the user both options and the freedom to choose between more options whenever the tiny home is moved.

The Earthwagon has 200 gallons of enclosed freshwater storage beneath the bathroom floor in a dedicated 40 sq ft compartment. We went with a two-pump system, very similar to a conventional well. One pump will actuate with a low-level switch to move water from a cistern, or collection of rain barrels, into the onboard storage tank. Once the fill-level is reached, the pump will shut off once again. There is about a sixty-gallon margin between the two levels. Depending on the usage, this rotation should only cycle a few times per week.

The second pump will keep a smaller 6-gallon tank bladder pressurized. This pressure tank must be designed as a pressure tank or a busted tank in a wet mess is all you will have. Between the rainwater collection and the onboard storage will be basic water filters. After the pressure tank, I purchased a multistage drinking water filter with a small spigot that is plumbed to the kitchen sink. There is also one more filter before the tankless hot water heater that will absorb any minerals before they have a chance to deposit in the many tubes that circulate water through the thing.

Not every tiny house has a shower because some lifestyles don’t need a shower at home. There are plenty of cases where showering at the gym or using locker room facilities provided by the college or workplace is preferable to spending space on a shower. Showers and moreover bathtubs do take up a lot of space and can be fairly costly.

A wet bath is growing in popularity and can be used with a tiny home. This is when the showerhead is hung to spray directly onto the floor of the bathroom into a drain and the shower area has been tiled anywhere water may splash. These can be very ergonomic with small spaces because they don’t require a big walled box to be built inside your tiny walled box. Speaking of, the shower inserts or bathtub inserts are just that. A plastic box that you can sometimes just slide in and hook up the plumbing easy as pie.

Custom shower solutions are as varied as the imagination can allow. Depending on how much you care about the appearance of your shower as well as if you even want a shower, the sky’s the limit. I know of one tiny house that is the master bathroom. It was cheaper than remodeling the old bathroom and it has a large glass walled shower at the back, with a huge jacuzzi tub in the center and a double vanity with a toilet at the front. Like everything else, every tiny house can be customized for any solution.

*Important* - Protect outside pipes from freezing! (Specifically pipes that are exposed to outside air passing from the ground to the tiny house)

A THOW must account for the outside temperature if there is any exposed plumbing between the home and the frost line, or the depth at which groundwater freezes. Depending on your climate, pipe insulation and skirting around the tiny house may be plenty but northern climates must take further measures like using electric heat tape.

This is not so much an issue with water in drain lines, as long as their sloped properly. Properly sloped drain lines do not need insulation. In the case of showers and tubs though, the p-trap beneath the drain may end up beneath the floor and outside the tiny house. The conventional p-trap has standing water that is very susceptible to freezing.

There are two main solutions to keep this from freezing: more electric heat tape or a water-less P-trap. In very cold environments, electric heat tape may be a great solution but can be tricky to install correctly. The water-less p-trap has two rubber flaps in a short vertical tube that open to let the water through but stay pressed together when not draining to create an air trap. Cold enough temperatures can cause moist flaps to freeze, nothing a cup of hot water down the drain won’t solve though before hopping into wash.

Ethan Waldman, founder of The Tiny House, shared a story at the Jamboree of a time in the Vermont winter when the kitchen sink had been left dripping all night. The drip, drip, drips moved too slowly and froze building up in the pipe during the night. Fortunately, after a quick trip crawling under the house with the hairdryer, all was melted and none of the pipes had burst.