This article will talk more about plumbing services, options, and how you could plumb any tiny house on wheels. Before we go further, here are some questions we will talk about in this article:

  • How does tiny house plumbing work?
  • Tiny House Plumbing Options
  • Tiny Houses on wheel plumbing on-Grid plumbing
  • Tiny House plumbing Off-grid Plumbing
  • Tiny House plumbing Off-grid Plumbing
  • How to Plumb a tiny house on wheels
  • Basic of Tiny House Plumbing
  • Tiny House Rough-in Plumbing
  • Install Tiny house Water inlet
  • Polar White City Water Flange
  • Install a Water Pressure Gauge
  • Install a Supply plumbing manifold
  • Install PEX lines
  • Insulate PEX lines
  • Install a Tiny house water heater
  • Tiny House drain plumbing
  • Install plastic drain to kitchen and bathroom sinks
  • Install the Bathroom shower 
  • Install the shower drain 
  • Preparing the subfloor for the shower waste line installation
  • Screw on the drain assembly to the shower stall
  • Combine all drains 
  • Finishes Touches

How does tiny house plumbing work?

Whether you are staying off or on a grid, bringing water into your tiny house on the wheels will be by hose or storage in the tank. What this means is that you connect to a water source when you stay in a tiny house. The distribution of this water is by cold and Hotline to the different endpoints. 

Tiny House Plumbing Options

However, with all said installation of plumbing in a tiny house on wheels is very easy. You can easily follow the flow by using the right things from one point to another. You can check the plumbing diagram for a better explanation. Immediately you bring water from an external source into your tiny house on wheels, it distributes through the cold lines to all sections of the house. The most important sections are the washer, shower, sink, bathroom, and water heater. Moreover, you should also distribute hot water from the heater to the other areas.When bringing water into your tiny houses on the wheels, here are some good options :

  • On-grid plumbing: Stay connected to the water source through the water house
  • Off-Grid Plumbing: Storage of water via the water tank

These are the most popular plumbing options for Tiny houses on wheels, however, they come with some pros and cons.

Tiny Houses on wheel plumbing on-Grid plumbing

When you connect your tiny house to the wheel, what this implies is that you are getting your water supply through a house from a stable water source. This source could either be an RV spigot or an outdoor faucet.

Furthermore, since your tiny house on wheels connects and disconnects easily from a water source, this is a credible house plumbing method. 

Tiny House plumbing Off-grid Plumbing

Off-grid tiny house on a wheel, plumbing is a method that is ideal for those who stay off the grid and need to store water in a tank. However, know that storing water means you need to create a space for this water tank in your tiny house. Also, consider that off-grid plumbing is more expensive than on-grid due to the complicated maintenance involved. 

After considering these factors, we suggest that future tiny house-on-wheels builders select on-grid plumbing options. This is the optima we choose because it serves our interests, is affordable, and is perfect for all tiny houses on wheels.

How to Plumb a tiny house on wheels

Tiny Houses on wheels plumbing takes a few days before finishing and you could learn how to do these in a few hours. Here is some explanation on plumbing your tiny house on wheels.

Basic of Tiny House Plumbing

When it comes to plumbing your tiny house, it is in two stages: Finish plumbing and rough plumbing.In Rough plumbing, this concerns the installation of water inlet, routing water tiles via several wall cavities, and connecting different drain pipes. During this process, the pipe installation passes through different areas like the shower, kitchen sink, and other water appliances present.

Moreover, Finish plumbing takes place after the completion of rough plumbing and other interior works. Some of these works include drywall or interior siding. At the finished plumbing phase, supply and drain lines connect to all appliances and fixtures. When the finished plumbing comes to an end , the tiny house on wheels  connects to the main water source throughout the house. Then all plumbing connections undergo a test for leaks.

Tiny House Rough-in Plumbing

All Tiny House on wheels plumbing starts with rough plumbing. A rough plumbing finishes before any insulation or interior sidings . For a supply rough in, we recommend using 1/2 or 3/4 PEX pipes for proper usage . However, in most cases, 1/2 pipes are better. 

The reason for using PEX is that it is affordable, highly durable, and simple to maintain. Also, unlike other pipes, you can install it easily and it doesn’t need many expensive tools. When compared to Copper or PVC, PEX remains the ideal choice. When you start the supply rough in process, PEX piles aren’t connected to fixtures and appliances.

 It is because you need insulation and interior wall before installation. Installing and fixing PEX is pretty straightforward, as you can just download some YouTube videos to get this done.

Install Tiny house Water inlet

Many tiny houses on wheels  integrate into the city through a water house from the main house. Before this , you will need to install a water inlet.

Polar White City Water Flange

For Tiny houses on wheels, we put an RV inlet close to the kitchen and bathroom. This is fine to reduce the cost of using PEX and other plumbing fittings. Also, where the water inlet stays depends on your taste, so there is no right or wrong location. You can find the house’s outdoor faucet between the bathroom and kitchen.

To install an inlet, wrap the plumber’s tape around the inlet threads. You do this using a good wrench, and then tighten the 1/2 PEX Brass adapter. Ensure that the fitting is tight but not too tight to avoid damaging the threads. You could check several online tutorials to help install brass threads. Ensure you install PEX before the inlet because it’s not possible to crimp after installation the inlet .

Don’t forget to use a hole saw to cut the hole big enough for this inlet to fit properly. Ensure you fasten the inlet flange to the siding using external screws. Finally, seal the gap by using spray foam, caulk, and 100% waterproof silicone.

Install a Water Pressure Gauge

It isn’t compulsory to install a water pressure gauge, but recommended. A water gauge can help monitor the performance of your tiny house plumbing in real time. Before you start with the installation, use a PEX cutter to sever the supply line where you intend to fix the gauge.

 You will then install a PEX tee fitting in the area. Also, start installing a brass-to-PEX fitting onto the water pressure gauge using plumber tape and some set of Wrenches. Then, crimp the pressure gauge assembly to the tee fitting.

Install a Supply plumbing manifold

When the water pressure gauge finishes installation , you can create a plumbing manifold. This is a system that distributes incoming water to several supply lines. The water which passes through the manifold passes through plumbing appliances and fixtures in your tiny houses on wheels. 

The easiest way to create a manifold is by branching off the main water supply line using a PEX tee fitting. In my Tiny home, I branched off my supply line and showed a new line to the kitchen sink, Outdoor faucet, shower, and water heater. The best decision is to install the manifold on a 1/2” plywood and attach the manifold to the wall interior using screws. 

Because manifolds have many connection points, there is a high suspicion of future leakages. When you install the manifold on the wall interior, it helps provide smooth access and prevents future freezing.

Install PEX lines

PEX lines installations start at the center of the studs. To install this PEX, use a 3/4” augur and an Impact driver to drill holes into the center of the stud where you are running the lines. To stop yourself from accidentally screwing through PEX lines when working on wall interiors, you should get safety plates over the studs.

Don’t also avoid not to kink your PEX lines when working in tight corners. To prevent this, use 90 degrees PEX parts when necessary. Moreover, have enough PEX to provide enough PEX lines during plumbing connections. Based on my experience, you should have more excess PEX than be short.

Insulate PEX Lines

When you are through with the installation of PEX and all connections remain crimped, insulate all pipes . This insulation process stops PEX pipes from Freezing in the winter  and water vapor from condensing because of temperature differences. For this installation, using a foam pipe to coat the supply lines. You should cut the pipe foams to the length you want and insulate them appropriately. 

Install a Tiny house water heater 

Tiny Houses on wheels water heaters work when you use gas or electricity to power the cold water. This heater has a cold water inlet and a hot water outlet. In my Tiny home, I have installed an electric tank water heater because it is more affirmed than a tankless water heater. 

This allows me to have peace of mind and don’t bother about any potential gas leaks. When you buy a water heater, fasten it using a bracket that comes with most water heaters. Try to install 1/2” brass-to-PEX fittings onto cold and hot water inlets. Connect the dedicated supply line to the cold inlet and another to the hot water inlet. 

Tiny House drain plumbing 

Drain plumbing on Tiny houses on wheels is possible before moving it to a parking spot. Irrespective of when you want to complete drain plumbing, do this for all interior works . Ensure you finish all cabinets and interior siding when moving into drain plumbing. 

Install plastic drain to kitchen and bathroom sinks 

When the installation of draw lines starts, you should use S traps or P traps to stop the greywater smell from entering the home. It’s possible to cut and join these pipes by using a rubber backing and plaster nut. 

Moreover, these traps don’t experience much water pressure like the PEX pipes, however, they can stop water from leaking into your house. To have a tight seal at all joints, get a nut, washer, and threaded ends. With this combination, you have what is a slip joint. When installing slip joints ensure that the threaded part is face up. Also, insert a plastic washer of the same size as the drain pipe. 

Install the Bathroom Shower 

For the shower in my bathroom, I purchased an all-in-one shower stall. You could consider building a DIY tile. While it might not be as attractive as expected, it’s affordable, waterproof, and durable. Let’s now talk about the installation of shower water and fiberglass showers. 

Install the Shower Drain

Buy a shower drain that fits your desired shower stall. The shower drain has a PVC part that allows you to attach a PVC drainpipe to the bottom. We recommend Oatley no caulk shower drain which has a 3” PVC component. These installations of these shower drains should correlate with the brand. 

Preparing the subfloor for the shower waste line installation

To prep your subfloor, you can use a hole saw or jigsaw by cutting a 2” hole in your subfloor to allow the shower drain to fit snugly. When using a 12” Metal drill bit, go straight through the middle of the hole. Continue with the drill through the subfloor insulation till it reaches the subfloor flashing. 

Moreover, go to the underside of the flashing and look for the hole you just drilled. When you find this hole at the core, cut out a 2” hole using a hole saw. Don’t also forget to connect the PVC pipe below by priming and cementing connections. Consider buying it on Amazon for great prizes.

Screw on the drain assembly to the shower stall

To stay in this process, move the shower stall from the hole, then drop the pre-assembled PVC and drainpipe via the hole. Furthermore, place the fiberglass washer on the drain and lower the shower stall. To avoid damage, check for other fittings and loopholes. 

Make sure that this washer stays on the drain. Place the rubber washer on the shower stall opening and tighten the top.

Combine all drains

When you have finished installing all drain components you should combine them into a single PVC line which will change the direction of dirty water. For kitchen and bathroom sinks, use 1/2 plastic drains and drain adapters to connect your plastic drain. When combining all drains ensure the slope of the main drain line to stop water inside the pipes.

Finishes Touches

Once all your drains connect easily to one drain pipe, you can connect extra 10 ‘2” PVC pipes to extend the line.  By dumping gray water away from tiny houses on wheels ,you get the best finishes. 

Frequently Asked Questions

What Kind of Plumbing Does Your Tiny House need?

You could use PEX, PVC, and Copper options because it’s easy to install and because they are durable. Although I consider PEX the most popular plumbing option and comes highly recommended. 

Is a Plumbing vent necessary in tiny houses on wheels?

Yes, you need to install a tiny house plumbing vent because it creates an avenue for air circulation. Since tiny houses are clumsy and tight, a plumbing vent helps with humidity and creates better living conditions.

How much do plumbing services in a tiny house cost?

Plumbing installations in tiny houses cost around $2,800-$7,000. However, labor cost isn’t included so you have to factor it in yourself. This just includes plumbing supplies and since tiny houses don’t need many pipes you are good.

Tiny House plumbing- An easy DIY guide including Costs, Tanks, and diagrams 

Plumbing in a tiny house on wheels is very difficult if you are just starting. But what I learned after learning some strategies about plumbing is that it can be easy. This Guide will explain how to install plumbing in your tiny houses and how you can connect things like showers, toilets, and tanks. We will discuss the cost of installing plumbing in your house.

How does tiny house plumbing work?

There are several differences between a tiny house and traditional houses when it concerns plumbing. They include how the water comes into the house, the optional onboard water tank, and operating a trailer.

What’s special about tiny hisses is that your house is too small and long runs aren’t needed. When designed right, plumbing is easy. You need to take your time when planning so that things don’t get complicated. 

Just like it happens I’m traditional houses, you will need a water supply distributed into your house. The lines coming out of the water heater are hotly supplied into your shower and sink. Let me explain below.

Tiny House plumbing Diagram

If you look carefully, you will notice a vivid layout of all the pipes and drains laid out in your small house plumbing system

Drain Lines

Most water supply lines are with PEX which is color coded. You can buy a roll of some Red PEX or blue colored PEX. Drain lines are not seen under the shower and kitchen sink. Both of these are on the floor and at the bottom of the trailer. They are easily connected to an RV sewer line connection or a Septic tank.

PEX Plumbing Makes Tiny house Plumbing easy

For some time copper and PVC lines usage for plumbing  is difficult to connect and would break at the slightest sign of freezing. These days modern plumbing using PEX can be a good solution.

PEX is a Cross-linked Polyethylene water line and is very affordable. This is perfect for plumbing as it can withstand harsh weather conditions. Over the years, it has become popular and used by many plumbing companies. What makes PEX great is that it’s super easy to quickly connect fittings. These fittings make PEX tubing easy and create a watertight connection. 

Quick connectors,” Push Fittings”  or’ ”Shark bites” curb lots of Appeals. What makes it better is that even when there are errors during connection, you could use a magnet to disconnect the fittings. Moreover, unlike other water line alternatives, you can bend it around the corner. However, avoid exceeding the bend limits and don’t pass 7” in diameter

Tubing Size

When it comes to minimum bend radius and diameter, you need to be careful. The bending radius is 8 times the diameter of PEX. When you overbend the PEX pipe, it deforms the shape and restricts water flow. Don’t forget that when you kink the PEX line, it is necessary to throw it away and use a fresh section.

Tiny House water Hookups

There are two avenues to hook your water up to your tiny house on wheels. One of these ways is short term, while the other one suits long term. For those who want to stay mobile, there is a major challenge: Freezing. Whichever methods you use, insulation is very important. 

RV Water Inlet

The first way to use a spigot as a water source is through the RV water inlet. When using this method, get a safe house as regular ones come with nasty chemicals. For your small house, you can use an RV water inlet to let water enter.


  • Easy to hook up
  • Used in most public places
  • Inlet connects and disconnects easily
  • Perfect for Tiny houses on wheels


  • Highly prone to freezing
  • Can be expensive
  • There are common leaky hose

Direct Connection

This is another option for Tiny houses which aren’t mobile. Although I have used the above method before, it can freeze quickly even at moderate temperatures. However, I have started using a PEX line that is insulating.


  • Doesn’t freeze too much
  • The exterior is very attractive
  • Cheaper than other methods
  • Highly durable



  • Can be rigid when it comes to movement
  • You will need to Bury a waterline
  • Very technical to use
  • Tiny House water tanks

Most people prefer living in their tiny houses on wheels while traveling. If you are in this category, I recommend getting a water tank . It helps make living comfortably in a small house easy. An average American uses about 100 gallons daily. 

Based on my experience living in these tiny houses on wheels, you will need about 11 gallons daily. The water  used to cook, wash, or do other cleaning activities makes it very important for everybody. Ensure you also put your tank over the axis. When pumping water from a  storage tank to a sink, you will need to consider some options m

12 Volt Sink Pump from the water tank

This is a good option when you have a 12 Volt pump to draw water from a tiny house. This is great for cold water because you can easily draw water through the lines.

Simple Foot Pump Sink From Water Tank

If you don’t like the 12-volt pumps, you could consider using a foot pump. This is a simple option that needs just some connections and parts. 

How much does plumbing in a tiny house cost?

Plumbing a tiny house on a wheel doesn’t cost much more except if you hire a plumber. Using PEX is a nice option and makes your drain lines go through short runs. However, if you avoid hiring a plumber, the cost will be small. If not, expect to spend between $100-$200 per hour.

Some examples of plumbing costs of Tiny houses are :

  • Five right-angle robot push fitting $50.50
  • A 25-foot roll of Red PEX: $14.76
  • One Tee style push fitting: $13.44
  • Shower P Trap: $ 4.35
  • PEX deburring tool: $10.96
  • Shark bite Removal Tool: $2.00

The list above isn’t exhaustive and there are many things you need to buy when it comes to water plumbing, Budget about $370 to $ 400.

Additional Tiny house plumbing costs

These factors factored asides the budget of plumbing systems. The primary one is labor, especially when you call a plumber. Hiring plumbing should cost around $100-$200 per hour. The working hours should be between 5 and 10 hours to work on the house. The plumber will work on shower sinks, water heater and drain lines. If you use a traditional toilet you will add some cost, but if you choose a composting toilet, there is no cost.

Moreover, there is a ‘tag fee’ tied to your water and sewer lime which can be expensive. Another cost that isn’t included is the water heater because I use a Rinnai V53e water heater, and I am doing fine. If you are using laundry machines, dishwashers, and bathroom rinks, you will need to add extra material costs and labor.

Tiny House plumbing tips

Because of my long experience in Tiny house on wheels, here are some tips I want to share. The most important tip is to have a shower and kitchen close to each other. With this, you will save yourself lots of work.. Here are some other good tips you should consider : 

Plan your system

A few hours of planning can save you some time. You won’t worry about any issues and headaches.

Consider Venting

It’s very important to vent your plumbing system to allow your drain lines to work perfectly. You can use an in-line air admittance valve which permits you to enter the water line easily. These valves fail because they aren’t perfect all the time. 

Plan your drains

This isn’t compulsory when installing your shower drain line. However, it can be a good way to make your plumbing systems better.

Organize exhaust venting

Ensure you have the right space to vent your exhaust to avoid troubles. However, there could be some problems when your tubes are big. When this happens, buy an externally mounted water heater.

Slope Drain lines properly

You need to slope your drain lines uniquely. If it is too shallow, there will be clogs, if it’s too steep, your solids won’t drain. 

Don’t level your tiny house 

If your tiny house isn’t perfectly level, all drain lines won’t  slip and clogs could happen. You should make sure your skin  drains properly and water doesn’t pool them. An excellent installed drain line will not work if the whole house is off. 

Consider the freezing lines 

You need to take frost prevention very seriously. Whenever possible keep your line on the side of a heated envelope running them within exterior walls vs interior walls. For easy connection of water sources in your tiny hike, insulate and use a water tape m

Have the house shut off

The ideal addition to a plumbing system is a $5 ball valve to help turn off the water in your home. This helps prevent leaks and makes your system last longer m

Carefully cut and deburr PEX 

Push fittings are nice, however, you will need to make sure they are properly cut. This is so that when you push the tubing into the fittings, it seals perfectly. Ensure you use a good deburr tool to make it clean. 

Avoid reusing fittings or tubing

If you must dissemble a fitting, the best thing is to replace the tubing and firing. You will find many brands of fittings rescued and they are very cheap. 

Tankless Hot Water Heaters are your friend 

Tankless hot water can be an excellent suggestion in the plumbing system. These tankers take cold water and run them over a heated coil exchange. This is nice because you can’t run out of water and it isn’t bulky. 

Use RV parts 

RVs have a nice feature that you can use to connect utilities at a campground. You could consider Fresh water inlets, sprayers, RV plugs, and access doors when connecting small houses to the grid. 

Always have access 

Ensure you always have a way to water when in your tiny house. It might not be convenient, but access to water lines is important. 


When it comes to the plumbing system, you need to consider following the guide above. This In-depth information has talked about the various plumbing systems, the cost implications of plumbing systems, and tips that can help you have a leak-free system.