Its been a busy scene over here at the island, I’ve been wrapping up the systems in the house and playing catchup on a lot of little chores that have been over looked. But the main reason I am writing today is to share what I have learned while doing the plumbing in the house. Its been surprisingly easy, albeit a bit labor intensive to add plumbing to the Golden Elephant.
I guess we should start with the materials and talk about how the PEX system works. Its fairly straight forward. PEX tubing is a high quality plastic pipe that uses brass fittings and connectors to turn corners, connect to other fixtures and allow for a myriad of custom installation options.
All of the materials needed for an install are available at a large home improvement box store. Lowes carries primarily PEX systems by a company called “Apollo” and HomeDepot carries a brand called “SharkBite”. I have no experience with the Sharkbite system and can not attest to its virtues or shortcomings.
When it came to purchasing materials, I went ahead and bought one 100′ roll of red and one 100′ roll of blue PEX tubing. There are two sizes available and most tinyhouse installations will only need the smaller 3/8ths size. While I was at the store, I purchased a lot of fittings, much more than I knew I would need. I got lots of “T” fittings, 90degree elbows, couplers and a few other random fittings. I didn’t need all that I purchased, but I was able to return all the ones I didn’t use and saved my self a few trips back to the store.
Connecting the tubes is fairly straight forward. The system works with these stainless steel collars that fit over the tube and compress around the brass fitting. It requires a special tool to tighten the collar around the tube. The tool is rather pricy, so its best to see if you can borrow one , as they run about $75. To tighten the collar, place it fully into the jaws of the PEX tool and press the handles together. It will emit a series of clicks as you tighten, don’t be afraid to tighten it all the way. The collar will press the plastic tube tightly against the brass fitting, assuring a leakproof seal.
To connect the fitting to the tube, slide the collar on to the tube and insert your brass fitting all the way into the tube, make sure it seats well on the end of the tube. Then place the collar into the PEX tightening tool and squeeze the handles together. It should look like the photo above when done correctly. PEX is pretty forgiving and the most labor intensive part of installing it is drilling all the holes in the walls for the tubes to run in. Its best to place the PEX tubes under the electrical in the walls, that way, in the event of a leak, you wont have water dripping on to your power cables.
As far as planning your system out, its best to keep things as simple as possible. I had a total of 5 fixtures that the system provided water to. The washer/dryer, the sink and shower and a cold water tap where the toilet is in the event that one day I want to add a conventional toilet. In designing my system, I made good use of this document provided by The Plastic Pipe Institute. It shows several different ways you can design your system. I chose the “Trunk and Branch” design. This was fairly straightforward to install and used the least amount of materials.
I’ve tried to illustrate the system in the above diagram. It might look a bit complex at first but is rather simple to install. After drilling the holes, I ran the tubes for the cold water first. The supply of water comes from this fitting on the side of the house:
It accepts a standard garden hose as an input and has a strainer built into at to filter the water coming in. After the water enters here it goes through the water system I have designed. I’ll go over that system here in a bit. After the water comes into the house, it get sent to the fixtures (sink,shower, etc) through its own cold water branch. One of those branches goes to the instant hot water heater.
The water is heated and then comes out and feeds hot water to the fixtures in the house through red PEX tubing. The two pipes run right next to each other on their way to the fixtures. The diagram above will help illustrate this layout. Connecting the PEX tubing to the fixtures is really a case by case basis. Most sinks, shower fixtures and taps can be purchased with PEX fittings on the end. I had no trouble finding ones that fit right into my system. Since that will vary on your house, I’ll leave it up to you to find the right product. There are several great things about PEX tubing, its flexible so its easy to bend it where you need it to go and because its a flexible plastic, its much more freeze resistant than other plumbing options. It’s simple to add to the system and it’s easy to correct mistakes (you can cut those collars off with a small pair of snips). There are lots of resources available online about PEX and I will try to answer any questions you might have when it comes to your own installation, just leave a comment!
I want to take a bit to talk about the water system I have put together for the Golden Elephant. I spent a few months living in La Casita while Cedric and Andrea were doing some bike touring and learned a lot. La Casita is supplied with water though a garden hose as well and I often found that there wasn’t enough water pressure to run the hot water heater for more than about 30 seconds at a time and that often my water tasted a bit like a garden hose. I have spent some time thinking about how this might be remedied and this is the solution I have come up with:
The system has several functions and is fairly straight forward to install. The input of the unit is designed to be connected to the water inlet mentioned above and the output is a standard PEX fitting for easy integration into your PEX system. The first stage of the system, the strainer, is used to remove any incoming particles in the water that may damage the pump, which is next in the system. The pump senses when water pressure is low and will kick on to add more pressure to the system , it can provide up to 30psi, about what you would get from a city hookup. This pump is self priming and can pull water , meaning that you could draw water from a freshwater tank if a city hookup wasn’t available. The next part of the system isn’t really nessicary but is in place to make sure that you can maintain pressure if you are pulling from a water source that doesn’t provide its own pressure. The pressure accumulator tank can hold the pressure that the pump add to the system and adds additional pressure to to the line and it can also be adjusted for how much pressure it adds.
The next part of the system, the inspection loop, is a bit of clear tubing that allows you to inspect the health of the system and the water thats flowing through it. The final part of the system, the filter, is pretty straight forward. Its standard filter with interchangeable filter cartridges. The ball valves on either side have a few functions. They allow you to cut off water to the filter so that the filter can be changed, they also allow for an easy place to turn off water to the rest of the house in the event that there is a leak .This system will provide nice clean drinking water and adequate water pressure in many situations and makes the house much more adaptable to a wide variety of living situations. Having all of the vital components in the system in a open and easy to reach space (in the Golden Elephant, this system is under the sink) makes it easy to work on and maintain.
I have considered making these system for anyone that doesn’t feel comfortable doing it themselves. The system pictured is our prototype system and our final product has a bit more fit and finish to it. The pump does come in two different models (both AC and DC power) and our finished product is mounted on a heavy duty plastic backplate thats easy to install. Feel free to drop me a line at firstname.lastname@example.org if you would like me to put one of these together for you. (for the cost of parts and labor)
I have been using the water system over the last week or so as I move on to other parts of the build. The water pressure has been good from all the sources and has made for a nice heated outdoor shower after a day of working on the house. This week I have been installing the runs for the integrated stereo system thats going in to the Golden Elephant and preparing for the installation of the air conditioner. I spent a few nights last week making a stainless steel mounting bracket for the Minisplit LG unit. I didn’t get around to getting the unit installed today as I had planned. But have been installing the ventilation fans, working on the porch and finishing some more electrical work today. Feel free to leave a comment below if you have any questions about PEX or about tinyhouses in general. As always, Be well and happy Tinyhousing!