Plumb Tuckered Out: Tiny House Plumbing

Long time no write. Things have certainly been busy! Just, not so much house-wise.. Though I will say we’re currently we’re working on the walls! I’ll get to that in another post, but for now let’s focus on tiny house plumbing.

Plumbing. Where on earth to start? First, we had to determine the piping layout/design. We finalized where we wanted our tub to be (whatever we end up using) and chose the definitive spots for our bathroom and kitchen sinks.

P1020828.jpg
We’re not using this cabinetry, but this is the basic layout of the back of our house. The dark cabinet on the left front is the divide between the bathroom and kitchen walkway. It also represents the size of the bookshelf we plan to install on that bathroom wall for food storage. On the right you can see the L-shape of the kitchen. The metal containers in the back right corner are for water storage and filtration.

We also determined what sort of water pumping/filtration system we would be using. Being that we are considering going off-grid sometime in the future, we were looking for a system that minimizes our electrical usage, and preferably does not require in-line water pressure. We found a few gravity powered filtration systems that seemed to fit the bill. We decided to go with Berkey water filters. Berkey makes a kind of water filter that has been shown to be so effective it can remove protozoa, trace minerals, bacteria, and even viruses in the water. Being that viruses are so incredibly small, this is a very impressive feat for a filter that only requires gravity to operate. We’ve also read that a lot of tiny housers have used Berkeys for its convenience and safety, which helped back up our decision.

Our plan is to rig up a stainless steel tank with about 4-6 of these filters (since the number of filters increases the amount of available water). This tank will drip into a large 40 gallon fresh water holding tank that we’re going to store in the dead space in the corner of our kitchen. Most people don’t realize that this is prime real estate in galley-style kitchens! Many big homes have a lazy Susan (or a corner pantry), but since we don’t need one, we can use this space to store our water filtration.

P1020817.JPG
Water will enter the house from an input near those containers. It will travel to a pump under the sink that will connect to the top filtration basin. The gravity-fed filtration system will fill the bottom barrel with fresh, clean water, and then be fed to the rest of the house from there.

After all that was figured out (which took a boatload of research), we then had to determine what materials we wanted to use for our piping. We knew we were against using CPVC because of the chlorination process and the use of pthalates and heavy metals needed to produce the pipe. We also determined copper wasn’t that great either because it could leach copper into the water supply – and while this is good for anti-bacterial applications, our water would already be pure because of our pre-filter. High copper has also been connected to Alzheimer’s and other related cognitive conditions, so we figured we wouldn’t take our chances. Besides the possible health concerns, a few studies have found that copper pipes have been failing far sooner than previously expected because of premature pin-hole leaks.

We would have loved to use stainless steel, but not only could we not find any, what little we did find (for like dairy production and such) was way too expensive and hilariously difficult to work with.

So we turned to PEX.

(Warning: mildly intensive chemistry discussion for the next few paragraphs. If you’re into that kind of stuff, stick around, if not, scroll down to the picture of the PEX pipe.)

For those of you who don’t know, PEX is a fairly new plastic piping product. The fact that it was plastic made us discount it almost straight away at first, but the more we looked around, the more we learned about it.

We initially hesitated on PEX because we’ve read a great deal of research about plastic leaching harmful chemicals into drinking water. This is to be expected with almost any product, plastic or metal. However, there is no 100% conclusive way to determine what will end up in your drinking water through your pipes, or even where it came from in the first place.

PEX, however, is a little different than other plastic pipe products. Unlike PVC, which is one of the most toxic plastics out there, PEX is made from LDPE, which is #2 plastic. Several types of food-service containers are made out of this sample plastic, and as far as plastic goes, this type tends to be pretty safe. However, even if LDPE is a fairly inert plastic on its own; the toxicity of a given plastic has less to do with what type of plastic you’re using and everything to do with the additives.

PVC, for example, is rather brittle or soft and rubbery depending on what it is used in. In order for PVC to have any of those properties, additives need to be mixed into the plastic and chemically bonded with the plastic in order to reinforce it and prepare it for sale as a certain product. These PVC additives can very often be hormone-disrupting chemicals that can throw off human biochemistry, or the biochemistry of chemical-sensitive animals. Sometimes these additives can even be heavy metals like lead.  In the case of PVC, the additives are typically loosely bonded to the plastic, which means they can fall out of the pipe into drinking water.

PEX stands for “cross-linked polyethylene”, which means “plastic that has been chemically bonded to itself”. You don’t need to know how this process works, but suffice it to say, this plastic is produced by making plastic arrange itself into a shape like a roll of chain linked fence. This can be done by either adding chemicals to the raw plastic, or, even better, by irradiating it with a high frequency light. This final type of PEX is called PEX-C, and has recently replaced copper and PVC piping in terms of availability, ease of use, and, best of all, cleanliness!

We found a recent study headed by Dr. Andrew Whelton of Perdue university that tested several different types of PEX pipes and seemed to demonstrate that PEX-C pipes were more resistant to abrasive chemicals used in water treatment, leached fewer chemicals and less harmful compounds than other types of PEX pipes, and proved to be more chemically inert overall. Not only were there fewer chemicals used in its production, but fewer of them made it into the drinking water! This sounded perfect to us after several weeks of botched research.

P1020881.JPG
Hark, PEX plumbing! These are the outputs in the bathroom under the sink. (The cardboard thing above it is a window. To the left of that is the bathroom fan.)

Now we had the hard part done. It was time to install everything! We drilled 3/4” inch holes in all of the studs where we wanted the pipe to run. Another great feature of PEX is that it feels like playing with LEGOs. It can be cut with a simple utility knife, and it can be bent around corners without fittings. We bought a few 90 degree bend moulds that allowed us to bend the pipe and keep it held at that angle whenever we needed the pipe to stick out of the wall or curve around a corner.

P1020876.JPG
Still in the bathroom – the pipes on the right head up to the shower. Not surprisingly, red is for hot water, blue for cold. Keeps things simple.

The fittings for PEX are also hilariously toy-like. Shark Bite makes a fitting that you literally just push onto the pipe for a permanent fit. Kinda like tinker toys. However, we went with crimp fittings from Viega because they are made with an even lower lead content than the low-lead fittings sold off the shelves these days. Crimp fittings are only slightly more complicated and require a vice grip to install, but they go on very quickly and without much of a fuss. We were able to pick them up locally from a Ferguson plumbing supply store.

P1020855.JPG
Our special PEX plumbing fitting tool. we clamped it together with a vice grip.
P1020859.JPG
This tool had a nifty way of checking to make sure the attachment was tight. If it around the ring, like this one did here, then it was secure.

Wherever we had an appliance, we installed a support plate that installed between the studs and provided a hole that the protruding pipe could rest on for support. This makes it so the water pressure doesn’t vibrate the pipe so much that it gets damaged. We also added foam insulation around our hot water lines.

P1020883.JPG
Not that you can tell, but there’s a camouflaged red pipe in there somewhere.
P1020984.jpg
The shower handle at the top and the tub faucet/handles below. The random tubes everywhere are actually starting to look like they’re there on purpose!

And now that’s mostly done! We left a pair of pipes hanging out of the wall for the hot water heater that we will attach once the wall where the heater goes is installed. All that’s left now is the drainage system, which we can install once we know the dimensions of our tub

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s