Building An Earthship In Darfield, B.C.

We are a family of five living in Darfield, BC.
Our house is six hundred square feet in total and we are feeling cramped.

We have decided to build an earthship!

So starts the adventure ...

Showing posts with label plumbing. Show all posts
Showing posts with label plumbing. Show all posts

Wednesday, July 15, 2009

More supply shopping

Tuesday found us on the way into Kamloops with a list of supplies we needed to complete the perimeter drain for the building, the thermal wrap and the rest of the materials to do the tire walls. We are now on our third row of tires. Sean and Anna left last Saturday on errands in the lower mainland. We sure miss their help! Things go slower without them!

As our tire walls increase in height, we need to start backfilling so that we have a same-level surface to work on. That meant putting in the perimeter drain and starting the thermal wrap. On Monday evening we sat down and made an extensive list of supplies that we needed for Wednesday, which is when we asked Alvin to return and do some trench digging. On our way into Kamloops Tuesday morning Chris hit the cell phone and started to get some prices.

Our biggest learning curve was on what kind of rigid insulation to buy for the thermal wrap. The thermal wrap is the layer of rigid insulation that is buried around the house (to the height of the roof) that contains the heat around the house and prevents any thermal heat we acquire in the house from seeping slowly out into the ground. For a better explanation of this go to Earthship Biotecture at: http://www.earthship.net/index.php?option=com_content&view=article&id=27:thermal-wrap-turbo-charge-your-earthship&catid=49:comfort&Itemid=30

Rigid insulation differs in kind and price. The blue kind is the one more generally accepted for burial. However, we found a white brand that was half the price. Most sales people told us that it was not acceptable for burial. However, we saw a little bit of text on the promotional material that indicated otherwise. Sharon Donchi (who used to arrange log home shows and now works at Home Depot) called the technical rep for this company and it turns out that it can indeed be buried. We however, wanted to achieve an R12 value, which is generally accepted by Code for a traditional basement wall. This less expensive brand was only R8. By the time we ran the numbers the blue brand was still more expensive but probably by only 10-20 per cent. Using the white brand may have been less expensive, but it did have a lower compression value AND it is not generally viewed by traditional building authorities as a product that can be buried. When all was said and done we decided on the blue brand.

Generally perimeter drains are constructed using a product called Big O. This is a black, perforated, flexible pipe that is laid in a slightly sloped drainage ditch around the building. The pipe is accompanied by filter cloth and drainage rock and then buried. The idea is that if water accumulates around and in the ground surrounding the house, it will drain into the pipe and be passed around and beyond the house. However, our family and friends had had issues with Big O collapsing over time so we decided to use perforated 4" PVC. We also decided to install three vertical cleanouts should we ever get a plug up. For us, digging through 10 feet of bermed earth is a bigger issue than with a traditional home! More pictures of the finished drain in a few days!

The PVC pipe was a lesson in going to the specialists. We priced this product at all the big box hardware stores and there was up to a $5 difference in a 10' piece (ranging from $20 locally to $15 at Rona Hardware). As we were driving past Andrew Sheret, I pulled in and Chris came back with a quote of $11.10 per piece. With savings in hand, we started loading up.

Today another volunteer earthship builder arrived. James is from Newfoundland but is moving to Victoria and decided that before he got a job there, he wanted to do a few things, inlcuding help us for a few days. We are glad to have his help and look forward to Friday when Sean and Anna return with their "mate" Josh.

The photos are fairly straight forward but I'm having trouble manipulating them and being able to put captions on them. The trailer shot is of 30 of our 140 pieces of rigid insulation. There are several shots of the drainage ditch and because I'm always behind the camera, Katie took some pictures of me, doing what I do best, apparently: sitting and supervising!

Tuesday, February 17, 2009

Plumbing the Earthship - the Toilets

Black water has been a sensitive topic in our household. Of many of the things we have considered doing this is one item we do not want to make a mess with ... at least not until it is ready to be used!

As you may remember black water is all of the waste water generated by your household that is too contaminated to be considered gray water. Here, contamination does not mean loaded with chemicals, but rather has unacceptable levels of pathogens making it unsuitable for drinking water or irrigation (loaded with feces in our case).

Our sources of black water are the two toilets we are planning to install. Some definitions of black water also include laundry and kitchen sink water due to the possibility of cleaning dirty diapers and the suspended solids contained in them respectively. The reality is that the level of pathogens in these gray water sources is minimal compared to toilet water, and proper gray water treatment is all that is required to handle these nutrient-rich gray water sources. See Create an Oasis with Greywater for a detailed discussion of the pros and cons of various gray water sources.

My initial position for our black water was that we would use a typical toilet hooked to a standard septic installation. I was worried about smell, a messy cleaning job, other people's perception of our toilet ... (need I go on).

Sandra surprised me by telling me that she was considering a composting toilet. Not willing to be left off of the green bandwagon (I am the family composter after all ... and the kids know what sheep manure means to me), we started researching this topic. We have now talked to numerous people who use composting toilets and checked them out in action. I have been converted ... we are now planning to install two composting toilets!

Manufacturers

Our investigation of manufacturers is limited to date, I have been looking exclusively at the Sun-Mar line of composting toilets. Unless another product catches my attention I plan to use their specifications in my house design. Sun-Mar is a Canadian manufacturer (which means I'm
supporting a local manufacturer ... who ironically is setup in Ontario while I am in BC), that has been around for a while and gets good reviews of their products. Down the road if I find another suitable manufacturer I may switch my alliegances.

Which Model to Choose?

A quick perusal of the Sun-Mar website led me to the CENTREX 3000 AC/DC central flush model or a combination of two of the Excel AC/DC stand alone units.

My initial selection of the CENTREX 3000 AC/DC model was based on a simple constraint, its ability to handle the volume of black water generated by a family of five. The central unit
allows multiple toilet connections and it processes the black water centrally, hopefully making it impossible to overload the system. The drawback is that the central unit needs to be installed below the toilets so that gravity and a little water flushes them. This is a problem in an earthship as I will not have a convenient basement to install this unit in. I believe that I can accomodate this unit in a crawlspace underneath one of the toilets. However, this implies digging and building a crawlspace, adding cost and complexity to the design.

I would prefer to install two seperate stand-alone units to minimize cost and system complexity but these stand alone units do not have the capicity required for five full time users. Two stand
alone units installed together do have the required capicity, but how would I ensure that both stand alone units were being used equally, and one was not being overloaded? I can just see myself policing the kids toilet use ...

Chris: Alright Katie which toilet did you just use? (reaching for my clipboard to add notes on monthly loads)

Katie (unhappily): The one in the utility room ...

Chris: And what did you do?

Katie: Dad!

And the kids are only getting older ...

For now I am planning on installing two stand-alone units. Hopefully, their pattern of use will balance out on its own and I will not have to resort to charting the volumes flushed down each one. I think this is the simple option and will prove to be more cost-effective in the long run.


The Plumbing Required

The unit I have selected has connections for a 2" fan assisted stack vent that is used with AC or DC electricity to vent the unit, and a 4" stack vent that allows the unit to be operated without electricity. Given that I always plan to have electricity (at worst 12 volts supplied by a solar system), do I need to install the 4" stack? Can I just make do with the 2" stack vent? For the time being I am assuming that I must install the unit with the 2" stack and the 4" stack.

The unit also has a 1" drain that is required for overflow control. Sun-Mar claims that this overflow is a precautionary measure in case the system is overloaded on a short term basis (Helen's next birthday party with 9 girls and parents?), and will not be used very often.

The drain needs to go to an existing septic field or approved recycling bed. My initial thoughts are to connect it to the existing septic system we have on site, and possibly provide a septic drain line out to an area that could eventually be used as a recycling bed.

Practical Considerations

The first thing I did was sketch out one of these toilets and discover that it was significantly bigger than a standard flush toilet. This meant laying out the bathroom yet again, and while I was in the middle of
doing that I came up with the bathroom layout of the decade. I had visions of CAD students whispering about the brilliance of this layout during Drafting 101! Unfortunately, Sandra did NOT think my new layout
was brilliant. She did not like it, and dashed my hopes of having my name enshrined right next to Crapper ... thank you Sandra!

It did force us to re-think our bathroom layout and we decided to move the second bathroom closer to the living room and put a shower in it. There were multiple reasons for this decision:
  • the two gray water planters now get their incoming water from adjacant plumbing
    fixtures, eliminating the need to move water between the two planters,
  • the bathroom across the hallway from the main bathroom would have required moving gray water under the adjacent hallway,
  • Sandra and I both like the idea of a bathroom close to our bedroom that does not have kids in it.
I have updated some of the pages on my plans page to reflect these changes.

Conclusion

I am still concerned about composting toilets from an aesthetic perspective.

I read in one of the Earthship books that if you consider your composting toilet to be like an indoor outhouse you will not be disappointed.

This is not exactly a blanket endorsement. I am relying on the improvements that have been made to composting toilets since Mike Reynolds wrote about them, as I have seen them and read about them.