So far, on this Earthship, we have used Cob for pack out, mudbricks for some internal walls, chip ‘n’ slip for others, and soon will be starting earthen renders on the walls. The upcoming session will be teaching a lot of these techniques, which will be a 2 week internship working on interiors of the ship. June 22nd – July 3rd.
Cob a very old technique for building with earth. Its the name given to the mixture of clay, aggregate and a binder, that is mixed (by foot, machinery or animal) and used primarily to build walls. It creates a very strong structure when it dries, and can be either load bearing (structural) or infill (between a post and beam structure).
“A cob cottage is the ultimate expression of ecological design. Made of the oldest, most available materials imaginable – earth, clay, sand, straw and water – cob houses are not only compatible with their surroundings, they ARE their surroundings, literally rising up from the earth. They are light, energy efficient, and cosy, with curved walls and built-in, whimsical touches.” Ianto Evens from Cob Cottage Company.
Mudbricks also use clay and straw, but in this technique they are made by pushing the mix into forms 270×270 (becoming 300mm walls with render) and letting the bricks dry. Bricks can be made faster and on a larger scale then cob, often made mechanically, and they are also faster to lay – a builder can lay up to 50 a day on straight walls. Mortar must be made for between each course and between each brick, about 20mm. In NZ we also use geo grid between every 3rd course, and 12 mm reo rods vertically that attach to the footings and join the vegas above. These mudbricks have been made previously in Golden Bay by Solid Earth and stored in the Coromandel, before being transported to site.
Building with earth is a very forgiving medium. If cob dries out, wet and remix. it the walls are splurging outward, saw it off. If the layer underneath is not smooth enough, wet and add another. It can be formed, sculpted, reshaped, changed and coaxed to your heart’s content. Renders are the usual way of finishing the internal walls of strawbale, cob, super adobe, mudbrick, rammed earth and earthship style houses. Three coats are usually applied, a shaping coat (the thickest – up to 10mm), brown coat (smoothing off, 3-6mm) and a final finish coat (2-3mm). Its is always a good idea to test your renders before applying, to get the right mix, which won’t be sandy (too much sand), or crack (too much clay). There is no straight recipe for this, as it depends on your soils, and your choice of binder, the usual mix would be 70% sharp sand, 30% clay (screened as you get to finer layers) and a binder of either chopped straw, wheat paste or casein. Poo optional . Tools vary too, depending on coat, the finish required and materials. Experiment and play are good teachers!
If you are interested in this internship, please email email@example.com and join us in June. Alternatively, if you are interested in Earth building of all sorts feel free to email me at firstname.lastname@example.org. I also hold earth building workshops, or can pass your details onto the right people!
We have set a date for another push, and that will be 2 weeks; 22nd june – 3rd july. We have places for 12 interns, and we will work full weeks. learning will be on the job site, focusing on; earth renders, mud bricks, bottle walls construction and finish carpentry. Sleeping will be off-site (backpackers options or local accommodation), and food not included. $95 per week per person.
If you are keen to join us, please email Gus Anning – email@example.com to register.
Its been an amazing journey, and I look forward to the remaining finishing work over winter.
In a general and quick run down, heres the focus of each of our weeks, from 1 to 10: WEEK 1 and 2 everyone was set to the tyre pounding task, getting 1100 or so in, over 10 courses (layers). Each was leveled, and geogrid was inserted between tyres every 3rd course into the earth berm. Drainage was filled behind, and the waterproofing layer (permathene) was laid under and behind the tyre wall, along with 2 layers of insulation. Week 3 and 4 was after the tryre work was complete and working on getting the slab and bound beam poured. Prep consisted of polythene water proofing under the floor, mussel shell insulation, laying plumbing and ALOT of steel tying. Week 5 was the start of the mud work – both mudbricks for internal walls and cob in the back wall to pack out the tyres. The bond beam was plated, and the wing walls finished. Week 6 was the start of the interior greenhouse framing, bathroom wall framing and working on the front tyre stem wall to recieve the cantilevered greenhouse. Week 7 saw Vegas (roof beams) going on, they were birds mouthed (levelled), cut to size and the back of the building insulated and wrapped. Week 8 saw the roof finally on! Also they grey water cell lined, plumbed, plus the electrical and plumbing inside the building. Week 9 saw the greenhouse built, bottle walls go up in the east and west entry. Also the by-fold doors hung in the west living space. Week 10 the grey water planter cell was filled and the velux windows installed. Plus framing for the bedrooms, the breakfast bar window in. The crew taking a break now, just waiting for glazing and doors hung to be water tight. More workshops coming in April and June to finish the inside.
Updates were posted on Earthship New Zealand (on fb), if you’d like to see more pics please visit the site here
All other queries please email firstname.lastname@example.org]]>
We are nearly 3 weeks into the Earthship build in the Coromandel now, of this 3 bedroom ‘Global model’ inspired home. A quick building site update: Progress is developing before our eyes daily – today finishing our last course of tyres (10 courses of about 75 per course). Cooling tubes are in and buried. Backfill, drainage, insulation are in behind the tyre walls, and water proofing of the east and south wall are done.
I am very excited to be part of a project taking serious steps towards off-grid green building. There are many advantages to Earthships, in its thermal mass qualities, water catchment and recycling, independent solar power supply and contained sewage. But seeing as these building were pioneered in the desert, we obviously need some changes for our climate and building code. Things to address include water proofing details (especially in the floor and behind the tire walls), reinforcement in case of tectonic movement, and design elements (such as vertical glass and eves). Its great to see changes in materials too, like the choice of mudbrick internal walls (rather than cans and cement), old sails used to protect the vapour barrier, and crushed mussel shell as insulation in the floor (with an R value of 2).
Its a privilege to be working with so many talented and qualified individuals on this project, which, in my opinion creates a wonderful petrie dish for creativity and forward thinking projects. Architects, Engineers, TCDC officials (Thames Coromandel District Council), building crew, a digger driver, electrician, plumber, students from 7 countries – all with skills and experiences to add.
I’d like to give special credit to our national and international crew (Ben Garrett, Justin Dudley, Sean Bozkewycz, Brenton Stockman, Peter Larson and myself) who are working to create both a productive work site AND an educational environment. This means the weeks are busy! Quite apart from work hours, we also include guest speakers, Earthship lectures & docco movie nights into our week. Its an energetic site, and a great place to be. Our community wouldn’t be complete without all the extras we enjoy – the Dj’s coming to play, our delicious meals headed by our wonderful chef Loli in the container kitchen and our morning yoga classes from Siests and Mary.
Lastly, a huge thank you to Gus & Sarah and their family for all their work, hosting us on their land and providing such a wonderful base of operations. The work hours put in are enormous, with everything from organizing sponsored clothing (thanks Cactus and Earth, Sea, Sky) to getting the coffee flown in by helicopter (true story). You’re the best guys!
There are still a few last minute places for students on this build, but be in quick, our start date for this build is confirmed at January 12th. Link HERE for all info. Any questions email email@example.com
Just a quick update on the progress of the Coromandel build and Workshops, starting January 12th!
Site preparations are going well with the resent installment of a 7m tipi which will be a chill space for everyone, along with a talking space for some of our speakers (more on that below!). Another 10m tipi will be installed at Christmas, so we have shelter (if it ever gets cold there!) and beautiful places to eat, make music and relax in.
So far we have confirmed:
*Kay Baxter – Kay is a heritage seed saver and has been an organic gardener for fifty years. She is a co-founder of the Koanga Institute in New Zealand and is an educator in the fields of Nutrient Dense Food Production, Regenerative Garden Design and Management. She is a researcher in the field of human health in relation to our environment and has authored many books including:
We invite you to join us on our 8 week intensive Earthship workshop, starting Mid January. The workshop will cover all facits of Earthship design and construction. We have 40 special places to learn from our core crew. The dream team of experienced Earthship builders from around the globe are passing on their knowledge to build a fully approved and functioning Earthship. We will be covering many topics such as Thermal, & Solar Heating & Cooling, Building with Natural & Recycled Materials, Water Harvesting, Storage and Filtration, Natural Flow Sewage Treatment, Finishing Options and techniques including cob & hempcrete, Permiculture design and food production. Solar Electric Systems, as well as the plans and the permitting process and much much more. During this time we invite you to camp on our land and become part of a community. With two tipi on site providing a classroom and communal dining. We have two vibrant chefs destined to prepare the high energy and nutritious meals required to sustain us. Topped off with a deep crystal clear river for daily renewal and a mountain hut climb finale, we hope you will join us on this amazing construction adventure.
REGISTRATIONS ARE OPEN! please click here for an online form.
For more info contact Rosa at firstname.lastname@example.org]]>
One of the key features of earthship is their use of waste materials in construction such as tires, bottles, cans etc. In the Waiheke earthship we are going to use bottles as underfloor insulation. We haven’t heard of any other earthships doing this, however it fits into the whole earthship ethos so I’m surprised that its not part of Mike Reynolds approach. The bottles will be laid on their side in a bed of sand over the damp proof membrane. Another layer of sand will cover the bottles and the spaces between them, and then a concrete pad poured over the top. On top of this we are going to have an earth floor for a more giving and comfortable feeling underfoot than a hard concrete finish.
According to our architect Graeme North, preliminary calculated R values for 100mm thick concrete floors insulated underneath with bottles laid in dense sand is approx. 1.65 m2oC/W and with bottles laid in pumice sand is approx. 2.06 m2oC/W.
This ignores the R value of the earth underneath the slab which varies according to floor perimeter length and with any edge insulation.
These figures have not been fully checked, and are calculated first order assumptions only, with considerable margin for error. The actual insulation values can only be proved by testing.