@garsett The plans I am working on will be a bit smaller then yours at 24 ft which is roughly 7.38 meters this being the central dome from which all living spaces are to connect. Bamboo is interesting. what we are planning to try is to build 36 radial arms that attach to a central hub mounted on a kingpin. these would allow us to attach our forms which will be 4 x 8 plywood (Very thin) it takes me a minute to compute the metric equivilant but if all should come together as planned then we simply pour the finished air crete into the form and work up to top removeing the previous days form and moving up in layers. The steel is left in place as it creates a semi monoque construction that gives extreme strength to the dome and also allows a conduit for electrical wireing the structure is thus built useing 1 inch steel tubeing bent to form. I was interested in the bender tool but have not gotten any feedback so I as a builder have looked into tubeing benders and they are common and available.
@garsett I think we think a lot alike might help to know the r value of aircrete is impressive. an 8 inch wall is 18. where I live in iowa we get cold it is recomended an R value of minnimum 14. So aircrete has good insulative properties :)
garsett last edited by garsett
Yes, aircrete is great for casting in moulds. I've researched all kinds of existing moulds and have found some interesting and inexpensive ones in India, used for temples. :-)
I also found out that you can use computer cut Expanded PolyStyreen (EPS) to create sophisticated moulds.
Then I also like sacred geometry, access to nature (also in cold climates), and the possibility to move the entire structure (like a yurt), which is possible with bamboo (you can just load an entire dome in a van) and a tunnel greenhouse kit, which at the same time solves the door and light problem of the domes, as the greenhouse lets in lots of light AND serves as temperature buffer.
All this is quite inexpensive, quick to build, eco- and people-friendly.
But what to use to cover the bamboo skeleton?
Hajjar actually gave me the idea to use a 'dome fabric' with a beautiful design. This is perhaps good for a warm climate, but I'm looking for insulated versions — or perhaps layers — for where it gets cold.
I think I've found a company that is willing to produce such 'dome comforters' with 7 integrated round windows (for the first floor which mainly serves as bedrooms) and 2 openings for the greenhouse and a large window. Re: natural materials there's still some research to do, and I have no idea yet of the price.
It should be possible to quickly tie the comforter to the bamboo structure with velcro straps.
Two domes with a greenhouse tunnel between. I love the idea. I think I may steel your idea. Reminds me of an earthship. It could also serve as an air lock for entering the occupied space preventing the complete dump of air in the living space.
We are planning to use night sky Radiant Cooling/heating in our dome. Not sure if it will be using the slab or water to store the heat/cooling. As I consider the build it seems like more insulation is needed for a proper off grid solution. I want avoid chemicals such as foam ect. So that leaves making thicker blocks or a dome over a dome and filling it with something like wood ash, wool, or perhaps cellulose.. Any ideas?
garsett last edited by
night sky Radiant Cooling/heating
Interesting! Will study. :-)
@HandyDan brilliant thoughts. speaking of earth ships. There is a science that I have done some considerable work on. Its called Anaerobic Methane bio digestion. I really make the worst vidieo's lol but Any one that has interest I can confidently say I can get you going on tgis. Whats more Domes are ideal for the process. here is a link. It will take you from start to finish. I have been working at this since 2008.
If you couple this with many other technologies, including solar, and you not only have the dome but you don't need to worry about the power lines. They tell me it can never be and they fight such know how tooth and nail. Alas, I say It's no longer reasonable to march to their tune. Do what you can and will.... :)
Brian I'm waiting for part 2 and 3 of the video.
Our location is off grid. It's not possible to connect to any service and even if it was I would not want to. Every situation is different and needs adaptation. Here the sun shines most of the year and it's very windy when no sun shines. Wee always have plenty of energy. A smart programmable charge controller diverts power and heats water instead of floating & degrading lithium batteries. In the winter when sun can't heat our slab or water mass we plan to use the excess wind power (breezy 7 kw) to heat the slab/water tank.
Cool tubes are also an option and we may include at least the hook-up for it. I burried a data logger as well as hung one under a tree and at 2 feet (8 feet recommended) the temperature is almost exactly the average of the days high and low. This hits the acceptable zone of temperature for me most of the year. However, for 3 weeks it's gets too hot (92°F) and another 3 weeks it gets to cold(54°F). My conclusion is that both thermal mass and insulation, as well as active heating & cooling are a must for my location.
The great thing about night sky radiant cooling is the fact that it uses a 45 watt circulation pump. Very reasonable energy usage.
I think 12 inches of cellulose between 2 dome shells may be the more cost effective way to achieve a truly energy efficient building at as low a price as possible. Of course this makes the building price less reasonable.
garsett last edited by
@HandyDan ! We're looking into 2 canvases; the inner canvas has edges that can carry insulation.
The outer canvas (poly-cotton or poly-hemp) can be very colourful.
@Brian-Spooner Did you find a good bender?
@Brian-Spooner Is your video about bio-digestion still available?
Kwagga last edited by
@garsett I am interested to know how you got on with using forms for your build. It seems to be the way to go, but given how liquid aircrete is, I wonder if the simple plywood forms suggested may just leak and not be effective.
Could you share a link to the Indian forms you reference?
@Kwagga Of course they would leak if not sealed.
Kwagga last edited by
@HandyDan Clearly. Thus, the question is, given that the foam collapses under pressure, therefore requiring shallow pours and thereby creating layers: how does one create a sealed form that is fit for purpose? It is imagined that it would be best conceived as either a multi layer form that is added to layer by layer, or a form that can be raised and adapted to the next level.
Having no form work experience, I do not have the answer.