Brad Davies wrote:There are probably as many green building techniques as there are green builders. Concrete is definitely not necessary for all of them there's cob, rammed earth, log homes, Wofati, tires, stone, and many more that I don't know about. Really depends on what you have, and what your goals are.
Nicola Marchi wrote:
As an architecture student, I can comfortably tell you that concrete is the only standard code compliant foundation material you can use without an engineer's specifications to bring to city hall now a days.
Rob Viglas wrote:Cordwood building can be done with cob and many of the buildings have glass bottles incorporated in the walls so I would think it would work with plastic ones, especially if they have some sort of texture for the cob to key into. Perhaps doing some small test samples would be helpful?
My search in building without concrete lies in the foundation. I used a rubble trench foundation with a concrete beam on top for my straw bale house and if I had to do it over I would probably use earth bags on top instead. Then there are wooden pier foundations but I would think there would be a need of larger framing members for the floor if you were to put a lot of weight such as cob or straw bales on it. Any thoughts or experience in this aspect of building without using concrete?
L. Jones wrote:
Many alternative foundations only work well for a reasonable time in dry climates. You can minimize concrete use with a rubble trench and bond beam, but the only way to eliminate it (IME) that works well in wet places is the wooden post foundation or the treated wood wall foundation - and then you have rot or preservative issues, as well as drafts, frozen plumbing and animals under the house issues. Charred black locust posts might do if you can find a good source of large black locust. Works well for sheds without plumbing to deal with.
I suppose I am skipping over dry-laid stone, which is a drafty foundation and expensive, time consuming and not trivial to acquire the skill to do well enough to put a house on. In most parts of Vermont you should at least be able to find material without looking too far, though it may not be good material for the purpose. Glacially processed rocks don't stack well, on average. If you plaster it to keep the drafts and rodents down or build with mortar, you might as well have used concrete in the first place...and you might actually use a good bit less, as a rock wall needs to be a lot thicker than reinforced concrete.
Depending what you have (or what the glaciers left you) there is another alternative, as seen in the barn I grew up with - large glacial boulders under each post of a post and beam. Think of it as "guilt-free precast concrete" and also as something that will crush you if it gets a chance, so move them with care. With care, you'll live and it will work. They simply need to be of sufficient size to spread the load depending what your soil will bear, and get below frost (or be sited on drained rubble that does not frost heave, as in a rubble trench). Then you need wood for the beams that support the floors...
I have at times looked to both strawbale and cob (which turn out to be silly here where straw is an expensive import from far away) and compressed earth blocks - and in all three cases a concrete foundation to get them up off the ground was highly advised.
I guess I have read of someone using baled plastic bottles as a foundation, but given what I've seen of plastic bottles+time, I have doubts about that long-term, so I would not bet my house on it.
If you have time and opportunity, I think it's a great idea to build several small test structures (shed, chicken coop, well or spring house) using whatever schemes you are considering for the house before diving into the house with a technique you've read about, but not actually built and observed over time at your site.
Lee Morgan wrote:And I also heard that the emissions for drying concrete are so much that they are actually one of the top producers of green house gases.
Lee Morgan wrote:http://www.youtube.com/watch?v=BdG0s8llQrA
Lee Morgan wrote:Can a rammed earth tire be left exposed without a covering agent like concrete? I would assume that their shell would last longer than the inhabitants of the home.
I also worry about the idea of using plastic sheeting everywhere.