5 DIY Green Building Techniques
Living Roof- New Academy of Sciences: Golden Gate Park, San Francisco
The Farm- Summertown, TN.
Adobe/Cobb/Strawbale- The Farm, Alex's Green Dragon Tavern: Summertown TN
The pictures from The Green Dragon, at the Ecovillage Training Center, at The Farm in Tennessee, show the progress of the project, which is still in construction. it was constructed to be the largest cobb structure east of the Mississippi. The roof construction pictured above was particularly difficult, as it caved in once and had to be built again. The structure uses a combination of almost all known natural building techniques, the walls are strawbale covered by cobb and then adobe for extra insulation. There is also use of earth bags, such as in the construction of the fireplace face. Earth bags are large strong bags, that you fill with dirt, to create something similar to a sandbag. These are incredibly strong. The Dragon Sculpture and large face inside the structure I made myself and took pictures of the process, I sculpted it out of cobb, which is dirt, clay and straw then covered it with a mixture of adobe and lime to harden it. We then painted it with store bought natural colorings and painted around it as we did the whole building with that orange coloring. Other highlights of the natural building process included custom wood fences that we built with the help of a local construction agency.
The living roof at the New Academy of Sciences building in Golden Gate Park S.F. is the largest example of a living roof. A living roof provides very good natural insulation and the moisture from the grass actually cools the building in the summer and insulates it in the winter. Living roofs can also be executed on a much smaller scale. The pictures of the smaller huts above are again from the Farm. Anyone can create a living roof like this. First spread old or recycled carpet pieces over a wooden foundation. Then spread dirt and and grass seeds on top. water and sunlight create the roof. The Green Dragon shows pictures of a living roof with seeds that have not yet sprouted, another picture from later on shows the building when weeds took hold of the roof. This is not a big deal because the building is still in progress.
The Rammed Earth at the Eden Project in Cornwall, England also uses a variety of natural building techniques. The rammed earth wall above uses techniques possibly old as the Great Wall of China. Rammed earth is similar to adobe and cob techniques, in that the soil is mostly clay and sand. The difference is that the material is compressed or tamped into place, modern forms utiilize heavy mechinisms and even machinery to compress the material.
Steve Kornher is the builder who has made flying concrete a notable building material. "Flying Concrete" or, Lightweight concrete has been used in this country for more than 50 years. Its strength is roughly proportional to its weight and its resistance to weathering is about the same as that of ordinary concrete. As compared with the usual sand and gravel concrete it has certain advantages and disadvantages. Among the former are the savings in structural steel supports and decreased foundation sizes because of decreased loads, and better fire resistance and insulation against heat and sound. Its disadvantages include greater cost (30 to 50 percent), need for more care in placing, greater porosity, and more drying shrinkage.
The principal use of lightweight concrete in Bureau work is in construction of underbeds for floors and roof slabs, where substantial savings can be effected by decreasing dead load. It is also used in some insulated sections of floors and walls.
Lightweight concrete may be obtained through use of lightweight aggregates, as discussed in the following sections, or by special methods of production. These methods include the use of foaming agents, such as aluminum powder, which produces concrete of low unit weight through generation of gas while the concrete is still plastic. Lightweight concrete may weigh from 35 to 115 pounds per cubic foot, depending on the type of lightweight aggregate used or the method of production. In Bureau construction, lightweight concretes have been limited to those whose lightness depends on inorganic aggregates which are light in weight.