Earth is everywhere and is good for building- a rich gift from the Creator who gives us all good things.In the past 30 years poly grain bags filled with sub-soil were joined with barbed wire into a hybrid natural material. Now earthbag is entering high seismic risk areas with new reinforcement techniques. Because earthbag is one of the cheapest, simplest, and most forgiving ways to build, it is spreading around the world. But earthen buildings need shapes a little different than for concrete block.
Soils must be matched to the right plaster. Details must be right for
strength.
Don't hesitate to ask people with more general experience if you are working with a local builder somewhat new to earthbag.  Above: The tools needed to build a whole building, photo by Owen Geiger of www.GRISB.org Some people build earthbag using backhoe machines to dig soil, fill buckets, and lift bags to the tops of walls as they rise. But few tools are really necessary. A few others are nice to have: a line level, some rope, some tarps or tubs for mixing things. A source of water to rinse tools, people, keep soil fill damp, and mix plaster is also very helpful. The total amount of water needed is very small. Some building layouts are available free to download on the Plans page. |
Earthbag is a rich family of related technologies. Among them are: Bag techniques: Standard earthbag Possibly safest for rectangular structures in seismic risk areas, separate bags make neat corners and are easy to build alone with mesh or solid weave bags. The simplest introduction is the Earthbag Info series of slide shows, available online in English. Longer articles are available at the Earthbag Articles page.Gravel or rubble bag The standard for footings and plinth walls. These bags are not damaged by water, and can support cement stucco in freezing climates. Gravel is usually 1- 2 inch maximum, but larger rubble chunks can be included in these doubled solid weave poly bags. Larger rubble can also be mixed in with sand instead of doubling the bags. Sand bag An alternate for plinth walls or higher in areas subject to flooding that requires wire mesh reinforcement. Eternally Solar has developed a new channeled bag type that may be more stable with loose fills. Insulation bag Lightweight materials can provide great insulation values as an extra layer next to a structural earth wall. Some experimental structures have used moderately firm fill like rice hulls with a reinforced structural skin on both sides. The easiest way to make a structural wall with great insulation value is to fill bags with scoria or pumice, light gravels made from volcanic rock. |
Traditional tube techniques Superadobe Solid weave tubes are quicker to build than separate bags, and easily shape curves. Domes and vaults have been tested by Cal-Earth.
New tube techniques: Hyperadobe Mesh tubing is less expensive and easier to handle, not requiring barbed wire. Best for non-hazardous areas. Hyper-wattle A new technique of smaller tubes filled with either straw clay or trash, perfect for upper walls on an earthbag base, or second story walls in non-hazardous locations. Straw-filled tubes dipped in clay slip are being tested for bearing walls of small residences or infill in larger structures. Plastic trash filling can make flood-resistant tubes that don't require chicken wire to function as infill between structural posts or columns. Light-weight foam trash-filled wattles may offer low-cost and insulated roof options for domes or rectangular buildings in hot climates. These can be covered with lime plaster, cement stucco or thin micro-cement coatings. They are also much less dangerous than heavy earthen roofs if plaster leaks and the roofing becomes damp. But a thick interior plaster is important to reduce flammability. These may be most appropriate in houses without interior corridors or interior stoves or heat sources to reduce chances of fire which could create toxic smoke. More information follows on the Wattles page. |
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These websites have great general information:Earthbag Building Earthbag Building Blog Earthbag Structures All sorts of buildings around the world Lots of updates and discussion Aid & self-help buildings for the developing world Builders with specific questions can search these three sites for information and then email a question to see if there is any more recent information not yet posted. EBS (EarthbagStructures is much smaller and focuses on shelters, transitional housing, and small houses and institutional buildings. It includes articles about soils and materials and issues that are specific to warm climates or to poverty-prone areas. I hope to add a FAQ list and possibly an open forum on this site in the near future. |
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