Earthbag construction just got a lot faster and much easier thanks to an innovation from United Earth Builders. Their Earth Home Builder is made from a repurposed auger and can more or less 3D print walls for a new building in a very short amount of time.
For those unfamiliar with the term, earthbag construction is just what it sounds like: bags are filled with soil or sand and those bags are laid on top of one another. The stacks form the starting point for walls. The layers of bags are often supported by adding cement between them like mortar, or securing the layers with barbed wire. The Earth Home Builder requires neither of those mid-construction additions; its reinforcement material consists of 5 1/2″ rebar hammered in at key points to keep the bags stable.
In ordinary circumstances, humans can fill earthbags at a rate of approximately 30 feet per hour. The Earth Home Builder can “print” the bags of earth at a rate of 400 feet per hour. The machine consists of a big hopper that holds the filling material and a spout where it spits out earth into an attached bag. The operator slowly lets the fill material out and a helper or two can manually guide the bag into place as it’s being filled.
After the bags have all been laid in place and secured, an external cover like plaster or adobe is applied to protect the bags from the elements and add extra stability. Some earthbag builders keep stacking the bags up into a dome to create a roof, but United Earth Builders finished off their example building with a traditional roof made of formed concrete and timber. The group is looking for nonprofits to work with in their endeavor to bring stable, inexpensive, quickly-constructed homes to the people and places that need them most.