United Earth Builders are 3D Printing Earthbag Houses

Over the last year and a half we have seen several different methods of 3D printing large structures, such as homes. We have seen both plastic and concrete used, and we have seen a variety of strategies employed. From printing an entire concrete structure in place with a giant 3D printer, to printing one wall at a time, and then transporting it to the build site, to printing interlocking bricks, such technology is certainly being explored to the max. Today another method of 3D printing large structures has been uncovered. This method is unlike any other we have seen prior.

A company called United Earth Builders, located in Joshua Tree, CA has created a method which could be considered part 3D printing, part manual labor. The process revolves around a building strategy called ‘earthbag construction’, which takes its roots from temporary flood control dike construction, along with historic military bunker building techniques. Ordinarily in earthbag construction, a team of several individuals fill giant elongated bag tubes with dirt. They lay the bags down similar to how an FDM 3D printer would lay extruded filament down. Layer by layer, the structure takes form, one course of bags after another. Traditionally a bonding agent like concrete or clay would be used as a type of mortar in between layers, and barbed wire would hold the bags in place for extra structural integrity.

It typically takes about an hour for a crew, by hand, to construct a 30 foot long single course section of earthbags. Each bag must be filled with dirt, before being placed into position. Although earthbag construction is an environmentally friendly, natural form of construction, it is extremely tedious work, and hard on the body.

What United Earth Builders has done, is create a vehicle driven 3D printing method which can lay down 400 feet of earthbags within an hour’s time. This is a 1,333% increase over that of manual earthbag laying. They do this by equipping a Bobcat T300 Skid Steer with a specialized component for quickly filling bags. The machine, driven by an individual, will lay down the filled bags until an entire structure is created. At that point, the team will hammer 5 1/2″ rebar down through the bags at certain points along the way, which keeps the bags stable. Once this is done, the walls can be covered with plaster to give it a nice smooth finish, while providing a bit more in terms of stability. From this point, the bags can continue to be placed on top of the structure, slowly angled towards the center, creating a dome like roof, or a traditional roof may be put into place.  Unlike traditional earthbag construction, United Earth Builders’ method requires no barbed wire or mortar.

Such a building technique can be very affordable, as well as safe for the environment. United Earth Builders will be giving a course on this construction method today in Weitchpec, CA, and plans to offer regular project courses sometime next year. Let’s hear your opinion on this type of pseudo 3D printing of homes in the 3D printing earthbag building forum thread on 3DPB.com.  Check out the video below to see just how this process works.