Test structure made by the Earth Home Builder auger

Test structure made by the Earth Home Builder auger


Owen,
“Thank you again Owen for talking with us over the years and giving us further inspiration to move forward with our own earthbag work. Hopefully the Earth Home Builder will prove to be what we hope it is and that is, most importantly, the pathway to actual Earth friendly affordable housing. What I can tell you so far about the EHB is this. It is AMAZING! You can break down the story all you want and short change the auger all you want, I have had some inquiries questioning the viabillity, but the bottom line is that by the end of the R&D project we were laying 20’ runs of 24” bag; hammering rebar pins and tamping in 7 minutes. Humans can’t do that especially in emergency situations with a crew of 1000. Let me rewind a bit to the beginning of the idea and eventual testing of the EHB auger.

Earthbag is very laborious, and unless you have a village you cannot build affordable homes even for the Third World. There comes a point when mechanization needs to occur or you are not able to proceed. We had looked up different companies that could help us out and stumbled upon one that invented a levee building machine that lays long tube 9 mil bag (clear plastic but hardy) at a wonderful rate and mimicked the way that we traditionally lay bag. I had a conversation with the inventor and owner and that sparked the imagination. Over the next year and a half I had come up with a method that would serve to be the format for using the auger for our R&D project.

Nine months ago, we had picked the plot of land and I had flown out to begin construction of a 400sqft square structure with pre-fab truss roofing. The goal of this experiment was to test whether or not we could build 7’ high walls to bond beam and support a roofing system. Using the more traditional methods outlined by the greater earthbag community which involved using road base as the wall fill (class 5) with zero cement stabilization, rebar pinnings instead of barbed wire, and a reinforced bond beam top tie in all of the walls and to place the roof, we were ready.

This was a total learning experience. The inventor was teaching me the limits and how to use the auger while I was teaching his crew of 6 how to build a home with it. This structure was built on a cement pad with a slope and in a confined space, which hindered how we ultimately wanted to build. We wanted to build one full course (apx. 80’) per layer, but we had to build one 20’ run at a time and one wall at a time. The slope of the pad forced us to overcome a 9” deviation from the east side of the wall to the west side. That meant that we had to fill the bag to near capacity at one end and thin it out at the other. Not easy to do, especially by hand. The conditions were not optimal but the auger and crew performed to perfection; we were able to overcome the deviation and make the 7’ mark at level.

The process began with laying a 9mil waterproofing membrane on grade and start laying our first bag. Wall by wall we began to lay each layer slowly as we learned how to get the fill in the bag correctly so that we could achieve a near uniform thickness. We then used a plate compactor to tamp the bags level, near level, and took measurements on several points of the bag so we could clearly see where we needed to fill the bag more or less in order to reach a level bag. To keep the walls plumb, the bag spotter and his sometimes back up would plumb the bags with a 6’ level. Anyone who knows how wide a 24” bag lays knows that it can be very forgiving. Moving the bag into place was not an issue. With the auger holding up the bag, the spotter was able to easily adjust for plumb and straightness of the bag. After the layer was placed, the tamper crew would come up right behind and tamp the bag for optimal compaction and for the rebar crew to pin the bags with rebar. The best run for the process was 7 minutes. 20’ of bag, tamped and rebar pinned. It was amazing to watch. In regard to door and window bucks, once a bag is laid you can immediately tamp it. We would lay one bag to the left of the door buck, start laying the left side and by the time the auger was finished laying, the previous bag was tamped and ready to receive the next layer. In all my years of earth building I had never seen such a smooth transition, the wall went up quick.

By the time we were finishing the second wall, we had called in some local friends to begin stucco work on the interior. One wall with one experienced guy was done in one day. He mixed his own mud and applied it while we continued on. There were no issues with wall adhesion and we had used chicken wire for reinforcement.

I also must mention that there was near zero waste so far. No spillage, every bit of earth was used and every bag length was measured properly. The lumber for the door/window bucks was reclaimed from stuff on site. The bond beam forms and roofing was purchased and pre-fab because of time constraints.
The bond beam was formed just in time for a 1:00pm pour with a telescoping conveyor attachment. We were literally wrapping the last rebar pieces together when they showed up. The forms held and we poured the whole thing in 45 minutes, 6yds of material at about a 4 – 4.5 slump.

Two days after some R&R, because we were pulling 12 hour days to make up for the extra bag being late and the form work (I was the only carpenter), we pulled the forms and we were pleased with the result. The anchor bolts were lined up and ready to receive the green treated top plate for the truss hangers and roof.

Side Note: For anyone questioning the strength of the earthbag, we also shot a 12 gauge slug into the wall and it stopped at 2”. I’ll send photos.

I flew back out to California the next day and have been talking back and forth with the R&D crew which they have been reporting that there are no issues. The roof attached fine, the stucco is almost complete and the door and windows are in. I will send photos as well.

I should also note that we had a building inspector and talked with contractors/engineers in the local area of the build and they reinforced the truth that the medium with which you build does not matter as long as it meets code. Our simple structure did and they allowed us to build without permits and solely as an R&D project.

As there are probably a few questions I will field them as best as I can, but this still is R&D in the works and we have to further experiment. We are holding another project in Weitchpec, CA on the 30th of June to build a 40’x40’ home which will be recorded and distributed at a later date. Another thing I need to mention is that the auger can only lay bag up to 8’ on a bobcat. We are looking for other options to use in regard to equipment, anything that has a reach with an auxiliary PTO, most likely a Skytrak telehandler. That blog post is to come!

Anyone who would like for us to come and build for them with the auger, please feel free to email us and we will get to you as soon as we can. We are out on projects until August. Our main focus is to train people for humanitarian efforts. Non-profits that are focused on the affordable housing or humanitarian housing movement should contact us so that we discuss how we can train your crew on everything earthbag and get an EHB for your organization afterward.

Thank you all again for your input and shared experiences and we hope to have more for you soon!”
James & Fox
United Earth Builders

Previous blog post: The Earth Home Builder: Mechanized Earthbag Construction


Comments

United Earth Builders Progress Report — 4 Comments

  1. Hello!

    I came across your wonderful projects very recently. Quick synopsis, I am an undergraduate at UC Davis. I have been working on a project where we are attempting to implement cooling room technologies such as the “CoolBot” (http://storeitcold.com/) which is an attachment to a standard AC-unit to have it maintain cool-room viable temperatures for a pilot project that is currently being implemented in Nyanza, Kenya. The issue then becomes building the structures themselves, we were imagining a 6’x6’7′ structure. One of the things we have been experimenting with was potentially concrete mixed with rice to use it as building materials. However, I see you mentioning in this blog that deploying this kind of technology in developing countries has some complications without mechanical labor. I was hoping you could elaborate and share some insights with me on this thought based on your experience. Thank you!

    • Some communities work together just fine such as in Vanuatu (see previous blog posts on this site). Many others are reluctant to change. The existing building methods they’ve chosen have evolved over long periods of time and so people don’t want to change or learn new things sometimes. Many poor people are already busy doing laborious jobs for long hours. Building very small structures as you describe should be no problem though. Email me and I’ll guide you in the right direction. My email is at the top of the page.

  2. I wish they would build a small shed and smash a car into it for testing purposes. It wouldn’t cost much or take long with a machine like this, and it would be great for marketing. (Sorry, we need our car. Please ask someone else.)

    Let the plaster cure at least 30 days. Be sure to invite the building inspector, and video everything carefully from two angles.

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