I just found these new videos on YouTube and know very little about them. I’m eager to learn how they propose to build the large vaults, because these are very difficult to build with earthbags.
The first one is an animated video showing how to build a dome. The second video is a fly-through of a proposed project in Haiti.
Building an Ecological Dome:
Ecological Emergency Village in Haiti:
More information (see Projects)
These videos appear to very professionally conceived and well thought out, and indeed when you go the the authors’ website you can see that they were produced by a Dutch architectural firm. While there is little explanation on their site about details of how the proposed buildings would be built, the translation of one paragraph is:
“Emergency housing for Haiti comprising one bedroom dwellings. The houses are built according to the chain-line principle. The streets follow the checkerboard pattern. Ecological concept: The houses are built of clay and silt bags.”
One of my concerns about the plan as shown in the videos is that the straight sections of walls on the domed buildings have no buttressing. But then if their plan is to abut these structures next to each as shown in the second video, then perhaps the double-thick walls would become self-buttressing. This may be what they mean by “the chain-line principle”.
If the scale of each dome is small enough they may be fairly stable, but to do this in a seismic zone like Haiti, does worry me, particularly if the bags are filled with unstabilized earth. Issues of how to waterproof the domes are critical to the success of such a project.
The vaulted structures shown in the second video are even more worrisome, particularly if they expect to also build these with earthbags. I am not aware of a single successful earthbag vault that has been built at this scale. I once made one that spanned about 8 feet, and I only accomplished this with lower walls about 30 inches thick and using a special cross-hatch pattern of laying bags over an arch form. Anything larger than this would be of dubious stability as far as I am concerned. To do this in Haiti could be catastrophic.
Wow, they certainly don’t dream small in that second video. I imagine the lakes are manmade from the excavation for the bags?
In the second video if you freeze it at about 1:24 or so it looks like the vaults are not bags. A quonset (sp?) type I think.
Anyway, great blog Dr. Geiger- I love reading and gaining new skills. Already planning the guesthouse.
Yeah, I saw the ponds and thought the same thing. That’s a good idea.
I watched the video again at 1:24, but I don’t see any quonset structure. I see large vents on the ends.
very interesting, thanks for the post.
one of my favorite house plans involves vaults as well. i too would like to know more details about how they plan to build these. keep us posted!
what if one were to complete one or both end walls first and complete the arch around that. Proceeding to extend the arch lengthwise down the barrel vault away from the ends, towards the center in a staggered stepped fashion rather than completing one course at a time as in a dome?
hope that makes sense. let me know if you think that would work.
tim
Tim, you’re probably talking about the method used to build Nubian vaults: http://ppr-foundation.org/la-voute-nubienne—earth-roofs-in-the-sahel-_en376b376.html
This works fine with small adobes stuck together with mud (in desert regions), but earthbags won’t stay together in the same way — they’ll just fall down.
thanks for the link. that is the method i was thinking of. i wish i had some land i could experiment for myself with the earthbags. have you knowledge of failed attempts using eathbags to make a vault?
i’m not so sure it couldn’t be done. maybe adding short sections of rebar pounded into the bags to connect the courses?
i saw on your website the use of a quonset metal building which was used a a permanent form to build a vault with earthbags. do you think there would be a way to use this metal quonset form but after the earthbag arch is complete to remove the form to continue the vault or for another building?
http://www.earthbagbuilding.com/plans/carriagehouse.htm
The carriage house was built by Kelly Hart, the other person who runs this blog. He could give you full details. The quonset hut would need to stay in place — the bags would collapse without it. More than just rebar is needed.
He also built an arched entry to his dome house, and thinks the maximum safe span for earthbag vaults is about 8 feet.
I have never seen any successful earthbag vaults beyond about 8 ft. span. Nader Khalili, who built many vaulted structures, switched to ferrocement for the vaulted portion, as did Iliac Diaz with his earthbag school rooms in the Filippines. For a while there was a video posted at YouTube by a Canadian group building a small vaulted earthbag structure, using a wire mesh form for the vault, and it show exactly how the weight of the bags could not support themselves and it eventually collapsed. They since removed the video. Using the commercial steel vault as a form for building with earthbags is completely viable, as I have proved with the Carriage House, but I would never consider even trying to remove the form.