Adobe Dome & Nubian Vault
Adobe Dome Construction
CUIDAD Obregon, Sonora, Mexico – March 2000
Early on in Mexico, we learned that it was relatively easy to build a variety of walls that made for a comfortable house. The perpetual problem that was difficult to overcome was how to build a roof out of something other than concrete. Wood was rarely an option in the Sonoran Desert region not only due to scarcity, but the termites as well. It became a process of exploring endless options.
Inevitably, when one searches for alternative roofing options, that search leads to an exploration of masonry vaults and domes in the spirit of Hassan Fathy in Egypt who popularized Nubian vaults built with adobes. We brought adobe dome and vault advocate, Simone Swan, to Obregon along with her assistant, Jesusita Jimenez, to show us the ropes in constructing an adobe dome. In this case, we used our straw/clay blocks in an attempt to gain some additional insulation.
During her visit we built a small dome for our dear old friend, Don Juan Morales, who was living on the Save the Children site as the official produce gardener and groundskeeper. It was fun and much easier than we had thought. We quickly threw together a foundation of large pieces of concrete rubble and over a four day period constructed a small dome that was approximately 4 meters by 4 meters. The construction of both the walls and dome was relatively easy.
There were two very important lessons that we learned on that project. One was that the straw/clay blocks didn’t have the compressive strength needed. Over time, they began to settle and weaken the structure of the dome. The second was of equal importance. It was easy to build the dome, but to cover it with a weather-proof coating was extremely difficult. As was the case with the majority of lime plasters we tried in Mexico over earthen materials, the delamination of the plaster remained a continual problem.
CUIDAD Obregon, Sonora, Mexico – 2001
As part of our no-concrete or wood roof exploration, we built a Nubian vault out of straw/clay blocks. The vault shape follows a catanary arch. The larger rectangular space that was afforded by the vault, made it more attractive than the dome interior that had to be square. It was constructed in the outskirts of Obregon in an area known as Xochitl, where the “Casas que Cantan” project took place.
We undertook this project before we had learned the problems we encountered on the dome – lack of compressive strength with the straw/clay blocks and the difficulty in finding a dependable weatherproof coating. Nonetheless, it was a wonderful project watching brothers Emiliano and Teodoro Lopez build it. We learned an additional lesson that, unlike the dome, which was easy to build, the vault was much more complex and clearly beyond the skills of the average person. We didn’t continue with our research into vaults as it was all to obvious that it was something that would ultimately be limited to a few highly skilled individuals.
Funds to build this vault was donated to us by the Amaterra Foundation.