Jun 262010
This is the way Hanno Burtscher, dubbed “The Earthman”, finds the right earth to use to build a wall. He picks up a clump of soil and feels the grains with his hands, looks for clay content, mixes it with water and kneads it like dough. He smells it; then puts a small amount in his mouth to taste it.
“The tongue can feel the small grains” he says, to my shocked reaction.“Almost all earth can be used. You go to a location and use what is available. It is a straightforward way to construct a house using a 2,000 year old technique.”
This inexpensive technique is called rammed earth, used in the building of walls with raw materials of the earth like clay, gravel and sand. These sustainable materials when mixed together, then rammed and compacted with a simple tamper, result in a strong, durable wall that stores heat which it then releases during the evening and night. This evens out daily temperature variations and reduces the need for air conditioning and heating.
The soil used is the subsoil, leaving the topsoil for agricultural uses. Ideally the soil from the construction site can be used, thus reducing cost and energy used for transportation. When the building is demolished, the earth returns to the soil and can be recycled again and again.
This balance is inherent in everything –manpower combined with minimal use of machines, absorption and release, and in the mixture of the natural materials.
Hanno likens the mixture to human skeleton. The skeleton provides the body structure and protection. “The aggregates of rammed earth which include gravel, sand, and all minerals, provide the structure and the load. Clay is the glue that binds all the aggregates together and keep them in place. All these components have to be balanced (in order to create a strong body/wall).”
The beauty of rammed earth is that there is no fixed formula; it varies from place to place using the type of raw earth materials that are locally available. It is surprising to hear Hanno say aside from the science, the whole technique is mainly about faith, common sense and feeling. Touch the mixture, listen for the sound of the gravel mixed with the clay, taste it if you are so inclined. It is a “human approach” that can be used anywhere in the world, especially in countries where wood is scare and manpower is abundant; and when you want to minimize the high carbon emissions from steel and concrete.
A finished wall using this method is like music to Hanno. He touches it in awe, lost in a kind of symphonic epiphany and an appreciation for what nature has provided and built upon by a chorus ofmen and women. These same men and women who are now working with Hanno share the same pride and joy when a wall is finished with smiles and shouts of “Phoom jai, phoom jai” (“Proud, proud!”).
Rammed earth is more than just a green way of building, “Green is a by-product”, albeit an important one. For him, it is a calling, a way of honestly connecting with the earth, with the people he works with, and ultimately with himself. It is about creating a powerful thing of natural beauty for all to experience, to touch and to rest in. It is to create an environment out of natural materials for the children and teachers of Panyaden to learn about and to interact with.
There is a quirky little ritual that Hanno has just started to help him connect with the work team and to help thembond with the earth they will be working with. Encouraging the foreman and the workers around him to do the same, he picks up a handful of soil, spits into it, kneads it and throws it back to the ground. Everyone laugh but they do it too. In that instant,the golden threads of camaraderie that bind person-to-person, person-to-nature are interwoven.
Mark Roselieb(Project Manager, Chiangmai Life Construction) with the Rammed Earth Team
Note: To read up on rammed earth and other forms of earth architecture, Hanno recommends
1) The book is aboutthe work of my master, Martin Rauch. It is currently not available but there will soon be the second print of the book as well as a new onecoming out. Check out his website: http://www.lehmtonerde.at/w16.html
Title: Rammed Earth
Author: Otto Kapfinger
Hardcover: 160 pages
Publisher: Birkhäuser Basel; 1 edition (December 1, 2001)
Language: English, German, Italian
ISBN-10: 3764364610
ISBN-13: 978-3764364618
2) This book talks about rammed earth and other styles of earth techniques -
Title: Earth Architecture
Author: Ronald Rael
Paperback: 208 pages
Publisher: Princeton Architectural Press; 1 edition (May 19, 2010)
Language: English
ISBN-10: 1568989458
ISBN-13: 978-1568989457
3) A beautiful book about vernacular architecture including rammed earth and other techniques categorized according to the building material from all over the world. A gem!
Title: Built by hand
Author: Eiko Komatsu
Hardcover: 480 pages
Publisher: Gibbs Smith; 1 edition (September 26, 2003)
Language: English
ISBN-10: 158685237X
ISBN-13: 978-1586852375
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