Archive for March, 2008

Tamper Design


My favorite tamper is pictured here. It is quite heavy, which means that even though it takes work to lift it, you don’t have to put as much muscle into the down-stroke. Also, the base of this tamper is about as wide as the bag is, so one tamp will cover the entire width of the bag. I used this quite successfully in tamping the earthbags that were filled with scoria.

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My Favorite Tamper

Tampers for earthbag walls come in many different types and sizes. Some prefer casting the base out of concrete. Some prefer all steel. I even tried a big clunky one made entirely of wood. (It looked like a primitive tool recovered from an archeological site.) Or you could buy one from Home Depot.

So here’s my favorite tamper. Actually, there’s two – a long and a short handled version with the same steel base design. An agile 45”version is used for lightly tamping bag contents during filling. The long handled tamper (55”) has more gripping surface, making it easier to apply greater force when tamping walls. Both can be used for wall tamping, of course, but it’s convenient to have both sizes. Having two or more tampers on-site enables other workers to help out and choose the most appropriate size.

Steel base: The design is very simple. The base is made of scrap 3/8” plate steel. There’s a good chance you’ll find lots of small scraps at a local welding shop that will work just fine. There’s one 6” x 6” bottom piece, four angled ribs and one 4” piece of 1-3/4” steel pipe welded together. Drill the pipe as shown to accept a ¼” hex head bolt to secure the handle. Grind the edges, remove any rust and oil, and apply your choice of spray paint.

Handles: I much prefer wood handles over metal. They don’t get as hot as metal and have a more comfortable, natural feel. Sand the wood to eliminate splinters and round the end slightly. Fit the handle to the pipe and pre-drill through the wood. Several thin coats of tung oil will protect the wood. The following link has a good summary of tung oil and application instructions: http://www.mastergardenproducts.com/tungoil.htm.


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Nader Khalili has Died

Nader Khalili

The Father of Earthbag Building, Nader Khalili, died peacefully, surrounded by his family, a couple of days ago. He was 71 years old.

Here is part of a letter sent out by his family to former students:

“The flames that ignited him in life and the quest that brought each of you to Cal-Earth to learn from him have touched all of us and led us on this path….the right path……. for arts, humanity and the environment. His work and words have inspired us and his spirit is powerfully alive in every work and word, building and echo that your enthusiastic and loving hands have helped to create for this world.

His soul imbues every grain of sand and every memory contained in Cal-Earth, which expresses so much of his personal life of the last 17 years.  And your works, like seeds have been growing and flourishing in every corner of the world…”

Born as an Iranian, Nader lived most of his life in the United States, gaining an architectural degree. He worked on the design of high-rise buildings and taught architecture in Southern California. In 1991 he founded Cal-Earth (the California Institute of Earth Art and Architecture)  based in the desert region of Hesperia , California. From this center, he taught classes and workshops on the use of both bricks and bags to fashion domes, arches, vaults, and irregular shapes. These forms sprang from his early exposure to  Middle Eastern architecture.

The earthbag concept evolved from attending a 1984 NASA symposium for brainstorming ways to build shelters on the moon.  He realized that bags filled with lunar “dirt” could be stacked into domes or vaults to provide shelter. This concept was later refined to include stretching barbed wire between the courses of bags to help stabilize the structure. Nader never referred to this building technique as earthbag building; he preferred to call it  “Super Adobe,” referring to the fact that he generally filled the bags (or long tubes) with an adobe soil mix.

In 1999 Nader was issued a U.S. Patent for his Super Adobe technique and he subsequently tried to require contractual arrangements for its use. At this point, however, he had been publicizing the idea for so long it was not an enforcable patent, and few would comply with his request.

This fact points to the complex nature of Nader’s personality. He truly loved humanity and the arts, and was an eloquent and passionate speaker. He often said that his ideas were a gift to humanity and he hoped they would provide shelter for the poor and disadvantaged. At the same time, he wanted to control the economic potential of his invention, and he pursued this vigorously.

Nader was the author of several books, including Ceramic Houses and Earth Architecture: How to Build Your Own, about literally making ceramic houses, and Sidewalks on the Moon, an autobiography. He also wrote several books about the the mystic poetry of Rumi. Interestingly, he never really wrote a book about his Super Adobe invention, allowing others to take the lead in doing this.

With the passing of Nader Khalili we have come to a point where his ideas and work can truly become universal. All of us who explore the potential of the earthbag concept and expand on its possibilities can help further his vision for bettering the world. We owe a great debt to this truly inspired individual. May he rest in peace!

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It’s easy to be distracted and even wowed by glitzy features in a new house – a built-in entertainment unit, hot tub, walk-in closets, custom cabinets, and more. But the next time you’re in a stick frame house, really stop to think about what the house itself is made of. It’s actually just a thin shell of wood sticks covered with sheetrock (chalk and paper) on the inside, and often fiberboard (sawdust and toxic glue) on the outside. The materials in these stick frame houses are like a ticking time bomb. You know they’re going to fail before too long and cause untold problems.

The wood will crack, bow, bend, split and attract all sorts of pests like termites. And stick built houses burn like crazy. Engineered wood products (OSB, etc.) off-gas toxic chemicals in fires that actually kill more people than the flames.

You can hear and feel the wind blowing through the walls of a stick frame house on a cold, windy day. Sit for a few minutes by a window or put your hand in front of an electrical outlet to feel the breeze coming through. That’s why heating and cooling bills are astronomical.

Try not to breathe while you’re in one of these conventionally built houses. A typical home has hundreds of volatile chemicals and because of this the number of people suffering from sick building syndrome is on the rise. Almost every product in these new homes off-gas chemicals that endanger one’s health.

Also, mold is an ever-present danger in stick frame houses, especially in humid climates, basements, bathrooms and kitchens. Particle board cabinets, heating ducts, paper facing on sheetrock, and other materials all foster the growth of mold.

And, frighteningly, stick frame houses are a death trap in hurricanes and tornadoes. Just ask residents of Greenburg, Kansas whose houses were wiped off the map, or those from New Orleans. Stick frame is no match for nature’s fury, whose storms are increasing in size and intensity almost yearly.

Doesn’t sound very comforting, does it? When will people catch on?

Natural building, in contrast, has a long, long track record and is far superior to conventional building in many ways. Let’s briefly compare stick frame building with two natural building options.

Straw-bale construction is a no-brainer. Regular readers of The Last Straw Journal know the benefits, but most of the general population doesn’t. Straw-bale homes are (deep breath) durable, environment and owner-builder friendly, fire resistant, insect and rodent resistant (once plastered), and provide excellent insulation. Straw-bale homes are safe, warm and quiet. One of the primary benefits of building with bales is the lower utility costs over the life of the building.

Earthbag building is ideally suited for areas prone to flooding, hurricanes, tornados, earthquakes and other natural disasters. Building with bags is a simple process of filling polypropylene feed or rice bags with soil, sand, gravel or similar material, and tamping the bags solid. You can use sand in the desert, soil in most climates, or porous volcanic rock such as scoria in cold climates. Scoria-filled bags approach R-30, at least those sealed with papercrete. (I lived in a house built this way through a Colorado winter and the R-30 value is for real.) In addition, unlike other earth building methods, no special mix is required. Just use what is readily available, often the soil on or near the site is best. Also, it is easy to make roundhouses, domes, vaults and organically shaped structures with earthbags.

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