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.

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: www.mastergardenproducts.com/tungoil.htm.

Nader Khalili has Died

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!

Natural Building in Comparison to Stick Frame

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.

Earthbag Tube Forming Machine

I recently got an email from Steve Cameron with the sketch shown below that he had drawn of a concept for filling and forming earthbag tubing into a uniform rectangular form on the wall being built.

Steve asked for any comments that I might have about this idea, so I wrote:

This is certainly an interesting idea, and a great drawing! I think that I understand your concept pretty well from the sketch. The squared bag shape would only retain that shape if the contents were solidified, as would happen with a soil/cement mix (which you specify); looser material would eventually force the bags into their more natural oval shape after the form were removed.

But then, I wonder, why bother with using the bag material at all? What you describe is pretty classic rammed earth with lifted forms, and there would be better adhesion with rammed earth directly upon rammed earth rather than with the bag material intervening.

If the purpose for forming the earthbags this way is mainly to reduce the work and material in plastering, I have to say that I don’t find the standard approach objectionable. All those crevasses between the bags give the plaster much better “tooth” than a smooth wall would, so there is an advantage to leaving these voids.

I should add, though, that the apparatus and concept is very clever, and shows great inventiveness; I suspect that it would actually function quite well as drawn.

I might mention that rammed earth is often formed with slip forms done in lifts of maybe 2 feet. The proper soil mix is 15-30% clay and the rest sand. Sometime a small amount (maybe 5%) of Portland cement is added as a stabilizer, but not always. This is one area where earthbags have an advantage, because you can get away with a larger variety of soil mixes.

Your suggested mix of 30% cement to 70% soil would be equivalent to a 3:7 mix of cement/sand concrete, which is very rich in cement! Standard soil cement mixes call for between 6 and 16% cement, depending on the specifics of the soil and the intended use.

Then Steve wrote back that the device was actually inspired by a photo he had seen on a site featuring the Natural Building Colloquium in Texas in 2007, which he redesigned to suit his own needs.

Using Earthbags as Ceiling Insulation

Owen and I have collaborated on a new article posted at earthbagbuilding.com that describes how to use earthbags filled with various natural insulating materials to insulate ceilings or roofs.

There seems to be a general lack of interesting ceiling options using sustainable building materials. For instance, when touring otherwise beautiful straw bale homes one often sees sheetrock covering conventional industrial insulation. Instead of using fiberglass batts or even manufactured cotton batts to insulate a roof, it is possible to use earthbags that are filled with a variety of insulating materials. These materials include rice hulls, crushed volcanic rock (such as scoria), vermiculite and perlite.

The insulating value of these ranges from about R-2 to R-3, so they are quite effective, and can also be quite inexpensive to install.

This article also describes how one might use mats made of natural fibers to cover and finish these earthbag ceilings.

Suspended ceilings, as described in this article, have a number of benefits. They conceal the roof structure, plumbing, venting and electrical wiring, as well as improve acoustics and insulation. And they can also greatly enhance the ambiance or hominess of a room.

Earthbag Building in Haiti

I spent several hours working on this project page: http://earthbagbuilding.com/projects/haiti.htm

I think it really is one of the best yet, because it shows the entire project from foundation to finish work on a simple home that would appeal to most people around the world; it was created by poor Haitians who had no prior experience; and it was done in a manner that I could easily recommend for others to follow. I think this really shows how earthbag building can realistically work for people throughout the world.

The house itself is a simple design (with some interest because it is an L shape) and was accomplished without any buttresses. Once finished it is nearly indistinguishable from their customary cement block homes, except that the walls are thicker…and it will be more comfortable to live in I am sure.

This home was built at Pwoje Espwa in Southern Haiti, where Father Marc has dedicated his life to serving and helping suffering children. This project not only houses over 700 children, but has an agricultural project, three schools, carpentry and masonry facilities, and an arts and crafts program. They have many ideas to help the Haitian economy and people living there. Because they are a non-profit, and are continuously struggling with funding, I encourage you to visit their website (www.freethekids.org) and consider making a donation to their cause.

Slide Show of Earthbag Buildings

I am very pleased to announce that there is now an extensive slide show of earthbag building projects up at www.earthbagbuilding.com. I spent several days selecting the best photos that I could find and formatting them to fluidly present a marvelous array of architectural styles and approaches to building with earthbags. There are already over sixty images assembled, and I expect to continue to enlarge the library over time.

The pictures are labeled so that if any of them attract further attention, the more detailed description of the project can be found on the projects page.

The pace of the slide show is controlled by the viewer by clicking on arrow buttons below the images, so one can browse as casually as one likes. This is a great way to become familiar with some of what is being created with earthbags. The photos depict both works in progress and completed projects.

So sit back and enjoy the show!

Earthbag Dome Building

Kelly Hart of GreenHomeBuilding.com has recently completed a web page with step-by-step instructions on earthbag dome building.

 

Complete with clear illustrations and detailed text, the instructions Kelly provides includes almost everything you need to know to build your own earthbag dome. Additional information is available at EarthbagBuilding.com and GreenHomeBuilding.com.

A key advantage of Kelly Hart’s system over other techniques is the use of scoria as a fill material. Scoria, a lightweight volcanic aggregate, is rot proof, fireproof, flood resistant, and does not attract rodents or insects. Scoria also has an insulation value approximately that of straw bale walls (R-30), making it ideal for extremes of hot and cold climates.

These earthbag domes are ideal for earthquake-prone regions such as Pakistan, Iran, Afghanistan and Turkey. Domes are inherently very stable, plus these particular domes are reinforced with barbed wire and plaster mesh to withstand seismic activity.

In addition, they cost only a fraction of concrete and steel monolithic domes, and also are much more environmentally friendly and more practical for do-it-yourselfers. Unskilled workers can learn the basics in a few hours and build their own shelter with minimal hand tools.

Kelly Hart and Dr. Owen Geiger are available for consulting on earthbag building projects.

Emergency Shelter for Pakistan

[Note: This design was originally published shortly after the Pakistani earthquake in October, 2005. Even though the information is a little dated now, it gives you a sense of the urgency Kelly and I felt at the time.]

The death toll mounts as winter closes in on the survivors of the recent earthquake in Pakistan. Emergency shelter is essential for the survival of up to 3 million — and time is of the utmost importance.

The Geiger Research Institute of Sustainable Building, along with Kelly Hart of GreenHomeBuilding.com, is finalizing an emergency shelter design that could save many thousands of lives and alleviate considerable suffering.

The challenge is to provide quick, safe, decent shelter with minimal tools and supplies to sustain life through the winter. Access to remote areas is extremely difficult, since many roads have been destroyed or blocked by landslides. Because of these and other difficulties, and the fact that winter will soon create a much more dire situation, fast easy-to-build temporary shelter (that can be upgraded to permanent housing later) seems most appropriate.

The proposed design incorporates a round earthbag structure partially inset into the ground. Rice bags or sandbags are filled with soil from the building site and tamped in place to create the walls. The roof is built with poles salvaged from destroyed buildings, covered with straw, grass, leaves or whatever is available, covered with plastic sheeting or tarps, and bermed with earth to hold in place. The size can be adapted to meet site-specific needs.

A typical shelter could be built in 90 hours, not including plastering. For example, this structure could be constructed by 5 unskilled workers working 6 hours a day for 3 days.

Free plans and specifications are posted at:
Emergency Shelter Plans for Pakistan

Earthbag Dome Building (another option for earthquake zones)

More earthbag building information at EarthbagBuilding.com