As you can imagine, we get quite a few emails from readers asking about earthbag building. Sometimes these questions and ideas are of interest to a larger audience and so we pass them along to you in this blog. (The best questions and comments also end up on Kelly’s Earthbag Building FAQs.)
Chris, one of our readers, just sent us this request:
“I’ll be starting a project of my own soon and can use all the help and inspiration I can get. At some point I hope you’ll consider doing a serialized article or blog post that follows an earthbag project from inception to finish. In my own case, the earthbagging itself seems pretty straightforward, it’s the planning and details that are intimidating. I don’t know about you, but following someone else’s example always emboldens me quite a bit.”
Riceland Dome, by Kelly Hart
Since Kelly is taking off on vacation, I’ll take a crack at this. Kelly has an excellent dome building guide that illustrates each step of construction called How to Build a Small Earthbag Dome.
The dome building method Kelly demonstrates in this step-by-step guide is the easiest, fastest method I am aware of. You could use tamped earth or lightweight fill material using this method. I highly recommend using scoria, vermiculite or perlite for lightweight earthbag construction, because of all the many benefits. For one, anyone can handle bags of lightweight fill material by themselves. It’s almost like handling bags of popcorn. In addition, these materials are also fireproof, rot proof, do not attract pests and create highly insulated structures. It’s also important to add that this modest sized dome (14 foot interior diameter) can readily be scaled up to 20 foot interior diameter with just a few modifications.
Sourabh Phadke in India has been quite productive lately in publicizing earthbag building in various ways. He is involved with a school there, where they have been experimenting with many aspects of natural building and green living, from compost toilets to creatively using recycled plastic bottles to earthen plasters over earthbag walls. Much of this has been documented with short educational videos that he narrated and put up on You Tube. You can see these at www.youtube.com/user/antiismistix.
Sourabh sent me his latest work, which is a charming slide show in PDF format called “The Rocket & the Rabbithole”. It outlines why and how they created a two-classroom school building with earthbags. This is now available for viewing at earthbagbuilding.com
Thank you Sourabh for all of your wonderfully entertaining and educational efforts!
Earthbag building (sometimes called sandbag building) started about one hundred years ago providing safe, bulletproof and bomb resistant shelters for the military. They proved to be fast, simple to construct and durable. The same qualities that make earthbags useful for military and flood control purposes apply to building houses. Now people all over the world are using the same basic process of filling and stacking bags to build their dream homes, home offices, shops and other commercial buildings.
The Fleming College Sustainable Building Design & Construction Progam project in 2008 was the Madoc Performing Arts Centre. Students of this annual summer program constructed a sustainable performing arts center in Madoc, Ontario, Canada. Since 2005, students of this program have been building sustainable public buildings for host communities. The buildings mix low impact, low technology materials with high-tech mechanical and energy systems.
The basis for the foundation for the Madoc Performing Arts Centre is a rubble trench. This type of foundation uses compacted stone in an excavated trench to provide bearing capacity for the building above. They used a grade of crushed limestone called “3 inch minus” which includes any aggregate that would fall through a 3 inch screen. The bottom of the trench has a drainage tile running in it, which slopes to carry water away from the building.
The earthbag grade beams that supports the main octagonal space are composed of woven polypropylene sack material that were obtained as a continuous tube. These tubes were filled with a site soil mixture of gravel, sand, silt and clay and then compacted firmly. Barbed wire is run between each course of earthbags to prevent slippage. They used two parallel runs of narrow bags with insulation (hempcrete) between the runs. Earthbag foundations are very low cost, and are strong enough for a large building like this. They are quite easy to build as they don’t require formwork.
For more photos and description of this project and its foundation, see www.earthbagbuilding.com.
What is the best way to build a low-cost home that doesn’t harm the planet? Most materials such as concrete and steel are highly processed and transported long distances, making them unaffordable to millions who are in need of housing. These high-tech materials also cause a great deal of harm to the environment. The answer is to utilize locally available, low-impact natural building materials such as earth, stone, straw and small diameter wood. This article explores several methods of using earth and sustainably harvested wood to cut housing costs to rock-bottom prices. And because the techniques are user-friendly, they are ideal for do-it-yourselfers.
Here’s another dirt cheap earthbag house – this one is in Mexico. I just found a new video about the house, and the owner’s daughter who helped build the house said it cost about $2,000! We need more stories like this. At some point people will stop paying ridiculously high prices and switch over to earthbag building and other natural building methods.
http://www.youtube.com/watch?v=P6IKMaSR1yU
This price, or something close to it, reveals the true cost of construction using earthbags. If you’re paying substantially more, then your money is going toward inflated prices for things. Sure, things are more expensive in the US than Mexico, but watch the video and see what I mean. That $2,000 house would cost maybe $125,000 (or more) in many places of the US. Part of the solution is to build your own small, simple house and avoid credit.
Shine On Sierra Leone, a human service foundation that provides education, mentoring and nutritional support to schools in Sierra Leone constructed a school building using earthbags. The building was made without power tools, but instead hand made tools. The idea was to use materials that are easily accessible to locals.
At first, the workers laughed at the idea of “building with bags” and very quickly, they became excited and took ownership in a way that brought the village together in an unprecedented way. They asked if they could name the building “Unity Building” because all of the tribes felt united and that they were essential. The roof is traditional, as the intended dome shape took some getting used to in the village. However, due the huge success of this building, they now want to build the first eco-dome village in Sierra Leone. The dome will make the buildings very, very affordable, as the roof is usually the most expensive part.
Illac Diaz of the Philippines has helped mount an exhibit of earthbag building at the La Salle Museum in Costa Rica. He posted lots of photos of the construction at http://illacdiaz.multiply.com/photos.
