Sunday, July 24, 2011

Chickens for Poor People, Part 2

Aimee, a fellow blogger who writes New To Farm Life, made another insightful and informative comment on my post, “Chickens for Poor People.” She said,

I mean, it [the tendency I spoke about to make chicken-keeping and other acts of self-reliance more complicated than necessary] might be another symptom of the same disease that causes helicopter parenting - an overwhelming anxiety that things will go to pieces if you aren't in total control of all variables at all times.

“I'd like to recommend Storey's guide to chickens (they have a whole series on farming). These guides are down to earth and relaxed, providing information but with a general attitude that even children can successfully raise animals of all types. Storey's chicken book has plenty of plans for simple chicken houses, too.

“My chickens roost in the rafters of the barn. Most breeds of chicken will do fine with a roof, a good windbreak, clean water and ample food. They need a few square feet apiece, minimum, to stretch and scratch. Chickens will be extra happy if they can also make wallows and take dirtbaths.”

That sounds like good advice. I'll have to find Storey's book when I get a chance. And it's helpful to realize that chickens, being birds after all, are quite able to survive without human intervention. (Otherwise, there'd be none on earth today!)

On another note, posting will be light over the next week (and maybe two). I've got a ton of homework to grade and I need to catch up.

Sunday, July 10, 2011

Chickens for Poor People

I'm working on a research-heavy post, but it's not quite ready. The information contained therein will be bad news to some folks (maybe quite a few folks), but then again, a lot of news about the world seems very bad nowadays. Anyway, I've been a bit busy – so here is a short (and hopefully somewhat lighter) post for this week.

An urban gardening education outfit called Growing Gardens hosts an annual “Tour de Coops” as part of their program of promoting urban chicken-keeping in Portland. The Tour de Coops originally started out as a bicycle tour of various local chicken-keeping homes, but has since grown geographically to the extent that many people drive from house to house to view chicken coops. Around a year and a half ago I started building a chicken coop in my back yard, thinking I could knock out the project in a few weeks. But my life got very busy and I quickly ran out of inspiration as I remembered the warnings I had heard in the chicken-keeping classes I had attended – warnings which distilled in my head into the message that “you must do everything just right or your birds will die!!!”

“How do you build a coop just right? What does just right look like?” I wondered. So I bought a book of chicken coop plans and I thought back to the chicken coops I had observed during the Tour de Coops which I had witnessed. As I sought to implement the things I had observed, I couldn't help but notice how much money I was dropping at Home Cheapo for what seemed to be the requisite building materials. The plan I chose from the book I bought seemed to me to be very basic, yet it was still more elaborate than I would have liked. At times I fumed about the potential cost per egg over the lifetime of my coop.

That got me thinking about the various coops I had seen during the Tour de Coops I had witnessed, as well as the general tone of the chicken-keeping classes I had attended. A large number of the coops I saw on tour and in class were, shall we say, palatial, with electric lighting, ventilation (and maybe even heating in one case), and all built by yuppie or post-yuppie types who viewed their birds as cute, affectionate members of their extended family. (How is a full-grown chicken “cute”?) “Where do you find the time or energy to build all that?” I wondered.

Immigrants and people outside American upper middle-class culture tend to view these things very differently. When I told some of my immigrant friends about my chicken coop project, almost all of them asked why I didn't just pick up a coop for free from Craigslist. Only one of them has built anything that is anywhere near as elaborate as coops, American-style seem to be becoming. But that's not the best part. After I started my coop, I noticed during my travels on bicycle that several back yards had birds who were housed in very simple boxes with chicken wire on their fronts. I kept thinking, “I could have done that!

All of which brings up an uncomfortable observation. It seems that many who have been thoroughly marinated in American upper middle-class culture have a fundamental blind spot when it comes to trying to do anything simply and frugally. Some of us who look for strategies for sustainable living render those strategies unsustainable by turning those strategies into status symbols. So we have “fair trade” coffeehouses, sanctimonious hybrid vehicle owners, people who browse issues of Real Simple whenever they visit Whole Foods Market, people who try to balance stressed-out materialism with a few hours a week at a yoga studio, people who build chicken palaces with full utility hook-ups in order to make a statement about “sustainability,” people who take their cars to a Tour de Coops. And we have whole industries devoted to catering to the self-image of these people.

What's needed is chickens for poor people – along with a truckload of other survival strategies for people who have fallen (or have jumped) off the upper middle-class train. (There are more of us each day in this country.) We also need competent teachers of these strategies. Some of the coops featured in the Tour de Coops may lately have been sending the wrong message. Growing Gardens will probably never read this post of mine, but if they do, I hope they will bear with a bit of gentle constructive criticism from a friend.

Friday, July 1, 2011

The Sound Foundations of Engineered Earth Construction

Earth construction has recently attracted great interest as post-Peak building method for the First World. (By post-Peak methods, I mean methods of producing useful products which are suitable for a declining or collapsing economy whose resource base is drying up.) The reasons for this interest have to do with looming resource constraints, in particular, the resources required for construction methods which have become standard over the last hundred years in the developed world. However, the principles of proper earth building design and construction must be thoroughly understood and properly implemented in order to avoid loss of life due to failure and collapse of buildings. There is a strong need for validation of techniques, practices and principles of structurally sound earth building. This validation must be accomplished via experimentation and mathematical modeling and analysis.

This validation is also of special interest in the Third World (also known as the developing world), where, according to at least one source, approximately one fifth of the world's population lives in adobe and rammed earth structures, and where, according to another source, more than 90 percent of the population in moderate to severe seismic zones is living and working in non-engineered earth buildings. A body of work now exists which documents the behavior of earth buildings when subjected to various loading events, including seismic and wind events. This development of this body of work has been spearheaded by engineering professionals, universities and governmental agencies both in the developing world and in the First World nations of the Global South.

This work reveals some surprising facts, both with regard to safe earth construction best practices and with regard to the flow of useful information in the developing world. As far as the flow of useful information, two things can be observed. First, there is a much greater proportion of public-minded engineering and technical professionals in the developing world compared to professionals in the First World. This is seen in the willingness of researchers to openly and freely disseminate their published work via the Web without charging rent on “intellectual property.” In the First World, on the other hand, rent-seeking vultures have restricted the free flow of potentially life-saving technical information in many cases. (Many of the publications from First World sources on the topic of earth construction are behind paywalls. One refreshing exception in the United States is the Getty Institute.) This is one reason why the Third World may be better poised for post-Peak adaptation than the First World. Secondly, the universities and professionals of the Third World are every bit as capable and competent as those in the First World, and in fact they may be far more creative.

In the literature which I have discovered, there are two categories of discussion regarding performance of earthen structures: the performance of non-engineered structures and the performance, experimental testing and analysis of engineered earthen structures. These discussions reveal the following observations:

  1. Almost all of the literature states that typical non-engineered earthen structures perform very poorly when subjected to severe and sudden wind loads or seismic events. This applies both to rammed earth (also known as tapia, taipal or pise de terre), cob and adobe structures. Rammed earth constructions and other earth structures can be highly susceptible to damage from earthquakes and other ground motion.

  2. The mechanism of disintegration of earth walls for various types of earth construction have been studied via shake table and compression tests. Among other things, these tests have documented the anisotropy of multi-layer rammed earth walls. A material that is anisotropic has physical properties that vary at different locations and in different directions in the material rather than being uniform throughout the material. This is important if there is a concern that a wall made of anisotropic material might have material properties that are not constant throughout the wall.

  3. Techniques for stabilization and reinforcement of earth structures have been studied. One study focused on two particular approaches: internal reinforcement via chicken wire or bamboo, and external reinforcement with bamboo or wooden members. Internal reinforcement did not work nearly as well as external reinforcement, which spread earthquake stresses over a large wall area, dissipating earthquake energy without causing major cracking.

  4. Proper reinforcement of earthen walls is key to surviving earthquakes and other environmental events. Unreinforced earthen structures suffered a number of typical failure modes. In addition, walls or wall elements that are reinforced internally with biodegradable materials like straw have been known to fail due to degrading of the reinforcement by insects and rot.

  5. As a result of laboratory tests, mathematical modeling and observations of actual earth structures in the aftermath of actual earthquakes, a number of governmental agencies and NGO's have published earth construction design guides. Many of these design guides agree on key points. In addition, there are countries in the developing world and the Global South which have formulated or are formulating earth building codes. New Zealand is one such case. Their New Zealand Earth Building Standards can serve as a repository of best practices and a starting place for model codes for earth building in other countries. Unfortunately, access to the New Zealand standards is not free.

  6. In addition to design guides for building professionals and code-enforcing officials, certain governments and NGO's have developed earth construction manuals for non-professional, unskilled builders who would be typical in rural or poor urban populations. Among the governmental agencies disseminating this design information is SENA (Servicio Nacional de Aprendizaje,, a national public entity of Colombia in South America, which publishes literature for public education and vocational training throughout South America. In addition, the Indian Institute of Technology at Kanpur has published the IAEE Guidelines for Earthquake Resistant Non-Engineered Construction, which is available in PDF form free of charge at the IIT Kanpur National Information Centre of Earthquake Engineering website. A 2011 draft update of these guidelines is also available from the International Institute of Seismology and Earthquake Engineering in Japan. Such guidelines embody low-cost, effective approaches for building safe earthen structures.

  7. Researchers have studied the challenge of reinforcing and retrofitting existing earthen structures which have historical significance. Recommended retrofit practices are emerging. Many of these retrofit practices involve addition of bamboo reinforcement to the exterior surfaces of earth walls, both outside and inside an earthen structure, in order to spread forces and stresses so that they don't result in concentrated failure at one point.

Many more facts could be gleaned from the available literature, but unfortunately, I am out of time. However, a list of references and cited works is included at the end of this post. Enjoy!

Additional References And Resources:

  1. Seismic Behavior and Rehabilitation Alternatives for Adobe and Rammed Earth Buildings,” Luis. E. Yamin, Camilo A. Phillips, Juan C. Reyes, Daniel M. Ruiz, 13th World Conference on Earthquake Engineering, 2004.

  2. Modern and historic earth buildings: Observations of the 4th September 2010 Darfield Earthquake,” H.W. Morris, 9th Pacific Conference on Earthquake Engineering – Building and Earthquake-Resilient Society, April 2011.

  3. Non-Engineered Construction In Developing Countries – An Approach Toward Earthquake Risk Reduction,” Anand S. Arya, 12WCEE 2000, Ministry of Urban Development, Government of India.

  4. Review of Non-Engineered Houses in Latin America with Reference to Building Practices and Self-Construction Projects,” Aikaterini Papanikolaou, Fabio Taucer, European Commission Joint Research Centre, 2004.

  5. Seismic Performance of Mud Brick Structures,” Joseph Hardwick and Jonathan Little, University of Bristol, EWB-UK National Research Conference 2010 and Engineers Without Borders UK, 2010.

  6. Low-Cost and Low-Tech Reinforcement Systems for Improved Earthquake Resistance of Mud Brick Buildings,” Dominic M. Dowling and Bijan Samali, The Getty Institute.

  7. Assessing the Anisotropy of Rammed Earth,” Quoc-Bao Bui, Jean-Claude Morel, 11th International Conference on Non-Conventional Materials and Technologies, 2009.

  8. Planning and Engineering Guidelines for the Seismic Retrofitting of Historic Adobe Structures,” E. Leroy Tolles, Edna E. Kimbro, William S. Ginell, The Getty Institute, 2002.

  9. An Improved Means of Reinforcing Adobe Walls – External Vertical Reinforcement,” Dominic Dowling, Bijan Samali, Jianchun Li, SismoAdobe 2005, Lima, Peru.

  10. Earthquake Resistant Rammed-Earth (Taipal) Buildings,” J. Vargas, Catholic University of Peru.