Where Does Rammed Earth Work?
Clifton Schooley is a green building professional specializing in insulated rammed earth construction and architectural design in Canada and worldwide. His vision is to create environments that are beautiful, artistic, sustainable and have a positive social impact. Clifton believes that both design and construction of a building must be intimately connected to bring maximum benefit to both people and the environment. Beyond rammed earth his ambition is to become an eco-developer and influence society on a larger scale. For more information, visit: www.rammedearth.info
Questions and Answers
Q: I am interested in building a rammed earth house either in Ohio or Nevada. Are there states where the technique doesn't work?
A: Rammed earth is suitable to use in any state. Since it is a durable material it can handle many types of climates from hot and arid to cold and humid. Rammed earth has been used successfully throughout history in a wide variety of environments on 6 continents.
Q: Hello, I live in south Mississippi. I am a police officer living on a single income, and have a wife, seven children, and one one the way. I am trying to plan a rammed earth home to accommodate my family. I want it to be self sufficient. My wife and I will be providing the labor, and materials must be paid for out of pocket. My question is do you know if any rammed earth homes have been built in this area? And if so, how have they faired with local code offices?
A: (Leonard Jones) Rammed earth buildings have existed for many centuries, on every continent, and nearly every climate. There is no reason you can't make it work in South Mississippi. However, most rammed earth buildings in the U.S. have been constructed in the arid climates of the Southwest. Those in high altitude locations are designed around the idea of using passive solar heating most months of the year with little need for cooling; those in low altitude locations are designed around the idea of minimizing solar gain and sheltering the occupants from the extreme, but dry, heat. As I recall from my own time in the South, the weather is anything but arid... So, you really can't use the same designs that are common in, say, Santa Fe and expect them to work well for you.
I can think of at least four issues that you should bear in mind as you design your house:
* You get a lot of rainfall down there along the Gulf Coast. Rammed earth is durable, but it will erode over time if directly exposed to rainfall or to "splashback" from rain falling nearby. This means that your design should include a verandah or very wide eaves around all sides of the house. A verandah could easily be turned into a screened porch and provide quite a bit of useful space.
* For the same reason, you should make sure that your house is built on high ground, with concrete foundations for the rammed earth walls that are high enough to ensure that floodwaters will rarely, if ever, touch the rammed earth.
* You will also need to ensure that either natural or powered ventilation is provided to take care of humidity problems that may occur, especially around bathrooms and the kitchen.
* Solar exposure of your house should also be very limited in your relatively hot climate. Otherwise, the interior of the house will tend to become and stay uncomfortably hot. Windows should be placed on the north side of the house unless they are well-shaded. A verandah and/or wide eaves will help with this.
I would like to suggest that you read the following two books; they will provide a great deal of information and will help you with design
and construction. You may be able to get them through your local library, perhaps through inter-library loan. But if necessary, I'd recommend that you buy them. The purchase price of a couple of books is minimal compared to what your house will cost, even if you build very economically. And... the value of good information when planning cannot be overestimated. These books are:
* Comfort in Any Climate by Michael Reynolds, Solar Survival Press. Reynolds is the "godfather" of the earthship, a building technique that uses old tires packed with earth for walls. In this book, he suggests some methods for making an earthen building comfortable in a variety of climates, including the hot, humid one where you live.
* The Rammed Earth House by David Easton, Real Goods Press. Easton is a noted architect and engineer who has designed a large number of rammed earth houses, mostly in California. He has studied rammed earth architecture and building methods world-wide and details his findings in this book. His comments regarding the important area of form building for rammed earth are particularly interesting and useful.
Additionally, I'd like to suggest that you and your wife carefully consider whether rammed earth is the best method for you to use. Review
these books and read about the rest of the methods detailed in the greenhomebuilding.com website. Rammed earth can be done on a low-tech, low-cost basis, but this usually happens in third-world locations where large amounts of low cost labor are available. When you add technology, the cost goes up. I have learned this the hard way on my own projects. Also, rammed earth walls should be done in substantial-sized sections - which requires devotion of quite a bit of time... This could be difficult given that you must continue to make a living while you are building. You will find that at least reasonable construction skills are required to do rammed earth; if you read Easton's book, you can see what is necessary and determine if your skills will be adequate. Several other methods, including adobe and earthbag come to mind when I think of a family-based project. These methods are technically simpler and are built in smaller units than rammed earth. This makes it easier to see progress as it is happening - and easier to get something useful done in a limited amount of time... If you have spent time in the military, as many police officers have, you may already have some experience in earthbags!! It's worth thinking and talking about...
Finally, unless you are planning to build in an area where building permits and inspections are not required, I'd suggest that you have an
informal discussion with someone in your local building department. Earthen buildings are "out of the ordinary" in most areas, and they may have questions, concerns, and issues that need to be addressed before you actually file a permit application.
Q: Is it possible to apply rammed earth in asia? What are the materials?
A: (Kelly) Rammed earth building can be, and has been, done all around the world, for many centuries. The Great Wall of China is partially rammed earth construction. All you need is soil that is a mix of clay (15-30%) and sand or other larger particles, without too many stones. This is moistened and then tamped or compressed into forms to create walls. Some Portland cement or other stabilizer can be added for greater durability if desired, but this is not necessary. Usually the walls are at least 18 inches thick. Doing this is hard work, and often is done with heavy machinery, but it can obviously be done by hand as well.
Q: I am a 5th year architecture student working on my graduation project. I am focusing on sustainable and green architecture. I have done some research on rammed earth, I would like to talk with someone in the construction end of the process. I am looking at using it in Taylor's Falls, MN and it seems like it should work but I'm not sure.
A: (Bruce King) Rammed earth, like all other earthen building systems, provides excellent thermal mass and almost no insulation. Thus, it would be very hard to keep comfortable in Minneapolis, and almost all the rammed earth I'm aware of in North America is being built in the desert southeast or California. Even in northern California, with a relatively benign climate, rammed earth homes without very careful attention to solar gain tend to be cold in winter.
C: (Kelly) I would add that it is possible to insulate the rammed earth walls on the outside to provide a more comfortable house in cold climates.
Q: I lived most of my life in Western Australia, where rammed earth is a pretty accepted method of constructing a home, and all my life wanted to build one. But now have moved to Europe. I live in the mountains, temp is 35 C (95 F) summer down to -15 C (0 F) winter. Can I make it work here?
A: (Leonard Jones) Rammed earth structures have been successfully built and utilized on every continent; some have been in use for very long periods of time. As an example, major sections of the Great Wall of China were built from rammed earth. You may wish to consult David Easton's book, "The Rammed Earth House," for more information about the history and application of rammed earth. (Easton is a California architect/engineer who has done a lot of work with rammed earth.) So, I would say that there is no reason you could not build a rammed earth house in Europe.
However, I would urge you to proceed with care. Many currently-built rammed earth houses are in dry/temperate climate areas that get a lot of sun, like the Southwest U.S. and your former home in Australia. A lot of the art and engineering surrounding these houses relates to these climates and to rammed earth use in conjunction with passive solar features to achieve comfort without a lot of supplemental heating and/or cooling. Depending on just exactly where in Europe you are located and the micro-climate where you plan to build, such a home may or may not work well on a thermal basis. Additionally, you will need to ensure that the rammed earth walls are well-protected from erosion by rain and/or surface water.
As you continue to research the potential of a rammed earth house, I would suggest a couple of things. First, investigate the older vernacular architecture in the local area - from the days when winter heating required a lot of human effort - before grid-based electricity and oil/gas fuel were common. People invariably figure out what works best for a given set of circumstances and it is reflected in what they build. If there are no rammed earth or similar buildings in the local area, there may be a good reason. Perhaps some other form of earthen construction would be more appropriate... or maybe something else altogether.
You may wish to investigate modifications from "the usual" that would make a rammed earth house work better in your particular climate. The best source I have found for this information is Michael Reynolds' "Comfort in Any Climate." Reynolds is the inventor of the rammed-earth-tire house known as the earthship. Earthships are similar in general method and intention to rammed earth houses, and the methods described in this book are generally applicable to rammed earth houses - or any earthen structure.
Q: I am attending George Brown College in Toronto, Ontario, and am taking Construction Engineering. Some day I would like to build custom homes with the distinction of the houses actually being good for the environment. What I would like to know is how rammed earth housing would suit the Canadian climate and where I can go to get as much info on rammed earth as possible.
A: (Leonard Jones) Rammed earth buildings have been constructed on every continent except Antarctica, including some pretty cold and snowy climates. I don’t know why it wouldn’t work in Canada, with due attention to the appropriate details. (The devil is always in the details; you will learn this early in your engineering career!)
To be honest, much of the most recent rammed earth work has been done in the sunny Southwest US, including Colorado, New Mexico, Arizona, California, and Texas. In these locations, rammed earth is most frequently used in combination with passive solar heating, and much of the recent literature is directed at these situations. But, what will work in Albuquerque is not likely to work in Toronto; some adaptations would be necessary. The best reference I have found on adapting earthen thermal mass homes to various climates is Comfort in Any Climate by Michael Reynolds. Reynolds is the originator of the “earthship,” a particular design that uses discarded tires rammed full of earth for walls. His book does not provide specific guidance, but is very good on general principles. See also Reynolds’ website at www.earthship.com/
For general information on rammed earth, I would recommend The Rammed Earth House (Real Goods Independent Living Book) by David Easton and Cynthia Wright. Easton and Wright are California architects who have designed many earthen houses; the book contains a lot of good practical information on form building and other construction methods. See also www.rammedearthworks.com/
Another very good book is Adobe and Rammed Earth Buildings: Design and Construction by the late Paul Graham McHenry. McHenry was professor emeritus at the University of New Mexico and was extremely knowledgeable of design principles and construction methods. Although his book contains much of the same information as Easton and Wright’s, but he takes a different approach – providing some interesting contrast. McHenry was the founder of the Earth Building Foundation, which used to maintain an interesting website, but I am no longer able to find the URL.
I would also encourage you to contact Charmaine Taylor at www.dirtcheapbuilder.com. Charmaine, under this URL, operates a small bookstore specializing in books, pamphlets, and other materials related to various types of natural building. She has gone to great lengths to collect rare items and make reproductions available to the natural building community. For this she deserves our support. She will have some of the above books available – and you may also want to purchase some of the pamphlets related to rammed earth.
Q: My wife and I are interested in the Earthship concept. We note that you are building a ram-earth structure. What has been your experience to date, and would you consider alternative building techniques other than building with ram-earth?
A: (Leonard Jones) My experience with rammed earth has been rather mixed to date. It is a very "mechanical" process, requiring a lot of equipment and logistical support compared to some other methods unless you are in a 3rd World situation with a lot of very cheap labor available. It has taken a lot of time and effort to get through all the planning and on to actual earth ramming. Nevertheless, I plan to persevere - to expedite things, I'll be adding some other elements into the basic rammed earth plan.
If I were starting over right now, I would strongly consider earth-bag (EB) construction. Building with EB's is very simple - you can start with not too much more than a bunch of woven polypropylene rice bags, a shovel and a pile of dirt. My favorite idea for EB's would be to build a circular wall up to 7-8 feet high, then top it with a yurt-like roof with a center compression ring and an outer tension cable. There are lots of other options. Kelly Hart's house, for example consists of EB walls with corbeled dome roofs (more or less, at least)
As you are just starting into the planning process, I'd strongly suggest that you do a lot of research. Reading books in the comfort of your home is a LOT easier and MUCH less expensive than making mistakes on your building site. Start with the material on the greenhomebuilding site; then move on to some books. For rammed earth construction, I'd suggest David Easton's The Rammed Earth House, for EB's I'd recommend Hunter and Kiffmayer's Earthbag Building : The Tools, Tricks and Techniques, and for strawbale, I'd recommend The Straw Bale House by Athena Steen and others. I would avoid books that claim to cover a wide variety of building techniques. They tend to be long on glossy photos but short on necessary detail.
Think through the building process carefully, inventory your skills and other resources, and compare them against the project requirements before you decide...
Q: We are thinking about building rammed earth around the Montrose Colorado area at the end of 2006 or the beginning of 2007. We run our own business and don't have time to construct the entire project ourselves. We would like to hire a contractor knowledgeable and experienced to build the major portion of the project, especially the walls. Where do we find a qualified contractor?
A: (Leonard Jones) There are a few contractors around who have done this kind of work before... But contractors come and go, and I'm not sure who is still in business right now.
Something you should be aware of for the purpose of scheduling your project. Rammed earth work should not be done if there is a chance that there could be a hard freeze while it is curing - say for the first week after it's done... Freezing will interfere with the curing of the cement in the mix and its bonding with the earth particles.
Q: My husband is a contractor in building wood frame houses. Recently a customer presented us with a book to build rammed earth houses. Her and her sister want to build one. They live in the south eastern tip of Georgia next to the Florida/Georgia border. I am concerned about the cost, equipment, materials to build, etc. My husband has me doing research on the subject and I have been trying to contact somebody I could talk to about this project. My husband doesn't feel comfortable taking this project on as he knows nothing about rammed earth houses. He is just a small business with maybe 1 or 2 more helpers. Please advise me as to what I can honestly tell my clients about building this kind of house in this area.
A: (Leonard Jones) Earthen houses have been built successfully in just about every area of the Earth. Here in the U.S. most of them are located in the arid SW US, but some have been built in the southern states. So, most of the available information is focused on this area. I am currently building one in South Central Colorado... an arid desert sort of place. There is no reason that a rammed earth house could not be built in SE Georgia, but there are a few concerns that I would have: 1) The foundation would have to be sufficiently high to keep water away from the rammed earth walls. 2) The roof overhang would have to be sufficiently wide to keep rain off of the walls.
Q: I am living in Taiwan and am considering building a rammed earth house in Taitong. Taitong is on the east coast and this is where most of the typhoons make landfall. How can I protect my walls from the rainfall from Typhoons? Is a rammed earth house a practical idea for this location?
A: (Leonard Jones) I encountered driven rain from a typhoon when I was in Korea years ago... Not a pleasant experience!! Thought I was going to drown standing straight up...At any rate, I'm glad to hear of your interest in constructing a rammed earth home in Taiwan.
A typical problem with rammed earth is that it typically will not stand up well to rain that is driven hard by high winds. Also, it will not withstand running water on the ground for long. Nevertheless, with proper precautions, it should be possible to design a rammed earth house that will stand up well in that climate.
What I would suggest in the case you describe would be to design the house with very wide roof overhangs on all sides. Perhaps a design that includes a rammed earth "core" with a veranda and/or screened porches all around would serve well. The house should be located on high ground, where flooding or storm draining will not be a problem. And... the house should have a water-damage-proof footer or foundation (concrete...?? rocks/rubble?? urbanite???) high enough to be above any anticipated water level around all sides to protect the rammed earth wall from lengthy water exposure.
Q: I am a contractor in Lubbock, TX and was considering approaching a fellow contractor about building rammed earth homes. See, Lubbock is a “booming” market for home building and construction in general! I have found, during the process of home remodeling, that this area has issues with termites at the base of the walls in several of the older homes! That’s what peaked my interest with rammed earth! Would Lubbock be a possible place to build rammed earth homes?
A: (Kelly) Rammed earth construction is getting a lot of attention these days, and for good reason. It is fairly common in the Southwest. For energy efficiency and comfort it is best to insulate the exterior to isolate the interior thermal mass. Or you can incorporate insulation, as is done with sirewall.com Another approach is to pour the mix as is done with formfreebuilding.com
Q: We're interested in green home building on the Big Island of Hawaii. Particularly rammed dirt homes, and was wondering if anybody we can reach out to for more information building in our particular area
A: (Kelly) I asked my sister who lives on the Big Island and works as a real estate appraiser, "Are you aware of any rammed earth homes in Hawaii? It requires clay with sandy soil, and I think there may not be much clay there." She replied: Not that I know of. The areas of the most affordable land do not have much soil to work with. I can't think of any resources that could provide information.
