Post by ReCOnnect Collective on Apr 24, 2015 23:44:33 GMT -7
This thread is to talk about anything related to Building, whether it is ideas that ReCOnnect wants to pursue or just ideas you find interesting.
Plastic Bottle Houses This link briefly discusses how building homes out of plastic bottles could potentially end homelessness.
Build It With Bales Build it with Bales is a very informative e-book that really delves into straw-bale construction. If you are planning on building with straw-bales this is a must read!
Earth Plaster A quick guide on creating Earth Plaster (different than Cob)
Cob Builders Handbook The Cob Builders Handbook is an in depth e-book that provides valuable information on cob construction. A great resource on building with Cob.
The Construction of a Yurt Another great book that details how to build a Yurt or the Mongolian Gehr. These giant sized tents can be used to travel or set up permanently. There would also be many ways to adapt the construction to incorporate many re-use friendly alternatives.
When you tell people you’re building an Earthship there are two stock responses. First there are the believers. These are the people who’ve watched Garbage Warrior, twice. They want to talk design and permits and timeline. They’re into it. The other stock response is an incredulous repeating of the word back to you with a question mark attached. Earthship?
Yes, Earthship. And here’s the story of how my family built an Earthship in southern Alberta this summer.
We didn’t rush in. After first reading about Earthships in The Geography of Hope by Chris Turner I passed the book along to my dad Glen. He was intrigued so we volunteered on a build near Wheatland, Wyoming. It was invaluable seeing one built first hand and meeting other volunteers and the crew. My dad even volunteered on another build in Hundred Mile House in central B.C. the next year.
A couple years later after everything was in place my parents went down to Taos, New Mexico to check out finished Earthships first hand. Suitably convinced they came back with plans for a three bedroom, two bathroom Global Model with a couple of modifications. Earthship roots
* Earthship founder, Michael Reynolds working on the Kinney Earthship.
Earthship founder, Michael Reynolds working on the Kinney Earthship.
Michael Reynolds is the father of the Earthship movement. A draft dodger from Ohio he ended up in Taos, New Mexico – a neo-hippy outpost on the high desert plain that’s ringed by mountains.
An architect by training and rabble-rouser by nature he was dissatisfied with standard home design and started building radically sustainable houses out on the mesa using garbage. Before recycling was a thing he was using bottles, cans and tires alongside natural and conventional building materials.
Building off-grid, self-sufficient homes out of garbage did not, at first, appeal to the Glen Kinney’s of the world. My dad has worked in oil and gas for 35 years. But for the past 20 years Reynolds has been perfecting the Earthship. And while it might sound a little wacky it has four walls, a roof, flush toilets and satellite TV just like any other North American home.
* Dawn Kinney in the greenhouse, which also serves as the main hallway in the Earthship.
Dawn Kinney in the greenhouse, which also serves as the main hallway in the Earthship.
The design revolves around six core concepts,
On-site electricity production Turning rainwater into drinking water On-site wastewater treatment Passive heating and cooling Food production Using readily available materials
An Earthship is a long skinny bungalow with an earth berm enveloping the back and sides with a greenhouse on the front. The back and side retaining walls are made of tires sledgehammered full of dirt. These tires become a 200-pound steel belt encased brick. Non-load bearing interior walls are made of aluminum cans sandwiched into a honeycomb matrix of concrete. But it’s not just the recycled materials that make it an Earthship it’s the whole package. Solar powered, off-grid home on the prairie
It generates electricity on-site with solar panels and batteries. Drinking water is caught by the metal roof and collected in four cisterns capable of storing 5,800 gallons of water. That water is treated and filtered down to five microns to make it ready to drink. Greywater from the showers and bathroom sinks is used to water a planter in the greenhouse that is already producing a bumper crop of tomatoes. That greywater is pumped back into the house and used to flush the toilets. Simple earth tubes and ceiling vents in the greenhouse keep the house cool in the summer. Passive solar design, thermal mass, lots of insulation and southern Alberta’s glorious bounty of sunlight keep the house warm in the winter.
While we plan on installing a wood stove, Earthships maintain a consistent livable temperature through the winter by maximizing passive solar gain and incorporating a tremendous amount of thermal mass into the building. The Earthship rises
* The Earthship walls were made out of 800 tires and 12,000 cans.
The Earthship walls were made out of 800 tires and 12,000 cans.
We hired the Earthship crew and Michael Reynolds himself, from New Mexico to come build the house. With them came another 30-35 volunteers who camped on-site. It was an amazing experience. Eight hundred tires were pounded and stacked by the end of the fourth day. Pounding tires isn’t the easiest job, but it sure is easier with a giant crew.
Around 12,000 cans were used throughout the build for interior walls, for the bond beam that sits on top of the tires and to help fill in and pack out the tires to get them to a level surface.
In five weeks we had almost an entire house. The roof was on, the walls constructed, and the systems worked. Now we’re down to the detail work, the sanding, staining and painting. They expect to move in by November 2014.
Media interest was through the roof. The CBC, CTV, Radio-Canada, the Calgary Herald, the Lethbridge Herald all did stories. Roughly 600 people packed themselves onto our property for an open house asking questions and gawking at the systems.
What began as a radical alternative in the New Mexico desert 30 years ago has evolved into an inspiring and surprisingly simple home. And the lessons learned from Earthships can be seen today in increasingly popular net-zero homes.
People want greener, cleaner, more energy efficient housing and they’re educating themselves about it. And whether you end up redoing the insulation on your existing home or building an Earthship, it all counts. I’m excited to be back for our third season of Green Energy Futures and we hope that these stories will help you build a better future.
(Mother Earth News) Expert advice on how to establish self-sufficient food production, including guidance on crop rotations, raising livestock and grazing management. Your 1-acre homestead can be divided into land for raising livestock and a garden for raising fruits, vegetables, plus some grain and forage crops. Illustration by: Dorling Kindersley
Everyone will have a different approach to keeping a self-sufficient homestead, and it’s unlikely that any two1-acre farms will follow the same plan or methods or agree completely on how to homestead. Some people like cows; other people are afraid of them. Some people like goats; other people cannot keep them out of the garden. Some people will not slaughter animals and have to sell their surplus stock off to people who will kill them; others will not sell surplus stock off at all because they know that the animals will be killed; and still others will slaughter their own animals to provide their family with healthy meat.
For myself, on a 1-acre farm of good, well-drained land, I would keep a cow and a goat, a few pigs and maybe a dozen hens. The goat would provide me with milk when the cow was dry. I might keep two or more goats, in fact. I would have the dairy cow (a Jersey) to provide the pigs and me with milk. More importantly, I would keep her to provide heaps and heaps of lovely cow manure to increase my soil fertility, for in order to derive any sort of living from that 1 acre without the application of a lot of artificial fertilizer, it would have to be heavily manured. RAISING A DAIRY COW
Cow or no cow? The pros and cons are many and various for a self-sufficient homestead. In favor of raising a cow is the fact that nothing keeps the health of a family — and a farm — at a high level better than a dairy cow. If you and your children have ample good, fresh, unpasteurized, unadulterated dairy products, you will be well-positioned to be a healthy family. If your pigs and poultry get their share of the milk by-products, especially whey, they likely will be healthy, too. If your garden gets plenty of cow manure, your soil fertility will continuously increase, along with your yields.
On the other hand, the food that you buy in for this family cow will cost you hundreds of dollars each year. Compared with how much money you would spend on dairy products each year, the fresh milk supply from the cow plus the increased value of the eggs, poultry and pig meat that you will get, along with your ever-growing soil fertility, will quickly make a family cow a worthwhile investment. But a serious counter-consideration is that you will have to take on the responsibility of milking a cow. (For different milking plans and estimated savings, see Keep a Family Cow and Enjoy Delicious Milk, Cream, Cheese and More.) Milking a cow doesn’t take very long — perhaps eight minutes — and it’s very pleasant if you know how to do it and if she is a quiet, docile cow — but you will have to do it. Buying a dairy cow is a very important step, and you shouldn’t do it unless you do not intend to go away very much, or unless you can make arrangements for somebody else to take over your milking duties while you’re gone. So let’s plan our 1-acre farm on the assumption that we are going to keep a dairy cow. 1-ACRE FARM WITH A FAMILY COW
Half of your land would be put down to grass, leaving half an acre arable (not allowing for the land on which the house and other buildings stand). The grass half could remain permanent pasture and never be plowed up at all, or you could plan crop rotations by plowing it up, say, every four years. If you do the latter, it is best done in strips of a quarter of the half-acre so that each year you’re planting a grass, clover and herb mixture on an eighth of your acre of land. This crop rotation will result in some freshly sown pasture every year, some 2-year-old field, some 3-year-old field and some 4-year-old field, resulting in more productive land. GRAZING MANAGEMENT Advertisements
At the first sign the grass patch is suffering from overgrazing, take the cow away. The point of strip grazing (also called intensive rotational grazing) is that grass grows better and produces more if it is allowed to grow for as long as possible before being grazed or cut all the way down, and then allowed to rest again. In such intensive husbandry as we are envisaging for this self-sufficient homestead, careful grazing management will be essential.
Tether-grazing on such a small area may work better than using electric fencing. A little Jersey cow quickly gets used to being tethered and this was, indeed, the system that the breed was developed for on the island of Jersey (where they were first bred). I so unequivocally recommend a Jersey cow to the 1-acre farmer because I am convinced that, for this purpose, she is without any peer. Your half-acre of grass, when established, should provide your cow with nearly all the food she needs for the summer months. You are unlikely to get any hay from the half-acre as well, but if the grass grows faster than the cow can eat it, then you could cut some of it for hay. INTENSIVE GARDENING
The remaining half of your homestead — the arable half — would be farmed as a highly intensivegarden. It would be divided, ideally, into four plots, around which all the annual crops that you want to grow follow each other in a strict crop rotation.
An ideal crop rotation might go something like this:
— Grass (for four years) — Plot 1: Potatoes — Plot 2: Legumes (pea and bean family) — Plot 3: Brassicas (cabbage family) — Plot 4: Root vegetables (carrots, beets, and so on) — Grass again (for four years)
Consider the advantages of this kind of crop rotation. A quarter of your arable land will be a newly plowed-up, 4-year-old field every year, with intensely fertile soil because of the stored-up fertility of all the grass, clover and herbs that have just been plowed-in to rot with four summers’ worth of cow manure. Because your cow will be in-wintered, on bought-in hay, and treading and dunging on bought-in straw, you will have an enormous quantity of marvelous muck and cow manure to put on your arable land. All of the crop residues that you cannot consume will help feed the cow, pigs or poultry, and I would be surprised if, after following this crop rotation and grazing management plan for a few years, you didn’t find that your acre of land had increased enormously in soil fertility, and that it was producing more food for humans than many a 10-acre farm run on ordinary commercial lines. HALF-ACRE CROP ROTATION
Some might complain that by having half your acre down to grass, you confine your gardening activities to a mere half-acre. But actually, half an acre is quite a lot, and if you garden it well, it will grow more food for you than if you were to “scratch” over a whole acre. Being under grass (and grazed and dunged) for half of its life will enormously increase the half-acre’s soil fertility. I think you will actually grow more vegetables on this plot than you would on a whole acre if you had no cow or grass break. Advertisements TIPS FOR THE SELF-SUFFICIENT HOMESTEAD
A dairy cow will not be able to stay outdoors all year. She would horribly overgraze such a small acreage. She should spend most of the winter indoors, only being turned out during the daytime in dry weather to get a little exercise and fresh air. Cows do not really benefit from being out in winter weather. Your cow would be, for the most part, better if kept inside where she would make lovely manure while feeding on the crops you grew for her in the garden. In the summer you would let her out, night and day, for as long as you find the pasture is not being overgrazed. You would probably find that your cow did not need hay at all during the summer, but she would be entirely dependent on it throughout the winter, and you could plan on having to buy her at least a ton. If you wanted to rear her yearly calf until he reached some value, you would likely need a further half-ton of hay. I have kept my cow on deep litter: The layer of straw gets turned into good manure, and I add more clean straw every day. I have milked a cow this way for years, and the perfect milk made good butter and cheese, and stored well. Although more labor-intensive, you could keep your cow on a concrete floor instead (insulated if possible), and giver her a good bed of straw every day. You would remove the soiled straw daily, and carefully pile it into a muck heap that would be your fount of fertility for everything on your acre.
Pigs would have to be confined in a house for at least part of the year (and you would need to provide straw for them), because, on a 1-acre farm, you are unlikely to have enough fresh land to keep them healthy. The best option would be a movable house with a strong movable fence outside it, but you could have a permanent pigpen instead.
The pigs would have a lot of outdoor work to do: They would spend part of their time plowing up your eighth of an acre of grassland, and they could run over your cultivated land after you have harvested your crops. They could only do this if you had time to let them do it, as sometimes you would be in too much of a hurry to get the next crop in. As for food, you would have to buy in some wheat, barley or corn. This, supplemented with the skim milk and whey you would have from your dairy cow, plus a share of the garden produce and such specially grown fodder crops as you could spare the land for, would keep them excellently.
If you could find a neighbor who would let you use a boar, I recommend that you keep a sow and breed her. She could give you 20 piglets a year, two or three of which you could keep to fatten for your bacon and ham supply. The rest you could sell as weanlings (piglets eight to 12 weeks old), and they would probably bring in enough money to pay for the food you had to buy for all your other livestock. If you could not get the service of a boar, you could always buy weanlings yourself — just enough for your own use — and fatten them.
Poultry could be kept in a permanent house in one corner of your garden, or, preferably, in mobile coops on the land, so they could be moved over the grassland and improve soil fertility with their scratching and dunging. I would not recommend keeping very many birds, as just a dozen hens should give you enough eggs for a small family with a few to occasionally sell or give away in summertime. You would have to buy a little grain for them, and in the winter some protein supplement, unless you could grow enough beans. You could try growing sunflowers, buckwheat or other food especially for them.
Goats, if kept instead of a dairy cow (or in addition to), could be managed in much the same way, however you would not have as much whey and skim milk to rear pigs and poultry on, and you would not build up the fertility of your land as quickly as you could with a cow. You would only get a fraction of the manure from goats, but on the other hand you would not have to buy nearly as much hay and straw — perhaps not any. For a farmer wanting to have a completely self-sufficient homestead on 1 acre, dairy goats are a good option.
Crops would be all of the ordinary garden crops (fruits and vegetables), plus as much land as you could spare for fodder crops for animals. Bear in mind that practically any garden crop that you grew for yourself would be good for the animals too, so any surplus crops would go to them. You would not need a compost pile — your animals could be your compost pile.
Half an acre, farmed as a garden with wheat grown in the other half-acre, is worth a try if you kept no animals at all, or maybe only some poultry. You would then practice a crop rotation as described above, but substitute wheat for the grass and clover field. If you are a vegetarian, this may be quite a good solution. But you could not hope to increase the soil fertility, and therefore the productiveness, of your land as much as with animals.
This article is an excerpt from The Self-Sufficient Life and How to Live It, written by the late John Seymour and first published by Dorling Kindersley in Britain in 1976. The book has become a treasured classic for back-to-the-landers and is now available in a beautifully illustrated 400-page edition.
After returning to Florida, she and some friends used the techniques she had learned to build a small pottery shed in her parents’ backyard. Some people predicted Florida’s humid air and torrential rains would melt her “mud hut” back into the ground. Following Hurricane Lili in 2002, however, the sturdy little building, which had cost just a few hundred dollars and a summer’s labor to build, proved to be one of the few buildings left standing in her neighborhood. Christina Ott had discovered cob building. Cob-Building Origins
Cob building gets its name from the Old English term for “lump,” which refers to the lumps of clay-rich soil that were mixed with straw and then stomped into place to create monolithic earthen walls. Before coal and oil made transportation cheap, houses were built from whatever materials were close at hand. In places where timber was scarce, the building material most available was often the soil underfoot.
Building with earth has a long and successful history. Cob construction is particularly easy to learn, requires no fancy equipment, uses local materials, and can be done in small batches as time allows — making it extremely accessible to a wide range of people. (See DIY Cob-Building Technique, later in this article.) After her initial success with cob, Ott traveled to Oregon to apprentice with the Cob Cottage Company. When her family relocated to the mountains east of Nashville, Tenn., Ott used her new skills to build a small cob house for just under $8,000. By age 23, she was mortgage-free and teaching cob-building workshops all over the United States as the “Barefoot Builder.”
In the U.K., tens of thousands of cob buildings are still lived in, some of them more than 500 years old. When the British immigrated to the United States, Australia and New Zealand in the 1700s and 1800s, they brought the technique with them. In Africa, the Arabian Peninsula, parts of Asia and what is now the southwestern United States, cob was developed independently by indigenous people. In Yemen, cob buildings stand that are nine stories tall and more than 700 years old.
However, with the industrial age came factories and cheap transportation in the West, making brick, milled wood, cement and steel readily available. Mass production led to mass marketing and the promotion of these new materials as signs of progress. The perception of cob as “poor people’s housing” led to its near demise. By 1985, there hadn’t been a new cob building constructed in the U.K. for more than 60 years, or in the United States for at least 120 years. Modern Cob Buildings
Today, building your own house is the exception to the norm, and it is almost unheard of to build with local materials. Instead, houses are built by specialists using expensive tools and expensive, highly refined materials extracted and transported long distances, often at great ecological cost. Industrial materials have many benefits — performance, predictability, speed and ease of installation — but they have in common that they must create a profit for the companies that manufacture them. The average number of members in U.S. households has dropped by more than half in the past 50 years. Yet, over the same time period, average home sizes have more than doubled. We are more comfortably housed than at any point in history, but practically enslaved by the payments (the word “mortgage” is French for “death contract”). Fortunately, we have other choices.
In the county where Ott lives, low-income housing is often a crumbling trailer home that is difficult to heat and cool and expensive to maintain. As she sits next to the woodstove in her cozy cob house, she explains that a quick fire in the morning warms the cob walls and will often keep the house warm for a day or more. She uses less than a cord of wood per year. Meanwhile, the same neighbors who laughed about her “dirt house” are stripping their own land of trees and burning trash just to keep from freezing. Some go through as many as 15 cords of wood per year. For less than what many people spend on a down payment, Ott has a house, and it performs well even by modern standards.
Cob’s thermal performance varies by climate region. While cob is a relatively poor insulator, it also has the ability to absorb large quantities of heat. These properties are valuable in regions such as the Southwest, but would be a disadvantage in the chilly Northeast, for example, where heat gains will quickly be lost. This weakness of cob can be solved by building interior walls of cob for mass heat storage while using better-insulating materials for exterior walls.
Anecdotal evidence and recent testing show cob walls are highly resistant to earthquakes. Unlike cement or adobe, which tend to shake apart in an earthquake, lumps of cob are woven together in the building process to form one large mass reinforced by straw fiber. Also, unlike cement, cob is easily repaired with the same material it was built from, and if torn down, there is no waste to be disposed of — only earth that can be returned to the ground or soaked in water and reused to build another room or house. Oregon Cob-Building Method
Outside Coquille, Ore., stands a constantly evolving collection of test buildings affectionately known as “Cobville.” Sculpted cob garden walls weave around and between the tiny cottages, giving each its own sense of space. Here, apprentices and workshop attendees learn and experiment with ingredients, methods and finishes. This is the headquarters of the Cob Cottage Company, which is largely responsible for the re-emergence of cob building in the United States. Founded by Ianto Evans, his wife, Linda Smiley, and Michael G. Smith, Cob Cottage Company started with the radical idea that, with a little direction, almost anyone can learn how to build a cob house.
Evans, a spry Welshman now in his 70s, has reimagined the cob of his birthplace in a more efficient form. The traditional British cob method, which was generally to stomp lumps of whatever clay soil was handy into place, relied on thick walls for strength. “Oregon cob,” by contrast, effectively does more with less. Builders make thinner but significantly stronger walls by tightly controlling the clay-and-sand mix and using lots of straw for reinforcement. “We have created in Oregon cob an almost-free building material most people can manufacture for themselves. It has fluidity of form, and it’s healthy, non-polluting and local. The buildings it inspires are sculptural, snug and permanent,” Evans says. Because you can provide much of the construction labor yourself, cob is very affordable.
But Evans speaks of cob and “natural building” (a term he helped popularize) less in terms of cob-construction methods and more in terms of the social movement it has become. “Building your own house for less than $10,000 is revolutionary, and, yes, you can do it,” he says. “Millions of people in other countries and our own ancestors have proven that.” Evans has seen firsthand the way people are empowered by building their own houses from earth. Cob-Building Community
Thirty years after its founding, Cob Cottage Company has much progress to report. Evans, Smiley and Smith’s book, The Hand-Sculpted House, has sold more than 30,000 copies worldwide. Their CobWeb newsletter documents 18 years of experiments and advances (and failures) in cob technology, and it is available at the Cob Cottage Company. Multiple nonprofits, such as the Natural Building Network, continue to promote cob building and work with code officials to streamline the approval process. Every year, natural builders host regional colloquia to swap techniques and foster camaraderie. Some travel hundreds of miles and sleep in tents to help each other with projects.
Cob Cottage Company alumni are building and teaching all over the world. Despite the downturn in the global economy — or maybe because of it — cob workshops are more popular than ever. On her first building project, Ott’s most steadfast supporter was an unemployed single mother who went on to build her own cob house after her first home was destroyed by a hurricane. Together, they built a building while chatting and watching kids run around the yard. A construction site is not a playground, but without the noise and danger of heavy machinery and without nails littering the ground, a cob-building site is a great deal more family-friendly. Most natural builders go to great lengths to keep that atmosphere on their job sites. Many times I’ve been grateful for that as I watched my young daughters hard at work atop the growing cob wall of a friend’s new bedroom.
If you are serious about building with cob, Evans strongly recommends that you seek hands-on experience, either at a workshop or by volunteering on a project. To find a workshop near you, visit the event calendars on the websites listed in the resources box to the left. Cob Pros and Cons
• Uses local, generally inexpensive or free materials • Can include creative, beautiful detail • Nontoxic • High thermal mass helps temperatures stay consistent and comfortable • Negligible environmental impact • Compatible with other natural materials (wood, stone, lime) • Fun to build with friends • Earthquake-resistant
• Labor-intensive • Needs additional insulation in cold climates • Will be unfamiliar to building code officials and insurers
Returning to basic shelter is a compelling idea, but in most of the United States, a complex combination of building codes, health codes, zoning codes, energy codes, deed restrictions and neighborhood covenants could indeed make you an “outlaw builder” if you decide to construct your own home. Ianto Evans refers to building and living in a low-cost, natural house as “a revolutionary act” and a challenge to “the greed of corporate commerce and the vigilance of its bodyguards, the governmental regulators.” I know people all over the country who are happily (and quietly) living in small cob houses with or without the approval of the local authorities, but knowing what you are getting into before you invest your time and money is important. Even a few thousand dollars (plus your time) is a lot to risk if there is a good chance a neighbor might object to your new dwelling. But the payoff of living cheaply in a house you love is substantial.
The permits for my last cob house were less than $1,000. Code compliance can be costly, however — more than $30,000 for permits in extreme jurisdictions. Perfectly safe alternatives to costly septic systems and wells exist, but they aren’t always legal. Minimum square footage requirements are often several times the size of what a person can afford to build without taking out a loan (which then gives the bank the final say on what you build). People have had their beautiful cottages torn down because they weren’t up to code. Others have built their small houses as “accessory buildings” or kept the footprint under 200 square feet to avoid code scrutiny. Finally, some builders have gone the extra mile to get tiny houses and natural materials approved or even added to the local code. Terry Herb’s recent e-book, No Building Codes, is an excellent starting point.
Your local city or county building department will be able to give you the best information, and the American Society for Testing and Materials has recently issued standards for building with earth. DIY Cob Building Technique
We highly recommend you read at least one book on cob before you tackle a project. See the resources section below for our suggested reading. — MOTHER EARTH NEWS
Prepare the mixture. Cob is a mixture of approximately 1 part clay, 4 parts sand and 1 part straw. You can buy bagged clay in powdered form (go to Laguna Clay for local distributors) and masonry sand from your local supply store. However, most soil is a mixture of some part clay, some part sand and other materials, so you’ll save money if you use your own soil. If you are paying for soil, ask the supplier for your local variant of “compactable fill” or “road base.”
The “soil” we refer to is not the rich, black stuff in your garden or the top few inches of your lawn where everything grows. It is the subsoil below that, with little or no organic matter in it.
Build a foundation. Cob walls are heavier than those made of light timber. Before you build with cob, you will need a foundation that will keep your work up and away from damp ground and a roof that will keep it out of the rain. Natural builders call this having a good “hat and boots.”
Remove all vegetation and topsoil from your site, and mark out the perimeter of your cob construction with paint or pegs.
During rainy weather, water must move away quickly to keep cob dry. Dig a trench that will encircle the structure and lead water away. Backfill the trench with compacted gravel.
Stone or reclaimed concrete chunks (urbanite) make an excellent foundation. Lay your stones on tamped, solid ground within the gravel trench perimeter. You are finished when the foundation material feels absolutely solid beneath your feet.
Mix. Break up soil manually and soak it at least overnight in enough water to turn it into pudding. Pudding is a lot easier to mix with sand than clods of clay are.
The simplest way to mix cob is with your feet. (Music and friends make this a lot of fun.) Spread a 5-gallon bucket of sand on the center of your tarp, then a bucket of wet clay over that, then another bucket of sand.
Mix the sand and clay to form a pile, adding about two more 5-gallon buckets of sand as you mix. Sprinkle straw over your pile. Keep using the tarp to flip your pile, and mix it until the straw is distributed throughout the pile.
Break the mixture into balls — called “cobs” — of whatever size feels manageable, typically about the size of a softball. Make some test sections by molding some cobs together and letting them dry about one week to see how they hold up. You do not want a crumbly mix.
Build and sculpt. Place the wet cobs where desired and smash them into one another to form a single unit. If building a wall, place one cob for the outside face, one for the inside, and one for the middle. Meld together. Continue this process until you’ve formed your structure.
As you work, use your thumbs to knit the straw fibers from one cob lump into the cobs around it. Leave a rough surface for your next layer to stick to by covering the freshly laid cobs with thumb-sized holes, and wet the surface before applying new cob.
Everything you build is an excuse to get artistic. Improve a blank expanse of wall with a carved niche for a candle or special object. Sculpt an alligator or dragon bench to sit on. The steps are the same whether you’re making something big or small; it’s just a matter of scale.
Plaster. To finish the structure, apply plaster in at least two coats: a “brown” coat to even out imperfections, and a final coat, which can be polished or sealed with linseed or hemp oil. A standard lime plaster consists of 1 part lime putty, 3 parts sand and a quarter-part fiber.
Mix the plaster by foot or paddle in a bucket or trash can. Chop straw into tiny fibers using a weed trimmer inside a garbage can (wear eye protection and a dust mask). Cellulose insulation also makes a wonderful plaster fiber. Apply plaster to a slightly damp surface with a firm pushing motion. Plasters will often crack at the line where you stopped or started, so pick unobtrusive points for breaks. Seal plaster by painting it with several coats of linseed or hemp oil.
Maintain. Store leftover plaster in a sealed jar for repairs. Scratches can be rubbed out with rough sandpaper and re-oiled. Large cracks or breaks should be filled with reconstituted plaster, polished, and then oiled after they’ve dried.