Natural Builder’s ~ Natural Thoughts

by Laurie Burnham 7/08

I spent my summer vacation playing in the mud.

Well, not exactly playing, but rather learning to build with it at a workshop conducted through Seven Generations Natural Builders. I flew to upstate NY, camped out in a tent for a week, and worked in the hot sun, elbow to elbow with six other very sweaty but eager novice builders, all to gain insight into a “new” method of construction which turns out to be as old as the dirt under our feet.

Dirt (actually clay soil), sand and straw combined with a little water make a versatile, durable building material that has been used all over the world since ancient times. If you apply it as a wet material it is called “cob” from the Welsh word for lump, and if you make bricks of it, allowing it to dry, it is “adobe”, which can be seen in the Pueblo dwellings of the American SW. The beautiful photos in the book Built by Hand, tell the story; throughout history the majority of the Earth’s people have resided in homes made of the Earth, and most continue this legacy today. These dwellings are as unique as the cultures that build them, the materials being so adaptable and allowing for personal variations throughout the building process, but also share an intrinsic beauty through the way they harmonize with their particular surroundings. 

Each morning we gathered around 7:30 to make the day’s cob. Cob can be mixed by hand- uh, foot, in a ‘dance’ akin to stomping grapes. Using a large tarp as the base, you first combine the dry ingredients, making a well in the top for the water. By dragging the corner of the tarp towards you and back, the cob is folded in on itself until well mixed. In-between folding, you dance on it, squishing it into a regular consistency. Then you add a few handfuls of straw, and stomp this in with more of a “come on Baby, let’s do the twist” action to cover it with the mud mixture. The straw forms a matrix, which gives the cob strength; the sand prevents the clay from cracking when dry. You can also make “Bob Cob,” mixing the ingredients with a Bobcat tractor. Purists frown on this, but we did eventually try it, and it sure saved us some time, though there was a problem with a hydraulic leak… which is why the purists frown!

Once you’ve got a good mix, you form it into balls or lumps and apply it to the wall, building up layer by slow layer to form walls that are usually 12- 18” think. When dry, cob walls provide excellent thermal mass or ‘heat battery’, which means they absorb heat from the sun, and then slowly release it as the air around them cools, a very useful property for distributing heat in the wintertime.

I’d been interested in cob construction for about three years, since I came across a book called The Hand-Sculpted House. As an artist, I was thoroughly intrigued by the sculptural qualities of the buildings I saw in this beautifully illustrated ‘how-to’ book. Some of them reminded me of Hobbit homes (for you Tolkien fans) or fairy-tale cottages, with meandering lines, rounded corners, undulating walls, and warm natural materials. They looked like they were raised right up from the earth, which in fact they were, forming a totally integrated retreat for the soul. These seemed like places where one could really live and connect to themselves, their loved ones, and the world around them.

After reading the book, I’d made a few attempts at mixing cob in my back yard, but was unsure of the “right” combination of materials. As our incredibly knowledgeable and easy-going instructor, Mark Krawczyk, reminded us again and again, there is no right or wrong, “it just all depends.” The mix you need is determined by the intended use. Mark told us it’s like making Tex-Mex food; the same basic ingredients used in different combinations or forms results in different, delicious dishes. So you can make a very strong cob by using many long strands of straw in the mix, or you can make a finish plaster by using smooth sand, a rich ‘clay slip’ mixture and very short, finely cut pieces of straw.

Most days we’d work until 9 and then come in for breakfast. The hosts, Paul and Sasha, had bought 70 acres in upstate NY near the town of Binghamton, and had built a straw bale house for themselves and their two children. Their home is beautiful, and surprisingly… normal looking. “This is straw bale?” I asked. In fact, it’s a tradition when you’ve built with natural materials to install a “truth window”, a small window with a view of the exposed inner materials, because people don’t believe the walls are actually straw, or cob. And the house was also large…I’d been expecting more of a “cottage”, but here was a two-story structure with four bedrooms, a spacious loft area, open kitchen, exposed wood beams, and terra cotta colored plaster on the walls. Paul, a high school English &Literature teacher, told us that he’d never even put a bookcase together when he decided to build with straw bale. He and Sasha, a therapist, are passionate about conserving resources, so this type of construction was a “natural” fit. Using straw bales to form the bulk of the building’s walls has several advantages. First of all, straw is of course a natural material, so there’s little construction waste and no formaldehyde or other chemicals often used in today’s manufactured materials polluting your home environment. It’s also an excellent insulator. It keeps things cool in the summer and warm in the winter, while allowing air to pass through, letting the structure breathe. Lastly, stacking bales requires little technical skill, just patience and the ability to use a “plumb line” as your guide for keeping the walls straight.

The architect who worked with them on their project, Laura Intscher of “Secret Base Design”, had never worked this way before, but was so taken with this construction method that she designed and built a very high-end straw bale home for herself and family, and now only does natural building or “green” projects.

We toured Laura’s home, which looked more like a museum, with its open space, clean lines, and subdued color palette favoring a Japanese aesthetic. Indeed, with the entire South wall made of plate glass (to take advantage of ‘passive’ solar heat, also known as “light coming through the windows”) and the huge Japanese lanterns hung over the kitchen bar, a hungry couple had once mistaken the home for a fancy Asian restaurant. Laura said they use only the masonry fireplace (a traditional European design in which a high temperature fire is maintained for an hour or so each day with the heat stored within the mass of the heavy fireplace to slowly provide a radiant heat source for twenty four hours or more) built onsite by a craftsman from Canada, as their primary source of heat well in to January (remember, this is snow country!) all the while supplementing with radiant heat under the cast concrete floors. The heat is generated by geothermal coils: water enters the system at 55 degrees, only needing to be cranked up 10-15 degrees to keep things toasty. Ingenious! Efficient! Inexpensive! I began to wonder why this isn’t a more standard approach to building.

“Natural” vs “Green” building: is there a difference?

Over the course of the week, several discussions examined the idea of “green” vs. “natural” building. I thought they were the same thing, but soon learned there are some important considerations that can cause proponents of each view to end up in very different camps.

“Natural building” refers to a philosophy advocating sustainable practices, using locally available, minimally processed materials and methods seen in traditional cultures the world over. It tends to be more “low tech” and human-scale (no McMansions here.) The building will be positioned in harmony with the land (perhaps bermed into a hillside to take advantage of the consistent temperature of the earth and to create a lower overall profile), as well as the angle and direction of the sun during different seasons, and the natural flow and availability of water over the area.

“Green” building, while going several steps in the right direction, has in many ways been co-opted by corporations as more of a label for certain products or a marketing device, rather than a philosophy of sustainability. In other words, the aim isn’t so much to lessen the processing of items or to reduce consumption, but rather to create a more efficient end product. While I think this is a good start, there are some problematic aspects to it. For instance, installing granite or marble counter tops is certainly using a natural product, but if they are quarried in one far away place, finished in another, shipped to a distributor in California or New York to then be sent to the Mid-West, some of the earth-friendly gleam is tarnished, and a huge carbon footprint created (all of the gas/oil/energy consumed to process and ship it), by the time they arrive at your door.

The way I sorted it out for myself was to ask: can this product be locally sourced and does this product or method solve a problem? If it can and does, without creating other equal problems or environmental concerns, then it’s acceptable, whether you call it “green” or “natural”.

So, after a hearty, healthy breakfast we’d work on various aspects of the project, breaking for lunch at 1:00, and dinner at 6 or 7. Life broke down into a pretty simple routine: when you got too hot you went and jumped in the above-ground pool or the pond down the lane, washed off a few layers of grime and sweat, and joined back in to work and dry out in the sun. The work was satisfyingly physical and results quantifiable: put the cob on the wall, the wall gets taller. Simple as that. The group laughed a lot, worked well together, and the feeling of community made the effort seem even more worthwhile.

We were a varied bunch. First, guiding and encouraging us all was our instructor, Mark. He has a woodworking shop on the banks of Lake Champlain where he makes furniture from hand-hewn trees. But really he has explored so many facets of creating a sustainable, self-sufficient life style, and traveled widely to work and study with people out there living this way, that it’s difficult to apply a label to what he does. I was blown away by this guy’s knowledge about construction methods, from ancient to what we’d call conventional, about materials and techniques, and about different aspects of forestry. A real naturalist and a born teacher, he was always able to explain concepts in simple terms, with a dry sense of humor, and to lend a helping hand when needed.

There was one guy from Vermont, an obviously caring and involved teacher who was implementing a sustainability curriculum at his high school, one ex-boxer turned social worker who was preparing for her entry into Grad school (and taught me some cool guitar chords), a young electrician from Seattle who’d quit his job to travel the country in a VW van, working on farms along the East coast. There was a recent college grad sampling workshops and zeroing in on his purpose in life (a sustainable, natural life!) Then there was the self-proclaimed Anarchist, a big guy with a sweet nature, dedicated to social equality within our communities. There was the computer wiz returning home to the East from California. He kept bees, converted his car to run on veggie oil and was planning to create a “food forest” at his parent’s farm using the guidelines of Permaculture. And there was me, an artist/ teacher/ soccer Mom from the mid-west who didn’t mind getting her hands dirty.

Yes, we were a varied bunch with a common purpose. Our main objective was to build a straw bale tool shed connected to a cob-walled green house.  Participants of an earlier workshop had laid the “French drain”, or rubble trench foundation, and built up the lower walls using a combination of rammed earth (feed-bags and old tires packed w/ dirt), and cob.

Our group was lucky- we got to sample so many things- it was a smorgasbord of natural building techniques! We raised the level of the cob walls, we created slip-forms and built the foundation walls, we mortared stone, we even helped select and fell a nice, straight White Oak to be used as the central support beam for our structure. I helped strip all of the bark from the slender trunk, preparing it for our use. With hand tools and a chain saw we carved and notched the poles and beam to fit together securely, and raised the frame for the roofline. And finally, after several hard and rewarding days’ work, we got to stack some straw bales, learning to ‘sew’ them into place to create the walls of the tool shed.

Now, back home with my two boys, having seen, felt and experienced the materials, I am happily looking forward to my first project: using cob to build a bread oven at our farm. One of the most wonderful and unique aspects to cob building is that it is very democratic; old & young, men & women alike can safely be on the construction site, enthusiastically participating in this communal experience. In no time, my sons will be as good at this as I am. My mom can help if she wants to. And we’ll have some delicious homemade pizza to share as we sit back and admire our job well done, together. After that come the mosaic-encrusted cob garden benches, and the straw bale potting shed, and…