Friday, May 23, 2008

Week 2: Stump to Sticker

While the concrete grade beam cured under a blanket of plastic, the Natural Building students set about to the task of harvesting some trees on the Yestermorrow campus. The trees would then be milled in preparation for their delivery to the project site and use on the building. All of this excitement would be commandeered by Nick Zandstra, an experienced woodsman whom bears a slight resemblance to movie star Owen Wilson. Nick brought his portable, Woodmizer Sawmill (, as well as many tools of the tree felling trade to the Yestermorrow. Just as importantly, he brought a flexible attitude which would serve well in trouble-shooting some of the tree-felling.

The class began with an overview of the characteristics of wood and the various tree species inhabiting the Northeastern United States. The students then took a tour of the Yestermorrow campus and worked on identifying different types of trees. Nick also pointed out many of the factors that should be taken into consideration when looking for a tree to fell. Some of these include the application(s) of the wood to be cut, the amount of potential knots in a tree from the branches, and being aware of the other trees or obstacles in the area that could be affected by or cause problems in the felling.

Next, Nick went into a brief overview of chainsaw safety and spoke about some of the different models available on the market. At this point, Nick showed the class a tree he had pre-selected to be cut down. However, in the time since deciding on the specific tree and teaching the class, one of the Natural Building students had set up their outdoor living space within proximity to the Eastern White Pine that Nick had his eye on. This posed a potential problem since Nick originally wanted to fell the tree in that direction. (I must interject here that I was keenly interested in this situation, since the above mentioned living space consisted of my Vanagon camper and a pop-up gazebo that I had erected). After some discussion and to my relief, Nick decided to drop the tree in another direction. However, I remained uneasy since the tree was leaning towards my unsuspecting van. In turn, this gave Nick a perfect opportunity to talk about how to control where a tree will fall.

Nick prefers a tree-felling method known as the open-face bore method, which may be referred to as the bore notch or simply, the open-face method. The important thing to remember is that this method involves leaving a “hinge” about a 1/3 of the way into the tree, and leaving a small section of the tree, opposite the open face notch, that keeps the tree from falling until this section is cut. This is often referred to as the “release” or the “latch”. This method offers several advantages over more traditional methods of tree-felling. Most importantly, this method allows for the sawyer to be in control of the tree until the last cut is made, given him or her one last chance to view the escape path and look for possible hazards. Since the saw is out of the tree for the final cut, rather than deep inside the trunk, this method allows the sawyer to walk away from the tree faster and with the saw in hand. By utilizing a hinge, a sawyer can control where a tree will fall and decrease the chance of a tree kicking back towards them, which is when a tree literally jumps off the stump and back towards the sawyer. As an added bonus, this method allows for obtaining the most amount of wood from the tree. More information on tree-felling methods and safety can be found in forestry books and on the internet. (A good description of this method is offered at

After deciding where he wanted the tree to fall, Nick demonstrated the notch cut, which is oriented in the direction of the fall path. This consists of a 70 degree cut down into the tree and meets up with a horizontal cut, about 1/3 of the way into the trunk, resulting in a tall, wedge-shaped notch. You want to cut the tree as close to the ground as possible, but also give yourself enough room to work with the saw. Next, Nick made a plunge cut into the heart of the tree to separate the fibers and prevent tear-out. A problem often associated with tree-felling is know as splintering, or tear-out. This occurs when the fibers in the middle of the tree pull out of the falling tree and remain on the stump. This can be remedied by making a horizontal plunge cut into the middle, or heartwood, section of a tree perpendicular to the open-face notch. By doing this, a sawyer can separate the fibers of the tree from the stump, but still maintain control of the tree. The next cut involved another horizontal plunge into the tree, this time from the sides (with the front being the side with the open-face notch). Once the bar of the chainsaw was completely inserted into the tree, he worked his way carefully toward the notch and left about a two-inch hinge between this cut and the notch. With the saw still in the tree, Nick cut towards the rear and made sure to leave a small section of the back of the tree in tact. This produces the latch, or release point, where the final cut is made. This step is integral to maintaining complete control of the tree. Finally, Nick took one last look for any possible obstacles and also made sure every one else was in a safe area. As Nick cut the latch and quickly walked away, the class witnessed an act of near perfection as the tree fell within a couple of feet of the chosen fall path. Meanwhile, I finally breathed a sigh of relief knowing my home on wheels was safe, at least for the moment!

Wednesday, May 21, 2008

Week 2: Foundations

After enjoying a relaxing weekend, the students in the Natural Building Certificate Program at Yestermorrow greeted each other Monday morning and readied themselves for the week ahead. The days would be divided into two separate classes: Foundations and Stump to Sticker. The latter course would focus on the processes involved in milling local lumber, while the former would cover the basics of designing a good foundation. Both classes would relate directly with the project at Knoll Farm since the students would be pouring the foundation for the structure and using the milled lumber in the building.

Having established a visual foundation of the project, as well as an understanding of natural building materials and methods, the class set about understanding the physical foundation of the building on Monday. Led by the eccentric-jack-of-all-trades, Robert Riversong, the students learned about the many different styles of foundations in the world of building. From slab-on-grade to full cellar to frost wall, the class discovered the importance of a good foundation as well as the importance of choosing the correct style for a particular site. For the project on Knoll Farm, a rubble trench foundation was chosen for its lessened use of concrete, and hence, a reduced impact on the environment. Concrete happens to be the most widely used man-made product in the world and its manufacturing and transportation accounts for upwards of ten percent of total, global energy use. Therefore, it is of paramount importance that the reduced use of concrete occurs, while the research and development of alternatives continues so that more environmentally friendly options become available.

The rubble trench foundation was also chosen for its superior draining capability. Vermont is known for its very wet soils and the site at Knoll Farm proves the point quite well! A layer of bedrock at the site keeps rainwater near the surface and offered a challenging design aspect for the foundation. To remedy this situation, filter fabric was laid at the bottom of the trench below the frost line. Then, a few inches of small rocks, also known as rubble, were backfilled on top of the fabric. This was followed by the placement of a perforated, drainage pipe over the layer of rubble. More rubble was then poured over the pipe and then the filter fabric was wrapped over the “rubble-pipe sandwich”. The rubble trench was then completed by backfilling more small rocks into the trench to bring the level up to grade, or ground level. This design allows the inevitable flow of water to go through the foundation, while keeping the drainage pipe free of debris. Since the water is always on the move there is very little chance of freezing, or frost-heaving, which can cause a foundation to move and consequently wreak havoc on the structural integrity of a building and/or its components.

With the rubble trench in place, the students began the task of leveling out the top of the rubble in preparation for the pouring of a concrete grade beam. The grade beam distributes the weight of the structure onto the rubble trench, while also forming the “footprint”of the building. Additionally, the grade beam serves as a barrier for any water that might make its way into the structure. By using a contractor's level, the students were able to sight the level of the rubble within an 1/8 of an inch all around the footprint. This would assure an even and level pour of the concrete for the structure to sit upon...and this was just Monday.

Tuesday found the class putting together the form boards for the grade beam. While some concrete contractors often throw away the form boards after a pour, instructor Robert Riversong came up with a method of reusing them within the floor of the structure, which would be built later. By wrapping plastic around the top, inside, and bottom of the 2x12 boards, the students were able to keep the forms free of concrete. Simple ideas such as this one can save a lot of money, as well as reduce the resources used in a project.

Having squared off the form boards to the correct dimensions for the footprint, the students used Wednesday morning to lay three, parallel runs of rebar inside the forms. In a foundation, the rebar is usually set about two inches off the bottom and adds structural integrity to the concrete beam. In terms of a more natural material for this application, bamboo is often used since it possesses a similar tensile strength to the steel found in rebar. With the everything set for the pour, the students sat down to lunch and awaited the concrete truck to roll up the hill.

A concrete pour could be compared to the chaos that ensues when a raindrop hits an anthill: once the first drop hits, it is a scramble to make sure everyone is in the right place and doing their job properly. Depending on factors such as the weather and the amount of water in the concrete mix, the material can set up quite fast and being prepared is the key. As the driver of the truck guided the chute over the forms, the students quickly went to work spreading the concrete inside the boards. Once an area was filled, the truck would move on down the line the process would repeat itself. Meanwhile, other students used “skree boards”, two foot long 2x4's, to smooth out the top of the beam and ensure even coverage throughout. In perhaps the most satisfying aspect of the pour, still other students used metal trowels to finish the beam with a silky-smooth texture.

As the truck neared the last section of the beam, the final ooze of concrete crept out of the chute. In a humanistic twist of fate, the amount of concrete ordered barely missed filling out the form. Such is the nature of the beast in the world of building, be it natural or conventional. While the truck driver cleaned out the chute of the truck, a second order of concrete was placed. However, the minimum order for delivery far exceeded the amount needed for the empty area. So, in a creative twist of fate, the students brainstormed for some alternative uses for the extra material. These are the types of real-life situations found in Yestermorrow classes that would not be found in the conventional classroom. The result, after the second truck came and went, were several concrete-block stairs which were imprinted with the shapes of leaves from around the site and a concrete bench to commemorate the site.

By paying careful attention to the design of the foundation at Knoll Farm, the use of concrete was minimized without sacrificing the structural integrity of the grade beam. This attentive planning also provided the ability to reuse the form boards that helped to shape the beam. Thinking about these logistics also helped make for an easier pour, despite having to order more concrete. In the end, the problem quickly turned into a creative solution. The natural beauty infinitely imprinted on the concrete stairs will serve as a reminder of the ability to turn an unwanted situation into a lasting, loving memory.

Friday, May 16, 2008

Week 1: Intro to Natural Building

Arriving from all over the United States and with origins as far away as France, the six students in the Natural Building Certificate Program at Yestermorrow trickled into the campus in the Mad River Valley on Sunday, May 11, to start a summer-long journey into the world of building with natural materials. This revolutionary, hands-on experience is in its second year of existence and is designed to inform students on the characteristics and potential of natural building materials, the infinite applications of these materials, and involves a real-life project in which the students will put their knowledge to the test. Building on the success of 2007's inaugural Natural Building Certificate program, this year's project scope has been expanded in scale while remaining true to the ideas of local material use. This year's project site is located on a beautiful hillside amongst the birch and maple trees of Knoll Farm and overlooks the lush, green mountains of the Mad River Valley.

Upon arriving at the Yestermorrow campus, new students were greeted by informed and welcoming interns who participate in a popular work-trade program offered by the school. After getting settled into their respective living quarters, ranging from strawbale cabins to tent platforms nestled in the woods, from campus dorm rooms to Vanagon campers, the students sat down to a delicious spread of local food-fare, lovingly created by the creative kitchen staff of Yestermorrow. Pleasantly plump from dinner, the students and instructors continued with an informal meet and greet and laid the groundwork for the groundbreaking coursework ahead of them.

For the better part of Monday and Tuesday, the students listened and questioned with inspiration and intention as instructors Jacob “Deva” Racussin and Ben Graham discussed many of the different natural building materials and the even more varied uses of them in the world of construction. A focus on materials native to Vermont were highlighted in direct relation to their use in the project on Knoll Farm. Unlike many areas of the United States that have been degraded and depleted of their natural resources, the state of Vermont offers much of the natural beauty, and hence materials, that have made their home here for millenia. However, many of the students were amazed at how readily available many of the materials are to most localities. As with dialects or food dishes, natural building materials vary from place to place. Some of the more universal materials generally found in most places include clay and sand for plasters and finishes, strawbales used in highly-insulated wall systems, a variety of soft and hardwoods from trees used in their natural state or milled into framing lumber, timberframes, flooring or trimwork, and stone to build a variety of foundation systems, as well as landscaping and other aesthetic details.

On Wednesday the crew loaded into the trusty, campus van and headed off on the scenic highways of Vermont for a tour of structures utilizing some of the materials and applications they became familiar with over the previous two days. The first stop offered an interesting blend of natural and conventional building materials and emphasized how the two can be used in harmony to achieve high-efficiency while treading lighter on the earth. Having built and designed the timberframe for the home, instructor Ben Graham gave the students a first-hand tour of the structural system while Jacob Racussin, better known as “Deva” and an earthen-plaster master, highlighted the benefits of the strawbale-infill walls and how they work synergistically with natural plasters. While utilizing the natural strength and beauty of a timberframe structure, more high-tech systems such as radiant flooring and a wood-fired boiler were integrated into the house providing warmth for the home through the cold, Vermont winter. While the extent of conventional heating and cooling systems can be
reduced or even replaced through attention to detail and passive-solar design, the integration of these systems into natural structures offers a hybrid combination that may be more realistic and appealing to some home-owners.

The next stop on the tour focused on the ability to create structures from materials found right on site and how the concept of “living off the land” can be applied to the context of natural building. By adhering to some of the tenets of permaculture to actually grow and harvest your own building materials and observing what materials are available on the land, the homeowner is able to utilize natural materials for structures while symbiotically creating a food supply. Some of the highlighted structures included a wood-fired sauna made from on-site materials and a passive, solar-powered composting toilet system. The students noted that by understanding natural processes and becoming familiar with native, food-producing plants, a homeowner can actually work with nature to improve the eco-system on a given property, rather than degrade a piece of land in pursuit of the whimsical desires of the conventional “American Dream”.

The next site visit continued the theme of using materials from the property, while integrating the ideas of reuse and community. Set on a hillside with 130 mile views of Vermont's Green Mountains, a home made of straw and clay sat humbly, whispering the stories of the estimated 500 people who helped build the structure. By engaging the local community into the building process, the homeowners not only helped to educate and inspire others on the wonders of natural building, but also got a amazing amount of free labor! The idea of “work parties” has been lost in our pursuit of the consumer mentality so often found in America. The revival of this not-so-long-ago tradition represents an integral part of the ideals of natural building and most importantly, they are really fun for folks of all ages.

The final destination of the tour showed the application of natural building in the context of a public space. Faced with a growing student population and needing more classroom space, a Waldorf school outside of Plainfield, Vermont approached course instructor Ben Graham about designing a new space for the 8th grade students. Ben's approach to the design was truly inspiring and rather unique, especially considering the school wanted a structure that could be moved at a later date. Additionally, the natural build students had the chance to speak with the Waldorf students about their impression of the space. It was noted that the natural light entering the classroom helped the students to focus and put them at ease. One eighth grader mentioned that while the kids in the main building complained about being too hot in the warmer months or chilly in the winter, the students in the strawbale classroom stayed comfortable year-round, even sporting t-shirts in January. The benefits of natural building extend not only to the environment, but also to the people occupying these beautiful spaces.

Having passed on some knowledge of natural building materials and techniques and shown the students some real-life applications of their uses, instructors Jacob and Ben challenged the students to create their own scale models of some natural wall systems. The fun started Thursday when the group traveled to some local spots within a few minutes of the campus to gather some materials for the project. The first stop took the collective to a beautiful vein of clay that had been exposed by the meticulous work of a small brook. The natural properties of the material were quickly noted when one student unintentionally showed the rest of the class how to take a mud bath! After filling up some buckets with the slippery, yet sticky material, the class headed off to another quarry to gather some sand.

Upon returning to the Yestermorrow campus (and after a few students changed into less muddy clothes!), the class divided into two groups and began the process of designing models of two different natural wall systems: a straw-bale wall and a wood-chip clay wall. The latter system involves an insulative infill of wood-chips mixed with a clay slip and can be formed within a variety of wall structures, from traditional stud frames to lath and plaster systems to a wicker-like style known as waddle and daub. The straw bale system is often used as a highly insulative wall system for timber frame structures and can also be utilized with more conventional post and beam or stud frames.

The process of designing the systems proved challenging, yet rewarding, as the students gathered more materials from the campus grounds and started to see how the individual pieces fit together as a whole. By offering advice, yet taking a step back from their role as instructors, Jacob and Ben guided the process but left the details up to each group. Rather than presenting a classroom lecture, this approach resulted in a more thorough, hands-on and comprehensive understanding of the respective systems, and embodies the style of learning found in so many of the classes offered at Yestermorrow. Each group presented their model on Friday, which fostered a further understanding of how the systems work and the purpose and function of each material. Additionally, these models will serve as visual aids for future Yestermorrow students to observe and improve upon.

As Friday came to a close, the students and instructors embraced in group hugs and a great feeling of accomplishment. The week was a great start to a wonderful summer in the mountains of Vermont. As I walked back to my Volkswagen home-on-wheels after an evening of food, drink, and celebration, I reminisced on how perfectly the week came together. The campus of Yestermorrow and the students and teachers it attracts provide an infectious energy that is wonderfully contagious. While I thought about the week ahead and beginning work on the project at Knoll Farm, the moon peaked out from behind the Green Mountains, casting a soft light over the campus and reminded me to instead enjoy the moment at hand.