Building the small cob house was my first attempt to create a home that would embody, demonstrate, and make possible the lifestyle that I wanted. The idea was to build a house for free from what was readily available on my property or in the surrounding area. The belief was that without the expenses of
a modern house, without utility bills and loan payments, and with a house designed for our climate and my needs, that I would be more free to pursue my dreams.
Upon research and further inquiry, I established that the most abundant material on my land, as it is mostly pasture, was the earth itself. People have built earthen homes all over the world since people have been building houses, so it is a tried and tested method, although not necessarily in Ohio.
The Native Americans living here at the time of the arrival of the British settlers were building long houses and wigwams out of wood frames with many layers of bark over them. The Ohio settlers built mostly log cabins out of the surrounding forest. This was at a time when Ohio was a mature forest land and large trees were plentiful.
I had access to some nice straight tulip poplar trees that I used to frame the roof, but had to drive down the street to find black locust to use as rot resistant posts that sit in the wet ground. Gone were the four foot diameter trees of Ohio old growth forests. Dirt was everywhere, however, and the ideal mix for cob, a sand to clay ratio of about 3:5, lay right below my feet at the convergence of a sand stone ridge and a bed of typical Athens red clay. All I needed now was some long thin pliable material to use as a sort of rebar to help hold the mixture together. Typically dry straw is used, as straw does not decompose if kept dry and remains strong through the generations. I read about using hay or any other cut and dried fibrous material, but instead of experimenting I chose to purchase straw from a local farmer. All that was needed to complete the mix was water, and after excavating a large pit just down stream from a spring, a small pond began to develop right next to the building site.
The unique challenges of building with Cob in an often cold and wet climate like that of Athens, Ohio is that cob must be kept reasonably dry. If it remains water logged for too long, it simply turns back into mud and walls collapse. To address this issue Ibuilt the roof extra large with wide overhangs to block the blowing rain. The cob walls were then build upon a stone foundation that is raised off the ground high enough to keep them safe from piled snow and flowing water.
Cob, like brick or stone, provides little in the way of insulation, but rather works on a principle called thermal mass. Being enormously heavy, cob can store a lot of heat or cold. If the structure is heated all day by the sun or from within by a fire then it absorbs this heat like a sponge and slowly releases it. In this was temperature changes are slow in a cob house, but once it is sufficiently warmed, it stays that way for a long time. Ideally a house like this could be oriented to receive as much Winter sun as possible, and this was my theory: take advantage of passive solar gain. I slowly discovered what I have always known, however-that Athens has grey, almost sunless winters. I was happy that I built a small house and could heat it with wood alone.
So the project progressed slowly, growing as I had resources and time and help. I had immense help from friends and family and an accomplished artistic architect, Greg Howison, currently of Vinton County, lived with me and helped mix cob for two months. In about a year I was ready to move in. More to come….. Next info on building the living roof.