What Is Cob?
Although I use a mixture of natural materials in my work the one I use the most is cob. Cob is both an ancient and modern building material used in different forms and under different names throughout the ages and around the world. From the adobe (mud brick) Pueblo cliff dwellings of the south western United States, to the impressive mud architecture of Mali. From the towering ancient mud sky scrapers of Yemen and quaint cob cottages of Wales and the south west of England, to the modern cob renaissance started in the late 20th century in Oregon. Even today approximately one third of the worlds population live in homes made of mud.
The cob that I make is called "Oregon Cob" and is a mixture of clay rich sub soil (ideally dug on site), coarse sand and straw. This trinity of materials gives you a binder, an aggregate and a fibre. The clay rich soil sticks everything together, the sand offers compressive strength allowing you to build tall, self supporting structures with minimal shrinkage as they dry and the straw gives tensile strength that helps to weave the whole mass of the structure together. It is a remarkably versatile mixture and different combinations of these three basic materials lend themselves to different applications; from a coarse building material to a fine finishing plaster and from a dense thermal mass to a light, fluffy insulating layer. Cob also naturally lends itself to sculptural forms and artistic expression and is wonderfully tactile to work with and live around.
The cob that I make is called "Oregon Cob" and is a mixture of clay rich sub soil (ideally dug on site), coarse sand and straw. This trinity of materials gives you a binder, an aggregate and a fibre. The clay rich soil sticks everything together, the sand offers compressive strength allowing you to build tall, self supporting structures with minimal shrinkage as they dry and the straw gives tensile strength that helps to weave the whole mass of the structure together. It is a remarkably versatile mixture and different combinations of these three basic materials lend themselves to different applications; from a coarse building material to a fine finishing plaster and from a dense thermal mass to a light, fluffy insulating layer. Cob also naturally lends itself to sculptural forms and artistic expression and is wonderfully tactile to work with and live around.