cob (material)

Cob, cobb or clom (in Wales) is a natural building material made from subsoil, water, some kind of fibrous organic material (typically straw), and sometimes lime. The contents of subsoil naturally varies and if it does not contain the right mixture it can be modified with sand or clay. Cob is fireproof, resistant to seismic activity, and inexpensive. It can be used to create artistic, sculptural forms and has been revived in recent years by the natural building and sustainability movements.