Appropriate Technology Asia

Earth Construction

Indigenous building techniques in the region make considerable use of earth. In Ladakh, China and certain parts of Nepal, earth is used in several ways.

The first of these is known as rammed earth. Earth is poured into a mould, consisting of side and end shutters kept under tension using ropes at the top and wedges at the base. This earth is then consolidated by stamping or pounding. When the mould is full, the shutters are removed and the whole assembly is moved along to allow the next section to be constructed. Earth is also used as a mortar to bind stone walls. Certain areas hand-moulded mudbricks (adobe) are also commonly used.

Earth construction is ideally suited for such buildings as it generally has better thermal efficiency than cement and concrete structures. However, the nature of the material renders it vulnerable to damage from moisture. The durability of earth walls can be improved by stabilising them with cement or lime, in concentrations of 5-6%. The existing use of mud mortar can also be improved to increase the air-tightness of the buildings, which is necessary for reducing heating costs. ATA uses block-based construction technology such as compressed earth blocks (CEB) and hand-cut adobe, and rammed earth techniques that use improved formwork and soil stabilisation to improve the durability and thermal efficiency of traditional rammed earth construction techniques.