WHAT IS EARTH BUILDING?

Earth construction is an ancient technique which has been refined until today it involves knowledge of soil science, engineering and building construction. The most common ways of building with earth are described in the side bar to the right.

The beginnings of Rammed Earth can be traced deep into the history of civilisation. The Great Wall of China, 7.5 metres high and 9 metres wide in places, was built of Rammed Earth and stone (246-209 BC), and in Germany and France there are several buildings of rammed earth over 400 years old.

Earth homes are economical to build, and the relationship of earth building to the environment can not be matched by any other building material. There is no smell of synthetics, no sound of mechanical systems and no rattling when the wind roars. A home of Earth is simply a constructed environment that grows from the earth, yet remains as a natural, sustainable environment.

The design of earth homes, and their thick walls, make interior temperatures quite stable on a daily and yearly basis. In summer, the walls of the home are cooled at night, and their thickness and construction allow them to hold that cold through the heat of the next day. In winter, the homes are heated by the sun during the day and the walls release heat during the night and help keep us warm. The technique - "thermal storage" - works very well. In our homes already constructed, the daily temperature changes average only 5 degrees.

1. Mud Brick

Also known as "adobe" or puddle brick, this is possibly the best-known form, used both in custom-built and low-cost projects. Once identified, suitable soil is mixed with water and sometimes a waterproofer/stabiliser, and then moulded into bricks using simple wooden or steel forms.

Sun-baked, the bricks are laid using a mortar comprising the same elements used to make the brick. The mixing process can be achieved manually or by using a motorised pug-mill. A popular and cheap stabiliser is asphalt emulsion, which results in a completely waterproof structure without the need for rendering.

2. Compressed Soil Bricks

This method relies on mechanical pressure to compress soil to a density which allows the bricks to be used as building units. The plant used for the process can either be a manual lever-operated system or a high-production hydraulic press. Many brick designs have been used around the world, including interlocking dry-stack shapes, and even partially hollow forms.

3. Rammed Earth

Rammed earth involves the incremental compression of a soil/stabiliser mixture using pneumatic rams within sturdy shutters. Compressed to a stone-like density, the resultant wall is smooth and extremely strong. this method offers great design freedom in terms of form and texture.