An Introduction to Building with Adobe
Construction of adobe buildings can be traced back to 500BC, and the method of construction has changed little during the intervening 2000 years or so, except that nowadays, the adobe mixture can have asphalt added and then be hydraulically pressed into brick molds. But the traditional method of packing the mix into the brick molds by hand is still widely used and a more satisfying method.
The brick molds are usually made from wood, to the required size of the brick.
The components comprising of clay, sand, straw and animal dung are mixed with the water then packed into the mold, ensuring that all the air has been pressed out of the mix. Once this has set, the mold is removed leaving a formed adobe brick, which will be left for up to a week to harden, depending on the weather.
Once sufficient quantities of bricks have been prepared, (a single storey house can require 6,000 bricks) the construction of the building walls can be commenced.
The bricks are laid in the traditional fashion known as a running bond, the mortar being made from the same mix as the bricks, but of a more watery consistency and without the straw component. The foundations can comprise of poured concrete or the traditional method of footing which is to compress the earth to support the weight of the walls above it.
This is the fourth in a series of articles on natural green materials for buildings, the previous ones being on straw, logs and rammed earth.
As with the previous articles, the descriptions and method used for the buildings is to illustrate the aesthetic quality, durability and suitability of the material, and not to be used as a technical construction manual.
We shall begin with the components of the mixture used when building with adobe.