Adobe
From Wikipedia, the free encyclopedia.
- This page deals with adobe, the construction material. For information about the software company, see Adobe Systems.
Adobe is a building material composed of water, sandy clay and straw or other organic materials, which is shaped into bricks using wooden frames and dried in the sun . Adobe structures are extremely durable and account for the oldest extand buildings on the planet. Adobe buildings also offer significant advantages in hot, dry climates, as they remain cooler as it stores and releases heat very slowly.
The word "adobe" is Spanish and comes from the Arabic "at-tub", the brick, and from the Coptic "tObe". The word may be pronounced ah-doh-beh or uh-doh-bee. Buildings made of sun-dried earth are common in the Middle East, North Africa, and in Spain (usually in the Mudejar style). The method of brickmaking was imported to the Americas in the 16th century by Spaniards.
A distinction is sometimes made between the smaller adobes, which are about the size of ordinary baked bricks, and the larger adobines, some of which are as much as from one to two yards long.
In more modern usage, the term "adobe" has come to mean a style of architecture that is popular in the desert climates of North America, especially in New Mexico. Cf. stucco.
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Composition of adobe
An adobe brick is made of soil mixed with water and an organic material such as straw or animal dung. The soil composition typically contains clay and sand. Straw is useful in binding the brick together and allowing the brick to dry evenly. Dung offers the same advantage and is also added to repel insects.
Adobe bricks
Bricks are made in an open frame, 25 cm (10 inches) by 36 cm (14 inches) is a reasonable size, but any convenient size is fine for your own use. After the mud is put into the frame the frame is removed. After a few hours the bricks are put on edge to finish drying. Bricks should be dried in the shade to avoid cracking.
Use the same mixture you use to make bricks for mortar when laying the bricks and for plaster on the interior and exterior walls. Some ancient cultures used concrete for the plaster to avoid rain damage. It is sometimes useful to include occasional pieces of wood as you lay a wall to give something to nail insulation onto, and stone can be used for additional strength.
The largest structure ever made from adobe (bricks), was the Bam Citadel, which suffered serious damage, up to 80%, by an earthquake on December 26, 2003. Other large adobe structures are the Huaca del Sol in Peru, built using 100 million signed bricks, and the ciudellas of Chan Chan, also in Peru.
Thermal properties
Because an adobe wall, either made of bricks or using a rammed earth technique, is quite massive it will hold heat or cold. A south facing adobe wall may be left uninsulated in order to collect heat during the day. It should be thick enough that it remains cool on the inside during the heat of the day but should be thin enough that the heat can be transferred through the wall by evening. Such a wall can be covered with glass to increase heat collection. Used in a passive solar home, such a wall is called a Trombe wall. Adobe has a large thermal mass, therefore this type of construction is only good in tropical climates. In temperate climates it is almost impossible to heat a home of this type as the heat is leached by the ground and the walls.
Around the world
See also Hassan Fathy, mudbrick
External links
Earth Architecture - A website whose focus is contemporary issues in earth architecture.