Adobe

Adobe is a building material made from loam and natural things. The word "adobe" means mudbrick in Spanish. People have used this material for thousands of years, and it is one of the oldest building materials known.

You can see adobe buildings all over the world.

In places with Spanish history, like the Southwestern United States, the word adobe can mean any building made from earth. These buildings look similar to others made from cob or rammed earth. Adobe buildings have existed since before 5,100 BP, showing they have a very long history.

Description

Adobe bricks are small, rectangular blocks that dry quickly in the air. They are made from soil and other natural materials. These bricks can be stuck together to build structures. Adobe bricks come in different shapes and sizes. Some common sizes are about 20 cm by 10 cm by 30 cm and weigh around 10 kg. Others can be larger, up to about 45 kg. When bricks get too heavy, the material can be packed directly into place, a method called rammed earth.

Strength

In dry places, buildings made from adobe can last a very long time. Some of these buildings are among the oldest in the world. They stay cool or warm better than others because they are thick. But they can be damaged during earthquakes unless they are made stronger. Big earthquakes have hurt many adobe buildings, like in the 1976 Guatemala earthquake, the 2003 Bam earthquake, and the 2010 Chile earthquake.

Distribution

Buildings made from sun-dried earth can be found all over the world. Places like the Middle East, Western Asia, North Africa, West Africa, South America, and parts of the United States and Europe have such buildings. People in areas like the Southwestern United States, Mesoamerica, and the Andes have used adobe for thousands of years. The Puebloan peoples built their homes with adobe using their hands or baskets before the Spanish showed them how to make bricks. Adobe bricks were also used in Spain from the Late Bronze and Iron Ages. Adobe is popular because it is easy to make and cheap.

Etymology

The word adobe has been used for about 4,000 years. It started in Middle Egyptian around 2000 BC as a word for "mud brick." The word then passed through Late Egyptian and Coptic, into Arabic, and finally into the Old Spanish language. English took the word from Spanish in the early 1700s, and it still means a type of mud brick.

Today, in English, adobe can also describe a building style found in dry places in North America, like in New Mexico, no matter how the building is made.

Composition

An adobe brick is made from earth mixed with water and natural materials like straw or dung. The soil usually includes sand, silt, and clay. Straw helps the brick stay together and dry evenly. Dung can also help the brick stay together. The best soil for making adobe has about 15% clay, 10–30% silt, and 55–75% fine sand. Sometimes modern adobe is made stronger with special materials.

Material properties

Adobe walls stay standing because they push down into the foundation. The blocks need to be strong enough to stay upright.

Adobe is a good material for keeping buildings comfortable. The thick walls can store heat. On hot days, the walls warm up slowly from the sun and air outside. After sunset, the walls release heat inside for several hours. This helps keep the temperature inside steady, which is why people have used adobe for a long time.

Uses

Adobe bricks are made by pressing mud into a wooden frame. In North America, they are usually about 25 by 36 cm (10 by 14 in) in size. After putting the mud in the frame, it is removed when the bricks start to set. They are then turned to dry completely. Drying them in the shade helps prevent cracking.

The same mud mixture, without straw, is used to make mortar and plaster for walls. Some cultures added lime-based cement to the plaster to protect it from rain. Adobe bricks can be shaped in many ways, as long as they dry evenly and have materials like straw or cement to make them stronger. Builders often test the soil first to make sure it has the right mix of sand and clay.

Adobe walls need strong support because they are very heavy. Builders often use deep footings and add steel to help the walls stay steady. Adobe walls are usually not built higher than two stories because they do not hold much weight. When making windows or doors, a lintel is placed above to hold the bricks in place. Wooden or concrete beams are placed on top of the walls to support the roof.

Adobe roofs are made using a mix of soil, water, sand, and organic materials pressed into wooden forms to create bricks. These bricks are then laid on a framework of wood or metal beams. In dry climates, traditional flat adobe roofs are still used. Heavy wooden beams called vigas are placed on top of the walls, with smaller beams called latillas on top of them. Brush is laid over the latillas, and then the adobe bricks are applied. Over time, the roof may need reshaping and weeds removed to keep it in good condition. Adobe roofs can be fire-proof depending on the materials used.

Adobe around the world

The largest building ever made from adobe is the Arg-é Bam, built by the Achaemenid Empire. Other big adobe buildings include the Huaca del Sol in Peru, which has 100 million bricks, and the ciudellas of Chan Chan and Tambo Colorado, also in Peru.

People still build with adobe today in many places. Examples include houses in Kyrgyzstan, Romania, and Sa'dah, Yemen. There are also famous adobe sites like the Poeh Museum in New Mexico, US, and the Taos Pueblo in Santa Fe, New Mexico. The Great Mosque of Djenné in Mali is made from a type of adobe called banco.