Adobe - AbsoluteAstronomy.com

Natural building

A natural building involves a range of building systems and materials that place major emphasis on sustainability. Ways of achieving sustainability through natural building focus on durability and the use of minimally processed, plentiful or renewable resources, as well as those that, while...

material made from sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

, water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, and some kind of fibrous or organic material (sticks, straw

Straw

Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such as barley, oats, rice, rye and wheat. It has many uses, including fuel, livestock bedding and fodder, thatching and...

, and/or manure

Manure

Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...

), which the builders shape into bricks using frames and dry in the sun. Adobe buildings are similar to cob

Cob (building)

Cob or cobb or clom is a building material consisting of clay, sand, straw, water, and earth, similar to adobe. Cob is fireproof, resistant to seismic activity, and inexpensive...

and mudbrick

Mudbrick

A mudbrick is a firefree brick, made of a mixture of clay, mud, sand, and water mixed with a binding material such as rice husks or straw. They use a stiff mixture and let them dry in the sun for 25 days....

buildings. Adobe structures are extremely durable, and account for some of the oldest existing buildings in the world. In hot climate

Climate

Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

s, compared with wooden buildings, adobe buildings offer significant advantages due to their greater thermal mass

Thermal mass

Thermal mass is a concept in building design which describes how the mass of the building provides "inertia" against temperature fluctuations, sometimes known as the thermal flywheel effect...

, but they are known to be particularly susceptible to earthquake damage.

Buildings made of sun-dried earth are common in the West Asia, North Africa

North Africa

North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

, West Africa

West Africa

West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

, South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, southwestern North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

(usually in the Mudéjar

Mudéjar

Mudéjar is the name given to individual Moors or Muslims of Al-Andalus who remained in Iberia after the Christian Reconquista but were not converted to Christianity...

style), Eastern Europe and East Anglia, particularly Norfolk, known as 'clay lump. Adobe had been in use by indigenous peoples of the Americas

Indigenous peoples of the Americas

The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

in the Southwestern United States

Southwestern United States

The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...

, Mesoamerica

Mesoamerica

Mesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...

, and the Andean region

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

of South America for several thousand years, although often substantial amounts of stone are used in the walls of Pueblo

Pueblo

Pueblo is a term used to describe modern communities of Native Americans in the Southwestern United States of America. The first Spanish explorers of the Southwest used this term to describe the communities housed in apartment-like structures built of stone, adobe mud, and other local material...

buildings. (Also, the Pueblo people built their adobe structures with handfuls or basketfuls of adobe, until the Spanish introduced them to the making of bricks.) Adobe brickmaking was used in Spain already in the Late Bronze Age and Iron Age, from the eighth century B.C. on. Its wide use can be attributed to its simplicity of design and make, and the economy of creating it.

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 may be one to two yards (1-2 m) long.

Etymology

The word adobe ə has existed for around 4,000 years, with little change in either pronunciation or meaning. The word can be traced from the Middle Egyptian

Middle Egyptian

Middle Egyptian is the typical form of Egyptian written from 2000 BCE to 1300 BCE .Although evolving into Late Egyptian from the 14th century, Middle Egyptian remained in use as literary standard language until the 4th century AD. As such, it is the classical variant of Egyptian that historically...

(c. 2000 BC) word dj-b-t "mud [i.e., sun-dried] brick." As Middle Egyptian evolved into Late Egyptian

Late Egyptian

Late Egyptian is the stage of the Egyptian language that was written by the time of the New Kingdom around 1350 BC – the Amarna period. Texts written wholly in Late Egyptian date to the Ramesside Period and later...

, Demotic

Demotic (Egyptian)

Demotic refers to either the ancient Egyptian script derived from northern forms of hieratic used in the Delta, or the stage of the Egyptian language following Late Egyptian and preceding Coptic. The term was first used by the Greek historian Herodotus to distinguish it from hieratic and...

, and finally Coptic

Coptic language

Coptic or Coptic Egyptian is the current stage of the Egyptian language, a northern Afro-Asiatic language spoken in Egypt until at least the 17th century. Egyptian began to be written using the Greek alphabet in the 1st century...

(c. 600 BC), dj-b-t became tobe "[mud] brick." This evolved into Arabic al-tub (الطّوب al "the" + tub "brick") "[mud] brick," which was assimilated into Old Spanish as adobe [aˈdobe], still with the meaning "mud brick." English borrowed the word from Spanish in the early 18th century.

In more modern English usage, the term "adobe" has come to include a style of architecture popular in the desert

Desert

A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

climate

Climate

s of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, especially in New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

. (Compare with stucco

Stucco

Stucco or render is a material made of an aggregate, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as decorative coating for walls and ceilings and as a sculptural and artistic material in architecture...

Composition

An adobe brick is a composite material

Composite material

Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...

made of clay mixed with water and an organic material such as straw or dung. The soil composition typically contains clay

Clay

and sand

Sand

. Straw is useful in binding the brick together and allowing the brick to dry evenly. Dung

Feces

Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...

offers the same advantage and is also added to repel insects. The mixture is roughly half sand (50%), one-third clay (35%), and one-sixth straw (15%) by weight.

Adobe bricks

Bricks are made in an open frame, 25 cm (10 in) by 36 cm (14 in) being a reasonable size, but any convenient size is acceptable. The mixture is molded by the frame, and then the frame is removed quickly. After drying a few hours, the bricks are turned on edge to finish drying. Slow drying in shade reduces cracking.

The same mixture to make bricks, without the straw, is used for mortar and often for plaster on interior and exterior walls. Some ancient cultures used lime-based cement for the plaster to protect against rain damage.

The brick’s thickness is preferred partially due to its thermal characteristics, and partially due to the stability of a thicker brick versus a more standard-sized brick. Depending on the form into which the mixture is pressed, adobe can encompass nearly any shape or size, provided drying time is even and the mixture includes reinforcement for larger bricks. Reinforcement can include manure, straw, cement

Cement

In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

, rebar

Rebar

A rebar , also known as reinforcing steel, reinforcement steel, rerod, or a deformed bar, is a common steel bar, and is commonly used as a tensioning device in reinforced concrete and reinforced masonry structures holding the concrete in compression...

or wooden posts. Experience has shown straw, cement, or manure added to a standard adobe mixture can all produce a stronger, more crack-resistant brick. A general testing is done on the soil content first. To do so, a sample of the soil is mixed into a clear container with some water, creating an almost completely saturated liquid. After it is sealed, the container is shaken vigorously for at least one minute. It is then allowed to sit on a flat surface for a day or so until the soil has settled into layers or remains in suspension. Heavier particles settle out first, so gravel will be on the bottom, sand above, silt above that and very fine clay and organic matter will stay in suspension for days. After the water has cleared, percentages of the various particles can be determined. Fifty to 60 percent sand and 35 to 40 percent clay will yield strong bricks. The New Mexico US Extension Service recommends a mix of not more than 1/3 clay, not less than 1/2 sand, and never more than 1/3 silt.
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

Huaca del Sol

The Huaca del Sol is an adobe brick temple built by the Moche civilization on the coast of what is now Peru. The temple is one of several ruins found near the peak of Cerro Blanco, in the coastal desert near Trujillo, Peru...

in Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, with 100 million signed bricks, the ciudellas of Chan Chan

Chan Chan

The largest Pre-Columbian city in South America, Chan Chan is an archaeological site located in the Peruvian region of La Libertad, five km west of Trujillo. Chan Chan covers an area of approximately 20 km² and had a dense urban center of about 6km²...

and Tambo Colorado

Tambo Colorado

Tambo Colorado is a well-preserved Inca adobe complex near the coast of Peru, also known as Puka Tampu, Pucallacta or Pucahuasi.- Location :...

, both in Peru (in South America).

Thermal properties

An adobe wall can serve as a significant heat reservoir due to the thermal properties inherent in the massive walls typical in adobe construction. In tropical and other climates typified by hot days and cool nights, the high thermal mass of adobe levels out the heat transfer through the wall to the living space. The massive walls require a large and relatively long input of heat from the sun (radiation

Radiation

In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...

) and from the surrounding air (convection

Convection

Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....

) before they warm through to the interior and begin to transfer heat to the living space. After the sun sets and the temperature drops, the warm wall will then continue to transfer heat to the interior for several hours due to the time lag effect. Thus, a well-planned adobe wall of the appropriate thickness is very effective at controlling inside temperature through the wide daily fluctuations typical of desert climates, a factor which has contributed to its longevity as a building material. In addition, the exterior of an adobe wall can be covered with glass to increase heat collection. In a passive solar home, this is called a Trombe wall

Trombe wall

A Trombe wall is a sun-facing wall separated from the outdoors by glass and an air space, which absorbs solar energy and releases it selectively towards the interior at night. The essential idea was first explored by Edward S. Morse and patented by him in 1881...

Adobe wall construction

When building an adobe structure, the ground should be compressed because the weight of adobe bricks is significantly greater than a frame house, and may cause cracking in the wall. The footing is dug and compressed once again. Footing depth depends on the region and its ground frost level. The footing and stem wall are commonly 24 and 14 inches, much larger than a frame house because of the weight of the walls. Adobe bricks are laid by course. Each course

Course (architecture)

A course is a continuous horizontal layer of similarly-sized building material one unit high, usually in a wall. The term is almost always used in conjunction with unit masonry such as brick, cut stone, or concrete masonry units .-Styles:...

is laid the whole length of the wall, overlapping at the corners on a layer of adobe mortar. Adobe walls usually never rise above two stories because they are load bearing and have low structural strength. When placing window and door openings, a lintel is placed on top of the opening to support the bricks above. Within the last courses of brick, bond beams are laid across the top of the bricks to provide a horizontal bearing plate for the roof to distribute the weight more evenly along the wall. To protect the interior and exterior adobe wall, finishes can be applied, such as mud plaster, whitewash or stucco. These finishes protect the adobe wall from water damage, but need to be reapplied periodically, or the walls can be finished with other nontraditional plasters providing longer protection.

Adobe roof

The traditional adobe roof has been generally constructed using a mixture of soil/clay, water, sand, and other available organic materials. The mixture was then formed and pressed into wood forms, producing rows of dried earth bricks that would then be laid across a support structure of wood and plastered into place with more adobe. For a deeper understanding of adobe, one might examine a cob building. Cob

Cob (building)

Cob or cobb or clom is a building material consisting of clay, sand, straw, water, and earth, similar to adobe. Cob is fireproof, resistant to seismic activity, and inexpensive...

, a close cousin to adobe, contains proportioned amounts of soil, clay, water, manure, and straw. This is blended, but not formed like adobe. Cob is spread and piled around a frame and allowed to air dry for several months before habitation. Adobe, then, can be described as dried bricks of cob, stacked and mortared together with more adobe mixture to create a thick wall and/or roof.

Roof materials

Depending on the materials available, a roof can be assembled using lengths of wood or metal to create a framework to begin layering adobe bricks. Depending on the thickness of the adobe bricks, the framework has been performed using a steel framing and a layering of a metal fencing or wiring over the framework to allow an even load as masses of adobe are spread across the metal fencing like cob and allowed to air dry accordingly. This method was demonstrated with an adobe blend heavily impregnated with cement to allow even drying and prevent major cracking.

Traditional adobe roof

More traditional adobe roofs were often flatter than the familiar steeped roof as the native climate yielded more sun and heat than mass amounts of snow or rain that would find use in precipitous roofs. Cement may be introduced to prevent moisture from penetrating the composite of mud and organic matter. Vigas

Viga (architecture)

Vigas are wooden beams characteristic of older adobe construction in the southwestern United States of America, and commonly encountered for ornamental rather than functional purposes in Pueblo Revival Style architecture...

are beams across the roof that support the roof.

Raising a traditional adobe roof

To raise a flattened adobe roof, beams of wood or metal should be assembled and span the extent of the building. The ends of the beams should then be fixed to the tops of the walls using the builder’s preferred choice of attachments. Taking into account the material from which the beams and walls are made, choosing the attachments may prove difficult. A combination of the bricks and adobe mortar that are laid across the beams creates an even load-bearing pressure that can last for many years depending on attrition.

Once the beams are laid across the building, it is then time to begin the placing of adobe bricks to create the roof. An adobe roof is often laid with bricks slightly larger in width to ensure a larger expanse is covered when placing the bricks onto the beams. This wider shape also provides the future homeowner with thermal protection enough to stabilize an even temperature throughout the year. Following each individual brick should be a layer of adobe mortar, recommended to be at least an inch thick to make certain there is ample strength between the brick’s edges and also to provide a relative moisture barrier during the seasons where the arid climate does produce rain.

Attributes

Depending on the materials, adobe roofs can be inherently fire-proof, which is a valuable attribute when the fireplace is kept lit during the cold nights. The construction of the chimney can also greatly influence the construction of the roof supports, creating an extra need for care in choosing the right materials. The builders can make an adobe chimney by stacking simple adobe bricks in a similar fashion as the surrounding walls.

External links

Building With Awareness A detailed how-to DVD video that shows adobe wall construction and their use as thermal mass walls
Cal-Earth (The California Institute of Earth Art and Architecture) has developed a patented system called Superadobe, in which bags filled with stabilized earth are layered with strands of barbed wire to form a structure strong enough to withstand earthquakes, fire and flood.
Earth Architecture - A website whose focus is contemporary issues in earth architecture.
Earth Architecture and Conservation in East Anglia - British organisation that focuses on the proper maintenance and conservation of earth buildings in a region of the UK that has a long history of building with mud.
Kerpic.org - A website on earthen architecture researches stabilized with gypsum.
Kleiwerks - International organization recognized for their unique contribution to modern earthen and natural building techniques throughout the world, their focus is on education through hands on experience. Very experienced experts are contactable and there are regular demonstrations in the area.
Valle de Sensaciones - Artistic construction with adobe, Experimental ground and theme park for creative living close to nature
World Monuments Fund - Adobe Missions of New Mexico - Description of a project of the World Monuments Fund
World Monuments Fund
World Monuments Fund is a private, international, non-profit organization dedicated to the preservation of historic architecture and cultural heritage sites around the world through fieldwork, advocacy, grantmaking, education, and training....

for the preservation of adobe churches in New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

, in the United States.
Mud house - India's rural tradition

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