A brick is a type of block used to build walls, pavements and other elements in
masonry
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...
construction. Properly, the term ''brick'' denotes a block composed of dried
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
, but is now also used informally to denote other chemically cured construction blocks. Bricks can be joined using
mortar, adhesives or by interlocking them. Bricks are usually produced at
brickworks
A brickworks, also known as a brick factory, is a factory for the manufacturing of bricks, from clay or shale. Usually a brickworks is located on a clay bedrock (the most common material from which bricks are made), often with a quarry for cl ...
in numerous classes, types, materials, and sizes which vary with region and time period, and are produced in bulk quantities.
''Block'' is a similar term referring to a rectangular building unit composed of similar materials, but is usually larger than a brick. Lightweight bricks (also called lightweight blocks) are made from
expanded clay aggregate
Lightweight expanded clay aggregate (LECA) or expanded clay (exclay) is a lightweight aggregate made by heating clay to around in a rotary kiln. The yielding gases expand the clay by thousands of small bubbles forming during heating producing ...
.
Fired bricks are one of the longest-lasting and strongest
building material
Building material is material used for construction. Many naturally occurring substances, such as clay, rock (geology), rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materia ...
s, sometimes referred to as artificial stone, and have been used since circa 4000 BC. Air-dried bricks, also known as
mud-brick
A mudbrick or mud-brick is an air-dried brick, made of a mixture of loam, mud, sand and water mixed with a binding material such as rice husks or straw. Mudbricks are known from 9000 BCE, though since 4000 BCE, bricks have also been fi ...
s, have a history older than fired bricks, and have an additional ingredient of a mechanical binder such as straw.
Bricks are laid in ''courses'' and numerous patterns known as ''bonds'', collectively known as
brickwork
Brickwork is masonry produced by a bricklayer, using bricks and mortar. Typically, rows of bricks called '' courses'' are laid on top of one another to build up a structure such as a brick wall.
Bricks may be differentiated from blocks by s ...
, and may be laid in various kinds of
mortar to hold the bricks together to make a durable structure.
History
Middle East and South Asia
The earliest bricks were dried
mud-brick
A mudbrick or mud-brick is an air-dried brick, made of a mixture of loam, mud, sand and water mixed with a binding material such as rice husks or straw. Mudbricks are known from 9000 BCE, though since 4000 BCE, bricks have also been fi ...
s, meaning that they were formed from clay-bearing earth or mud and dried (usually in the sun) until they were strong enough for use. The oldest discovered bricks, originally made from shaped mud and dating before 7500 BC, were found at
Tell Aswad
Tell Aswad ( ar, تل أسود, "Hill Black"), Su-uk-su or Shuksa, is a large prehistoric, neolithic tell, about in size, located around from Damascus in Syria, on a tributary of the Barada River at the eastern end of the village of Jdeide ...
, in the upper
Tigris
The Tigris () is the easternmost of the two great rivers that define Mesopotamia, the other being the Euphrates. The river flows south from the mountains of the Armenian Highlands through the Syrian and Arabian Deserts, and empties into the ...
region and in southeast
Anatolia
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
close to
Diyarbakir.
Mud-brick construction was used at
Çatalhöyük
Çatalhöyük (; also ''Çatal Höyük'' and ''Çatal Hüyük''; from Turkish ''çatal'' "fork" + ''höyük'' "tumulus") is a tell of a very large Neolithic and Chalcolithic proto-city settlement in southern Anatolia, which existed from appr ...
, from c. 7,400 BC.
Mud-brick structures, dating to c. 7,200 BC have been located in
Jericho
Jericho ( ; ar, أريحا ; he, יְרִיחוֹ ) is a Palestinian city in the West Bank. It is located in the Jordan Valley, with the Jordan River to the east and Jerusalem to the west. It is the administrative seat of the Jericho Gove ...
, Jordan Valley. These structures were made up of the first bricks with dimension 400x150x100 mm.
Between 5000 and 4500 BC, Mesopotamia had discovered fired brick.
The standard brick sizes in Mesopotamia followed a general rule: the width of the dried or burned brick would be twice its thickness, and its length would be double its width.
The
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...
n inhabitants of
Mehrgarh
Mehrgarh (; ur, ) is a Neolithic archaeological site (dated ) situated on the Kacchi Plain of Balochistan in Pakistan. It is located near the Bolan Pass, to the west of the Indus River and between the modern-day Pakistani cities of Quetta, Ka ...
also constructed, air-dried
mud-brick
A mudbrick or mud-brick is an air-dried brick, made of a mixture of loam, mud, sand and water mixed with a binding material such as rice husks or straw. Mudbricks are known from 9000 BCE, though since 4000 BCE, bricks have also been fi ...
structures, between 7000 and 3300 BC.
[Possehl, Gregory L. (1996)] and later the ancient
Indus Valley
The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmir, ...
cities of
Mohenjo-daro
Mohenjo-daro (; sd, موئن جو دڙو'', ''meaning 'Mound of the Dead Men';[Harappa
Harappa (; Urdu/ pnb, ) is an archaeological site in Punjab, Pakistan, about west of Sahiwal. The Bronze Age Harappan civilisation, now more often called the Indus Valley Civilisation, is named after the site, which takes its name from a mode ...]
,
[History of brickmaking](_blank)
''Encyclopædia Britannica''. and
Mehrgarh
Mehrgarh (; ur, ) is a Neolithic archaeological site (dated ) situated on the Kacchi Plain of Balochistan in Pakistan. It is located near the Bolan Pass, to the west of the Indus River and between the modern-day Pakistani cities of Quetta, Ka ...
. Ceramic, or ''fired brick'' was used as early as 3000 BC in early Indus Valley cities like
Kalibangan
Kalibangān is a town located at on the left or southern banks of the Ghaggar (Ghaggar-Hakra River) in Tehsil Pilibangān, between Suratgarh and Hanumangarh in Hanumangarh District, Rajasthan, India 205 km. from Bikaner. It is also identifi ...
.
In the middle of the third millennium BC, there was a rise in monumental baked brick architecture in Indus cities. Examples included the
Great Bath at Mohenjo-daro, the fire altars of
Kaalibangan, and the granary of
Harappa
Harappa (; Urdu/ pnb, ) is an archaeological site in Punjab, Pakistan, about west of Sahiwal. The Bronze Age Harappan civilisation, now more often called the Indus Valley Civilisation, is named after the site, which takes its name from a mode ...
. There was a uniformity to the brick sizes throughout the
Indus Valley
The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmir, ...
region, conforming to the 1:2:4, thickness, width, and length ratio. As the Indus civilization began its decline at the start of the second millennium BC, Harappans migrated east, spreading their knowledge of brickmaking technology. This led to the rise of cities like
Pataliputra
Pataliputra (IAST: ), adjacent to modern-day Patna, was a city in ancient India, originally built by Magadha ruler Ajatashatru in 490 BCE as a small fort () near the Ganges river.. Udayin laid the foundation of the city of Pataliputra at the ...
,
Kausambi
Kosambi (Pali) or Kaushambi (Sanskrit) was an important city in ancient India. It was the capital of the Vatsa kingdom, one of the sixteen mahajanapadas. It was located on the Yamuna River about southwest of its confluence with the Ganges at ...
, and
Ujjain
Ujjain (, Hindustani language, Hindustani pronunciation: Help:IPA/Hindi and Urdu, d͡ːʒɛːn is a city in Ujjain district of the States and territories of India, Indian state of Madhya Pradesh. It is the fifth-largest city in Madhya Prad ...
, where there was an enormous demand for kiln-made bricks.
By 604 BC, bricks were the construction materials for architectural wonders such as the
Hanging Gardens of Babylon
The Hanging Gardens of Babylon were one of the Seven Wonders of the Ancient World listed by Hellenic culture. They were described as a remarkable feat of engineering with an ascending series of tiered gardens containing a wide variety of tre ...
, where glazed fired bricks were put into practice.
China
The earliest fired bricks appeared in Neolithic China around 4400 BC at
Chengtoushan
Chengtoushan () was a Neolithic settlement located on the northwestern edge of Dongting Lake in Li County, Hunan, China.
The site is at the village of Chengtoushan, Chengtoushan Town, Li County, it is about northwest of the county seat and nor ...
, a walled settlement of the
Daxi culture
The Daxi culture (5000–3300 BC) was a Neolithic culture centered in the Three Gorges region around the middle Yangtze, China. The culture ranged from western Hubei to eastern Sichuan and the Pearl River Delta. The site at Daxi, located in the Qut ...
. These bricks were made of red clay, fired on all sides to above 600 °C, and used as flooring for houses. By the
Qujialing period (3300 BC), fired bricks were being used to pave roads and as building foundations at Chengtoushan.
According to Lukas Nickel, the use of ceramic pieces for protecting and decorating floors and walls dates back at various cultural sites to 3000-2000 BC and perhaps even before, but these elements should be rather qualified as
tile
Tiles are usually thin, square or rectangular coverings manufactured from hard-wearing material such as ceramic, stone, metal, baked clay, or even glass. They are generally fixed in place in an array to cover roofs, floors, walls, edges, or o ...
s. For the longest time builders relied on wood, mud and rammed earth, while fired brick and mud-brick played no structural role in architecture. Proper brick construction, for erecting walls and
vaults, finally emerges in the third century BC, when baked bricks of regular shape began to be employed for vaulting underground tombs. Hollow brick tomb chambers rose in popularity as builders were forced to adapt due to a lack of readily available wood or stone.
[Lukas Nickel: Bricks in Ancient China and the Question of Early Cross-Asian Interaction, ''Arts Asiatiques'', Vol. 70 (2015), pp. 49-62 (50f.)] The oldest extant brick building above ground is possibly
Songyue Pagoda
The Songyue Pagoda (), constructed in AD 523, is located at the Songyue Monastery on Mount Song, in Henan province, China.Yetts, 124. Built during the Northern Wei Dynasty, this pagoda is one of the few intact sixth-century pagodas in China and is ...
, dated to 523 AD.
By the end of the third century BCE in China, both hollow and small bricks were available for use in building walls and ceilings. Small fired bricks were first mass-produced during the construction of the tomb of China's first Emperor,
Qin Shi Huang
Qin Shi Huang (, ; 259–210 BC) was the founder of the Qin dynasty and the first emperor of a unified China. Rather than maintain the title of "king" ( ''wáng'') borne by the previous Shang and Zhou rulers, he ruled as the First Emperor ( ...
di. The floors of the three pits of the
terracotta army
The Terracotta Army is a collection of terracotta sculptures depicting the armies of Qin Shi Huang, the first emperor of China. It is a form of funerary art buried with the emperor in 210–209 BCE with the purpose of protecting the emperor in ...
were paved with an estimated 230,000 small bricks, with the majority measuring 28x14x7 cm, following a 4:2:1 ratio. Up until the Middle Ages, buildings in Central Asia were typically built with unbaked bricks. It was only starting in the ninth century CE when buildings were entirely constructed using fired bricks.
The carpenter's manual ''
Yingzao Fashi'', published in 1103 at the time of the
Song dynasty
The Song dynasty (; ; 960–1279) was an imperial dynasty of China that began in 960 and lasted until 1279. The dynasty was founded by Emperor Taizu of Song following his usurpation of the throne of the Later Zhou. The Song conquered the rest ...
described the brick making process and
glazing techniques then in use. Using the 17th-century encyclopaedic text ''
Tiangong Kaiwu
The ''Tiangong Kaiwu'' (), or ''The Exploitation of the Works of Nature'' was a Chinese encyclopedia compiled by Song Yingxing. It was published in May 1637 with funding provided by Song's patron Tu Shaokui.Needham, Volume 5, Part 7, 36.Song, x ...
'', historian
Timothy Brook
Timothy James Brook (Chinese name: 卜正民; born January 6, 1951) is a Canadian historian, sinologist, and writer specializing in the study of China (sinology). He holds the Republic of China Chair, Department of History, University of British Co ...
outlined the brick production process of
Ming Dynasty
The Ming dynasty (), officially the Great Ming, was an Dynasties in Chinese history, imperial dynasty of China, ruling from 1368 to 1644 following the collapse of the Mongol Empire, Mongol-led Yuan dynasty. The Ming dynasty was the last ort ...
China:
Europe
Early civilisations around the
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
, including the
Ancient Greeks
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cultu ...
and
Romans
Roman or Romans most often refers to:
*Rome, the capital city of Italy
* Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a lette ...
, adopted the use of fired bricks. By the early first century CE, standardised fired bricks were being heavily produced in Rome. The
Roman legion
The Roman legion ( la, legiō, ) was the largest military unit of the Roman army, composed of 5,200 infantry and 300 equites (cavalry) in the period of the Roman Republic (509 BC–27 BC) and of 5,600 infantry and 200 auxilia in the period of ...
s operated mobile
kiln
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...
s, and built large brick structures throughout the
Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
, stamping the bricks with the seal of the legion. The Romans used brick for walls, arches, forts, aqueducts, etc. Notable mentions of Roman brick structures are the Herculaneum gate of Pompeii and the
baths of Caracalla
The Baths of Caracalla ( it, Terme di Caracalla) in Rome, Italy, were the city's second largest Ancient Rome, Roman public baths, or ''thermae'', after the Baths of Diocletian. The baths were likely built between AD 212 (or 211) and 216/217, durin ...
.
During the
Early Middle Ages
The Early Middle Ages (or early medieval period), sometimes controversially referred to as the Dark Ages, is typically regarded by historians as lasting from the late 5th or early 6th century to the 10th century. They marked the start of the Mi ...
the use of bricks in construction became popular in
Northern Europe
The northern region of Europe has several definitions. A restrictive definition may describe Northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54th parallel north, 54°N, or may be based on other g ...
, after being introduced there from Northwestern Italy. An independent style of brick architecture, known as
brick Gothic
Brick Gothic (german: Backsteingotik, pl, Gotyk ceglany, nl, Baksteengotiek) is a specific style of Gothic architecture common in Northeast and Central Europe especially in the regions in and around the Baltic Sea, which do not have resourc ...
(similar to
Gothic architecture
Gothic architecture (or pointed architecture) is an architectural style that was prevalent in Europe from the late 12th to the 16th century, during the High and Late Middle Ages, surviving into the 17th and 18th centuries in some areas. It e ...
) flourished in places that lacked indigenous sources of rocks. Examples of this architectural style can be found in modern-day Denmark, Germany, Poland, and
Kaliningrad
Kaliningrad ( ; rus, Калининград, p=kəlʲɪnʲɪnˈɡrat, links=y), until 1946 known as Königsberg (; rus, Кёнигсберг, Kyonigsberg, ˈkʲɵnʲɪɡzbɛrk; rus, Короле́вец, Korolevets), is the largest city and ...
(former
East Prussia
East Prussia ; german: Ostpreißen, label=Low Prussian; pl, Prusy Wschodnie; lt, Rytų Prūsija was a province of the Kingdom of Prussia from 1773 to 1829 and again from 1878 (with the Kingdom itself being part of the German Empire from 187 ...
).
This style evolved into the
Brick Renaissance Brick Renaissance is the Northern European continuation of brick architecture after Brick Romanesque and Brick Gothic. Although the term Brick Gothic is often used generally for all of this architecture, especially in regard to the Hanseatic citi ...
as the stylistic changes associated with the
Italian Renaissance
The Italian Renaissance ( it, Rinascimento ) was a period in Italian history covering the 15th and 16th centuries. The period is known for the initial development of the broader Renaissance culture that spread across Europe and marked the trans ...
spread to northern Europe, leading to the adoption of
Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...
elements into brick building. Identifiable attributes included a low-pitched hipped or flat roof, symmetrical facade, round arch entrances and windows, columns and pilasters, and more.
A clear distinction between the two styles only developed at the transition to
Baroque architecture
Baroque architecture is a highly decorative and theatrical style which appeared in Italy in the early 17th century and gradually spread across Europe. It was originally introduced by the Catholic Church, particularly by the Jesuits, as a means t ...
. In
Lübeck
Lübeck (; Low German also ), officially the Hanseatic City of Lübeck (german: Hansestadt Lübeck), is a city in Northern Germany. With around 217,000 inhabitants, Lübeck is the second-largest city on the German Baltic coast and in the stat ...
, for example, Brick Renaissance is clearly recognisable in buildings equipped with terracotta reliefs by the artist Statius von Düren, who was also active at
Schwerin
Schwerin (; Mecklenburgisch dialect, Mecklenburgian Low German: ''Swerin''; Latin: ''Suerina'', ''Suerinum'') is the Capital city, capital and List of cities and towns in Germany, second-largest city of the northeastern States of Germany, German ...
(
Schwerin Castle
Schwerin Castle (also known as ''Schwerin Palace'', german: Schweriner Schloss, ), is a schloss located in the city of Schwerin, the capital of Mecklenburg-Vorpommern state, Germany. It is situated on an island in the city's main lake, Lake Schwer ...
) and
Wismar
Wismar (; Low German: ''Wismer''), officially the Hanseatic City of Wismar (''Hansestadt Wismar'') is, with around 43,000 inhabitants, the sixth-largest city of the northeastern German state of Mecklenburg-Vorpommern, and the fourth-largest city ...
(Fürstenhof).
Long-distance
bulk transport
Bulk cargo is commodity cargo that is transported unpackaged in large quantities.
Description
Bulk cargo refers to material in either liquid or granular, particulate form, as a mass of relatively small solids, such as petroleum/ crude oi ...
of bricks and other construction equipment remained prohibitively expensive until the development of modern transportation infrastructure, with the construction of
canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow un ...
,
road
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation.
There are many types of ...
s, and
railway
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
s.
Industrial era
Production of bricks increased massively with the onset of the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
and the rise in factory building in England. For reasons of speed and economy, bricks were increasingly preferred as building material to stone, even in areas where the stone was readily available. It was at this time in
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
that bright red brick was chosen for construction to make the buildings more visible in the heavy fog and to help prevent traffic accidents.
The transition from the traditional method of production known as hand-moulding to a mechanised form of mass-production slowly took place during the first half of the nineteenth century. Possibly the first successful brick-making machine was
patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
ed by Henry Clayton, employed at the Atlas Works in
Middlesex
Middlesex (; abbreviation: Middx) is a Historic counties of England, historic county in South East England, southeast England. Its area is almost entirely within the wider urbanised area of London and mostly within the Ceremonial counties of ...
, England, in 1855, and was capable of producing up to 25,000 bricks daily with minimal supervision. His mechanical apparatus soon achieved widespread attention after it was adopted for use by the
South Eastern Railway Company for brick-making at their factory near
Folkestone
Folkestone ( ) is a port town on the English Channel, in Kent, south-east England. The town lies on the southern edge of the North Downs at a valley between two cliffs. It was an important harbour and shipping port for most of the 19th and 20t ...
. The
Bradley & Craven Ltd Bradley & Craven Ltd was a manufacturing company specializing in brickmaking machinery in Wakefield England. It was founded in 1843 by two young engineers, William Craven and Richard Bradley to manufacture what was then revolutionary machinery for ...
'Stiff-Plastic Brickmaking Machine' was patented in 1853, apparently predating Clayton. Bradley & Craven went on to be a dominant manufacturer of brickmaking machinery. Predating both Clayton and Bradley & Craven Ltd. however was the brick making machine patented by Richard A. Ver Valen of Haverstraw, New York, in 1852.
At the end of the 19th century, the Hudson River region of
New York State
New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. stat ...
would become the world's largest brick manufacturing region, with 130 brickyards lining the shores of the Hudson River from Mechanicsville to Haverstraw and employing 8,000 people. At its peak, about 1 billion bricks were produced a year, with many being sent to New York City for use in its construction industry.
The demand for high office building construction at the turn of the 20th century led to a much greater use of
cast
Cast may refer to:
Music
* Cast (band), an English alternative rock band
* Cast (Mexican band), a progressive Mexican rock band
* The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis
* ''Cast'', a 2012 album by Trespassers William
* ...
and
wrought iron
Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a ...
, and later, steel and
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
. The use of brick for
skyscraper
A skyscraper is a tall continuously habitable building having multiple floors. Modern sources currently define skyscrapers as being at least or in height, though there is no universally accepted definition. Skyscrapers are very tall high-ris ...
construction severely limited the size of the building – the
Monadnock Building
The Monadnock Building (historically the Monadnock Block; pronounced ) is a 16-story skyscraper located at 53 West Jackson Boulevard in the south Loop area of Chicago. The north half of the building was designed by the firm of Burnham & Root ...
, built in 1896 in Chicago, required exceptionally thick walls to maintain the structural integrity of its 17 storeys.
Following pioneering work in the 1950s at the
Swiss Federal Institute of Technology and the
Building Research Establishment
The Building Research Establishment (BRE) is a centre of building science in the United Kingdom, owned by charitable organisation the BRE Trust. It is a former UK government national laboratory that was privatised in 1997. BRE provides researc ...
in
Watford
Watford () is a town and borough in Hertfordshire, England, 15 miles northwest of Central London, on the River Colne.
Initially a small market town, the Grand Junction Canal encouraged the construction of paper-making mills, print works, a ...
, UK, the use of improved masonry for the construction of tall structures up to 18 storeys high was made viable. However, the use of brick has largely remained restricted to small to medium-sized buildings, as steel and concrete remain superior materials for high-rise construction.
Bricks are often made of
shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...
because it easily splits into thin layers.
Methods of manufacture
Four basic types of brick are un-fired, fired, chemically set bricks, and compressed earth blocks. Each type is manufactured differently for various purposes.
Mud-brick
Unfired bricks, also known as
mud-bricks, are made from a mixture of
silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...
,
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
,
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...
and other earth materials like
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
and stone, combined with tempers and binding agents such as chopped straw, grasses,
tree bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the tissues outside the vascular cambium and is a nontechnical term. It overlays the wood and consist ...
, or dung.
Since these bricks are made up of natural materials and only require heat from the Sun to bake, mud-bricks have a relatively low
embodied energy
Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' in the product itself. The concept can be useful in determining the effectiveness of energy-produ ...
and
carbon footprint
A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, place or product, expressed as carbon dioxide equivalent (CO2e). Greenhouse gases, including the carbon-containing gases carbo ...
.
The ingredients are first harvested and added together, with clay content ranging from 30% to 70%. The mixture is broken up with
hoes
Hoe or HOE may refer to:
* Hoe (food), a Korean dish of raw fish
* Hoe (letter), a Georgian letter
* Hoe (tool), a hand tool used in gardening and farming
** Hoe-farming, a term for primitive forms of agriculture
* Backhoe, a piece of excavatin ...
or
adze
An adze (; alternative spelling: adz) is an ancient and versatile cutting tool similar to an axe but with the cutting edge perpendicular to the handle rather than parallel. Adzes have been used since the Stone Age. They are used for smoothing ...
s, and stirred with water to form a homogenous blend. Next, the tempers and binding agents are added in a ratio, roughly one part straw to five parts earth to reduce weight and reinforce the brick by helping reduce shrinkage. However, additional clay could be added to reduce the need for straw, which would prevent the likelihood of insects deteriorating the organic material of the bricks, subsequently weakening the structure. These ingredients are thoroughly mixed together by hand or by treading and are then left to ferment for about a day.
The mix is then kneaded with water and molded into rectangular prisms of a desired size. Bricks are lined up and left to sundry for three days on both sides. After the six days, the bricks continue drying until required for use. Typically, longer drying times are preferred, but the average is eight to nine days spanning from initial stages to its application in structures. Unfired bricks could be made in the spring months and left to dry over the summer for use in the fall. Mud-bricks are commonly employed in arid environments to allow for adequate air drying.
Fired brick
Fired bricks are burned in a kiln which makes them durable. Modern, fired, clay bricks are formed in one of three processes – soft mud, dry press, or extruded. Depending on the country, either the extruded or soft mud method is the most common, since they are the most economical.
Clay and shale are the raw ingredients in the recipe for a fired brick. They are the product of thousands of years of decomposition and erosion of rocks, such as
pegmatite
A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic com ...
and
granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...
, leading to a material that has properties of being highly chemically stable and inert. Within the clays and shales are the materials of
aluminosilicate
Aluminosilicate minerals ( IMA symbol: Als) are minerals composed of aluminium, silicon, and oxygen, plus countercations. They are a major component of kaolin and other clay minerals.
Andalusite, kyanite, and sillimanite are naturally occurr ...
(pure
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
), free silica (
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
), and decomposed rock.
Normally, bricks contain the following ingredients:
#
Silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
(sand) – 50% to 60% by weight
#
Alumina (clay) – 20% to 30% by weight
#
Lime
Lime commonly refers to:
* Lime (fruit), a green citrus fruit
* Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide
* Lime (color), a color between yellow and green
Lime may also refer to:
Botany ...
– 2 to 5% by weight
#
Iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...
– ≤ 7% by weight
#
Magnesia – less than 1% by weight
Shaping methods
Three main methods are used for shaping the raw materials into bricks to be fired:
* Molded bricks – These bricks start with raw clay, preferably in a mix with 25–30% sand to reduce shrinkage. The clay is first ground and mixed with water to the desired consistency. The clay is then pressed into steel moulds with a
hydraulic
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counter ...
press. The shaped clay is then fired ("burned") at to achieve strength.
* Dry-pressed bricks – The dry-press method is similar to the soft-mud moulded method, but starts with a much thicker clay mix, so it forms more accurate, sharper-edged bricks. The greater force in pressing and the longer burn make this method more expensive.
* Extruded bricks – For extruded bricks the clay is mixed with 10–15%
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
(stiff extrusion) or 20–25% water (soft extrusion) in a
pugmill
A pugmill or pug mill is a machine in which clay or other materials are mixed into a plastic state or a similar machine for the trituration of ore. Industrial applications are found in pottery, bricks, cement and some parts of the concrete and asp ...
. This mixture is forced through a
die
Die, as a verb, refers to death, the cessation of life.
Die may also refer to:
Games
* Die, singular of dice, small throwable objects used for producing random numbers
Manufacturing
* Die (integrated circuit), a rectangular piece of a semicondu ...
to create a long cable of material of the desired width and depth. This mass is then cut into bricks of the desired length by a wall of wires. Most structural bricks are made by this method as it produces hard, dense bricks, and suitable dies can produce perforations as well. The introduction of such holes reduces the volume of clay needed, and hence the cost. Hollow bricks are lighter and easier to handle, and have different thermal properties from solid bricks. The cut bricks are hardened by drying for 20 to 40 hours at before being fired. The heat for drying is often
waste heat
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...
from the kiln.
Kilns
In many modern
brickworks
A brickworks, also known as a brick factory, is a factory for the manufacturing of bricks, from clay or shale. Usually a brickworks is located on a clay bedrock (the most common material from which bricks are made), often with a quarry for cl ...
, bricks are usually fired in a continuously fired tunnel kiln, in which the bricks are fired as they move slowly through the kiln on
conveyors
A conveyor belt is the carrying medium of a belt conveyor system (often shortened to belt conveyor). A belt conveyor system is one of many types of conveyor systems. A belt conveyor system consists of two or more pulleys (sometimes referred to ...
, rails, or kiln cars, which achieves a more consistent brick product. The bricks often have
lime
Lime commonly refers to:
* Lime (fruit), a green citrus fruit
* Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide
* Lime (color), a color between yellow and green
Lime may also refer to:
Botany ...
, ash, and organic matter added, which accelerates the burning process.
The other major kiln type is the Bull's Trench Kiln (BTK), based on a design developed by British engineer W. Bull in the late 19th century.
An oval or circular trench is dug, wide, deep, and in circumference. A tall exhaust chimney is constructed in the centre. Half or more of the trench is filled with "green" (unfired) bricks which are stacked in an open lattice pattern to allow airflow. The lattice is capped with a roofing layer of finished brick.
In operation, new green bricks, along with roofing bricks, are stacked at one end of the brick pile. Historically, a stack of unfired bricks covered for protection from the weather was called a "hack". Cooled finished bricks are removed from the other end for transport to their destinations. In the middle, the brick workers create a firing zone by dropping fuel (coal, wood, oil, debris, etc.) through access holes in the roof above the trench. The constant source of fuel maybe grown on the
woodlot A woodlot is a parcel of a woodland or forest capable of small-scale production of forest products (such as wood fuel, sap for maple syrup, sawlogs, and pulpwood) as well as recreational uses like bird watching, bushwalking, and wildflower apprecia ...
s.
The advantage of the BTK design is a much greater energy efficiency compared with
clamp or
scove kilns. Sheet metal or boards are used to route the airflow through the brick lattice so that fresh air flows first through the recently burned bricks, heating the air, then through the active burning zone. The air continues through the green brick zone (pre-heating and drying the bricks), and finally out the chimney, where the rising gases create suction that pulls air through the system. The reuse of heated air yields savings in fuel cost.
As with the rail process, the BTK process is continuous. A half-dozen labourers working around the clock can fire approximately 15,000–25,000 bricks a day. Unlike the rail process, in the BTK process the bricks do not move. Instead, the locations at which the bricks are loaded, fired, and unloaded gradually rotate through the trench.
Influences on colour
The colour of fired clay bricks is influenced by the chemical and mineral content of the raw materials, the firing temperature, and the atmosphere in the kiln. For example, pink bricks are the result of a high iron content, white or yellow bricks have a higher lime content.
Most bricks burn to various red hues; as the temperature is increased the colour moves through dark red, purple, and then to brown or grey at around . The names of bricks may reflect their origin and colour, such as
London stock brick
London stock brick is the type of handmade brick which was used for the majority of building work in London and South East England until the growth in the use of Flettons and other machine-made bricks in the early 20th century. Its distinctive y ...
and Cambridgeshire White. ''Brick tinting'' may be performed to change the colour of bricks to blend-in areas of brickwork with the surrounding masonry.
An impervious and ornamental surface may be laid on brick either by
salt glazing, in which salt is added during the burning process, or by the use of a
slip
Slip or SLIP may refer to:
Science and technology Biology
* Slip (fish), also known as Black Sole
* Slip (horticulture), a small cutting of a plant as a specimen or for grafting
* Muscle slip, a branching of a muscle, in anatomy
Computing and ...
, which is a glaze material into which the bricks are dipped. Subsequent reheating in the kiln fuses the slip into a glazed surface integral with the brick base.
Chemically set bricks
Chemically set bricks are not fired but may have the curing process accelerated by the application of heat and pressure in an autoclave.
Calcium-silicate bricks
Calcium-silicate bricks are also called sandlime or flintlime bricks, depending on their ingredients. Rather than being made with clay they are made with
lime
Lime commonly refers to:
* Lime (fruit), a green citrus fruit
* Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide
* Lime (color), a color between yellow and green
Lime may also refer to:
Botany ...
binding the silicate material. The raw materials for calcium-silicate bricks include lime mixed in a proportion of about 1 to 10 with sand,
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
, crushed
flint
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fir ...
, or crushed siliceous rock together with mineral
colourant A colourant/colour additive (British spelling) or colorant/color additive (American spelling) is a substance that is added or applied in order to change the colour of a material or surface. Colourants can be used for many purposes including printing ...
s. The materials are mixed and left until the lime is completely hydrated; the mixture is then pressed into moulds and cured in an
autoclave
An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizat ...
for three to fourteen hours to speed the chemical hardening.
[McArthur, Hugh, and Duncan Spalding. ''Engineering materials science: properties, uses, degradation and remediation''. Chichester, U.K.: Horwood Pub., 2004. 194. Print.] The finished bricks are very accurate and uniform, although the sharp
arris
In architecture, an arris is the sharp edge formed by the intersection of two surfaces, such as the corner of a masonry unit; the edge of a timber in timber framing; the junction between two planes of plaster or any intersection of divergent a ...
es need careful handling to avoid damage to brick and bricklayer. The bricks can be made in a variety of colours; white, black, buff, and grey-blues are common, and pastel shades can be achieved. This type of brick is common in Sweden as well as Russia and other
post-Soviet
The post-Soviet states, also known as the former Soviet Union (FSU), the former Soviet Republics and in Russia as the near abroad (russian: links=no, ближнее зарубежье, blizhneye zarubezhye), are the 15 sovereign states that wer ...
countries, especially in houses built or renovated in the 1970s. A version known as
fly ash brick
Fly ash brick (FAB) is a building material, specifically masonry units, containing fly ash and water. Compressed at and cured for in a steam bath, then toughened with an air entrainment agent, the bricks can last for more than cycles. Owing ...
s, manufactured using
fly ash
Fly ash, flue ash, coal ash, or pulverised fuel ash (in the UK) plurale tantum: coal combustion residuals (CCRs)is a coal combustion product that is composed of the particulates (fine particles of burned fuel) that are driven out of coal-fired ...
, lime, and gypsum (known as the FaL-G process) are common in South Asia. Calcium-silicate bricks are also manufactured in Canada and the United States, and meet the criteria set forth in ASTM C73 – 10 Standard Specification for Calcium Silicate Brick (Sand-Lime Brick).
Concrete bricks
Bricks formed from
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
are usually termed as blocks or
concrete masonry unit
A concrete masonry unit (CMU) is a standard-size rectangular block used in building construction. CMUs are some of the most versatile building products available because of the wide variety of appearances that can be achieved using them.
Tho ...
, and are typically pale grey. They are made from a dry, small aggregate concrete which is formed in steel moulds by vibration and compaction in either an "egglayer" or static machine. The finished blocks are cured, rather than fired, using low-pressure steam. Concrete bricks and blocks are manufactured in a wide range of shapes, sizes and face treatments – a number of which simulate the appearance of clay bricks.
Concrete bricks are available in many colours and as an engineering brick made with sulfate-resisting Portland cement or equivalent. When made with adequate amount of cement they are suitable for harsh environments such as wet conditions and retaining walls. They are made to standards BS 6073, EN 771-3 or ASTM C55. Concrete bricks contract or shrink so they need movement joints every 5 to 6 metres, but are similar to other bricks of similar density in thermal and sound resistance and fire resistance.
Compressed earth blocks
Compressed earth block
A compressed earth block (CEB), also known as a pressed earth block or a compressed soil block, is a building material made primarily from an appropriate mix of fairly dry inorganic subsoil, non-expansive clay, sand, and aggregate. Forming compre ...
s are made mostly from slightly moistened local soils compressed with a mechanical hydraulic press or manual lever press. A small amount of a cement binder may be added, resulting in a ''stabilised compressed earth block''.
Types
There are thousands of types of bricks that are named for their use, size, forming method, origin, quality, texture, and/or materials.
Categorized by manufacture method:
* Extruded – made by being forced through an opening in a steel die, with a very consistent size and shape.
** Wire-cut – cut to size after extrusion with a tensioned wire which may leave drag marks
* Moulded – shaped in moulds rather than being extruded
** Machine-moulded – clay is forced into moulds using pressure
** Handmade – clay is forced into moulds by a person
* Dry-pressed – similar to soft mud method, but starts with a much thicker clay mix and is compressed with great force.
Categorized by use:
* Common or building – A brick not intended to be visible, used for internal structure
* Face – A brick used on exterior surfaces to present a clean appearance
* Hollow – not solid, the holes are less than 25% of the brick volume
** Perforated – holes greater than 25% of the brick volume
* Keyed – indentations in at least one face and end to be used with rendering and plastering
* Paving – brick intended to be in ground contact as a walkway or roadway
* Thin – brick with normal height and length but thin width to be used as a veneer
Specialized use bricks:
* Chemically resistant – bricks made with resistance to chemical reactions
**
Acid brick Acid brick or acid resistant brick is a specially made form of masonry brick that is chemically resistant and thermally durable. – acid resistant bricks
*
Engineering
Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...
– a type of hard, dense, brick used where strength, low water porosity or acid (flue gas) resistance are needed. Further classified as type A and type B based on their compressive strength
**
Accrington
Accrington is a town in the Hyndburn borough of Lancashire, England. It lies about east of Blackburn, west of Burnley, east of Preston, north of Manchester and is situated on the culverted River Hyndburn. Commonly abbreviated by locals to ...
– a type of engineering brick from England
*
Fire
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products.
At a certain point in the combustion reaction, called the ignition ...
or refractory – highly heat-resistant bricks
**
Clinker – a vitrified brick
** Ceramic glazed – fire bricks with a decorative glazing
Bricks named for place of origin:
*
Cream City brick
Cream City brick is a cream or light yellow-colored brick made from a clay found around Milwaukee, Wisconsin, in the Menomonee River Valley and on the western banks of Lake Michigan. These bricks were one of the most common building materials u ...
– a light yellow brick made in Milwaukee, Wisconsin
*
Dutch brick
Dutch brick (Dutch: IJsselsteen) is a small type of yellow brick made in the Netherlands, or similar brick, and an architectural style of building with brick developed by the Dutch. The brick, made from clay dug from river banks or dredged fr ...
– a hard light coloured brick originally from the Netherlands
*
Fareham red brick
Fareham red brick is a famous red-tinged clay brick, from Fareham, Hampshire
Hampshire (, ; abbreviated to Hants) is a ceremonial and non-metropolitan county in western South East England on the coast of the English Channel. Home to two ...
– a type of construction brick
*
London stock brick
London stock brick is the type of handmade brick which was used for the majority of building work in London and South East England until the growth in the use of Flettons and other machine-made bricks in the early 20th century. Its distinctive y ...
– type of handmade brick which was used for the majority of building work in London and South East England until the growth in the use of machine-made bricks
*
Nanak Shahi bricks Nanakshahi bricks ( pa, ਨਾਨਕਸ਼ਾਹੀ ਇੱਟ) were decorative Brick, bricks used for structural walls during the Mughal Empire, Mughal era.
Uses
This variety of brick tiles were of moderate dimensions and could be used for reinfo ...
– a type of decorative brick in India
*
Roman brick
Roman brick can refer either to a type of brick used in Ancient Roman architecture and spread by the Romans to the lands they conquered; or to a modern type inspired by the ancient prototypes. In both cases, it characteristically has longer and f ...
– a long, flat brick typically used by the Romans
*
Staffordshire blue brick
Staffordshire blue brick is a strong type of construction brick, originally made in Staffordshire, England.
The brick is made from the local red clay, Etruria marl, which when fired at a high temperature in a low-oxygen reducing atmosphere ta ...
– a type of construction brick from England
Optimal dimensions, characteristics, and strength
For efficient handling and laying, bricks must be small enough and light enough to be picked up by the bricklayer using one hand (leaving the other hand free for the trowel). Bricks are usually laid flat, and as a result, the effective limit on the width of a brick is set by the distance which can conveniently be spanned between the thumb and fingers of one hand, normally about . In most cases, the length of a brick is twice its width plus the width of a mortar joint, about or slightly more. This allows bricks to be laid ''
bonded'' in a structure which increases stability and strength (for an example, see the illustration of bricks laid in ''English bond'', at the head of this article). The wall is built using alternating courses of ''stretchers'', bricks laid longways, and ''headers'', bricks laid crossways. The headers tie the wall together over its width. In fact, this wall is built in a variation of ''English bond'' called ''English cross bond'' where the successive layers of stretchers are displaced horizontally from each other by half a brick length. In true ''English bond'', the perpendicular lines of the stretcher courses are in line with each other.
A bigger brick makes for a thicker (and thus more insulating) wall. Historically, this meant that bigger bricks were necessary in colder climates (see for instance the slightly larger size of the Russian brick in table below), while a smaller brick was adequate, and more economical, in warmer regions. A notable illustration of this correlation is the
Green Gate
The Green Gate ( pl, Brama Zielona, german: former Koggentor, now Grünes Tor) in Gdańsk, Poland, is one of the city's most notable tourist attractions. It is situated between Long Market (''Długi Targ'') and the River Motława.
History
Wi ...
in Gdansk; built in 1571 of imported
Dutch brick
Dutch brick (Dutch: IJsselsteen) is a small type of yellow brick made in the Netherlands, or similar brick, and an architectural style of building with brick developed by the Dutch. The brick, made from clay dug from river banks or dredged fr ...
, too small for the colder climate of Gdansk, it was notorious for being a chilly and drafty residence. Nowadays this is no longer an issue, as modern walls typically incorporate specialised insulation materials.
The correct brick for a job can be selected from a choice of colour, surface texture, density, weight, absorption, and pore structure, thermal characteristics, thermal and moisture movement, and fire resistance.
In England, the length and width of the common brick remained fairly constant from 1625 when the size was regulated by statute at 9 x x 3 inches (but see
brick tax
The brick tax was a property tax introduced in Great Britain in 1784, during the reign of King George III, to help pay for the wars in the American Colonies. Bricks were initially taxed at 2 s 6 d per thousand. The brick tax was eventually abol ...
), but the depth has varied from about or smaller in earlier times to about more recently. In the United Kingdom, the usual size of a modern brick (from 1965) is , which, with a nominal mortar joint, forms a ''
unit size
Unit may refer to:
Arts and entertainment
* UNIT, a fictional military organization in the science fiction television series ''Doctor Who''
* Unit of action, a discrete piece of action (or beat) in a theatrical presentation
Music
* Unit (album), ...
'' of , for a ratio of 6:3:2.
In the United States, modern standard bricks are specified for various uses; The most commonly used is the modular brick has the ''actual dimensions'' of × × inches (194 × 92 × 57 mm). With the standard inch mortar joint, this gives the ''nominal dimensions'' of 8 x 4 x inches which eases the calculation of the number of bricks in a given wall. The 2:1 ratio of modular bricks means that when they turn corners, a 1/2 running bond is formed without needing to cut the brick down or fill the gap with a cut brick; and the height of modular bricks means that a soldier course matches the height of three modular running courses, or one standard
CMU course.
Some brickmakers create innovative sizes and shapes for bricks used for plastering (and therefore not visible on the inside of the building) where their inherent mechanical properties are more important than their visual ones. These bricks are usually slightly larger, but not as large as blocks and offer the following advantages:
* A slightly larger brick requires less mortar and handling (fewer bricks), which reduces cost
* Their ribbed exterior aids plastering
* More complex interior cavities allow improved insulation, while maintaining strength.
Blocks have a much greater range of sizes. Standard co-ordinating sizes in length and height (in mm) include 400×200, 450×150, 450×200, 450×225, 450×300, 600×150, 600×200, and 600×225; depths (work size, mm) include 60, 75, 90, 100, 115, 140, 150, 190, 200, 225, and 250.
They are usable across this range as they are lighter than clay bricks. The density of solid clay bricks is around 2000 kg/m
3: this is reduced by frogging, hollow bricks, and so on, but aerated autoclaved concrete, even as a solid brick, can have densities in the range of 450–850 kg/m
3.
Bricks may also be classified as ''solid'' (less than 25% perforations by volume, although the brick may be "frogged," having indentations on one of the longer faces), ''perforated'' (containing a pattern of small holes through the brick, removing no more than 25% of the volume), ''cellular'' (containing a pattern of holes removing more than 20% of the volume, but closed on one face), or ''hollow'' (containing a pattern of large holes removing more than 25% of the brick's volume). Blocks may be solid, cellular or hollow.
The term "frog" can refer to the indentation or the implement used to make it. Modern brickmakers usually use plastic frogs but in the past they were made of wood.
The compressive strength of bricks produced in the United States ranges from about , varying according to the use to which the brick are to be put. In England clay bricks can have strengths of up to 100 MPa, although a common house brick is likely to show a range of 20–40 MPa.
Uses
Bricks are a versatile building material, able to participate in a wide variety of applications, including:
* Structural walls, exterior and interior walls
* Bearing and non-bearing sound proof partitions
* The fireproofing of structural-steel members in the form of
firewalls,
party wall
A party wall (occasionally parti-wall or parting wall, also known as common wall or as a demising wall) is a dividing partition between two adjoining buildings that is shared by the occupants of each residence or business. Typically, the builder ...
s, enclosures and
fire towers
* Foundations for
stucco
Stucco or render is a construction material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, exterior walls, and as a sculptural and a ...
*
Chimney
A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator, or fireplace from human living areas. Chimneys are typic ...
s and
fireplace
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design.
...
s
* Porches and terraces
* Outdoor steps, brick walks and paved floors
*
Swimming pool
A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming or other leisure activities. Pools can be built into the ground (in-ground pools) or built ...
s
In the United States, bricks have been used for both buildings and pavement. Examples of brick use in buildings can be seen in colonial era buildings and other notable structures around the country. Bricks have been used in paving roads and sidewalks especially during the late 19th century and early 20th century. The introduction of asphalt and concrete reduced the use of brick for paving, but they are still sometimes installed as a method of
traffic calming
Traffic calming uses physical design and other measures to improve safety for motorists, pedestrians and bicycle-friendly, cyclists. It has become a tool to combat speeding and other unsafe behaviours of drivers in the neighbourhoods. It aims ...
or as a decorative surface in
pedestrian precincts. For example, in the early 1900s, most of the streets in the city of
Grand Rapids
Grand Rapids is a city and county seat of Kent County in the U.S. state of Michigan. At the 2020 census, the city had a population of 198,917 which ranks it as the second most-populated city in the state after Detroit. Grand Rapids is the ...
,
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...
, were paved with bricks. Today, there are only about 20 blocks of brick-paved streets remaining (totalling less than 0.5 percent of all the streets in the city limits). Much like in Grand Rapids, municipalities across the United States began replacing brick streets with inexpensive
asphalt concrete
Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and tarmac, bitumen macadam, or rolled asphalt in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads, parkin ...
by the mid-20th century.
In Northwest Europe, bricks have been used in construction for centuries. Until recently, almost all houses were built almost entirely from bricks. Although many houses are now built using a mixture of
concrete block
A concrete masonry unit (CMU) is a standard-size rectangular block used in building construction. CMUs are some of the most versatile building products available because of the wide variety of appearances that can be achieved using them.
Tho ...
s and other materials, many houses are skinned with a layer of bricks on the outside for aesthetic appeal.
Bricks in the
metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the sc ...
and
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
industries are often used for lining
furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
s, in particular
refractory
In materials science, a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, ...
bricks such as
silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
,
magnesia,
chamotte and neutral (
chromomagnesite)
refractory bricks. This type of brick must have good
thermal shock
Thermal shock is a type of rapidly transient mechanical load.
By definition, it is a mechanical load caused by a rapid change of temperature of a certain point.
It can be also extended to the case of a thermal gradient, which makes different par ...
resistance, refractoriness under load, high melting point, and satisfactory
porosity
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...
. There is a large refractory
brick industry
A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...
, especially in the United Kingdom, Japan, the United States, Belgium and the Netherlands.
Engineering brick
Engineering bricks are a type of brick used where strength, low water porosity or acid (flue gas) resistance are needed. Engineering bricks can be used for damp-proof courses.
Clay engineering bricks are defined in ''§ 6.4.51'' of ''British Sta ...
s are used where strength, low water porosity or acid (flue gas) resistance are needed.
In the UK a
red brick university
A red brick university (or redbrick university) was originally one of the nine civic universities founded in the major industrial cities of England in the 19th century.
However, with the 1960s proliferation of plate glass universities and t ...
is one founded in the late 19th or early 20th century. The term is used to refer to such institutions collectively to distinguish them from the older
Oxbridge
Oxbridge is a portmanteau of Oxford and Cambridge, the two oldest, wealthiest, and most famous universities in the United Kingdom. The term is used to refer to them collectively, in contrast to other British universities, and more broadly to de ...
institutions, and refers to the use of bricks, as opposed to stone, in their buildings.
Colombian architect
Rogelio Salmona
Rogelio Salmona (April 28, 1929 – October 3, 2007) was a French Colombian architect. He was noted for his extensive use of red brick in his buildings and for using natural shapes like spirals, radial geometry and curves in his designs. Dur ...
was noted for his extensive use of red bricks in his buildings and for using natural shapes like spirals, radial geometry and curves in his designs.
Limitations
Starting in the 20th century, the use of brickwork declined in some areas due to concerns about earthquakes. Earthquakes such as the
San Francisco earthquake of 1906
At 05:12 Pacific Standard Time on Wednesday, April 18, 1906, the coast of Northern California was struck by a major earthquake with an estimated moment magnitude of 7.9 and a maximum Mercalli intensity of XI (''Extreme''). High-intensity sha ...
and the
1933 Long Beach earthquake
The 1933 Long Beach earthquake took place on March 10 at south of downtown Los Angeles. The epicenter was offshore, southeast of Long Beach, California, on the Newport–Inglewood Fault. The earthquake had a magnitude estimated at 6.4 , and a m ...
revealed the weaknesses of unreinforced brick masonry in earthquake-prone areas. During seismic events, the mortar cracks and crumbles, so that the bricks are no longer held together. Brick masonry with
steel reinforcement
Rebar (short for reinforcing bar), known when massed as reinforcing steel or reinforcement steel, is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and aid the concrete under tension. ...
, which helps hold the masonry together during earthquakes, has been used to replace unreinforced bricks in many buildings. Retrofitting older unreinforced masonry structures has been mandated in many jurisdictions. However, similar to steel corrosion in
reinforced concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having hig ...
, rebar rusting will compromise the structural integrity of reinforced brick and ultimately limit the expected lifetime, so there is a trade-off between earthquake safety and longevity to a certain extent.
Gallery
File:Chilehaus - Hamburg.jpg, Chile house in Hamburg
(male), (female) en, Hamburger(s),
Hamburgian(s)
, timezone1 = Central (CET)
, utc_offset1 = +1
, timezone1_DST = Central (CEST)
, utc_offset1_DST = +2
, postal ...
, Germany
A block of fired bricks.jpg, A block of Bricks manufactured in Nepal to build Ancient Stupa
File:Berlín, Museo de Pérgamo 05.jpg, Ishtar Gate
The Ishtar Gate was the eighth gate to the inner city of Babylon (in the area of present-day Hillah, Babil Governorate, Iraq). It was constructed circa 575 BCE by order of King Nebuchadnezzar II on the north side of the city. It was part ...
of Babylon
''Bābili(m)''
* sux, 𒆍𒀭𒊏𒆠
* arc, 𐡁𐡁𐡋 ''Bāḇel''
* syc, ܒܒܠ ''Bāḇel''
* grc-gre, Βαβυλών ''Babylṓn''
* he, בָּבֶל ''Bāvel''
* peo, 𐎲𐎠𐎲𐎡𐎽𐎢 ''Bābiru''
* elx, 𒀸𒁀𒉿𒇷 ''Babi ...
in the Pergamon Museum
The Pergamon Museum (; ) is a listed building on the Museum Island in the historic centre of Berlin. It was built from 1910 to 1930 by order of German Emperor Wilhelm II according to plans by Alfred Messel and Ludwig Hoffmann in Stripped Class ...
, Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...
, Germany
Opus reticulatum 2.JPG, Roman opus reticulatum
''Opus reticulatum'' (also known as reticulate work) is a facing used for concrete walls in Roman architecture from about the first century BCE to the early first century CE. Facings are a type of polygonal masonry used to apply a smooth finish to ...
on Hadrian's Villa in Tivoli, Italy
Tivoli ( , ; la, Tibur) is a town and in Lazio, central Italy, north-east of Rome, at the falls of the Aniene river where it issues from the Sabine hills. The city offers a wide view over the Roman Campagna.
History
Gaius Julius Solinu ...
(2nd century)
Munich Frauenkirche.jpg, Frauenkirche, Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the States of Germany, German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the List of cities in Germany by popu ...
, Germany, erected 1468–1488, looking up at the towers
Torun sw Jakub szczyt zach.JPG, Eastern gable of church of St. James in Toruń
)''
, image_skyline =
, image_caption =
, image_flag = POL Toruń flag.svg
, image_shield = POL Toruń COA.svg
, nickname = City of Angels, Gingerbread city, Copernicus Town
, pushpin_map = Kuyavian-Pom ...
(14th century)
Radzyn Chelm zamek zendrowka.jpg, Decorative pattern made of strongly fired bricks in Radzyń Castle (14th century)
File:Mudéjar Teruel (1361857538).jpg, Mudéjar
Mudéjar ( , also , , ca, mudèjar , ; from ar, مدجن, mudajjan, subjugated; tamed; domesticated) refers to the group of Muslims who remained in Iberia in the late medieval period despite the Christian reconquest. It is also a term for ...
brick church tower in Teruel
Teruel () is a city in Aragon, located in eastern Spain, and is also the capital of Teruel Province. It has a population of 35,675 in 2014 making it the least populated provincial capital in the country. It is noted for its harsh climate, with a ...
, Spain, (14th century)
thornbury.twochimneys.arp.750pix.jpg, Brick sculpting on Thornbury Castle
Thornbury Castle is a Tudor castle in the place of Thornbury, in Gloucestershire, England, situated next to the parish church of St Mary, founded in the Norman era. Construction was begun in 1511 as a further residence for Edward Stafford, 3rd ...
, Thornbury, near Bristol
Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
, England. The chimney
A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator, or fireplace from human living areas. Chimneys are typic ...
s were erected in 1514
Rijksmonument450429.JPG, A typical brick house in the Netherlands.
Lopen uusi kirkko.jpg, A 19th-century brick church in Loppi
Loppi (; Swedish also ) is a municipality in Finland. It is located in the province of Southern Finland and is part of the Tavastia Proper region, located about 50 kilometers (about 30 miles) south of the city of Hämeenlinna. Loppi was founded ...
, Finland
Rieten dak old farmhouse.jpg, A typical Dutch farmhouse near Wageningen
Wageningen () is a municipality and a historic city in the central Netherlands, in the province of Gelderland. It is famous for Wageningen University, which specialises in life sciences. The municipality had a population of in , of which many t ...
, Netherlands
Capilla San Sebastián Mártir a.jpg, Baroque brick Parish of San Sebastián Mártir, Xoco in Mexico City
Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...
, was completed in 1663
St Michael and All Angels Church, Blantyre, Malawi Brick Detail 2.JPG, Decorative bricks in St Michael and All Angels Church, Blantyre, Malawi
BiblioBarco.jpg, Virgilio Barco Public Library, Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish period and between 1991 and 2000, is the capital city of Colombia, and one of the larges ...
, Colombia
Maria Claudia Cali edificio FES.jpg, FES Building, Cali
Santiago de Cali (), or Cali, is the capital of the Valle del Cauca department, and the most populous city in southwest Colombia, with 2,227,642 residents according to the 2018 census. The city spans with of urban area, making Cali the second ...
, Colombia
Brick likn india.JPG, A brick kiln, Tamil Nadu
Tamil Nadu (; , TN) is a States and union territories of India, state in southern India. It is the List of states and union territories of India by area, tenth largest Indian state by area and the List of states and union territories of India ...
, India
SW 4th Avenue MAX station.jpg, Brick sidewalk paving in Portland, Oregon
Portland (, ) is a port city in the Pacific Northwest and the largest city in the U.S. state of Oregon. Situated at the confluence of the Willamette and Columbia rivers, Portland is the county seat of Multnomah County, the most populous co ...
, U.S.
CambridgeMAFireplugB.jpg, Brick sidewalk in Cambridge, Massachusetts
Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. As part of the Boston metropolitan area, the cities population of the 2020 U.S. census was 118,403, making it the fourth most populous city in the state, behind Boston, ...
, U.S.
Porotherm style clay block brick angle 1.jpg, Porotherm style clay block brick
Cegly01.jpg, Moulding bricks, Poland
Normanby Brick.jpg, Brick made as a byproduct of ironstone
Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially. Not to be con ...
mining Normanby – UK
Brick making in Hainan - 01.jpg, Fired, clay bricks in Hainan
Hainan (, ; ) is the smallest and southernmost province of the People's Republic of China (PRC), consisting of various islands in the South China Sea. , the largest and most populous island in China,The island of Taiwan, which is slightly l ...
, China
Stanley_Dock_warehouses.jpg, The largest brick warehouse in the world, Stanley Dock Tobacco Warehouse, Liverpool
Liverpool is a city and metropolitan borough in Merseyside, England. With a population of in 2019, it is the 10th largest English district by population and its metropolitan area is the fifth largest in the United Kingdom, with a popul ...
, UK
Foraine brick en.jpg, Medieval heir to the Roman brick
Roman brick can refer either to a type of brick used in Ancient Roman architecture and spread by the Romans to the lands they conquered; or to a modern type inspired by the ancient prototypes. In both cases, it characteristically has longer and f ...
in the Toulouse
Toulouse ( , ; oc, Tolosa ) is the prefecture of the French department of Haute-Garonne and of the larger region of Occitania. The city is on the banks of the River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Par ...
region, the "Foraine" brick has kept the same large and flat format.
(Albi) North views of the Ste Cécile Cathedral.jpg, The Albi Cathedral
The Cathedral Basilica of Saint Cecilia ( French: ''Basilique Cathédrale Sainte-Cécile d'Albi''), also known as Albi Cathedral, is the seat of the Catholic Archbishop of Albi. First built in the aftermath of the Albigensian Crusade, the grim ex ...
(France) was built using "Foraine" bricks.
See also
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*
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References
Further reading
*
*
*
*
*
*
*
* Hudson, Kenneth (1972) ''Building Materials''; chap. 3: Bricks and tiles. London: Longman; pp. 28–42
*
External links
Brick in 20th-Century ArchitectureBrick Industry AssociationUnited States
Brick Development AssociationUK
Think Brick AustraliaInternational Brick Collectors Association
{{Authority control
Building materials
Masonry
Soil-based building materials