Different Types of Bricks Used to Construct Home
M.E. Structural Engineer
“Architecture begins when you place two bricks carefully together.”
A home is a place where you can feel comfortable, and feel as if you are with yourself. It does not matter whether your home is in an apartment or bungalow, as long as your heart is there. The home physically is made with different components, namely structural components and non-structural components. Beams, columns, foundations etc. are structural components while doors, windows, tiles, paints etc. are non-structural components. The wall can be either of a structural component or non-structural component. The wall is an important basic component of the building which cannot be changed very often, once it gets built. Hence, choosing suitable wall units for the home wall is an important task, as so many options are available like bricks, stone, concrete blocks, wood etc.
History of Bricks
The earlier Bricks were dried brick, 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 shaped mud dates before 7500 BC.
According to ‘Frederick S. Merritt’ (author of Building Design and Construction Handbook) Brick is a rectangular masonry building unit, not less than 75% solid, made from burnt clay, shale, or a mixture of these materials.
No other building material can match brick’s elegance and classic style. Bricks are most common and widely used wall units all over the globe, since the soil for manufacturing of bricks is hugely available everywhere except desserts and rocky area. These days many different types of bricks for houses, are available. Hence, we are going to give you the information regarding different types of bricks from which you will be able choose as per your choice.
According to ‘R. Barry’ (author of the Construction of Buildings, Volume 7), it is not possible to classify bricks as good or as bad because some are good for one purpose and not for another. Bricks may be classified in accordance with their uses, quality, shape, raw material, manufacturing method etc.
Classification of Bricks Based on code ‘IS 1077: 1992’
Bricks classifications are based on different criteria.
Classification of Bricks is Done Based On:
- Burning of Brick
- Manufacturing Method
- Raw Material
- Using Location
- Weather-resisting Capability
- Purpose of Using
(a) Classification of Bricks Based on Quality
01. First Class Bricks
This type of brick is good quality brick as compared to other bricks. These are made from good quality of clay. These types of bricks are regular in shape and size. They have sharp edges and smooth surfaces. First class bricks are thoroughly burnt and are of red, cherry or copper colour. They are made by table moulding in the kiln. They do not absorb more than 20% water of its own dry weight, when immersed in fresh water for 24 hours.
These types of bricks have a crushing strength of around 105 kg/cm2. These types of bricks give ringing sound when struck together. These bricks are free from flaws, cracks, stones, chips etc. and most durable. They are used for permanent and superior nature of work, and also for load bearing walls.
Also Read: Various Shapes of Brick used in Construction
02. Second Class Bricks
These types of bricks have moderate quality. There are slight irregularities in the shape and size of second-class bricks. These types of bricks are moulded by ground moulding. Due to ground moulding, they don’t have sharp edges and smooth surfaces. They do not absorb more than 22% water of its own dry weight, when immersed in fresh water for 24 hours. These types of bricks have a crushing strength around of 70 kg/cm2.
03. Third Class Bricks
They are of poor-quality bricks. These types of bricks are over burnt or under burnt. Third class bricks are not regular in size and shape. They have unfair edges and rough surfaces. These types of bricks are also moulded by ground moulding and burnt in clamps. They do not absorb more than 25% water of its own dry weight, when immersed in fresh water for 24 hours.
These types of bricks have a crushing strength around of 35 kg/cm2. Third class bricks give dull sound when struck together. Third-class bricks are used in temporary structures.
04. Fourth Class Bricks
Fourth class bricks are of very poor-quality bricks and brittle in nature. Hence, they cannot be used for construction purpose. They are crushed and used as aggregates in the manufacturing of brick bat concrete. They are commonly used in a broken form, in road construction, foundations and floors as coarse aggregates.
(b) Classification of Bricks Based on Burning
01. Unburnt Bricks
They are also known as sun-dried bricks. It is believed that first-time when the bricks were used, they were in the sun-dried form (unburnt Bricks), in Egypt some 6000 years ago. Sun-dried bricks are used for temporary structures. They are not that much strong as they are dried through sunlight. These types of bricks have less fire and water resistance. Sunburnt bricks are not suitable for permanent structures.
02. Burnt Bricks
The bricks which are nowadays used commonly, are burnt bricks. They are prepared and burnt in a kiln. Burnt bricks have high strength as compared to unburnt bricks, still some defects remain there hence they are classified as:
- First Class Bricks
- Second Class Bricks
- Third Class Bricks
- Fourth Class Bricks
Which have already been discussed.
03. Over Burnt Bricks
These types of bricks are fired at high temperature and for a longer period of time than conventional bricks. As a result, the shape of over burnt brick is distorted. Over burnt bricks are used as coarse aggregate in the concrete of slab and beam which will not come in contact with water.
Also Read: Brick Flooring: All you Need Know
(c) Classification of Bricks Based on Manufacturing Method
01. Extruded Brick
It is manufactured by forcing clay and water into a steel die, with a very regular shape and size, then cutting the resulting column into shorter units with wires before firing. It has three or four holes constituting up to 25% volume of the brick. The holes in bricks reduce the weight of the bricks, making them cheaper and easier to use than dry pressed. The rough faces make it easier to apply finishes.
Extruded common bricks are economical type of brick that can be used for construction, where the faces are to be hidden or covered. It is used in constructions with limited budgets.
02. Moulded Brick
There are two types of moulded bricks such as hand moulded bricks and machine moulded bricks. Hand moulded bricks are shaped in moulds by hand.
Hand moulding of bricks is extensively used and can be made either on the table or on the ground. Machine moulded bricks are the soft irregular edges of bricks which are produced by moulding material in mould box machine.
03. Dry Pressed Brick
They are traditional types of bricks which are made by compressing clay into moulds. Dry pressed bricks have a deep frog on one bedding surface and shallow frog in another. These types of bricks are high quality bricks than an extruded brick.
Also Read: Your Mentor to Guide You to Buy Bricks
(d) Classification of Bricks Based on Raw Materials
01. Burnt Clay Bricks
It is the most used bricks. It requires plastering when used in construction works. These types of bricks are usually made from clay by burning. Burnt clay bricks are the common type of bricks for construction work. First class bricks, second class bricks, third class bricks, fourth class bricks are example of burnt clay bricks.
02. Fly Ash Bricks
As the name suggests, these types of bricks are manufactured by using fly ash. It contains a high volume of calcium oxide in it. That is why usually described as self-cementing. Fly ash brick expands when coming into contact with moisture. They are less porous than burnt clay bricks. It provides a smooth surface so it doesn’t need plastering. These bricks have better properties than clay bricks and great resistant to freeze-thaw cycles.
The advantages of fly ash bricks over clay bricks are that they have high strength, high fire insulation, uniform sizes for better joints.
03. Concrete Bricks
Concrete bricks or blocks are made from concrete. They are low-quality bricks and also, have low compression strength. It is the least used bricks. Concrete bricks are used above and below the damp proof course. These bricks are used for facades, fences and internal brick works because of their sound reductions and heat resistant qualities. Concrete bricks are also called mortar brick.
It may be of different colors if the pigment is added during manufacturing. These types of bricks can be manufactured in sizes, as required. The advantages of concrete bricks over clay bricks are that they can be manufactured at the construction site, it reduces the quantity of mortar required, and can be manufactured to provide different colours during its production.
04. Sand-Lime Bricks
These types of bricks are made from lime and sand hence named as sand lime bricks. They are also known as calcium silicate bricks. Sand-lime bricks are used for various purpose in construction i.e. ornamental works in buildings, masonry works etc. For manufacturing sand-lime bricks, sand, fly ash and lime are mixed and moulded under pressure. During the process of wet mixing, a chemical reaction takes place, which bonds the mixtures. Then, these mixtures are placed in the moulds under pressure. The greyish colour of these bricks gives an aesthetic view. These types of bricks offer more uniform appearance and smooth finish than the burnt clay bricks, that’s why it does not require plastering. Sand-lime bricks are used as load bearing members as they are much stronger.
05. Fire Bricks/ Refractory Bricks
Fire bricks are special types of bricks which are capable of withstanding very high temperatures without affecting its shape, size and strength. They are also termed as refractory bricks. The use of refractory bricks is restricted, to the making of inner walls of furnaces for the manufacture of metals and for similar high-temperature applications. The firebricks are also classified on the basis of their reactivity towards its melting at high temperatures.
(i) Acidic Bricks:
They are resistant to the melts of acidic composition (but will react with the melts of basic composition). Example of these types of bricks is silica bricks.
(ii) Basic Bricks:
Basic bricks are resistant to the melts of basic composition. Hence, they will not be suitable for use in those furnaces where acidic melts are being heated. Magnesia bricks and bauxite bricks are examples of basic bricks.
(iii) Neutral Bricks:
Neutral bricks are non-reactive to both the acidic and basic melts. Hence these find applications in heating either type of melts. Examples of these types of bricks are chromite bricks and chrome – magnesite bricks.
The firebricks are further classified on the basis of their compositions
(iv) Fire Clay Bricks:
These bricks are an important class of refractory materials of the acidic group. The raw material for its manufacturing can withstand very high temperatures without softening or fusing. Such clay is often available under the coal layers in nature. Silica and alumina are the two main constituents of fire Clay.
These are manufactured in a manner, similar to the common building bricks. The selected clay is crushed into the fine powder and moulded into the brick unit. These are then dried and burnt in the continuous kiln at very high temperature (1600 to 1900 centigrade). They are cooled gradually before taking out from the kiln. They are sub-divided into three types on the basis of temperature.
- High Duty (1482 to 1648 Centigrade)
- Medium Duty (1315 to 1481 Centigrade)
- Low Duty (870 to 1314 Centigrade)
These three types of bricks have high bearing capacity and low coefficient of thermal expansion. They are generally used as a lining material in reverberatory furnaces and steel making furnaces. The refractory bricks are further classified into following types based on composition.
Also Read: Tests to Check Compressive Strength of Brick
- Silica Fire Bricks:
These are made from mostly silica, which may range from 95 per cent or above. The remaining material is usually calcium oxide which acts as a binding agent. These are acidic in nature. Their raw materials are pure quartz (SiO2), or sandstone of high silica content. The moulded units are burnt at about 1500 Centigrade. They are extensively used in Bessemer converter as lining material because, slag in that case, is acidic in nature.
- Magnesite Fire Bricks:
They are classified among the basic refractories or fire bricks. Their raw material is magnesium oxide. The major source for it is Dolomite rocks.
- Bauxite Fire Brick:
They also form a very important class of basic fire bricks. They are made from the rock Bauxite which is mixed with some clay (Fire Clay type).
- Chromite Fire Bricks:
This belong to the neutral class of fire bricks. The raw material used for these type of fire bricks is a mineral called CHROMITE. The mineral is the double oxide of chromium and iron in its composition. These types of fire bricks are capable of resisting both the acidic and basic environments in a furnace. Chromite fire bricks are normally used in the steel-making furnaces.
(e) Classification of Bricks Based on Usage Location
01. Facing Bricks
Facing bricks are those bricks which are visible and are fixed on the face of the wall. These types of bricks are used in facade of the building. These bricks are standard in size, stronger than other bricks and also have better durability. They provide an aesthetic view to the building or home. There are many types of facing bricks which uses different technology and techniques. Facing bricks should be weather resistant as they are generally used on the exterior wall of buildings. Extruded bricks are one type of facing bricks. Further, the facing bricks are of different types:
(i) Fletton Brick:
Fletton bricks are the most common engineering bricks in construction. These types of bricks are very hard and dense, with a pink, patchy colour. Fletton bricks tends to have a texture where bricks rest against each other in the kiln. Flettons bricks have been used throughout UK since the start of the 20th century.
(ii) Arch Bricks:
Arch bricks are those bricks used in bricklaying that are burnt down immediately. Because of this, they can be over burnt which means they are distorted in shape. Despite their distorted appearance, they are quite high in quality.
(iii) Salmon Bricks:
Since Salmon bricks are near the outside of the kiln during the burning process, these types of bricks are slightly under burnt. It means that they’ll be softer than the arch bricks. They are not high-quality bricks.
(iv) Water-Struck Bricks:
For manufacturing these types of bricks, alluvial clay with very high moisture content is pressed into moulds and water is used as a lubricant to release the wet clay from the hardwood moulds. As the clay sides out of the moulds an unusual surface finish is created, which, after firing, results in a textural patina that has never been replicated by any other brick-making process.
02. Backing Bricks
Backing bricks don’t have any special features. They are just provided behind the facing bricks to provide support.
(f) Classification of Bricks Based on Weather Resisting Capability
01. Severe Weather Grade Bricks
These types of bricks can withstand repeated freeze-thaw actions. They are useful for countries where severe freeze-thaw action happens.
02. Moderate Weather Grade Bricks
Moderate weather grade bricks are used in tropical countries. These types of bricks can also be useful for hot-weather countries where freeze-thaw action doesn’t happen much. They can withstand high temperature.
03. No Weather Grade Bricks
(g) Classification of Bricks Based on Purpose of Using
01. Common Bricks
These types of bricks are the most common bricks used in construction. They don’t have any special features or requirements. They have low resistance, low quality, low compressive strength. Common bricks are generally used for the construction of the interior walls.
02. Engineering Bricks
These bricks are popular for many reasons. Engineering bricks have high compressive strength and low water absorption capacity. They have good damp proof, load-bearing capacity and chemical resistant properties. They have a uniform red colour. They are classified as Class A, Class B, Class C. Class A bricks are the strongest but Class B bricks are most used. They are used for mainly civil engineering works like sewers, manholes, ground works, retaining walls, damp proofing courses etc.
These types of bricks are burned at an extremely high temperature to form a strong and dense product. They are also used in structural designing and also used in special applications where strength, frost resistance, acid resistance, low porosity is required. Engineering bricks are generally used for basements where chemical or water attacks are prevalent.
(h) Classification of Bricks Based on Shape
Based on shape bricks are classified in to following types:
- Bullnose Bricks
- Coping Bricks
- Cownose Bricks
- Paving Bricks
- Purpose-made Bricks
- Cant or Splayed Bricks
- Arch Bricks
Above listed bricks are discussed in the article, Various Shapes of Brick used in Construction Remaining types of bricks based on shape are,
01. Air Bricks
These types of bricks contain holes to circulate air. Air bricks are used in cavity wall and suspended floors.
02. Capping Bricks
These bricks are used to cap the tops of freestanding or parapets walls to offer protection and visual appeal.
03. Brick Veneers
04. Curved Bricks
These bricks are curved in shape. They are used in pavements, arcs etc.
(i) Classification of Bricks Based on Cavities
Classification of Bricks Based on Cavities
- Hollow Bricks
- Perforated Bricks
- Channel or Gutter Bricks
To know more about these three types of bricks refer the article, Various Shapes of Brick used in Construction.
(j) Classification of Bricks Based on Region
01. Staffordshire Blue Bricks
These are a strong type of construction brick, originally made in Staffordshire, England. These types of bricks are made from the local red clay, Etruria marl, which when fired at a high temperature in a low-oxygen reducing atmosphere takes on a deep blue colour and attains a very hard, impervious surface with high crushing strength and low water absorption.
02. Roman Bricks
As the name suggests Roman bricks find its history back to ancient Rome. Ancient Roman bricks were made in a variety of dimensions, but were always flatter and longer than traditional bricks
03. Cream City Bricks
Cream City bricks are made from a red clay containing elevated amounts of lime and magnesia. This clay is common in regions of Wisconsin, especially near Milwaukee. When the bricks are fired, they become creamy-yellow in colour. Clay found along Milwaukee’s river banks was naturally high in magnesia and lime, giving the brick its unique colour and durability.
04. London Stock Bricks
These types of bricks are the handmade bricks which were used for most of the building work in London and South East England. Its characteristic yellow colour and soft appearance come from the yellow local clay from which the bricks were made.
05. Dutch Bricks
06. Nanak Shahi Bricks
These bricks are from India. They were decorative bricks used for structural walls during the Mughal era.
Summing up, bricks have been in use for thousands of years from the earliest of civilizations to the most recent buildings. Simply put, it lasts! Bricks are made from clay or shale and fired in a kiln at approximately 2000 degrees Fahrenheit to fuse the particles together. It continues to be used throughout the world because it looks great in both traditional or contemporary architecture, is readily available in all colours, textures and sizes. It won’t burn and requires minimal maintenance.
Building a house exclusively of Bricks can be costly, but it’s a sensible investment that pays off. Interior walls made of bricks help adjust the building’s temperature, as they store heat and cool air. In winter, the walls offer warmth, while on a hot summer day they have a cooling effect. This creates a pleasant indoor climate, which means a healthy house. Different types of bricks are used at different places based on local availability.