Building Materials

Building materials

Building material is any material which is used for construction purposes. Many naturally occurring substances, such as clay, rocks, sand, and wood, even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes.

The total cost of building materials

In history there are trends in building materials from being natural to becoming more man-made and composite; biodegradable to imperishable; indigenous (local) to being transported globally; repairable to disposable; chosen for increased levels of fire-safety, and improved seismic resistance.. These trends tend to increase the initial and long term economic, ecological, energy, and social costs of building materials.

Economic costs

Initial economic cost of building materials is the purchase price. This is often what governs decision making about what materials to use. Sometimes people take into consideration the energy savings or durability of the materials and see the value of paying a higher initial cost in return for a lower lifetime cost. For example, an asphalt shingle roof costs less than a metal roof to install, but the metal roof will last longer so the lifetime cost is less per year. Some materials may require more care than others, maintaining costs specific to some materials may also influence the final decision. Risks when considering lifetime cost of a material is if the building is damaged such as by fire or wind, or if the material is not as durable as advertised. The cost of materials should be taken into consideration to bear the risk to buy combustive materials to enlarge the lifetime. It is said that, 'if it must be done, it must be done well'.

Ecological costs

Pollution costs can be macro and micro. The macro, environmental pollution of extraction industries building materials rely on such as mining, petroleum, and logging produce environmental damage at their source and in transportation of the raw materials, manufacturing, transportation of the products, retailing, and installation. An example of the micro aspect of pollution is the off-gassing of the building materials in the building or indoor air pollution. Red List building materials are materials found to be harmful. Also the carbon footprint, the total set of greenhouse gas emissions produced in the life of the material. A life-cycle analysis also includes the reuse, recycling, or disposal of construction waste. Two concepts in building which account for the ecological economics of building materials are green building and sustainable development.

Energy costs

Initial energy costs include the amount of energy consumed to produce, deliver and install the material. The long term energy cost is the economic, ecological, and social costs of continuing to produce and deliver energy to the building for its use, maintenance, and eventual removal. The initial embodied energy of a structure is the energy consumed to extract, manufacture, deliver, install, the materials. The lifetime embodied energy continues to grow with the use, maintenance, and reuse/recycling/disposal of the building materials themselves and how the materials and design help minimize the life-time energy consumption of the structure.

Social costs

Social costs are injury and health of the people producing and transporting the materials and potential health problems of the building occupants if there are problems with the building biology. Globalization has had significant impacts on people both in terms of jobs, skills, and self-sufficiency are lost when manufacturing facilities are closed and the cultural aspects of where new facilities are opened. Aspects of fair trade and labor rights are social costs of global building material manufacturing.

Naturally occurring substances

Brush

Brush structures are built entirely from plant parts and were used in primitive cultures such as Native Americans and pygmy peoples in Africa. These are built mostly with branches, twigs and leaves, and bark, similar to a beaver's lodge. These were variously named wikiups, lean-tos, and so forth.

An extension on the brush building idea is the wattle and daub process in which clay soils or dung, usually cow, are used to fill in and cover a woven brush structure. This gives the structure more thermal mass and strength. Wattle and daub is one of the oldest building techniques. Many older timber frame buildings incorporate wattle and daub as non-load bearing walls between the timber frames.

Ice and snow

Snow and occasionally ice, were used by the Inuit peoples for igloos and snow is used to build a shelter called a quinzhee. Ice has also been used for ice hotels as a tourist attraction in northern climates.

Mud and clay

Clay based buildings usually come in two distinct types. One being when the walls are made directly with the mud mixture, and the other being walls built by stacking air-dried building blocks called mud bricks.

Other uses of clay in building is combined with straws to create light clay, wattle and daub, and mud plaster.

Wet-laid clay walls

Wet-laid, or damp, walls are made by using the mud or clay mixture directly without forming blocks and drying them first. The amount of and type of each material in the mixture used leads to different styles of buildings. The deciding factor is usually connected with the quality of the soil being used. Larger amounts of clay are usually employed in building with cob, while low-clay soil is usually associated with sod house or sod roof construction. The other main ingredients include more or less sand/gravel and straw/grasses. Rammed earth is both an old and newer take on creating walls, once made by compacting clay soils between planks by hand; nowadays forms and mechanical pneumatic compressors are used.

Soil, and especially clay, provides good thermal mass; it is very good at keeping temperatures at a constant level. Homes built with earth tend to be naturally cool in the summer heat and warm in cold weather. Clay holds heat or cold, releasing it over a period of time like stone. Earthen walls change temperature slowly, so artificially raising or lowering the temperature can use more resources than in say a wood built house, but the heat/coolness stays longer.

People building with mostly dirt and clay, such as cob, sod, and adobe, created homes that have been built for centuries in western and northern Europe, Asia, as well as the rest of the world, and continue to be built, though on a smaller scale. Some of these buildings have remained habitable for hundreds of years.

Structural clay blocks and bricks

Mud-bricks, also known by their Spanish name adobe are ancient building materials with evidence dating back thousands of years BC. Compressed earth blocks are a more modern type of brick used for building more frequently in industrialized society since the building blocks can be manufactured off site in a centralized location at a brickworks and transported to multiple building locations. These blocks can also be monetized more easily and sold.

Structural mud bricks are almost always made using clay, often clay soil and a binder are the only ingredients used, but other ingredients can include sand, lime, concrete, stone and other binders. The formed or compressed block is then air dried and can be laid dry or with a mortar or clay slip.

Sand

Sand is used with cement, and sometimes lime, to make mortar for masonry work and plaster. Sand is also used as a part of the concrete mix. An important low-cost building material in countries with high sand content soils is the Sandcrete block, which is weaker but cheaper than fired clay bricks.

Stone or rock

Rock structures have existed for as long as history can recall. It is the longest lasting building material available, and is usually readily available. There are many types of rock throughout the world, all with differing attributes that make them better or worse for particular uses. Rock is a very dense material so it gives a lot of protection too; its main drawback as a material is its weight and awkwardness. Its energy density is also considered a big drawback, as stone is hard to keep warm without using large amounts of heating resources.

Dry-stone walls have been built for as long as humans have put one stone on top of another. Eventually, different forms of mortar were used to hold the stones together, cement being the most commonplace now.

The granite-strewn uplands of Dartmoor National Park, United Kingdom, for example, provided ample resources for early settlers. Circular huts were constructed from loose granite rocks throughout the Neolithic and early Bronze Age, and the remains of an estimated 5,000 can still be seen today. Granite continued to be used throughout the Medieval period (see Dartmoor longhouse) and into modern times. Slate is another stone type, commonly used as roofing material in the United Kingdom and other parts of the world where it is found.

Stone buildings can be seen in most major cities; some civilizations built entirely with stone such as the Egyptian and Aztec pyramids and the structures of the Inca civilization.

Thatch

Thatch is one of the oldest of building materials known, Thatch is another word for grass; grass is a good insulator and easily harvested. Many African tribes have lived in homes made completely of grasses and sand year-round. In Europe, thatch roofs on homes were once prevalent but the material fell out of favor as industrialization and improved transport increased the availability of other materials. Today, though, the practice is undergoing a revival. In the Netherlands, for instance, many new buildings have thatched roofs with special ridge tiles on top.

Wood and timber

Wood has been used as a building material for thousands of years in its natural state. Today, engineered wood is becoming very common in industrialized countries.

Wood is a product of trees, and sometimes other fibrous plants, used for construction purposes when cut or pressed into lumber and timber, such as boards, planks and similar materials. It is a generic building material and is used in building just about any type of structure in most climates. Wood can be very flexible under loads, keeping strength while bending, and is incredibly strong when compressed vertically. There are many differing qualities to the different types of wood, even among same tree species. This means specific species are better suited for various uses than others. And growing conditions are important for deciding quality.

"Timber" is the term used for construction purposes except the term "lumber" is used in the United States. Raw wood (a log, trunk, bole) becomes timber when the wood has been "converted" (sawn, hewn, split) in the forms of minimally-processed logs stacked on top of each other, timber frame construction, and light-frame construction. The main problems with timber structures are fire risk and moisture-related problems.

In modern times softwood is used as a lower-value bulk material, whereas hardwood is usually used for finishing and furniture. Historically timber frame structures were built with oak in Western Europe, recently douglas fir has become the most popular wood for most types of structural building.

Many families or communities, in rural areas, have a personal woodlot from which the family or community will grow and harvest trees to build with or sell. These lots are tended to like a garden. This was much more prevalent in pre-industrial times, when laws existed as to the amount of wood one could cut at any one time to ensure there would be a supply of timber for the future, but is still a viable form of agriculture.

Man-made substances

Fired bricks and clay blocks

Bricks are made in a similar way to mud-bricks except without the fibrous binder such as straw and are fired ("burned" in a brick clamp or kiln) after they have air-dried to permanently harden them. Kiln fired clay bricks are a ceramic material. Fired bricks can be solid or have hollow cavities to aid in drying and make them lighter and easier to transport. The individual bricks are placed upon each other in courses using mortar. Successive courses being used to build up walls, arches, and other architectural elements. Fired brick walls are usually substantially thinner than cob/adobe while keeping the same vertical strength. They require more energy to create but are easier to transport and store, and are lighter than stone blocks. Romans extensively used fired brick of a shape and type now called Roman bricks. Building with brick gained much popularity in the mid-18th century and 19th centuries. This was due to lower costs with increases in brick manufacturing and fire-safety in the ever crowding cities.

The cinder block supplemented or replaced fired bricks in the late 20th century often being used for the inner parts of masonry walls and by themselves.

Structural clay tiles (clay blocks) are clay or terracotta and typically are perforated with holes.

Cement composites

Cement bonded composites are made of hydrated cement paste that binds wood, particles, or fibers to make pre-cast building components. Various fiberous materials, including paper, fiberglass, and carbon-fiber have been used as binders.

Wood and natural fibers are composed of various soluble organic compounds like carbohydrates, glycosides and phenolics. These compounds are known to retard cement setting. Therefore, before using a wood in making cement bonded composites, its compatibility with cement is assessed.

Wood-cement compatibility is the ratio of a parameter related to the property of a wood-cement composite to that of a neat cement paste. The compatibility is often expressed as a percentage value. To determine wood-cement compatibility, methods based on different properties are used, such as, hydration characteristics, strength, interfacial bond and morphology. Various methods are used by researchers such as the measurement of hydration characteristics of a cement-aggregate mix; the comparison of the mechanical properties of cement-aggregate mixes and the visual assessment of microstructural properties of the wood-cement mixes. It has been found that the hydration test by measuring the change in hydration temperature with time is the most convenient method. Recently, Karade et al. have reviewed these methods of compatibility assessment and suggested a method based on the ‘maturity concept’ i.e. taking in consideration both time and temperature of cement hydration reaction.

Bricks were laid in lime mortar from the time of the Romans until supplanted by Portland cement mortar in the early 20th century. Cement blocks also sometimes are filled with grout or covered with a parge coat.

Concrete

Concrete is a composite building material made from the combination of aggregate and a binder such as cement. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generally gravel and sand), Portland cement and water.

After mixing, the cement hydrates and eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term "concrete".

For a concrete construction of any size, as concrete has a rather low tensile strength, it is generally strengthened using steel rods or bars (known as rebars). This strengthened concrete is then referred to as reinforced concrete. In order to minimize any air bubbles, which would weaken the structure, a vibrator is used to eliminate any air that has been entrained when the liquid concrete mix is poured around the ironwork. Concrete has been the predominant building material in the modern age due to its longevity, formability, and ease of transport. Recent advancements, such as insulating concrete forms, combine the concrete forming and other construction steps (installation of insulation). All materials must be taken in required proportions as described in standards.

Fabric

The tent is the home of choice among nomadic groups all over the world. Two well-known types include the conical teepee and the circular yurt. The tent has been revived as a major construction technique with the development of tensile architecture and synthetic fabrics. Modern buildings can be made of flexible material such as fabric membranes, and supported by a system of steel cables, rigid or internal, or by air pressure.

Foam

Recently, synthetic polystyrene or polyurethane foam has been used in combination with structural materials, such as concrete. It is lightweight, easily shaped, and an excellent insulator. Foam is usually used as part of a structural insulated panel, wherein the foam is sandwiched between wood or cement or insulating concrete forms.

Glass

Glassmaking is considered an art form as well as an industrial process or material.

Clear windows have been used since the invention of glass to cover small openings in a building. Glass panes provided humans with the ability to both let light into rooms while at the same time keeping inclement weather outside.

Glass is generally made from mixtures of sand and silicates, in a very hot fire stove called a kiln, and is very brittle. Additives are often included the mixture used to produce glass with shades of colors or various characteristics (such as bulletproof glass or lightbulbs.

The use of glass in architectural buildings has become very popular in the modern culture. Glass "curtain walls" can be used to cover the entire facade of a building, or it can be used to span over a wide roof structure in a "space frame". These uses though require some sort of frame to hold sections of glass together, as glass by itself is too brittle and would require an overly large kiln to be used to span such large areas by itself.

Glass bricks were invented in the early 20th century.

Gypcrete

Gypcrete is a mixture of gypsum plaster and fibreglass rovings. Although plaster and fibres fibrous plaster have been used for many years, especially for ceilings, it was not until the early 1990s that serious studies of the strength and qualities of a walling system Rapidwall, using a mixture of gypsum plaster and 300mm plus fibreglass rovings, were investigated. It was discovered, through testing at the University of Adelaide, that these walls had significant, load bearing, shear and lateral resistance together with earthquake-resistance, fire-resistance, and thermal properties. With an abundance of gypsum (naturally occurring and by-product chemical FGD and phosphor gypsums) available worldwide, gypcrete-based building products, which are fully recyclable, offer significant environmental benefits.

Metal

Metal is used as structural framework for larger buildings such as skyscrapers, or as an external surface covering. There are many types of metals used for building. Metal figures quite prominently in prefabricated structures such as the Quonset hut, and can be seen used in most cosmopolitan cities. It requires a great deal of human labor to produce metal, especially in the large amounts needed for the building industries. Corrosion is metal's prime enemy when it comes to longevity.

Steel is a metal alloy whose major component is iron, and is the usual choice for metal structural building materials. It is strong, flexible, and if refined well and/or treated lasts a long time.

The lower density and better corrosion resistance of aluminum alloys and tin sometimes overcome their greater cost.

Copper is a valued building material because of its advantageous properties. These include corrosion resistance, durability, low thermal movement, light weight, radio frequency shielding, lightning protection, sustainability, recyclability, and a wide range of finishes. Copper is incorporated into roofing, flashing, gutters, downspouts, domes, spires, vaults, wall cladding, building expansion joints, and indoor design elements.

Other metals used include chrome, gold, silver, and titanium. Titanium can be used for structural purposes, but it is much more expensive than steel. Chrome, gold, and silver are used as decoration, because these materials are expensive and lack structural qualities such as tensile strength or hardness.

Plastics

The term "plastics" covers a range of synthetic or semi-synthetic organic condensation or polymerization products that can be molded or extruded into objects, films, or fibers. Their name is derived from the fact that in their semi-liquid state they are malleable, or have the property of plasticity. Plastics vary immensely in heat tolerance, hardness, and resiliency. Combined with this adaptability, the general uniformity of composition and lightness of plastics ensures their use in almost all industrial applications today. High performance plastics such as ETFE have become an ideal building material due to its high abrasion resistance and chemical inertness. Notable buildings that feature it include: the Beijing National Aquatics Center and the Eden Project biomes.

Papers and membranes

Building papers and membranes are used for many reasons in construction. One of the oldest building papers is red rosin paper which was known to be in use before 1850 and was used as an underlayment in exterior walls, roofs, and floors and for protecting a jobsite during construction. Tar paper was invented late in the 19th century and was used for similar purposes as rosin paper and for gravel roofs. Tar paper has largely fallen out of use supplanted by asphalt felt paper. Felt paper has been supplanted in some uses by synthetic underlayments, particularly in roofing by synthetic underlayments and siding by housewraps.

There are a wide variety of damp proofing and waterproofing membranes used for roofing, basement waterproofing, and geomembranes.

Ceramics

Fired clay bricks have been used since the time of the Romans. Special tiles are used for roofing, siding, flooring, ceilings, pipes, flue liners, and more.

Building products

In the market place the term "building products" often refers to ready-made particles/sections, made from various materials, which are fitted in architectural hardware and decorative hardware parts of a building. The list of building products excludes the building materials used to construct the building architecture and supporting fixtures, like windows, doors, cabinets, etc. Building products, rather, support and make building materials work in a modular fashion.

"Building products" may also refer to items used to put such hardware together, such as caulking, glues, paint, and anything else bought for the purpose of constructing a building.

Sustainability

In 2017, the buildings and construction together consumed 36% of the final energy produced globally while being responsible for 39% of the global energy related CO2 emissions. The shares from construction industry alone were 6% and 11% respectively. Energy consumption during the building-material production, predominantly due to their use of electricity, is a dominant contributor to the construction industry's share. Embodied energy of relevant building materials in the US are provided in the table below.

Types of Building Materials – Properties and Uses in Construction

Building material is any material used for construction purpose such as materials for house building. Wood, cement, aggregates, metals, bricks, concrete, clay are the most common type of building material used in construction. The choice of these are based on their cost effectiveness for building projects.

Many naturally occurring substances, such as clay, sand, wood and rocks, even twigs and leaves have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic.

The manufacture of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, plumbing, roofing and insulation work. This reference deals with habitats and structures including homes.

Types of Building Materials Used in Construction

1. Natural Construction Materials

Construction materials can be generally categorized into two sources, natural and synthetic. Natural materials are those that are unprocessed or minimally processed by industry, such as lumber or glass.

Synthetic materials are made in industrial settings after much human manipulations, such as plastics and petroleum based paints. Both have their uses.

Mud, stone, and fibrous plants are the most basic materials, aside from tents made of flexible materials such as cloth or skins. People all over the world have used these three materials together to create homes to suit their local weather conditions.

In general stone and/or brush are used as basic structural components in these buildings, while mud is used to fill in the space between, acting as a type of concrete and insulation.

A basic example is wattle and daub mostly used as permanent housing in tropical countries or as summer structures by ancient northern peoples.

2. Fabric

The tent used to be the home of choice among nomadic groups the world over. Two well-known types include the conical teepee and the circular yurt. It has been revived as a major construction technique with the development of tensile architecture and synthetic fabrics.

Modern buildings can be made of flexible material such as fabric membranes, and supported by a system of steel cables or internal (air pressure.)

3. Mud and clay

The amount of each material used leads to different styles of buildings. The deciding factor is usually connected with the quality of the soil being used. Larger amounts of clay usually mean using the cob/adobe style, while low clay soil is usually associated with sod building.

The other main ingredients include more or less sand/gravel and straw/grasses. Rammed earth is both an old and newer take on creating walls, once made by compacting clay soils between planks by hand, now forms and mechanical pneumatic compressors are used.

Soil and especially clay is good thermal mass; it is very good at keeping temperatures at a constant level. Homes built with earth tend to be naturally cool in the summer heat and warm in cold weather. Clay holds heat or cold, releasing it over a period of time like stone.

Earthen walls change temperature slowly, so artificially raising or lowering the temperature can use more resources than in say a wood built house, but the heat/coolness stays longer.

Peoples building with mostly dirt and clay, such as cob, sod, and adobe, resulted in homes that have been built for centuries in western and northern Europe as well as the rest of the world, and continue to be built, though on a smaller scale. Some of these buildings have remained habitable for hundreds of years.

4. Rock

Rock structures have existed for as long as history can recall. It is the longest lasting building material available, and is usually readily available. There are many types of rock throughout the world all with differing attributes that make them better or worse for particular uses.

Rock is a very dense material so it gives a lot of protection too, its main draw-back as a material is its weight and awkwardness. Its energy density is also considered a big draw-back, as stone is hard to keep warm without using large amounts of heating resources.

Dry-stone walls have been built for as long as humans have put one stone on top of another. Eventually different forms of mortar were used to hold the stones together, cement being the most commonplace now.

The granite-strewn uplands of Dartmoor National Park, United Kingdom, for example, provided ample resources for early settlers. Circular huts were constructed from loose granite rocks throughout the Neolithic and early Bronze Age, and the remains of an estimated 5,000 can still be seen today.

Granite continued to be used throughout the Medieval period (see Dartmoor longhouse) and into modern times. Slate is another stone type, commonly used as roofing material in the United Kingdom and other parts of the world where it is found.

Mostly stone buildings can be seen in most major cities, some civilizations built entirely with stone such as the Pyramids in Egypt, the Aztec pyramids and the remains of the Inca civilization.

5. Thatch

Thatch is one of the oldest of materials known; grass is a good insulator and easily harvested. Many African tribes have lived in homes made completely of grasses year round. In Europe, thatch roofs on homes were once prevalent but the material fell out of favor as industrialization and improved transport increased the availability of other materials.

Today, though, the practice is undergoing a revival. In the Netherlands, for instance, many of new builds too have thatched roofs with special ridge tiles on top.

6. Brush

Brush structures are built entirely from plant parts and are generally found in tropical and subtropical areas, such as rainforests, where very large leaves can be used in the building. Native Americans often built brush structures for resting and living in, too.

These are built mostly with branches, twigs and leaves, and bark, similar to a beaver’s lodge. These were variously named wikiups, lean-tos, and so forth.

7. Ice

Ice was used by the Inuit for igloos, but has also been used for ice hotels as a tourist attraction in northern areas that might not otherwise see many winter tourists.

8. Wood

Wood is a product of trees, and sometimes other fibrous plants, used for construction purposes when cut or pressed into lumber and timber, such as boards, planks and similar materials. It is a generic building material and is used in building just about any type of structure in most climates.

Wood can be very flexible under loads, keeping strength while bending, and is incredibly strong when compressed vertically.

There are many differing qualities to the different types of wood, even among same tree species. This means specific species are better for various uses than others. And growing conditions are important for deciding quality.

Historically, wood for building large structures was used in its unprocessed form as logs. The trees were just cut to the needed length, sometimes stripped of bark, and then notched or lashed into place.

In earlier times, and in some parts of the world, many country homes or communities had a personal wood-lot from which the family or community would grow and harvest trees to build with. These lots would be tended to like a garden.

With the invention of mechanizing saws came the mass production of dimensional lumber. This made buildings quicker to put up and more uniform. Thus the modern western style home was made.

9. Brick and Block

A brick is a block made of kiln-fired material, usually clay or shale, but also may be of lower quality mud, etc. Clay bricks are formed in a molding (the soft mud method), or in commercial manufacture more frequently by extruding clay through a die and then wire-cutting them to the proper size (the stiff mud process).

Bricks were widely used as a construction material in the 1700, 1800 and 1900s. This was probably due to the fact that it was much more flame retardant than wood in the ever crowding cities, and fairly cheap to produce.

Another type of block replaced clay bricks in the late 20th century. It was the Cinder block. Made mostly with concrete.

An important low-cost material in developing countries is the Sandcrete block, which is weaker but cheaper than fired clay bricks.

10. Concrete

Concrete is a composite building material made from the combination of aggregate (composite) and a binder such as cement. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generally gravel and sand), Portland cement and water.

After mixing, the cement hydrates and eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term concrete.

For a concrete construction of any size, as concrete has a rather low tensile strength, it is generally strengthened using steel rods or bars (known as rebars). This strengthened concrete is then referred to as reinforced concrete.

In order to minimize any air bubbles, which would weaken the structure, a vibrator is used to eliminate any air that has been entrained when the liquid concrete mix is poured around the ironwork. Concrete has been the predominant material in this modern age due to its longevity, formability, and ease of transport.

11. Metal

Metal is used as structural framework for larger buildings such as skyscrapers, or as an external surface covering.

There are many types of metals used for building. Steel is a metal alloy whose major component is iron, and is the usual choice for metal structural construction. It is strong, flexible, and if refined well and/or treated lasts a long time. Corrosion is metal’s prime enemy when it comes to longevity.

The lower density and better corrosion resistance of aluminum alloys and tin sometimes overcome their greater cost. Brass was more common in the past, but is usually restricted to specific uses or specialty items today.

Metal figures quite prominently in prefabricated structures such as the Quonset hut, and can be seen used in most cosmopolitan cities. It requires a great deal of human labor to produce metal, especially in the large amounts needed for the building industries.

Other metals used include titanium, chrome, gold and silver. Titanium can be used for structural purposes, but it is much more expensive than steel. Chrome, gold, and silver are used as decoration, because these materials are expensive and lack structural qualities such as tensile strength or hardness.

12. Glass

Clear windows have been used since the invention of glass to cover small openings in a building. They provided humans with the ability to both let light into rooms while at the same time keeping inclement weather outside. Glass is generally made from mixtures of sand and silicates, and is very brittle.

Modern glass “curtain walls” can be used to cover the entire facade of a building. Glass can also be used to span over a wide roof structure in a “space frame”.

13. Ceramics

Ceramics are such things as tiles, fixtures, etc. Ceramics are mostly used as fixtures or coverings in buildings. Ceramic floors, walls, counter-tops, even ceilings. Many countries use ceramic roofing tiles to cover many buildings.

Ceramics used to be just a specialized form of clay-pottery firing in kilns, but it has evolved into more technical areas.

14. Plastic

The term plastics covers a range of synthetic or semi-synthetic organic condensation or polymerization products that can be molded or extruded into objects or films or fibers. Their name is derived from the fact that in their semi-liquid state they are malleable, or have the property of plasticity.

Plastics vary immensely in heat tolerance, hardness, and resiliency. Combined with this adaptability, the general uniformity of composition and lightness of plastics ensures their use in almost all industrial applications today

15. Foam

More recently synthetic polystyrene or polyurethane foam has been used on a limited scale. It is light weight, easily shaped and an excellent insulator. It is usually used as part of a structural insulated panel where the foam is sandwiched between wood and cement.

16. Cement composites

Cement bonded composites are an important class of construction material. These products are made of hydrated cement paste that binds wood or alike particles or fibers to make precast building components. Various fibrous materials including paper and fiberglass have been used as binders.

Wood and natural fibres are composed of various soluble organic compounds like carbohydrates, glycosides and phenolics. These compounds are known to retard cement setting. Therefore, before using a wood in making cement boned composites, its compatibility with cement is assessed.

Wood-cement compatibility is the ratio of a parameter related to the property of a wood-cement composite to that of a neat cement paste. The compatibility is often expressed as a percentage value.

To determine wood-cement compatibility, methods based on different properties are used, such as, hydration characteristics, strength, interfacial bond and morphology.

Various methods are used by researchers such as the measurement of hydration characteristics of a cement-aggregate mix; the comparison of the mechanical properties of cement-aggregate mixes and the visual assessment of microstructural properties of the wood-cement mixes.

It has been found that the hydration test by measuring the change in hydration temperature with time is the most convenient method. Recently, Karade et al. have reviewed these methods of compatibility assessment and suggested a method based on the ‘maturity concept’ i.e. taking in consideration both time and temperature of cement hydration reaction.

17. Building Materials in Modern Industry

Modern building is a multibillion dollar industry, and the production and harvesting of raw materials for building purposes is on a worldwide scale. Often being a primary governmental and trade key point between nations.

Environmental concerns are also becoming a major world topic concerning the availability and sustainability of certain materials, and the extraction of such large quantities needed for the human habitat.

18. Virtual Building Materials

Certain materials like photographs, images, text may be considered virtual. While, they usually exist on a substrate of natural material themselves, they acquire a different quality of salience to natural materials through the process of representation.

19. Building Products

When we talk about building products we refer to the ready-made particles that are fitted in different architectural hardware and decorative hardware parts of a building.

The list of building products exclusively exclude the materials, which are used to construct the building architecture and supporting fixtures like windows, doors, cabinets, etc. Building products do not make any part of a building rather they support and make them working.

What are Eco-Friendly Building Materials used in Construction?

Today many people that are building or remodeling their houses choose to use eco-friendly building materials. An eco-friendly building material is one that increases the efficiency of energy used and reduces impact on human well-being and the environment.

There are many different materials that can be used that are eco-friendly; from foundation, to insulation, to interior and exterior wall finishes, flooring, and countertop materials.

Categorization of Building Materials

Categorized based on Activity and Vendor Specific

Civil materials

Waterproofing and Chemical additives

Paving, flooring, dado and similar finishes

Paints, colors, white washing, distempering and wood finishes

Wood work

Roofing and ceiling

Doors and windows

Water supply and sanitary fittings

Electrical works

Firefighting system

Miscellaneous

Excavation work

Road works

Evaluating Eco-friendly Materials

Why eco-friendly materials?

Phenomenal growth in the construction industry that depends upon depletable resources.

Production of building materials leads to irreversible environmental impacts.

Using eco-friendly materials is the best way to build an eco-friendly building.

Stone quarrying leads to eroded hills, like this picture showing the site of makarana marble quarry, brick kilns in the fringes of the city lead to denudation of topsoil, dredging for sand damage the river biodiversity etc.

What is Eco-friendly material?

Dictionary: describes a product that has been designed to do the least possible damage to the environment. US EPA – EPP program defines as: “products or services that have a lesser or reduced effect on human health and the environment when compared with competing products or services that serve the same purpose”

Thus we talk of two issues – one that it does the least possible environmental damage and two that it is a comparative scale as there are very few materials that are completely eco-friendly.

One more point to note when we talk of eco-friendly construction is that it consist of two parts – Material and Technique.

A material by itself can be eco-friendly, e.g. Bamboo.

Or Even conventional materials can become eco-friendly based on the construction technique that is used. E.g. rat trap bond developed by Lauri Baker, which require less number of bricks and are more heat insulating than normal walls and therefore eco-friendly.

Properties of Eco-Friendly Building Materials

The various properties of the Eco-friendly materials and techniques are –

Materials can be eco-friendly also if they can assist in reduction of the energy used in the building during operation and maintenance.

It is difficult to get a material that has all these properties, and it thus becomes a comparative assessment to identify eco-friendly materials.

Source of Material

a. Renewable source

Rapidly renewable sources e.g. wood from certified forests

b. Reuse of Waste

­ Salvaged products –e.g. old plumbing, door frames

­ Recycled contents – agriculture/ industrial waste e.g. Bagasse Board

Embodied Energy

Scalar total of energy input required to produce the product including transporting them to the building site

Aluminium and steel has the most embodied energy because to the high energy required to produce them. Compared to timber that requires very less energy for production.

Reduce Pollution

­Air Pollution– Use of materials with low VOC emissions e.g. Cement Paints

­Water Pollution – Materials that prevent leaching.

­Land Pollution– Materials that reuse waste that would otherwise have resulted in landfill. E.g. Flyash Bricks.

Performance

­Reduce material use

­These are energy efficient and also help reduce the dead load of a building. E.g. Ferrocement

­Durability & Life Span

Material that are exceptionally durable, or require low maintenance e.g. PVC pipes.

Materials can be eco-friendly based on how they perform. Use of certain material or techniques can reduce the amount of material required.

Durability – The longer the life of a material the lesser it is required to replace and thus reduces the quantity required to produce.

Energy Conservation

­ Materials that require less energy during construction e.g. precast slabs.

­ Materials that help reduce the cooling loads- e.g. – aerated concrete blocks.

­ Products that conserve energy – e. g. CFL lamps.

­ Fixtures & equipments that help conserve water e.g. Dual flush cisterns

Recyclable

­ Reuse or Recycle as different product e.g. steel, aluminum.

­ Biodegradable – that decompose easily e.g. wood or earthen materials.

Types of Eco-friendly Building Materials

Conventional Eco-friendly materials

Bamboo, Bamboo Based Particle Board & Ply Board, Bamboo Matting

Bricks sun dried

Precast cement concrete blocks, lintels, slab. Structural and non-structural modular elements

Calcined Phosphogypsum Wall Panels

Calcium silicate boards and Tiles

Cellular Lightweight Concrete Blocks

Cement Paint

Clay roofing tiles

Water, polyurethane and acrylic based chemical admixtures for corrosion removal, rust prevention, water proofing

Epoxy Resin System, Flooring, sealants, adhesives and admixtures

Ferro-cement boards for door and window shutters

Ferro-cement Roofing Channels

Fly-ash Sand Lime Bricks and Paver Blocks

Gypsum Board, Tiles, Plaster, Blocks, gypsum plaster fibre jute/sisal and glass fibre composites

Laminated Wood Plastic Components

Marble Mosaic Tiles

MDF Boards and Moldings

Micro Concrete Roofing Tiles

Particle Boards

Polymerised waterproof compound

Portland Pozzolana Cement Fly-ash / Calcined Clay Based

Portland Slag Cement

RCC Door Frames

Ready Mix Cement Concrete

Rubber Wood Finger Joint Board

Stone dust

Waterproof compound, adhesive, Polymer, Powder

Potential Eco-friendly materials & techniques

Bagasse Board – BMTPC

Bricks from Coal Washery Rejects -CBRI, Roorkee

Building Blocks From Mine Waste – SERC

Burnt Clay FlyAsh Bricks – CBRI, Roorkee

Coir Cement Board – CBRI, Roorkee

Compressed Earth Blocks – BMTPC

EPS Composites and Door Shutters -CBRI, Roorkee

Fibre Fly Ash Cement Boards -BMTPC

Fibre Reinforced Concrete Precast Elements, Wall panels, Blocks, Manhole Covers – SERC

Fibrous Gypsum Plaster Boards – CBRI, Roorkee

Fly Ash Cellular Concrete, Fly Ash Cement Brick, Blocks – BMTPC

Fly Ash Lime Cellular Concrete – CBRI, Roorkee

Flyash Lime Gypsum Brick – BMTPC

Insulating Bricks from Rice Husk Ash- Central Glass and Ceramic Research Institute, Kolkata

Jute Fibre Polyester -BMTPC

Non Erodible Mud Plaster – CBRI, Roorkee

Polytiles – CBRI, Roorkee

Timber from trees such as Poplar, Rubber, Eucalyptus – BMTPC

Precast walling roofing components – CBRI, Roorkee

Prefab Brick Panel System – CBRI, Roorkee

Recommended eco-friendly alternatives

1. Structural System –

Alternatives to Cement Concrete (plain / reinforced) – cement, sand, aggregate, steel

Base Materials for R.C.C. and Steel Systems

a. Pozzolana Material content (Fly-ash / Slag / Calcinated Clay) attained through use of Blended Portland Cement (BPC) and /or direct addition of pozzolana material

b. Sand and aggregate from pulverized debris and /or sintered fly-ash for concrete and mortar

c. Recycled steel forms and reinforcement bars

Alternatives Systems

a. Ferro cement and

b. Pre-cast components for columns, beams, slabs, lofts, balconies, roofs etc.

c. Ready Mix Concrete

d. Use Resinous curing agents

2. Masonry

Alternatives to Fired clay bricks, cement concrete blocks, stone

a. Use of Fly ash + sand + lime bricks / blocks

b. Pulverized debris + cement bricks / blocks,

c. Industrial waste based bricks / blocks,

d. Aerated lightweight BPC concrete blocks,

e. Phospho-Gypsum based blocks

f. Lato blocks (laterite + cement)

3. Mortar

a. Sand from pulverized debris and / or sintered flyash

b. Pozzolana Material content

4. Plastering – Alternatives to cement, sand, plaster of paris, gypsum

a. Calcium Silicate Plaster

b. Cement Plaster

c. Use of Fiber reinforced clay plaster

d. Phospho-Gypsum Plaster

e. Non-erodable Mud Plaster

f. Use Resinous curing agents

5. Roofing and ceiling– Alternatives to Ferrous / non-ferrous sheets, tiles, thatch

a. Fibre Reinforced Polymer Plastics instead of PVC and Foam PVC, Polycarbonates, acrylics & plastics

b. Micro Concrete Roofing Tiles

c. Bamboo Matt Corrugated Roofing Sheets

6. Flooring, paving and road work –Alternatives to wood, stone, ceramics, concrete

a. Fly ash / industrial waste / pulverized debris blocks in BPC

b. Lime-pozzolana concrete paving blocks for all outdoor paving.

c. Bedding sand from pulverized debris

7. Tiles for interiors

a. Terrazzo floor for terraces and semi covered areas

b. Ceramic tiles (non-vitrified)

c. Mosaic Tiles/ Terrazzo Flooring

d. Cement Tiles

e. Phospho-Gypsum Tiles

f. Bamboo Board Flooring

8. Windows, Doors and openings – Steel, aluminum, timber, glass, R.C.C., PVC, Stone

a. Ferro cement and Pre-cast R.C.C. lintel, chajja and jalis

b. Masonry bond combinations for jali work

Alternatives to Timber and Aluminum / Steel frames

a. Ferrocement

b. Pre-cast R.C.C. Frames/ Frameless Doors

c. Bamboo Reinforced Concrete Frames

d. Hollow recycled steel channels and recycled Aluminium Channels and Components

Shutters and Panels – alternatives to timber, plywood, glass, aluminum

a. Red Mud based Composite door shutters,

b. Laminated Hollow Composite Shutters

c. Other wood alternatives

9. Electrical

Alternatives for Aluminum, brass, PVC, G.I., S.S.

a. Use unplasticised PVC or HDPE products

b. Where applicable use products with recycled aluminum and brass components

10. Water supply, Sanitary and Plumbing System

a. R.C.C., uPVC, G.I., C.I. pipes instead of lead, A.C. pipes

b. Where applicable use products with recycled aluminum and brass components for fittings, fixtures and accessories

c. Use Polymer Plastic (Random) hot / cold water system instead of G.I.

d. Manholes and covers – use Pre-cast cement concrete and high strength unplasticised PVC instead of C.I.

11. Wood

­

Renewable timber from plantations with species having not more than 10 year cycle or timber from a government certified forest / plantation or timber from salvaged wood

­ Plywood should be phenol bonded and not urea bonded

­ Use of MDF Board

­ Instead of Plywood:

Bamboo Ply/Mat Board/ Fibre Reinforced Polymer Board,/ Bagasse Board /Coir Composite Board /Bamboo mat Veneer Composite/ Finger Jointed Plantation Timber Board / Recycled Laminated Tube Board / Aluminum-Foil+Paper+Plastic Composite Board.

e. Use of Mica Laminates and Veneer on Composite boards instead of natural timber.

12. Water proofing chemicals, additives, sealants and adhesives

a. Use of water based chemicals instead of solvent based.

b. Epoxy resins instead of tar felt / pitch

13. Painting, Polishing, Priming and similar surface finishing

a. Use of Cement Paint / Epoxy Resin Paint for external surfaces

b. Use of Water based paints, enamels, primers and polishes

Faswal is a great alternative to traditional foundation materials. It uses waste materials from wood mixed with cement to create a strong and durable foundation material. Faswal can be used instead of cinder blocks and is excellent for bottom foundation and wall construction. It is naturally strong, fire and wind and sound resistant, and has excellent insulating factors.

Two great choices for insulation are straw bale and cotton. Straw bale is used for many reasons; it is generally less expensive than other forms of insulation and has great insulating factors. It is very durable and can easily support a lot of weight; additional supports are not usually needed, which cuts down on the use of treated lumber

Cotton insulation is a good alternative to fiber glass insulation. This type of insulation is derived from natural cotton fibers that are recycled into insulation. It is very convenient and comes in a similar batting shape as traditional insulation. It is also very easy and safe to install and has a high fire rating and wonderful sound insulating qualities.

Earth plaster and milk paints are excellent eco-friendly choices for building materials. Earth plaster is made out of mud and can be used as an interior or exterior finish. You can manipulate the plaster to create various finishes; including curves, angles, and clean finished walls. It does not need to be painted, as it comes in a variety of colors that are natural to the mud.

Milk paints are made up of milk earth and pigments from the earth in a variety of colors. Milk paints provide for a wide variety of colors without the use of harsh chemicals that are found in traditional house paints.

There are some great choices for eco-friendly flooring; cork flooring, bamboo, and recycled wood flooring are all excellent options. Cork flooring is a great alternative to wood; it is environmentally friendly; it only uses the bark from the tree and does not kill the tree as a result from harvest. The bark is a great renewable resource as it grows back completely within nine years. Cork flooring is very comfortable, durable, and insulating, and can last for many years.

Bamboo is another great choice for a renewable resource. Bamboo is not a wood at all, but rather a grass that only takes three years to fully mature. When processed, bamboo can have an attractive appearance similar to wood flooring. It is a very strong and durable type of flooring and performs very much like a traditional hardwood floor.

If you are determined to have wood floors, recycled wood flooring is a great option. This type of flooring often uses hardwood that would otherwise never be used again. The wood may be taken from demolition sites or trees that were torn down but never used. It is often cheaper to prepare recycled wood instead of new wood product and is just as beautiful and durable as new wood.

There are even materials for countertops that are eco-friendly. Two great choices are recycled glass/cast concrete and recycled plastic. Recycled glass/cast concrete uses both recycled glass and concrete with recycled materials in it. The glass used in this material cannot be broken down any further, so it is a good fit for countertop construction. It can also be used in the bathroom and surrounding fireplaces.

Recycled plastic is another good option for countertops. You can obtain many different styles using different types of recycled plastic. It can also be used in bathrooms and other places around the home. It is very durable and can stand up to heat, depending on how it is manufactured, and is very water resistant.

There are many different eco-friendly building materials available on the market today. You can virtually build and furnish an entire home from only eco-friendly materials. Eco-friendly materials are not only good for the Earth, but are equally good for your wallet. Many of the building materials that are eco-friendly have great insulating factors or are cheaper to produce than traditional materials.