From Academic Kids
Building material is any material which is used for a construction purpose. Just about every type of available material has been used at one time or another for creating various human and animal homes, structures, and technologies. This reference deals with habitat structures including homes.
Human building materials
Living spaces and their related structures have been created using myriad materials, from mud to metal, and from plastic to grass. Today the production and assembly of various building materials is a multibillion dollar industry, and much environmental concern has recently surfaced about the effects of such a massive resource extraction on a global scale.
Mud, stone, and brush
Mud, stone, and brush are probably the most basic building materials aside from tents made of flexible materials such as cloth or leather. Peoples all over the world have used these three materials together to create homes to suit their local weather conditions. In general stone and 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.
Some examples are the wattle and daub mostly used as permanent housing in tropical countries or as summer structures by ancient northern peoples.
Dirt and clay
The amount of each material used leads to different styles of buildings. Building with mostly dirt and clay such as cob and sod, 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.
Mostly stone buildings are those seen in most major cities as well as the Pyramids in Egypt, the Aztec pyramids and the remains of the Inca civilisation. Dry-stone walls have been built for as long as humans have put one stone on top of another.
Brush structures are built entirely from plant parts and are generally found in tropical 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.
Thatch may in fact be one of the oldest of building 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 very prevalent, but are rare in modern times; there are still craftspeople who specialize in the profession.
Wood is a product of trees used for construction purposes when cut 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 in to place.
In earlier times most 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.
A brick is a block made of kiln-fired material, usually clay or shale, but also may be of mud, etc. Clay bricks are formed in a moulding (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).
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 minimise any air bubbles (that 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.
Metal is used as structural framework for larger buildings such as skyscrapers, or as an external surface covering. Steel is a metal alloy whose major component is iron, and is the usual choice for metal structural building materials. The lower density and better corrosion resistance of aluminium alloys sometimes overcome their greater cost. Metal figures quite prominently in prefabricated structures such as the Quonset hut.
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.
New materials and techniques
The tent has been revived as a major construction technique with the development of tensile architecture. Buildings can be made of flexible material such as fabric membranes, and supported by a system of steel cables or internal air pressure.de:Baumaterial eo:Konstrumaterialo