A brick is a type of construction material used to build walls, pavements, and other elements in masonry construction. Properly, the term brick denotes a unit primarily composed of clay, but it is now also used informally to denote units made of other materials or other chemically cured construction blocks. Bricks can be joined using mortar, adhesives, or by interlocking, and are usually produced at brickworks in numerous classes, types, materials, and sizes which vary with region, and are produced in bulk quantities. Bricks are laid in courses and numerous patterns known as bonds, collectively known as brickwork, and may be laid in various kinds of mortar to hold the bricks together to make a durable structure.
Most manufacturers blend different types of clay to achieve the desired properties of the raw materials, and bricks today come in various classes, colors, shapes, sizes, and textures. Regardless of the type of brick, the main ingredient is clay. Bricks in the Southeast are typically made of red clay, so the final result is a distinguishable shade of red, while in the upper Midwest, yellow clay is used with the result. Engineering bricks are used where strength, low water porosity, or acid (flue gas) resistance are needed.
In modern construction practices, bricks are categorized according to their component materials and method of manufacture, and there are seven common types: common burnt clay bricks, sand-lime bricks, engineering bricks, concrete bricks, fly ash clay bricks, fire bricks, and special bricks. Bricks consist of fired ceramic, clay, or cement materials that are cut into specific shapes, such as a rectangle, and used for building walls or furnaces. The oldest shaped bricks found date back to 7500 B.C. .
