General Classification of Bricks
There are literally thousands of different bricks, with a multitude of colours, finishes, characteristics and practical applications. To address all of the differences would be a massive task but there follows a broad overview of how bricks can be differentiated and generally classified in terms of variety, quality and type. Applying such broad criteria will enable bricks to be generally specified for different applications and uses.
A bricklayer will normally classify bricks according to three varieties: common bricks, facing bricks and engineering bricks.
Fig. 31 Common brick (frogged).
Common bricks are fired to a temperature of between 950 and 115 degrees centigrade and are cheaper simply because less fuel is expended in firing them at a lower temperature. They have no decorative faces and are general building bricks that can vary greatly in quality. ‘Commons’ are normally used for unseen work or below ground (if sufficiently durable).
Fig. 32 Facing brick (perforated).