Clinker brick

Common card · No. 397843

Clinker bricks are partially-vitrified bricks used in the construction of buildings. Clinker bricks are produced when wet clay bricks are exposed to excessive heat during the firing process, sintering the surface of the brick and forming a shiny, dark-colored coating. Clinker bricks have a blackened appearance, and they are often misshapen or split. Clinkers are so named for the metallic sound they make when struck together. Clinker bricks are denser, heavier, and more irregular than standard bricks. Clinkers are water-resistant and durable, but have higher thermal conductivity than more porous red bricks, lending less insulation to climate-controlled structures. The brick-firing kilns of the early 20th century—called brick clamps or "beehive" kilns—did not heat evenly, and the bricks that were too close to the fire emerged harder, darker, and with more vibrant colors, according to the minerals present in the clay. Initially, these clinkers were discarded as defective, but around 1900...

Read on Wikipedia · Image Wmeinhart, CC BY-SA 3.0