History of Brick Making
A brick is a block made of clay burnt in a kiln. It is one of the primary building materials known to mankind. Over time, bricks have appeared, gained prominence, lost importance and then come to the forefront again with various styles of architecture. Burnt bricks were used in ancient Indian, Babylon, Egypt and Roman civilizations. They are still being used as filler materials for framework structures as well as to construct load bearing structures. Down the ages, there have been various interesting historic and cultural references to bricks.
- Bricks find mention in the Bible; the tower of Babel was built with burnt bricks.
- Bricks were predominantly used in the Indus valley civilisation. In fact, the civilisation was first discovered when;
ancient bricks being used to build railway ballast came to the notice of a passing archaeologist.
- While the Taj Mahal was built in white marble, it had extensive scaffolding made entirely out of brick,
which was pulled down after completion.
Making the Brick
The process of making a brick has not changed much over the centuries or across geographies. Traditionally the main steps followed to make a brick are explained below
- Material Procurement : The clay is mined and stored in the open. This makes the clay soft and removes unwanted oxides.
- Tempering : This clay is then mixed with water to get the right consistency for moulding. Mixing is done manually with hands and feet. Sometimes and in certain areas, animal driven pug mills are used.
- Moulding : A lump of mix is taken, rolled in sand and slapped into the mould. Initially moulds were made of wood, now metal moulds are used. Sand is used so the brick does not stick to the mould.
- Drying : The mould is emptied onto the drying area, where the bricks are arranged in a herring bone pattern to dry in the sun. Every two days they are turned over to facilitate uniform drying and prevent warping. After two weeks they are ready to be burnt.
- Firing : The green bricks are arranged in a kiln and insulation is provided with a mud pack. Fire holes left to ignite the kiln are later sealed to keep the heat inside. This is maintained for a week. Firing like other operations also depends on the knowledge and experience of the brick maker.
- Sorting : After the kiln is disassembled, the bricks are sorted according to colour. Colour is an indication of the level of burning. Over burnt bricks are used for paving or covering the kiln while slightly under burnt bricks are used for building inner walls or burnt once again in the next kiln.
