Why bricks are red

Why are bricks red? Pale bricks are as easy to make as the red bricks. We prefer eating from plates made of white clay. So, why do we like our bricks red? During the Renaissance and the Baroque, visible brick walls were unpopular and the brickwork was covered with plaster. It was only during the midth century that visible brick walls regained some degree of popularity. Bricks rose in popularity when Flemish refugees brought bricks into East Anglia.

Their use spread and by the late 18th century, yellow 'stocks' became common in London Until , most bricks were red from the iron in the clay used. Palladian ideals led to the development of 'white' bricks, in which lime changed the brick to pale yellow, buff, or brown.

Accrington brick was shipped to America and used to build the foundations of the Empire State building. In Britain bricks are widely used for house building. Walls are usually built as double skin "cavity" walls effectively two single thickness brick walls with a gap between them. The cavity provides both thermal and sound insulation. While some engineering brick is used for apartment blocks, industrial buildings and the like these tend to be used for cladding.

The majority of bricks are used for housing and "brick veneer" is a standard house building method. Houses have lightweight wooden wall frames which are lined on the inside with plasterboard gyprock and covered on the outside by a veneer wall of brick.

For this purpose bricks don't have to be very strong. Three things determine the strength of the brick itself. The clay mixture, the compaction and the firing. In many places the local people simply use whatever is available to them.

The resulting mixture has water added to make a soft mud which is formed into rectangular blocks and either left in the sun to dry or are fired in a kiln. Fine grained clays tend to be denser, it fires better and produces stronger bricks. To increase their hardness bricks may be formed in a press to increase the density and remove any small pockets of air from the clay before firing.

The colour of bricks depends on the chemical and mineral content of the clay and the temperature it is fired at.

Iron gives bricks their red colour while yellow bricks have a lot of lime in them. Cooler temperatures produce red bricks, hotter temperatures progress through browns to greys. When built into a wall the wall strength is further determined by the shape of the brick does it have a frog in it - a frog is an indent in the surface to help them "key" together the strength of the mortar how much cement is used - it needs to be 4 parts sand to 1 of cement and the way the bricks are placed in relation to each other.

The size of bricks is important. Bricks must be large enough to minimise the amount of work needed to build with them but light enough for a bricklayer to easily handle them. Over the centuries an optimal size of brick has developed which doesn't vary much from country to country. Earlier bricks and traditional Balinese bricks tend to be thinner - about 2" thick. The dimensions, ie. It gives numerous possible combinations of brick placements in relation to each other permitting considerable creativity in the shape and form of brick structures.

In Indonesia bricks have been used for centuries. A calcareous clay contains more lime and gives a yellow colour. The presence of manganese oxide, by contrast, gives a brown colour to the brick..

Discover our wide range of facing bricks and choose from more than one hundred colours and styles. Every brick in our range is also available as a brick slip. If the air supply is reduced while firing , there will be insufficient oxygen in the air to combust the natural gas. The lack of oxygen is then compensated by drawing oxygen from the metal oxides present, ultimately causing discolouration. Combined with other available techniques, this can produce a wide range of different colour effects.

A short, reducing atmosphere will not colour the bricks fully but only the point at which the brick is exposed to the atmosphere. Braisingfacing bricks is an extreme form of reducing firing. With this technique ,a previously firedbrick is placed back into a special kiln. This is not to fire the brick again, but to expose it to a prolonged, intense, reducing atmosphere. Certain types of clay, such as whitefiring Westerwald clay, give a very aesthetic deep-grey colour after braising.

Take a look at the water-struck Alaska brick, a light metal-grey facing brick with soft nuances.