How Are Bricks Made?
You may not spend much time thinking about bricks, but society would crumble without them — literally. These little beauties hold up our schools, our hospitals and our homes.
From the ground to our shelves to your doorstep — find out how bricks are made and delivered in this month’s article.
Extraction
The single biggest material used to make bricks is clay.
Clay is one of the most abundant natural mineral materials on Earth, and every day it is extracted from the ground in quarries across the world.
But not all clay is the same. The clay used in brick manufacturing must possess the following traits:
- Sufficient plasticity
- Sufficient wet and air-dried strength
- Its particles must fuse together when subjected to appropriate temperatures.
Transport
Once extracted, the clay is transported to a local factory yard. Then, it is transported from the factory yard into the factory itself via a conveyor belt.
Crushing
The clay travels into size-reduction machines where it is crushed. This machine breaks up lumps and stones in the clay to produce a smooth product.
Tempering
Once the clay is smooth, it undergoes a process called ‘tempering’. This is where water is added to the clay in a mixing chamber with one or more revolving shafts. Hydrating the clay makes it softer, allowing it to be molded into a brick shape.
Molding
Many years ago, bricks were pressed into molds by hand. As brick manufacturing increased in scale, machines took over the molding process. But hand-pressed bricks still remain an important part of the market, as they allow for the creation of bricks in custom shapes and sizes.
There are three main processes for forming bricks using clay: extrusion, extrusion and dry press. The vast majority of bricks are made using the extrusion process. This is where the clay is pushed through a die to produce a column of clay. As the clay column leaves the die, coatings may be applied to alter its surface texture or colour. Finally, an automatic cutter slices through the clay column to create the individual brick.
Drying
The bricks, now in their traditional shape, are put into a dryer to remove all the water.
Bricks are placed in dryer chambers for around 24 hours (though this can be extended to up to 48 hours if needed) and heated at temperatures ranging from 38 ºC to 204 ºC. The exact duration and temperature will depend on the type of clay and forming method. In all cases, the heat, humidity and duration are carefully regulated to avoid cracking in the brick.
Hacking
Hacking is the process of loading a kiln car with bricks. This is done by robots or other mechanical methods. While this may seem like an inconsequential part of the process, the setting pattern of the bricks will actually influence their final appearance. Bricks placed face to face will have a more uniform colour than bricks that are cross set or placed back to back.
Hardening
Once all the bricks are loaded, the kiln car will enter a kiln tunnel or periodic kiln to be fired for between 10 and 40 hours. Kiln tunnels consist of various temperature zones which are continually operated and carefully regulated to yield the best quality product. Periodic kilns are loaded, fired, cooled and unloaded periodically.
Packaged and distributed
Once the bricks have cooled and hardened, the manufacturing process is complete and they are ready to be packaged and distributed to building sites and merchants across the UK.
Delivery
Once the bricks have reached a reputable merchant, they are delivered to commercial and domestic customers who have placed an order. At Hitchcock & King, we offer fast, reliable delivery. If you have a project and are unsure of how many bricks you need to order, give our handy brick calculator a try. Just enter your measurements, and the calculator will tell you how many bricks would be required.
We pride ourselves on our stock availability and quick turnarounds, so you can feel confident that you’ll receive your products when you need them. In addition to bricks, we offer a huge range of building supplies and materials to customers throughout London. Simply place an order and we’ll do the rest. Contact our team today.