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How Bricks Are Made

The Building Blocks of Bricks

Bricks are a strong, versatile material.  Humans have used them to create everything from houses to pizza ovens and more.  And we’ve had a lot of practice building with them.  The first bricks were used at least 5,000 years ago by masons in the Middle East, and since then have undergone some changes.

The first bricks were made out of baked clay, but they weren’t particularly sturdy and disintegrated easily when exposed to the elements.  It was the Babylonians who ultimately began the process of firing bricks, but it wasn’t until the 1800s that bricks became a popular and viable building material.

Bricks are so common nowadays that we barely notice them.   But how are bricks made?  Who makes them?  And what are they made out of?  What are the building blocks of the blocks that make our builds?

CHECK OUT:  The History of Pine Hall Bricks  →

The Raw Materials

All brick manufacturers have their own proprietary blend of materials that they use to make bricks.  But ultimately they’re all made of the same basic components.

Kaolin

Kaolin is a natural, white clay that can be found all over the world.  It has an extremely high melting point which makes it ideal for brick making.Kaolin

Shale

Shale is a sedimentary rock.  It’s so abundant that it makes up roughly 55% of all sedimentary rocks on the entire planet!  It’s a “flakey” mineral that’s formed when mud or clay condenses and is a common material used in a variety of other building components like cement.  Shale and Kaolin are ground together to make the basic body of the brick.

Other Minerals

Bricks also include several other minerals that are usually found in the clay itself when its mined from the earth.  These minerals can include sodium, potassium, and calcium.  When combined, they create a silicate liquid which is what helps give bricks their waterproof quality and contributes to their hardening process.  Silicates are also used in other everyday products like soap, detergent, and adhesives.

Additives

As mentioned, brickmakers usually have their own proprietary formulas for bricks.  There are many different kinds of bricks, which determine what sort of additives are incorporated into the mix!  Flocculents will create loose clusters in bricks.  Sand or ground scrap material improves brick strength.  A variety of other materials can also be added to change the melting point of the brick or even change their colors.

There are new colors and styles of bricks being developed all of the time, and we can help you pick out which one is right for you!

SEE MORE:  Check Out Our Brick Selection  →

stacked bricks

The Process

Making bricks is a fairly simple process.  It essentially consists of mixing minerals and other additives together, shaping the mixture into bricks, and firing them.  But the raw materials and process by which they’re turned into the familiar building blocks we all recognize involves a little more than you might expect.

Grinding and Combining Materials

Kaolin, shale and the other minerals that make up bricks aren’t grown on farms or made in labs.  Huge machines dig these components out of the ground from a type of mine called a rock quarry.  They’re open-air spaces and can go as deep as 50 feet into the ground.

The kaolin and shale are ground into small pieces and combined with the necessary minerals and any other additives that will create the desired brick shape, texture, and color.  Water is added to the dry mixture, creating a thick extrudable paste.

Extrusion

Once the paste has been well combined in a giant mixing chamber, it moves on to the extruding stage.  The paste is fed into a two-part chamber.  The first chamber dries out the clay which ensures that the bricks won’t crack before they’re fired.  The second chamber is a high-pressure tube that packs the paste tightly together so it can easily be pushed through the die by an auger.  Bricks are extruded to the desired width and then cut to size by a large rotating knife or a piece of thick wire.

Hand Molding

Some brick manufacturers are still devoted to making bricks by hand.  Bricks are pressed into molds and are coated by hand by a trained craftsman.  Our supplier, Old Carolina® is one such producer.  They create beautiful pavers and face bricks that bring a traditional, charming warmth to any project.

SEE OUR STOCK:  Old Carolina Bricks  →

Coating

Bricks are usually coated as they’re extruded.  The coating is dependent on how firm the brick is.  Some have a light coating of sand dusted onto it as it leaves the extruder.  However, the coating can be applied by brushes and rollers, or even by compressed air or a sandblaster.

Drying

Drying is an important part of the brick making process.  If the bricks aren’t properly dried before firing, they’ll crack and chip apart.  The bricks are slowly moved through a long tunnel dryer with humidity-controlled zones, and fans circulate hot hair across the bricks to speed the process along.

Firing

Once the bricks are dry, they’re ready for firing.  The composition of the bricks determines at what temperature the kiln is set.  Kilns maintain specific temperatures for each type of brick, and are usually between 1,652°F and 2,192°F.  During the firing process, the materials within the brick form a ceramic bond that hardens the brick and ensures that it keeps its shape.  Firing makes certain that bricks can stand up to all kinds of conditions like rain, heat, and cold, as well as foot and tire traffic.

Setting and Quality Control

After the bricks are fired, they’re cooled and stacked by large automated machines.  These brick handling machines can rotate and set bricks at a rate of 18,000 bricks per hour.  That’s literally tons of bricks every day!  Massive pallets of bricks are wrapped with steel bands and protected by plastic strips that protect the corners during transport.

Despite brickmaking being a fairly straight forward process, each batch of bricks undergoes quality testing.  Quality standards are determined by the American Society of Testing and Materials (ASTM) and include physical dimensions, density, and mechanical strength.  Many companies are developing their own methods of testing to ensure that their products stand up to the challenges of construction, as well as to the elements.

Dedication to Superior Products

Christie Cut Stone is dedicated to serving its customers and making our community beautiful.  Our suppliers use only the highest quality materials when molding their bricks, which makes for a stunning variety of choices suitable for any project you can dream up.  Let one of our knowledgable team members help you pick the right brick for your next upgrade!

Contact Us  →

Posted by Michael Christie at 1:30 PM