How bricks are made: Exploring your brick choices with PGH

Today the trusty brick remains a popular and preferred building material for Australian homeowners. But how much do you really know about bricks and how they are created?

Brick is timeless. Just look out your front window and you’ll likely see brick used in various colours, styles, shapes, and sizes on houses up and down your street. If you’re building a new home or renovating an existing home and are considering building with brick, you may be curious about what goes into making a brick.

With that in mind, let’s run through some of the most frequently asked questions regarding brick – how they are made, what they are made of, different brick terms, brick classifications, and much more. If you are considering using brick in your next build, these brick FAQs will get you excited about the all the possibilities.

How are bricks made?

There are two common methods for creating bricks . The first is extrusion, which is used at all PGH Bricks & Pavers’ production sites. The other is the dry pressed method.

Extruded bricks and our Morada range

Extrusion involves forcing clay through a die. This method creates the holes that are commonly seen in a brick. The holes reduce the weight of the bricks, making them lighter, and assisting in the drying and firing processes.

Extruded bricks can have a variety of textures and additives added to the face of the brick, as different techniques produce different textures. Textures range from smooth face to wire cut and even rougher textures. Rough textures make it easier to apply finishes such as paint or cement rendering.

Dry pressed bricks

Dry pressed bricks are made by pressing clay into individual moulds at a very high pressure, which produces highly desirable, solid, and premium bricks. After forming, extruded bricks and dry pressed bricks are both dried to remove their water content. They are then fired in kilns to temperatures greater than 1,000°C. The colour of the clays and shales, the maximum temperature, and other techniques used during firing determine the fired colour of the brick.

How are bricks coated?

Some bricks are coated with a coating or glaze (paint like substances) when they are being extruded. These provide coloured finishes, ranging in sheen from matte through to gloss, and offer rough textures through to smooth, porcelain-like finishes, which are kiln fired onto the surface of the brick.

What is double brick?

Double brick is the term for two brick walls that are separated by a cavity that reduces thermal transmission from the exterior of the home to the interior. Double brick has many benefits as a structure for your home. It is exceptionally durable and requires minimal maintenance.

Using double brick also eliminates the need for a timber frame, which means that your new home’s structure is more resistant to fire.  It also means the home will have excellent thermal properties, helping to keep it naturally warmer in winter and naturally cooler in summer.

By eliminating the need for a timber frame, double brick also reduces the risk of termites or decay, while also applying the acoustic benefits of brick, which will reduce the impact of unwanted noise.

What is the difference between solid bricks and extruded brick?

Extruded bricks are often referred to as “bricks with holes”. These are manufactured with holes to ensure that they are evenly fired. The holes in extruded bricks also act as a method for decreasing the weight of the product, which can be beneficial for bricklayers when building with brick.

Australian Standards note that the holes, up to 30% of the material thickness, do not have an effect on the insulation or fire resistance of the brick.

“Double brick eliminates the need for a timber frame, meaning your new home is more resistant to fire.”

Comparatively, solid bricks are bricks that have been manufactured without holes. These are usually pressed and moulded, are heavier, and are often used on windowsills or door openings to prevent holes from being visible on the project’s exterior.

Solid brick has a greater thermal mass and provides benefits when used as a key part of a passive solar design. Solid bricks, being heavier than extruded bricks, can be requested by engineers to be used in mass retaining walls, or on walls where heavy fixings are being built.

Exposure grade brick versus general purpose brick

Are you wondering what the difference is between exposure grade bricks and general purpose bricks? It’s a key difference, and one that may impact your choice of brick for you new home.

What are exposure grade bricks?

Exposure grade bricks are built to withstand saline (salty) environments. The exposure grading is determined by an Australian Standards laboratory test, where a segment of brick is subjected to (and passes) 40 cycles of immersion in a salt solution and drying without degradation. Exposure grade bricks are recommended when building within 1km of a surf coast, or up to 100m from a non-surf coast.

The Coastal Hamptons range by PGH Bricks & Pavers is a fantastic example of an exposure grade brick range. Our Coastal Hamptons range conveys a relaxed and welcoming style while luxuriously showcasing the colours of the Australian coast and beaches.

What are general purpose bricks?

In contrast to exposure grade bricks, general purpose bricks must demonstrate that they can survive under the environmental conditions outlined for the site where they are intended to be used. This can include marine environments, though general purpose bricks are not required to meet the loss criterion for exposure grade bricks. General purpose bricks will survive between 15 and 40 cycles when tested to Australian standards.

What is a colour-through brick?

Colour-through bricks are bricks which carry the face colour throughout the whole brick. If the brick were to be chipped or scratched, the colour that is underneath the face brickwork is consistent with that of the face brickwork.

The PGH Morada range, imported from Europe, is a beautiful example of colour-through bricks.  This alluring range features a stunning colour palette ranging from the grey all the way style of Ceniza to the luxury noir style of Nero.

For more information, including definitions and brick terms, visit the FAQ page on our website or contact us on 13 15 79.

(Photography by Shantanu Starick & Justin Alexander)