How can I identify different types of bricks?

The extruded/ wirecut method is the most popular method of brick production as a high volume of bricks can be manufactured quickly, around 20,000 bricks an hour.  The clay is driven through an extrusion head to form a continuous column of material in the desired width and depth. The column is then cut into smaller, more manageable pieces approx 1.5m in length known as ‘slugs’.  This is then cut into bricks of the desired length by row wires.

One distinctive characteristic of an extruded brick is that they tend to have perforations or core holes running through the bed of the bricks.  Perforated bricks require less energy for drying and firing and are also lighter and easier to handle.

This manufacturing process produces hard, dense bricks with a more consistent size and shape, sharper arises and a more contemporary appearance.  Extruded bricks are available in a wide range of styles including smooth, dragfaced, rolled texture, sandfaced or even glazed.

Soft mud bricks have a more traditional or reclaimed appearance, offering a softer and warmer brick aesthetic, without compromising on technical performance.

Soft mud brick moulding actually covers a number of manufacturing processes where bricks are formed using mould boxes.  Hand-making involves the forming of the clay by hand, coating in sand and throwing into a mould. Machine manufacturing of soft mud bricks follows the processes of hand making, recreating the hand thrown technique by throwing the clay into sanded moulds using belts.

Soft mud bricks are available in a traditional sanded finish or in a handmade/creased texture, featuring a “frog” indentation rather than perforations like extruded bricks. Waterstruck soft mud bricks are made by using water instead of sand to release the clay from the moulds, creating a distinctive textured finish. As with all other manufacturing processes the wet bricks are then dried and fired.

Engineering bricks have high compressive strength and low water absorption. They are used for their physical characteristics and not their appearance and are only classified by these properties. They were traditionally used in civil engineering and are most suitable for applications where strength and resistance to frost attack and water are important. 

Examples of situations where engineering bricks are used include ground-works, manholes, sewers, retaining walls and damp proof courses.  

Engineering bricks are rated as Class A or Class B, with Class A being the strongest but Class B being more common. Class A engineering bricks have a compressive strength greater than 125N/mm² and water absorption less than 4.5%. Class B engineering bricks have a compressive strength greater than 75N/mm² and water absorption less than 7%.

Engineering bricks are most commonly a smooth red colour although blue engineering bricks are also widely available. wienerberger manufactures a market-leading range of both red and blue engineering bricks.

Despite their name, common bricks are actually the least common brick types in the UK. They tend to have lower compressive strengths than facing bricks or engineering bricks and are generally lower quality. There is also less focus put into a consistent appearance on common bricks.  

Common bricks should not be used below ground level and are generally used for internal brickwork only.  

Damp-Proof Course or DPC bricks are bricks designed to have a low absorption rate, making them suitable for use as part of a damp-proof course construction.

DPC bricks fall into two classifications:

• DPC1 – suitable for buildings and external works use, with a maximum water absorption rate of 4.5%
• DPC2 – suitable for external works only, with a maximum water absorption rate of 7%

To create better resistance to the overturning of a wall in comparison to flexible damp-proof courses, build two courses of DPC bricks with a cement-rich mortar bedding as the base of a retaining or free-standing wall.  A rigid damp-proof course like this will be effective against rising damp, but not the downward flow of water.