Bricks are easy to work with and offer high levels of strength and longevity, with some bonus side effects that include,
- They are attractive and can provide your buildings with individual features.
- Low maintenance, bricks are durable and long-lasting. However, do remember to check them. Repointing is usually needed due to mortar not being as durable.
- Sustainability, bricks last a long time and can be reused.
The following blog will look at the four main bricks used in construction. These are,
- Common bricks
- Facing bricks
- Soft mud bricks
- Extruded or wire-cut bricks
- Engineering bricks
- Damp coursing bricks
While most bricks are manufactured from clay, you can also find concrete blocks. They can also be made with calcium silicate—a mix of water, sand, lime, and pigment for colour. Different bricks have different uses, so it is good to know what is available to be sure you select the right ones for your project. You can also identify bricks by colour, size and shape.
You will find British standard bricks are usually
- 215 in length
- 65 mm in height
- 102.5 in width
When calculating the number of bricks you need remember to factor in the mortar, usually 10mm.
Common Bricks
The name is a bit misleading as these are the UK’s least common brick types. These bricks have lower compressive strength than facing or engineering bricks and are unsuitable for use below ground. They also do not have a consistent appearance and are less attractive than other types of brick. The colour can also vary considerably, although they generally have a red tone. As a result, internal brickwork is their general location.
Facing Bricks
These are popular in the UK for exterior walls in the housing market and have been for thousands of years. They are popular due to their aesthetic qualities, and they are manufactured to be weather-resistant. The most popular types are soft mud bricks or extruded bricks.
Why Choose Soft Mud Bricks?
Creating the popular aesthetic appeal these bricks have is via the manufacturing process of forming the bricks using mould boxes. Sometimes they are handmade, where the clay is assembled by hand and then given a coating of sand before going into the mould. When manufactured by machine, it follows the hand-making process for the clay, but a machine belt drops the clay into sanded moulds.
These bricks provide excellent technical performance and a softer, warmer appearance. Their appearance makes them very useful when matching older bricks. The formation of soft mud bricks is influenced by the process of removing them from the mould with water, not sand, known as water-struck bricks. You can also select a handmade or creased textured brick with frog-like perforations. As with all bricks, they undergo a drying and firing process.
Why Choose Extruded Bricks?
Quickly manufactured, turning out around 20,000 bricks an hour. The high volume of production means a more economical brick. The process involves forcing clay through an extrusion head. This process forms a continuous column in the required width and depth. To further reduce the length of these columns, they cut them into ‘slugs’. These are more manageable pieces. Following this, row wires cut the bricks into the required length.
The manufacturing of the extruded brick does create a distinctive characteristic. This is where you can see core holes or perforations throughout the bed of bricks. Perforated bricks dry and fire quicker, and they are lighter to handle. Extruded bricks are popular due to the consistent sizing, hard density, economical pricing and the fact you can get a range of styles with contemporary appearances in different colours. These can include,
- Smooth
- Rolled texture
- Sand faced
- Glazed
- Drag faced
Engineering Bricks
Engineering bricks are widely used in civil engineering construction, for example, in groundworks, foundations, tunnels, maintenance holes, sewers and underground work. The reason for this is their low water absorption and high compression. In addition, they are useful because they are resistant to cold, chemicals, and water—making them damp-proof. Made from clay, with the wire-cut method allowing for economic production, they are mainly blue or red in colour. Perfect for structural work where there is a high probability of water damage.
There are two classifications of engineering bricks, both offering high levels of density and load-bearing ability. The compressive strengths of bricks are tested by crushing eight to twelve bricks in a Compressive Testing Machine – CTM until they fall to bits. Then noting the pressure at which that occurs. The compressive force is written as Newtons per mm of surface area—Nmm2. They can also be expressed as Kilogram-force per square millimetre, kgf/mm2
Class A Engineering Bricks.
Generally blue-coloured, these bricks have a compressive strength of around 125/Nmm2 that, is a 12.746 kgf/mm2
Class B Engineering Bricks
These have a lower compressive strength at 75/Nmm2 (7.647 8 kgf/mm²), which is still higher than soft-facing bricks at 3.5/Nmm2 (0.356 kgf/mm2). Class B are usually red engineering bricks.
Damp Coursing Bricks
These are used in construction because of their low absorption rate. Generally, DPC bricks are built in two courses. Bedding into the base of a free-standing or retaining wall with a rich cement and mortar mix.
Damp coursing bricks come with two classifications,
- DPC1 – which is suitable for building and external work. These have a maximum water absorption rate of 4.5%
- DPC2 – Only suitable for exterior work only. These have a maximum water absorption rate of 7%
There are quite a few more types of bricks on the market, which we can explore in a future blog, like fire or ventilation bricks and concrete blocks.
We Know Our Bricks
As a professional masonry and structural alterations subcontractor specialising in residential and commercial projects across the UK, we can help and advise on the suitability of the bricks for your construction. Please feel free to contact us using the online form.