Bricks

Frequently Asked Questions About Bricks.

Engineering Bricks:

Why and When Are They Used?

Engineering bricks had the second highest delivery rate across England, Scotland and Wales in 2020 with 117 million bricks. Engineering bricks differ from common bricks in their ability to withstand extreme weather conditions such as continual freezing and dampness. They are used upto DPC and are often used in the construction of sewers and tunnels due to their structural integrity.

How Do They Differ in Appearance to the Common Brick?

You will be able to identify engineering bricks by their smooth finish, whilst Class B engineering bricks can be both solid and perforated in form. The perforations in Class B engineering bricks provide a stronger key for several courses of brickwork - the mortar works into the perforations.

Class A and Class B Engineering Bricks: What is the Difference?

There are two types of engineering bricks, class A and class B, but what does the classification mean and what is the difference? The classifications of engineering bricks are based on the brick type’s water absorption tolerance and compressive strength tolerance. Simply put, the type of project that you are completing will dictate which classification of brick you will need. 

What is Compressive Strength?

The compressive strength of a brick is the ability to withstand heavier loading weights.

What is Water Absorption?

The water absorption of a brick is indicative of the brick’s resistance to freezing. The less absorbent the brick is, the more it will be resistant to freezing.

Class A Engineering Bricks:

Class A Engineering bricks are less commonly used in construction as they are often used for specialised projects. The bricks have a high tolerance for compressive strength of around 125N/mm² and an absorption rate of under 4.5%. Class A doesn’t mean a perfectly square brick - it means strength.

Class B Engineering Bricks:

Class B Engineering bricks are the most common classification with a compressive strength of 75N/mm² and an absorption rate of under 7%. Rather than specialised projects, class B engineering bricks are more commonly used upto DPC on houses.

Facing Bricks:

The function of a facing brick is purely aesthetic; common bricks aren’t all that aesthetically pleasing, so the job of the facing brick is to provide a neat exterior.

Soft Mud Bricks vs Extruded (Wirecut) Bricks:

There are two types of facing bricks, soft mud and extruded, so what is the difference? The main difference between the two types of brick is the method of production. 

Wirecut Bricks:

The process of extruding bricks is the most common method of production due to the ability to produce a high volume at a quick rate, averaging at around 20,000 bricks an hour. The name ‘extruded brick’ originates from the extrusion head that is used to process the clay into a continuous column (basically one long brick). It is after the clay has been passed through the extrusion head that the newly formed column is cut into smaller pieces of approximately 1.5m length and then cut by row wirecut to produce bricks. Unlike soft mud bricks, extruded bricks have distinctive perforations running through the centre of the brick. The perforations are made so that they are easier to handle and require less energy for firing and drying. These are commonly used for houses in towns or cities.

Soft Mud Bricks:

Soft mud bricks have a more traditional and warmer aesthetic than the extruded brick. Soft mud bricks can be made using two different processes, handmade and machine manufactured. To hand-make a soft mud brick, the clay is formed by hand, coated in sand and thrown into a mould. The machine manufactured soft mud bricks follow the same process as the hand-made, but the process is replicated by a machine. These are commonly used on houses in rural locations and more expensive properties.

Common Bricks:

Why and When Are They Used?

Unlike concrete bricks, common bricks have a lower compression strength and therefore are generally used for internal work rather than below ground level where the bricks are needed to maintain structural integrity. 

How Do They Differ in Appearance to the Common Brick?

Common bricks are often made using basic brick clay with the most well known colour being red. The red brick is not painted or coloured with treatment, but are naturally red from the clay’s iron content.