Howarth Timber & Building Supplies have several ranges of below ground bricks to choose from, all of which have their own fantastic benefits. For example, underground bricks are often used as a course of damp proofing, which is great for beneath conservatories as well as rooms that are being built below ground level, such as cellars or games rooms.
There are several types of brick that can be used for below ground work, such as:
Class A Engineering Bricks are much stronger and less porous (meaning they do not retain water) than other types of brick, and are ideally used in situations when strength is of huge importance, as well as applications that are in highly saturated locations, such as below ground work. They have a compressive strength greater that 125N/mm2 and a water absorption less than 4.5 per cent, meaning that they are great for courses of damp-proofing.
In the UK, Class A Engineering Bricks are typically blue in colour, because they are fired at a particularly high temperature.
Traditionally, this type of brick is used in civil engineering applications rather than for facing brickwork, as the bricks are less likely to be checked for chips that may make them less attractive.
It is essential that Engineering Bricks should be resistant against frost, and they must also have low levels of soluble salt.
Class B Engineering Bricks are more popular than Class A Engineering bricks. They are stronger and less porous than other common bricks, which makes them perfect for below ground work. They have a compressive strength greater that 75N/mm2 and a water absorption less than 7 per cent.
Typically, Class B bricks are red in colour and are known for their strength and durability.
Although it is becoming common for Class B Bricks to be used in place of facing bricks, it is often not recommended to use Class B Engineering Bricks for facing applications, as they are typically not inspected for faults.
They are also ideal for retaining walls.
Concrete common bricks are designed to be used for all types of construction work both above and below ground. They are popular because they are extremely hardy and can withstand most harsh conditions including freezing temperatures.
Sometimes concrete common bricks are hollowed out (this is often called “frogged”), rather than being solid.
Common Clay bricks are commonly used for general brick work, as they do not offer any physical qualities that make them attractive.