Engineering bricks are manufactured to be denser and stronger than ordinary facing bricks. They are supplied in accordance with two different classifications, Class A and Class B. This is based on minimum compressive strength and maximum water absorption not falling below 70 N/mm2 – 4.5% and 50 N/mm2 – 7% respectively. Engineering bricks are designed for use where strength and low levels of water absorption are paramount; traditionally this may be on applications such as retaining walls or for ground works.
The majority of engineering bricks sold in the UK are smooth red Class B bricks as they are among the cheapest bricks available to the construction industry; however there has been a recent influx in the popularity of Class A bricks. Their blue-black colour, quality and distinctive appearance means they lend themselves to facing applications. Class B bricks are considered less attractive as their colour is less uniform, yet there are some situations where they have been used instead of facing bricks to provide contrast in the appearance of brick clad buildings.
Richard Williams engineering bricks suppliers stock Class B engineering bricks, but can also supply a range of Class A bricks too.