UK Brick Types & Specifications

Class A engineering bricks have a minimum compressive strength of 125 N/mm² and maximum water absorption of 4.5%. Class B engineering bricks have a minimum strength of 75 N/mm² and maximum absorption of 7%. Class A bricks (typically blue/dark) are used for the most demanding applications — manholes, retaining walls, below DPC. Class B (typically red) are the more commonly used engineering brick for general below-ground and damp applications.

Bricks are rated F0 (passive exposure — internal or protected), F1 (moderate exposure — most UK walls), or F2 (severe exposure — exposed parapets, retaining walls, copings, below DPC). F2 bricks can withstand repeated freeze-thaw cycles when saturated. Always use F2 rated bricks in vulnerable positions — using F0 or F1 bricks in severe exposure leads to spalling and frost damage.

London stocks are traditional yellow-brown facing bricks originally made from London clay mixed with ash. They have been the predominant brick in London and south-east England for centuries. Modern London stocks are manufactured to replicate the appearance and are available in various shades from yellow to grey. They are typically softer than engineering bricks with compressive strengths around 20-40 N/mm².

For standard UK bricks (215 x 102.5 x 65 mm) in stretcher bond, you need approximately 60 bricks per m² of single-skin wall, including 10 mm mortar joints. For Flemish bond (one-brick wall), it is approximately 120 per m². Always add 5-10% for waste and cutting. See our Brick Dimensions reference for detailed bond pattern quantities.