Class B Engineering Brick Smooth Red Perforated 65mm

Please note that Class B engineering bricks may feature perforations that vary in number and pattern. These variations do not affect the structural integrity or performance of the bricks and are within manufacturing tolerances.

Engineering bricks are typically used underground for foundations, as damp-proof courses or in wet environments. If you're after an aesthetic brick please check out our range of facing bricks. 

What Are Red Engineering Bricks?

Red engineering bricks are high-performance masonry units fired in an oxygen-rich atmosphere. This firing process allows the natural iron content in the clay to oxidise, producing the brick’s characteristic red colour. The result is a smooth, uniform finish and a highly durable brick that can withstand demanding conditions.

Their dense composition and low water absorption suit them to environments where resistance to moisture, frost, and chemical attack is essential - such as retaining walls, damp-proof courses, and exposed brickwork.

Colour Variations: Although the typical colour is red, slight variations in shade can occur depending on the specific firing conditions and the raw materials used. This is a normal characteristic of the manufacturing process and does not affect the performance or functionality of the brick.

What Does “Class B” Mean?

The “Class B” designation is a performance classification under British Standard BS EN 771-1, indicating that the brick achieves:

• A minimum compressive strength of 75N/mm²
• A maximum water absorption rate of 7%
  
  

This means the brick is well-suited for use in loadbearing structures and environments exposed to moisture, frost, and aggressive ground conditions.

While Class A engineering bricks offer a higher strength and lower water absorption (usually 125N/mm² and ≤4.5%), Class B bricks strike a practical balance between strength, performance, and cost.

Perforated Design

This brick features perforations (three vertical holes running through its bed). These perforations can offer several benefits:

• Reduced Weight: Making the individual brick slightly lighter than a solid equivalent, aiding manual handling.
• Improved Mortar Key: The perforations allow mortar to key into the brick more effectively, enhancing bond strength.
• Consistent Firing: Can contribute to more even firing in the kiln, leading to uniform strength.
• Thermal Properties: May offer very slight improvements in thermal resistance compared to an identical solid brick, though this is not their primary purpose.

Note: Despite perforations, these bricks are engineered to meet the 75N/mm² compressive strength requirement for Class B.

Applications

• Foundations & Substructures: Providing durable and strong masonry below Damp Proof Course (DPC) level, especially in challenging ground conditions.
• Damp Proof Course (DPC) Bricks: Used as the actual DPC course (typically two courses) due to their extremely low porosity, preventing rising damp.
• Retaining Walls: Constructing robust retaining walls that are exposed to earth pressure and moisture.
• Manholes, Inspection Chambers & Sewerage Works: Their strength, durability, and resistance to moisture and chemicals make them perfect for underground drainage and utility structures.
• Bridge Abutments, Piers & Civil Engineering Works: Where high load-bearing capacity and extreme durability are essential.
• External Plinths & Cappings: Creating durable and weather-resistant features at the base or top of walls.

Benefits

• High Compressive Strength (75N/mm² min.): Certified Class B performance, capable of supporting significant structural loads.
• Low Water Absorption (<7.0%): Offers excellent resistance to moisture penetration, contributing to durability and frost resistance.
• Exceptional Durability & Longevity: Vitrified clay construction ensures a very long service life, even in aggressive environments.
• Superior Frost Resistance: The low water absorption makes it highly resistant to damage from repeated freeze/thaw cycles.
• Good Chemical & Sulfate Resistance: Suitable for use in ground conditions where sulfates or other aggressive chemicals may be present (check specific soil conditions against brick specification if very aggressive).
• Perforated Design: Can aid mortar key and slightly reduce unit weight without compromising the specified structural strength.
• Consistent Quality: Manufactured under controlled conditions to meet performance standards.
• Versatile Application: Suitable for a wide range of demanding structural uses below and above ground.