Wienerberger K209 Blue Perforated Class B 73 mm Engineering Brick
This brick is a perforated, extruded wirecut engineering unit designed for strength, moisture resistance, and structural use rather than appearance. Engineering bricks are classified by performance, not visual quality. Because clay and manufacturing can vary, mixing units from multiple packs is prudent to minimise tone variation.
Key Specifications
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Size:215mm × 102.5mm × 73mm
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Colour:Blue
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Texture:Smooth, Perforated Wirecut
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Water Absorption:? 7%
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Durability:F2
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Compressive Strength:? 75 N/mm²
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Pack Quantity:368
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Active Soluble Salts:S2
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Thermal Conductivity:0.840 W/(m·K)
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Reaction to Fire:Class A1
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Gross Dry Density:1800 kg/m³
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Size Tolerance:T2
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Range Tolerance:R1
Description & Usage Notes
The **K209 Blue Class B** perforated engineering brick is engineered for high-load and moisture-critical environments such as foundations, retaining structures, or damp-proof courses. With a strong compressive strength of ? 75 N/mm² and a low water absorption rating (? 7%), it performs reliably under demanding conditions. The F2 frost-resistance rating further supports its use in exposed applications. Because this is an engineering brick, surface appearance (colour, texture uniformity) is not the primary focus. For aesthetic facades, use a facing brick. Mix bricks from different packs to reduce visible variation. Use proper detailing—cavity design, flashing, drainage, mortar compatibility—to ensure longevity.
FAQs
Is 7% water absorption acceptable for engineering bricks?
Yes — for Class B engineering bricks, ? 7% absorption is standard and helps ensure durability in load-bearing and moisture-prone applications.
What does the F2 durability rating mean?
It means the brick is frost-resistant and suitable for general UK external exposure. In extremely harsh or marine environments, higher durability classes or protective design may be advisable.
Can this engineering brick be used as a facing brick?
It’s technically possible but not recommended. Engineering bricks aren’t manufactured for consistent visual quality, so for visible facades, a designated facing brick is usually a better choice.
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