Structural and Load-Bearing Work

Module 2: Structural and Load-Bearing Work 

This module equips bricklayers with the technical knowledge and practical skills to construct safe, durable, and regulation-compliant load-bearing structures, from foundations to reinforced walls.

2.1 Understanding Building Regulations for Structural Integrity

Compliance with UK Building Regulations (Part A) is critical for structural stability. Key aspects include:

• Wall Thickness Requirements: Minimum thickness for single-leaf (102.5mm) and cavity walls (255mm+).

• Lateral Support: Ensuring walls are tied to floors/roofs to resist wind loads.

• Damp Proofing: Mandatory DPC (Damp Proof Course) installation to prevent rising damp.

• Fire Resistance: Fire-rated materials in party walls (e.g., 60+ minutes for semi-detached homes).

• Foundations: Depth must exceed frost line (450mm minimum) and match soil bearing capacity.

Key Takeaway: Bricklayers must interpret architectural drawings and engineering specs to ensure designs meet Approved Document A (Structure).

2.2 Building Retaining Walls and Foundations

Retaining walls and foundations require specialized techniques to handle lateral pressure and subsidence risks:

Retaining Walls

• Gravity Walls: Thick, heavy masonry relying on mass to resist soil pressure.

• Cantilever Walls: Reinforced with steel or concrete for taller structures (>1m).

• Drainage Considerations: Weep holes and granular backfill to prevent hydrostatic pressure buildup.

Foundations

• Strip Foundations: Most common for brick walls; width depends on load (e.g., 600mm for 2-storey homes).

• Trench Fill: Concrete-filled trenches for unstable soils.

• Piled Foundations: Used in high-load or soft ground conditions.

Pro Tip: Always check ground conditions (clay shrinkage, water tables) before foundation work.

2.3 Calculating Loads and Stress Points

Structural brickwork must distribute weight efficiently to prevent cracking or collapse:

Load Types

• Dead Loads: Permanent weight (bricks, slabs).

• Live Loads: Variable forces (snow, occupants).

• Lateral Loads: Wind pressure, soil thrust (for retaining walls).

Critical Calculations

• Brickwork Strength: Standard bricks = 7N/mm² compressive strength; engineering bricks = 50N/mm²+.

• Bearing Capacity: Foundations must support ≥50kN/m² for typical housing.

• Lintel Sizing: Span + 150mm bearing each side (e.g., 1200mm opening → 1500mm lintel).

Tools: Load tables, span calculators, and BRE Digest 360 for reference.

2.4 Working with Concrete Blocks and Composite Materials

Modern construction often combines brickwork with blocks and composites for efficiency and insulation:

Concrete Blocks

• Dense Blocks: For load-bearing walls (7.3N/mm² strength).

• Lightweight Blocks: Better insulation but lower strength (3.6N/mm²).

• Cellular Blocks: Used in beam-and-block flooring.

Composite Systems

• Insulated Cavity Walls: Combining brick, block, and rigid foam (PIR/PUR) for U-values ≤0.18 W/m²K.

• Hybrid Lintels: Steel-reinforced with thermal breaks to prevent cold bridging.

• Thin-Joint Blockwork: Adhesive mortar for faster construction (requires precision).

Best Practices:

• Use Fletton bricks for high-load areas.

• Match mortar strength to blocks (e.g., M4 mortar for 7N/mm² blocks).

• Butterfly wall ties for composite cavity walls.

Why This Matters

• Safety: Misjudging loads or foundations risks catastrophic failure.

• Efficiency: Proper material selection cuts costs and construction time.

• Compliance: Non-compliance can lead to enforcement notices or demolition orders.

Next Steps: Pair this module with practical workshops on foundation laying and load-testing mock walls.