How Many Wall Ties Do I Need?
Quick Answer
2.5 per m² for standard cavity wall (900×450mm grid). 10m² = 25 ties
Based on: Standard cavity wall construction to PD 6697 / Approved Document A
Important: Wall tie spacing and type must comply with Building Regulations and the structural engineer’s specification. Increased density is required at openings, corners, and in exposed locations.
Standard Spacing Pattern
- Horizontal spacing: 900mm maximum (every 4th brick course horizontally)
- Vertical spacing: 450mm maximum (every 6th brick course)
- Density: 2.5 ties per m² minimum
- Pattern: Staggered (diamond pattern) for best performance
Extra Ties Required
- Around openings (doors, windows): Within 225mm of reveals, max 300mm vertical spacing
- At corners and returns: Within 225mm, max 300mm vertical spacing
- At movement joints: Within 225mm each side
- Exposed/coastal sites: May need closer spacing (consult engineer)
Example Calculation
- Wall area: 8m × 5m = 40m²
- Less openings: 2 windows (1.2 × 1.2m) + 1 door (2.1 × 0.9m) = 4.77m²
- Net wall area: 40 − 4.77 = 35.23m²
- Ties for main wall: 35.23 × 2.5 = 88 ties
- Extra ties at openings: ~30 extra
- Total: ~120 wall ties
Wall Tie Types
- Stainless steel (Type 2/general purpose): Most common for new build. Suitable for 50–100mm cavities.
- Stainless steel (Type 4/light duty): For timber-frame to masonry connections.
- Remedial ties (helical/resin): For replacing failed ties in existing walls.
- Basalt ties: Non-metallic alternative, good thermal performance.
Wall Tie Lengths
The tie must span the full cavity plus have minimum 50mm embedment in each leaf of masonry:
- 50mm cavity: 200mm tie
- 75mm cavity: 225mm tie
- 100mm cavity: 250mm tie
- 150mm cavity (with insulation): 300mm tie
Last updated: April 2026