How Many Scaffold Ties Do I Need?

Standard Tie Pattern

Under TG20:13 guidance for a standard independent tied scaffold:

• Horizontal spacing: Maximum 4m (every other standard)
• Vertical spacing: Maximum 4m (every other lift)
• Density: One tie per 16m² of scaffold face

Example Calculation

• Scaffold face: 10m wide × 8m high = 80m²
• Ties needed: 80 ÷ 16 = 5 ties minimum
• In practice: 3 ties across × 2 rows = 6 ties

Tie Types

• Through tie (box tie): Passes through a window/door opening with a cross member inside. Most secure.
• Ring bolt (anchor) tie: Expansion bolt drilled into masonry. Good strength.
• Reveal tie (friction fit): Wedges inside a window reveal. Least secure — use only when others are impractical.
• Lip tie: Hooks over a parapet or windowsill.

When You Need More Ties

• Sheeted/netted scaffold: Increased wind load — ties at 2.5m × 2.5m (one per 6.25m²)
• Loading bays: Additional ties around loading points
• Exposed/coastal sites: Reduced spacing per TG20 wind assessment
• Cantilever sections: Additional ties at cantilever points

Inspection Requirements

All scaffold ties must be inspected by a competent person before first use, at least every 7 days, and after adverse weather. Tie positions must be recorded on the scaffold design and checked during inspections.