What is the standard scaffold tie pattern per TG20?

The standard TG20 tie pattern for an unsheeted tube and fitting scaffold is: first tie within 4m of each end of the scaffold, then every 4m horizontally and 4m vertically (approximately every other lift and every other bay for a 2m lift / 2.4m bay scaffold). This gives a tie density of approximately 1 tie per 16m² of scaffold elevation.

How does sheeting affect tie requirements?

Sheeted scaffolds catch significantly more wind load, so the tie pattern must be intensified. TG20 requires: 2.5m horizontal and 2.5m vertical spacing for monofilament sheeted scaffolds. This approximately doubles the number of ties compared to an unsheeted scaffold. The scaffold design must also be checked for increased wind loading on standards and ledgers.

What types of scaffold ties are there?

Through ties: tube through a window opening with a transom inside (12.5 kN capacity, preferred type). Box ties: tube loop around a return wall or column (6.25 kN). Anchor ties: expanding bolt or resin anchor into masonry (15 kN). Reveal ties: tube jammed in a reveal (3 kN only, avoid as primary tie). Ring bolt ties: fixed to masonry ring bolts (varies). Always use through ties or anchor ties where possible.

What happens if I cannot tie at the standard pattern?

If ties cannot be placed at the TG20 pattern (e.g., due to building features, listed buildings), the scaffold becomes a 'design scaffold' requiring a specific design by a competent engineer. Additional measures may include: closer ties where possible, buttress bays, kentledge (weighted base), or raking tubes. Never omit ties without an engineered alternative.

How do I check existing scaffold ties?

Scaffold ties must be checked at every inspection (at least every 7 days): verify the tie is tight and secure, check it has not been removed or loosened by others, ensure the tie tube is properly coupled to the scaffold ledger or standard. Record the tie check on the scaffold inspection report (SG4 form). Any missing or defective tie must be replaced immediately.

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Scaffold Tie Calculator — TG20 Tie Pattern & Spacing

Calculate scaffold tie requirements per TG20 guidance. Determines tie pattern, spacing, quantity, and capacity for standard and sheeted scaffolds.

Scaffold Length

Total scaffold face length

Scaffold Height

Total scaffold height

Scaffold is Sheeted

Sheeted scaffolds need closer tie spacing

Primary Tie Type

Through ties preferred per TG20

How We Calculate This

This calculator determines the number and pattern of scaffold ties required per TG20 guidance, with adjustments for sheeted scaffolds.

TG20 tie patterns

Standard (unsheeted): 4m horizontal × 4m vertical
Sheeted: 2.5m horizontal × 2.5m vertical
First tie: Within 4m of each scaffold end
Through ties preferred: 12.5 kN capacity per tie

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.