Scaffold Tie Calculator
Tie count from perimeter and height, with spacing limits checked.
With the default inputs: Building perimeter 200 · Scaffold height 30 · Lift height 1.8 etc.Total ties 270 pcs
Edit the inputs below to recalculate.Inputs
Result
| Max vertical spacing | 5.40m |
| Max horizontal spacing | 4.50m |
| Ties per row | 45pcs |
| Rows over height | 6courses |
| Ties per storey | 45pcs |
| Area per tie | 22.22m² |
| Tie density | 45.0pcs/1000 m² |
Per JGJ 130, tie vertical spacing must not exceed three lifts (two for fully sheeted scaffolds) and horizontal spacing not exceed three bays; area per tie must stay under 40 m² for open and 27 m² for sheeted scaffolds (tighter above 50 m). Ties must sit near node points (within 300 mm), start at the first lift and be provided at both ends of linear and open scaffolds. This tool estimates quantity only - tie strength, stability and wind capacity must be calculated to JGJ 130 and confirmed by the temporary works design.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| Vertical spacing ≤ 3 lifts (2 if sheeted) | |
| Horizontal spacing ≤ 3 bays | |
| Per row = ceil(perimeter ÷ horizontal spacing) | |
| Total = per row × ceil(height ÷ vertical spacing) |
How to work it out
- Set the tie layout: typically three lifts vertically by three bays horizontally, with no tie tributary area above 40 m² (double scaffold under 50 m).
- Vertical spacing = lift × 3, horizontal spacing = bay × 3. At a 1.8 m lift and 1.5 m bay that is 5.4 m by 4.5 m.
- Count = (perimeter ÷ horizontal spacing) × (height ÷ vertical spacing), both rounded up.
- The first tie starts at the bottom lift, never the second, and the top is tied too — free height above the highest tie must not exceed two lifts.
- Open-ended scaffolds need ties at both ends, at spacing no greater than the storey height and no more than 4 m.
Where it goes wrong
- Dividing area without regard to lift and bay — 40 m² is an upper bound, but ties must land on standard/ledger nodes, and an area division puts them between nodes.
- Starting ties at the second lift — the base is then unrestrained and fails first; that is the classic scaffold collapse mode.
- Tying to non-structural elements — window frames, balustrades, pipes and parapets cannot take wind load, and the tie fails first in a gust.
- No ties at the ends of an open scaffold — the free ends overturn without restraint, which is why the code makes them mandatory.
Material and cost
Tie assembly with cast-in or through-bolt, tube and coupler 15-35 CNY per set, installation 10-20 per set. Forming holes in the structure adds 5-10 each.
On site
- Start ties at the first longitudinal ledger and keep them within 300 mm of the main node.
- Double scaffolds above 24 m need rigid ties — tube, coupler and cast-in anchor — not flexible wire or rebar loops.
- During finishing, remove ties lift by lift and make good immediately; stripping a whole area at once is a serious hazard.
Basis
- JGJ 130-2011 Technical code for steel tubular scaffold safety, Section 6.4
- GB 51210-2016 Unified standard for safety of building scaffolds
- JGJ 128-2019 Technical standard for frame scaffold safety in construction
FAQ
Why are ties so critical?
Why tighter spacing when sheeted?
Can wire rope replace a tie?
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Scaffold Tie Calculator. 2026-10-25. https://jianzhujisuan.com/en/scaffold-tie