What are the safety precautions for scaffolding erection

first, general core requirements:
specialized plan: all scaffolding erection must have a specialized plan, structural calculations, and approval; expert review is required if it meets the standards for high-risk projects.
material standards: steel pipes should preferably be φ48.3±0.36mm, free from rust, deformation, and cracks; different specifications of steel pipes must not be mixed.
acceptance and use: upon completion, the scaffolding must pass inspection, and a load limit sign must be posted. overloading and unauthorized connections to the external scaffolding are strictly prohibited.

second, key points for various types of scaffolding:
1. ground-supported coupler steel pipe scaffolding
applicable height: single row ≤ 20m; double row ≥ 24m requires a specialized plan; > 50m requires expert review.
foundation: flat and firm, with drainage ditches; base plate thickness ≥ 50mm, base 50~100mm above ground level.
fundamentals: construction: longitudinal and transverse ground-level bracing (≤200mm from bottom); rigid wall ties, close to main nodes (≤300mm deviation), vertical ≤4m, horizontal ≤6m; continuous scissor bracing for ≥24m across the entire facade, overlap ≥1m, 3 swivel couplers, included angle 45°~60°.
protection: working level fully covered with scaffold boards, 1.2m guardrail + 180mm toe board; fully enclosed with dense mesh netting; horizontal safety netting every ≤10m.
2. cantilever scaffolding
height limit: erection >20m requires expert review.
steel beams: section height ≥160mm, anchorage length ≥1.25 times cantilever length; unloading wire ropes provided (not included in stress calculations).
corners: radial steel sections are prohibited to avoid column reinforcement misalignment and unstable uprights.
protection: hard enclosure at the bottom + safety netting at the bottom.
3. portal scaffolding
complies with jgj76 standard and comes with a factory certificate of conformity.
wall ties have a load-bearing capacity ≥10kn, with additional ties at corners and openings; vertical spacing ≤4m.
uses hook-and-loop steel scaffold boards with locking hooks; steel wire rope unloading is provided for heights >24m.
4. attached lifting scaffolding (climbing scaffolding)
qualification requirements: requires professional contracting qualification; expert review is required for lifting heights >150m.
safety devices: essential fall protection, overturning protection, and synchronous control devices, independently fixed.
lifting requirements: electric/hydraulic drive; no load on the scaffolding and no one present during lifting; a warning zone for monitoring.

third, other protective and platform facilities
horizontal cantilever protective shed: specialized plan including pre-embedded components, tripods, and steel wire ropes; steel wire rope spacing ≤3m; 1.2m guardrails and warning signs are provided.
high-altitude operation platforms: ≥2m requires protective measures; mobile platforms must have an area ≤10㎡ and a height ≤5m; sturdy ladders must be provided.
hydraulic shaft load-bearing platforms: elevator shafts must be segmented and cantilevered, ≤20m; supported by ≥14# i-beams; the gap between the platform and the shaft wall must be ≤100mm; standing on the platform is strictly prohibited during movement.
material handling platforms: independently connected, external scaffolding is strictly prohibited; cantilevered platforms must have main/safety double steel wire ropes and load limit signs; cross-sectional area ≤20㎡, length-to-width ratio ≤1.5:1.
construction elevator access platforms: independent frame, erected simultaneously; platform board ≤5cm from elevator door, with rigid protection and zigzag bracing.
walkways: pedestrian width ≥1m, slope ratio ≤1:3; material handling width ≥1.5m, slope ratio ≤1:6; anti-slip strips and edge protection provided.

fourth, formwork support (full-span scaffolding)
critical boundaries: for erections ≥5m, a specific plan is required; for ≥8m/span ≥18m, expert review is required.
structure: uprights should be staggered, with top supports extending ≤200mm; ground supports ≤200mm from the bottom; continuous vertical + horizontal scissor bracing for ≥8m.
protection: ≥5m should be connected to the structure; ≥2m should have access measures; ≥10m should have horizontal safety nets every 6m; overloading and connecting to external scaffolding are strictly prohibited.

fifth, general safety prohibitions
scissor bracing and wall ties must be erected and dismantled simultaneously; dismantling later scaffolding before it is erected is strictly prohibited.
scaffold boards must be without gaps, protruding boards/jumping boards, and securely fixed.
a warning zone must be established during scaffolding lifting and dismantling, with dedicated personnel monitoring the process.