Scaffolding consists of temporary engineered structures designed to support workers, tools and materials during elevated construction activities. Proper specification must consider structural design, load capacity, global stability and regulatory compliance, especially with occupational health and safety standards for construction.
1. Technical Classification of Scaffolding
Scaffolding can be classified by structural system and application:
- Tube and coupler scaffolding: modular metal structure of steel tubes and connections. High geometric flexibility.
- Frame or facade scaffolding (multidirectional): industrialized system with standardized fittings, faster assembly and dimensional control.
- Mobile scaffolding: structure on casters, limited in height and dependent on floor stability and leveling.
- Mechanical or electric suspended scaffolding: platform supported by steel cables with controlled hoisting.
2. Load Calculation and Sizing
Sizing must consider:
- Dead load (self-weight of the structure);
- Live load (workers + tools + materials);
- Dynamic load (movement);
- Horizontal actions (wind).
Simplified platform load capacity typically ranges from 150 kg/m² to 450 kg/m², depending on scaffold class. More complex projects must follow structural criteria per applicable standards and design by a qualified professional.
3. Global Stability and Anchoring
Stability depends on:
- Level base and adjustable base plates;
- Diagonal and longitudinal bracing;
- Anchoring to the building at defined vertical intervals;
- Height-to-base ratio (slenderness).
For facade scaffolding, anchoring every 4 metres of height or per specific design is recommended.
4. Regulatory Compliance
Regulations set mandatory requirements such as:
- Guardrail with minimum height of 1.20 m;
- Toeboard at least 20 cm high;
- Non-slip, fully decked platform;
- Safe access by internal ladder or access tower;
- Design and technical responsibility when required.
5. Inspection and Control
Scaffolding must be inspected:
- Before starting work;
- After severe weather or impacts;
- Periodically per safety plan.
Deformation, excessive corrosion, loose connections and structural misalignment are critical failure factors.
Technical Conclusion
Scaffold selection and sizing must be treated as a technical, not only operational, decision. Poor specification increases structural risk, civil liability and labour exposure. Use of certified systems, with documented design and inspection, is essential in professional construction.
