Scaffolding is a temporary support structure used to give workers access to elevated work areas so that they can complete construction or maintenance tasks. Scaffolding is used in a variety of construction environments as well as being necessary for the repair and maintenance of most large buildings, including skyscrapers. Fall accidents are the number one safety hazard associated with all types of scaffolding.
There are two classifications of scaffolding; supported and suspended. The most commonly used supported scaffolds are frame scaffolds and the most commonly used suspended scaffolds are two-point scaffolds.
Frame scaffolds are very frequently used for basic residential construction and repair but since they are modular they can be utilized for large scale construction. When a large building in a city is undergoing repairs, frame scaffolds are often used to build what is essentially a shell around the building. Frame scaffolds are built from the ground up, unit by unit, and platforms are installed in between the support structures to be used as work surfaces. Once the scaffold reaches a height that is four times the minimum base dimension, it becomes unstable and it must be tied and braced against the building. A level base, proper assembly, and proper connection of the scaffold to the building are crucial to worker safety.
Two-point scaffolds are almost as ubiquitous as frame scaffolds because they are used to do routine maintenance and cleaning, such as window washing, on large commercial buildings. A two-point scaffold system is hung by ropes or cables on the side of a building and generally consists of the working surface, the support structure and guardrail, and the anchorage point which is normally on the roof of the building that is undergoing maintenance. Due to the often extreme heights, stability of the scaffold system is critical to worker safety. These scaffold systems can become very unstable in extreme wind or weather.
On any scaffold system, the number one hazard is the chance of a fall. Fall protection equipment is required on scaffolding and other procedures and equipment are used in order to prevent falls. Instability of the scaffold, failure of a support structure, improper construction of the scaffold, and improper use of fall protection equipment could all result in a fall accident.
Other scaffolding hazards include: