Scaffolding is a network of support frames and planks connected by joints that is temporarily erected to provide workers and their equipment access to the sides of buildings, interior walls and ceilings. Standard scaffolding is built modularly and for easy transport to multiple locations. It is utilized in adjusted forms for grandstand seating, exhibition stands, ski ramps and formwork and shoring.

Towering structures such as the Great Pyramids of Egypt or ancient Chinese temples identify the early use of scaffolding. However, scaffolding likely predates the ancient Egyptians and Chinese. Evidence of sockets found in the walls around Paleolithic cave paintings discovered in France suggests prehistoric humans used scaffolding more than 17,000 years ago. Ancient scaffolding was constructed of wood and secured using rope knots.

The purpose of scaffolding remains the same throughout history: provide laborers access to perform work in an area too high to reach. However, the technology has changed. Standards for safety, improved materials and stronger designs emerged in the early 20th century, significantly improving dangerous working conditions. Advances in metallurgy in the first part of the 20th century introduced tubular steel water pipes in place of timber poles, helping to standardize dimensions and improve structural stability.

Daniel Palmer Jones and David Henry Jones led the revolution in scaffolding construction. Several scaffold components developed then are still in prominent use today. Their “Universal Coupler,” which allowed for the construction of scaffolding without using rope, debuted in 1919 and quickly became an industry standard. Diagonal bracings began to appear in scaffolding around the middle of the century, further improving stability, particularly in scaffolding used on tall buildings.

Types

The precise names and terminology used to describe scaffolding types and terminology differ across regions. Types of scaffolding refer to the interaction between an existing building or structure, the weight supported and the construction.

These types include:

• Independent or birdcage scaffolding
• Single pole scaffolding
• Baker’s scaffolding
• Cantilever scaffolding
• Frame scaffolding
• Hanging or swing stage scaffolding
• Pump jack scaffolding
• Roll and fold scaffolding
• Tube and clamp scaffolding
• Hanging bracket scaffolding
• Bridging scaffolding
• Staging and lighting scaffolding
• Roofing scaffolding

Different types of scaffolding have various functions. There are two main characteristics of scaffolding. First, supported types use a system of frames, poles and planks from the base up, with the ground serving as the foundation. Supported varieties are very common and considered the easiest, cheapest, most convenient and safest way to erect scaffolding. They accommodate multiple tiers from which workers can perform their duties. As supported types scale up, the frames and planks connect by bolts and couplers or from steel tubes held in place by clamps. Hanging brackets connect different levels of scaffolding.

Suspended scaffolding is integrated into tall buildings or in areas where ground support is not an option. It requires hanging ropes or cables from a roof to hold up the scaffolding platform. Suspended scaffolding is raised or lowered using a lever or crank. Cantilever scaffolding receives support from the building itself with one end attached to the structure while the other end free.

Features

Each type of scaffolding offers a unique set of features. Various designs equip wheels or integrate unique options that permit the scaffolding to be relocated and set up again. Hanging scaffolding has the added benefit of effortless raising and lowering by a lever or crank system. It also provides easy access to very high building surfaces, removing the necessity for considerable construction effort supported scaffolding would demand. Single pole scaffolding for outdoor use and independent birdcage models for indoor use work well due to their ease of assembly and movability. In addition, it makes them attractive for small construction sites. Cantilever models work best in tight corners and hard-to-reach areas.

Applications

Applications of scaffolding are vast and diverse, matching numerous work purposes. Various uses include:

• Initial construction of a building

• Renovation work to exterior walls, interior walls and ceilings

• Roofing installation, upgrade and repair

• Restoration work on historic buildings and art or sculptures attached

• Window washing

• Window replacements

• Siding work

• Painting and sealing

Specifications

While scaffolding appears to be a relatively straightforward structure, its safe construction and use often relies on sophisticated engineering and interaction of multiple forces. Important specifications of scaffolding include:

• Safety load specifications

• Maximum bay lengths, lift heights, leg loads and tie spacing (horizontal, vertical and tie duty)

• Platform boarding arrangement

• Information of additional elements

• All detail pertinent to the design, installation and use of the scaffolding

Materials

The frames, planks, joints, braces and other components of scaffolding include one of or a combination of the following materials:

• Aluminum

• Steel or stainless steel

• Other durable metal alloys

• Plastics

• Fiberglass

• Wood

The basic modern scaffolding unit is constructed of lightweight tubes that allow modular designs of various sizes. The tubes are manufactured from steel or aluminum. Work environments with overhead power lines or similar hazards require filament-wound tubes made from elements such as glass fiber, nylon or polyester.

Selecting Scaffolding

General construction, interior and exterior painting, window washing and roofing are normal applications of scaffolding solutions today. Selection criteria in these areas are based on varying degrees of uniqueness needed for each job. For example, roofing scaffolding requires the necessary scaffolding functions of performing roof work. However, particular climates and work environments narrow the choices. This concept applies to all applications of scaffolding. A rudimentary understanding of scaffolding is necessary as additional features are evaluated for proper selection.

Examples of climate and environment considerations are as follows:

• Freezing temperatures – platform materials that less slick under icy conditions

• Storms – climates with high chance of lightning should use less metal materials

• Natural disasters – tornado weather requires extra safety harnessing options

While rules for using scaffolding vary from place to place, most scaffolding systems should be erected, regularly inspected and taken down under the supervision of a trained scaffolding contractor or designer.

Standards

AFOSH 127-7 - Scaffolding

ANSI A10.8 - Scaffolding safety requirements

BS 1139-1.2 - Metal Scaffolding

Image credit:

Grainger Industrial Supply