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Types of Scaffolds

What Is a Scaffold?

Scaffolds are temporary structures built to help workers reach areas that are well above ground level. They can also serve as access platforms. According to the Occupational Safety and Health Administration (OSHA), a scaffold is defined as:

“An elevated, temporary work platform” (n.d).

Main Categories of Scaffolds

There are two major categories of scaffolds as explained below.

Suspended Scaffolds
Suspended scaffolds are platforms that are hung from a permanent, solid structure such as a roof. They are supported by strong rope, wire, or other flexible materials. This type of scaffold is commonly used for activities like window cleaning or maintenance on high-rise buildings.
Supported Scaffolds
Supported scaffolds are built from the ground up using rigid supports such as brackets, poles, posts, legs, frames, or outriggers. These scaffolds are capable of holding substantial weight. However, they must be properly braced to prevent tilting, wobbling, or other dangerous movements.

Modern Variations of Supported Scaffolds

In modern times, technological advancements have expanded the types of supported scaffolds. Specialized equipment such as aerial lifts and scissor lifts are now recognized as types of supported scaffolds. These are frequently used in construction, manufacturing, and maintenance work.

Common Use Cases

Most of us have seen supported scaffolds in action, especially in the construction industry. These structures help workers reach elevated areas that are otherwise inaccessible from the ground. Additionally, two-point suspended scaffolds are often seen on high-rise buildings, especially for cleaning or exterior maintenance.

What Is Scaffolding Safety?

Isn’t a scaffold and scaffolding the same? Yes, it is often used interchangeably and as befitting the context requirements of a sentence. However, scaffolding also refers to the different parts such as platforms, poles, ropes, wires, ties, guys, connectors, etc.; that are put together to make a scaffold. Hence, when we speak of scaffolding, it can also mean all the components of a scaffold.

Scaffolding Safety

People who work at heights will often talk about and hear about scaffolding safety. This is because OSHA has developed regulations and recommendations that employers (who expect employees to work on scaffolds) must follow. The aim is to provide detailed guidance on the safe and secure use of scaffolds to minimize the hazards associated with scaffold use. It must also be noted that the regulations aim to protect the safety and health of employees involved in erecting, disassembling, moving, operating, repairing, maintaining, or inspecting scaffolds.

Major Hazards Associated with Scaffolds

The major hazards associated with scaffolds are falling, struck by, electrocution, and collapse. Using guardrail systems, toe boards, and fall arrest systems, ensuring scaffolds used are designed and built according to specifications, using recommended lumber and other platform materials, ensuring to maintain load capacity limits, undertaking regular inspections, and adopting other recommended safety measures will aid in protecting workers who use scaffolds to complete their work tasks, especially in the construction industry.

However, the subject of scaffolding hazards and safety measures to be adopted is a topic for another article. The rest of this article will focus on the different types of suspended and supported scaffolds available for use in various work environments and unique purposes.

Learn More About Scaffolding Safety

To completely understand the scaffolding safety requirements, enroll in our OSHA Scaffolding Safety Training online course developed to meet the criteria set out by OSHA’s scaffolding standard 29 CFR Subpart L.

Type of Suspended Scaffolds

Here are some of the more popular types of suspended scaffolds used today.

Two-Point Adjustable Suspension Scaffold

The scaffold platform is suspended by two cables that are connected to hangers at both ends. The hangers are usually attached to a permanent structure such as a tall building, and the scaffold can be adjusted for different heights.

Single-Point Adjustable Suspension Scaffold

This scaffold is also known as the boatswain's chair. This scaffold uses only one cable connected to a hook that is attached from above to a strong structure. This scaffold can also be moved easily to reach different heights.

Catenary Scaffold

A catenary scaffold is supported by several horizontal, parallel, and vertical ropes that are attached to another structure at the top.

Float Scaffold

A float scaffold is also referred to as a ship scaffold. It is hung from above, using ropes of a fixed length. The braced platform is placed on two parallel bearers. This platform cannot be adjusted for different heights.

Interior Hung Scaffold

This scaffold is attached to the roof or ceiling of a building. An interior hung scaffold cannot be adjusted for height and is of a fixed-length.

Multi-level Scaffold

A multi-level adjustable scaffold can be either a two-point or multi-point scaffold. This scaffold has several platforms at different heights and is attached to an overhead structure.

Multi-Point Adjustable Scaffold

A multi-point adjustable scaffold is attached to many overhead ropes. It is adjustable for use at different heights.

Needle Beam Scaffold

This is a simple scaffold platform attached to needle beams by two overhead ropes. It is fixed on a permanent structural base.

Image Source: OSHA. (n.d). Scaffolding eTool. Suspended Scaffolds. Website. https://www.osha.gov/etools/scaffolding

Type of Scaffold	Support Method	Adjustable Height	Common Use / Feature
Two-Point Adjustable	Two cables, one at each end	Yes	Common on tall buildings, adjustable platform
Single-Point Adjustable	One central cable	Yes	Known as boatswain’s chair, mobile and compact
Catenary	Multiple ropes (horizontal & vertical)	No	Supported by parallel ropes, used where flexibility is needed
Float (Ship)	Fixed-length ropes, two bearers	No	Simple setup, not height-adjustable
Interior Hung	Attached to roof or ceiling	No	Used indoors, fixed-height
Multi-Level Adjustable	Two or more points with multiple platforms	Yes	Multiple working levels at once
Multi-Point Adjustable	Several overhead ropes	Yes	Large platforms needing variable heights
Needle Beam	Two ropes suspended from needle beams	No	Basic design, ideal for light-duty tasks

Supported Scaffolds

Here are some types of conventional supported scaffolds used for different purposes.

The Frame or Fabricated Frame Scaffold

Frame scaffolds fabricated frame scaffolds are build using fabricated end frames. The integrity of the scaffold platform is due to the use of posts, horizontal supports, and other connecting elements. Fabricated frame scaffolds are usually built at one or two levels, but platforms can be added on for different heights. This is a popularly used scaffold as it is easy to use, can be used for different purposes, and is also cost-effective to build.

Ladder Jack Scaffold

This is a simple scaffold built using one platform which rests to brackets that are supported on ladders at either end. This is a low cost, easy to assemble scaffold; that can be moved easily. It is also best used with lightweight loads to carry out simple tasks.

Mast Climber Scaffold

A mast climber supported scaffold is mainly used when tasks must be done at great heights with a requirement to carry heavier loads to the top. This scaffold is built as a free-standing structure or can be attached intermittently using a beam to a permanent structure for better stability. The mast of the scaffold is constructed on a stationary base, while the platform is movable to reach different elevations. However, when used for tasks carried out at lower levels this scaffold may also be built on a mobile base.

Mobile Scaffold

This scaffold is built on wheels or casters and used when work tasks require constant movements; for example, when painting. The scaffold can be moved manually or propelled around. Adequate horizontal, vertical, and cross supports must be used to ensure the stability and strength of the scaffold to hold people, materials, and equipment.

Pump Jack Scaffold

A pump jack scaffold is a platform supported by moveable brackets on vertical poles. The mechanism used to move the scaffold up and down is similar to that of a vehicle jack – hence, the name! This scaffold is very economical to build and can be easily adjusted for different heights.

Tube and Coupler Scaffold

A tube and coupler scaffold is constructed by using tubing and coupling devices. It is a heavy-duty scaffold with several constructed levels to reach higher work levels. It also supports the carrying of heavy loads. While this scaffold is difficult to build due to the precise requirements, it is also a flexible type of scaffold that can be adapted for any work requirements.

Pole or Wood Pole Scaffold

This scaffold is made completely of wood. All parts from posts, poles, braces to bearers should be securely connected at fixed levels. This type of scaffold can rarely be reused, and not surprisingly, it is considered to be an outdated model and hardly used today.

S. No.	Type of Scaffold	Support Method	Adjustable Height	Common Use / Feature
1	Fabricated Frame	Metal frames, posts, and cross braces	Yes	Most common; versatile, easy to assemble, cost-effective
2	Ladder Jack	Platform resting on brackets placed on ladders	Limited	Lightweight, easy setup, used for low-height tasks
3	Mast Climber	Movable platform on a mast (stationary or mobile)	Yes	Heavy-duty; ideal for tall structures and heavy loads
4	Mobile	Scaffold built on wheels or casters	Yes	Great for tasks needing frequent movement
5	Pump Jack	Platform on vertical poles with a pump mechanism	Yes	Economical and height-adjustable
6	Tube & Coupler	Tubing connected with couplers	Yes	Strong and flexible, supports heavy loads
7	Pole/Wood Pole	Fully wooden components (posts, braces, etc.)	No	Outdated, rarely reused, mostly obsolete

Specialty Supported Scaffolds

There are also other various types of supported scaffolds used for specific purposes, such as in very narrow spaces, larger areas, or on slopes. These are:

Plasterers', Decorators', and Large-Area Scaffolds
Bricklayers' Square Scaffolds
Horse Scaffolds
Form Scaffolds and Carpenters' Bracket Scaffolds
Roof Bracket Scaffolds
Outrigger Scaffolds
Window Jack Scaffolds
Crawling Boards (Chicken Ladders)
Step, Platform, and Trestle Ladder Scaffolds
Stilts

Refer to this link for more details on specialty scaffolds.

Image Source: OSHA. (n.d). Scaffolding eTool. Supported Scaffolds. Website. https://www.osha.gov/etools/scaffolding

Scissor Lifts

Scissor lifts are a form of powered mobile scaffolds. It has one platform with guardrails fixed on cross beams attached to a motored base. Scissor lifts can be raised and lowered using the powered mechanism and can also be driven short distances to transport workers to different locations. It is a safe way for workers to reach heights. Scissor lifts are often used in warehousing operations, the construction industry, retail trade, and the entertainment industry.