Scaffolding is a temporary structure that is used either to support an original structure or to function as a platform for the workers to perform construction works. It is a framework of horizontal, vertical, and inclined members. Every scaffolding constructed must be strong and firm to support the weight of the workers and other construction materials laid on it.
|Fig.1. Steel Scaffolding
Scaffolding is designed for a particular construction work which varies in material, and layout. This is decided based on the type of work.
In this article, let's discuss the various components, types, and features of scaffolding used in construction work.
Features of Scaffolding
- Scaffolding are temporary structure erected close to the main work to provide a working platform for workers and to separate other storage of building materials, tools, and plants away from the main work for better safety and organizing. They are also called staging.
- Scaffolding is used for construction, maintenance, repair, alteration, demolition, painting, etc.
- Any construction work that needs access more than 1.5m in height from the ground level demands scaffolding.
- Scaffolding members can be made out of timber or steel.
Functions of Scaffolding
- Act as a working platform so that the worker can stand on the platform and perform the work safely and easily.
- Act a platform to load materials - so that workers can place materials and tools to conduct their work.
- As a walking platform, so that workers can have a walking path to transport materials and logistics.
Components of Scaffolding
The figure below shows a scaffolding arrangement depicting the important components of the framework. As shown, there are ground-floor and first-floor arrangements. The component - Standard (1) will be facing the main wall of the structure and workmen will stay on the platform boarding (2) during construction [ Figure 2]. The topmost platform in a scaffolding formwork is called as the Top Working Platform (TWP).
Let's familiarise each component of a scaffolding one by one. The major components of a scaffolding are:
|Fig.2. Components or Parts of a Scaffolding
2. Ledgers: Horizontal supporting members that run parallel to the wall or the facing main structure.
3. Braces: Diagonal members end fixed on the standards, to provide lateral support to the whole framework.
4. Putlogs: Putlogs are traverse members supported over the ledgers, with one end fixed on the wall at one end and the other end free, as shown in Figure 2. These members support elements to create a platform to support workmen.
5. Transoms: When both ends of a putlog are supported on ledgers, we call it a transom. In most cases, transom acts as handrails.
6. Bridle: This is a small member used to bridge an opening in the wall so that it can support one end of the putlog (Figure 3).
|Fig.3. Bridle for Scaffolding Connection in Wall Openings
7. Boarding: These are horizontal platforms to support the workmen and material. These boardings are supported on the putlogs. (Figure 2).
8. Guard Rail: These are rails provided at the working level parallel to the ledgers.
9. Toe Board: These are boards that are placed parallel to the ledgers and are supported on putlogs at the level of the working platform.
10. Mid Rails: Mid rails are also guard rails provided at mid between the boarding and the guardrail for extra support and safety as shown in Figure 2.
|Fig.4. Couplers used in Scaffolding Connection
|Fig.5. Scaffold Tie
Types of Scaffolding
|A. Supported Scaffolding Types
|B. Suspended Scaffolding Types
|1. Brick Layer Scaffolding
|2. Mason's Scaffolding
|3. Cantilever Scaffolding
|Interior Hung Scaffolding
|4. Trestle Scaffolding
|Two-Point (Swing Stage) Scaffolding
|5. Mast Climber Scaffolding
|6. Ladder Jack Scaffolding
|Multipoint Adjustable Scaffolding
|7 Mobile Scaffolding
|Single-point Adjustable Scaffolding
|8. Pole/Wood Pole Scaffolding
|Cantilever or Needle Scaffolding
A) Supported ScaffoldingSupport scaffolding, consists of platforms supported by standards anchored to the ground. Essentially, these platforms are built up from the ground level. Supported scaffolding provides sturdy support, and certain types allow for an unlimited number of layers. However, they can be challenging to use in situations where the ground is uneven or if there are space limitations at the base, such as on a roadway.
- Brick layer scaffolding or single frame scaffolding
- Mason's Scaffolding or Double Scaffolding
- Cantilever or Needle Scaffolding
- Trestle Scaffolding
- Mast Climber Scaffolding
- Ladder Jack Scaffolding
- Mobile Scaffolding
- Pole/Wood Pole Scaffolding
- Tube and Coupler Scaffolding
1. Brick Layer Scaffolding or Single Frame ScaffoldingBricklayer scaffolding is the most common and cheapest scaffolding type as the scaffold is made out of single-row. Hence it is also called single scaffolding supported on the main wall using putlogs. The fact it is cheap is because it can be easily constructed and dismantled. It is mainly used in brick masonry construction.
The putlogs (traverse members) are extracted from the gap that is remaining after the arrangement of standards and ledgers, to one end of the ledgers. It is placed at a gap of 1.2 to 1.5 m and usually has a length of around 90 cm.
When larger heights need to be achieved, additional cross bracings need to be provided for additional support.
Read More On: Single Frame Scaffolding – Pros & Cons
2. Mason's Scaffolding or Double Scaffolding
|Fig.8. Mason's Scaffolding or Double Scaffolding
3. Trestle Scaffolding
|Fig.10. Trestle Ladder
Image Credits: American Scaffold Institute
4. Mast Climber Scaffolding
|Fig.11.Mast Climber Scaffolding
5. Ladder Jack Scaffolding
|Fig.12. Ladder Jack Scaffolds
6. Mobile (Manual or Propelled) ScaffoldingMobile scaffolds are supported scaffolds with wheels or casters, intended for easy movement. They're commonly used in tasks like painting and plastering, where workers need to move around frequently.
|Fig.12. Mobile (Manual or Propelled) Scaffolding
7. Pole or Wood Pole ScaffoldingPole scaffolding involves using wood for all structural parts. However, apart from bamboo scaffolding, which is mainly used in Asia, steel scaffolding has become the preferred choice due to its enhanced safety, reusability, and strength.
|Fig.13. Pole and Wood Scaffolding
8. Tube and Coupler Scaffolding
|Fig.14. Tube and Coupler Scaffolding
B) Suspended Scaffolding
|Fig.15. Suspended Scaffolding
- Catenary Scaffolding
- Float Scaffolding
- Interior Hung Scaffolding
- Two-Point (Swing Stage) Scaffolding
- Multilevel Scaffolding
- Multipoint Adjustable Scaffolding
- Single-point Adjustable Scaffolding
- Cantilever or Needle Scaffolding
1. Catenary scaffolding
|Fig.16. Catenary Scaffold
2. Float Scaffolding
|Fig.17. Float Scaffolding
3. Interior Hung Scaffolding
4. Two-Point (Swing Stage) Scaffolding
|Fig.18. Two-Point (Swing Stage) Scaffolding
5. Multilevel Scaffolding
6. Multipoint Adjustable Scaffolding
|Fig.19. Multistage, multilevel and single-point scaffolds
7. Single-point Adjustable ScaffoldingSingle-point adjustable scaffolding, also known as boatswain scaffolding, resembles multipoint adjustable scaffolding but is suspended by a single rope or wire instead of multiple. It's commonly used by solo window washers and features a suspended chair for inspections, resembling the setup used by a boatswain on a ship.(Figure 19(d))
8. Cantilever or Needle Scaffolding
|Fig.20. Cantilever or Needle Scaffolding
- Ground is weak to support the standards (vertical members of the frame).
- To provide further stories in the existing building
- For repairing purposes
Scaffolding has been crucial for building tall structures throughout history. While wood scaffolding used to be common, steel is now more popular. New tools and alternatives like scissor lifts are also changing how some jobs are done. However, scaffolding remains essential and will keep evolving as we build taller and more complex structures.