Temporary works in construction cover the four major systems that support building operations: timbering, formwork, scaffolds, and shores. This guide explains each system, what it does, and how technicians use it safely on site.
Introduction: What Are Temporary Works in Construction?
Temporary works in construction are structures and systems that support construction operations but do not form part of the finished building. Moreover, they include timbering, formwork, scaffolds, and shores. Consequently, they protect workers, shape concrete, provide access, and support unstable structures.
In addition, temporary works are removed once the permanent works can stand alone. However, their temporary nature does not reduce their importance. In fact, failures in temporary works cause some of the most serious accidents in construction.
This guide therefore covers all four systems in one place, explaining what each does and how they differ.
Why Temporary Works in Construction Matter
Temporary works make permanent works possible. Without them, workers cannot excavate safely, cast concrete accurately, or work at height. Furthermore, temporary works protect adjacent structures and the public.
In addition, temporary works affect cost and programme. When technicians plan them well, work proceeds smoothly. On the other hand, poor temporary works cause delays, rework, and accidents. Therefore, every technician must understand all four systems.
1. Timbering: Supporting Excavations
Timbering supports the sides of trenches and excavations. Moreover, it prevents soil collapse and protects workers, services, and adjacent structures.
What Timbering Does
Timbering holds back soil that would otherwise fall into an excavation. In addition, it keeps the excavation open long enough for foundation, drainage, or utility work to proceed.
Main Components
- Poling boards – vertical members that resist earth pressure directly.
- Walings – horizontal members that transfer pressure to the struts.
- Struts – compression members that span the excavation width.
- Wedges – tapered pieces used for tightening and adjustment.
Key Points for Technicians
- Erect as you dig, never after excavation.
- Dismantle from the bottom up, backfilling as you go.
- Use the correct member sizes for the soil type and depth.
2. Formwork: Shaping Concrete
Formwork shapes and supports fresh concrete until it hardens. In addition, it controls the dimensions, position, and surface finish of every concrete element.
What Formwork Does
Formwork acts as a mould. Moreover, it holds the concrete in place while it gains strength. Consequently, the finished element matches the drawing.
Main Types
- Timber formwork – flexible and cheap, suited to irregular shapes.
- Plywood formwork – smooth finish, common for walls and slabs.
- Steel formwork – strong and accurate, suited to repetitive work.
- Aluminium formwork – light and durable, suited to rapid erection.
Key Points for Technicians
- Apply a release agent before casting.
- Brace and tie the formwork firmly.
- Strip only after the concrete gains sufficient strength.
3. Scaffolds: Providing Access at Height
Scaffolds provide safe access at height and support materials during construction. Moreover, they protect workers from falls and allow multiple trades to work simultaneously.
What Scaffolds Do
Scaffolds create working platforms at height. In addition, they support tools and materials close to the work face.
Main Types
- Frame scaffolds – fast to erect, suited to straight runs.
- Tube and clamp scaffolds – flexible, suited to irregular structures.
- System scaffolds – modular, suited to complex shapes.
- Tower scaffolds – freestanding, suited to interior work.
- Suspended scaffolds – hang from overhead, suited to facade work.
Key Points for Technicians
- Erect from the top down, dismantle from the top down.
- Tie scaffolds to the structure as you go.
- Inspect on completion and at least weekly thereafter.
4. Shores: Supporting Unstable Structures
Shores support structures and excavations that have become unstable. In addition, they protect adjacent buildings during demolition, alteration, and underpinning.
What Shores Do
Shores carry the weight of walls, floors, and soil that would otherwise collapse. Moreover, they hold structures in place while permanent repairs proceed.
Main Types
- Raking shores – inclined support for external walls.
- Flying shores – horizontal support between parallel walls.
- Dead shores – vertical support for needles and upper walls.
- Trench shores – support for excavation faces.
Key Points for Technicians
- Install from the top down, remove from the bottom up.
- Install raker shores in pairs and lace them together.
- Release the load gradually during dismantling.
How the Four Systems Compare
The table below compares the four systems across purpose, sequence, and risk.
| System | Purpose | Key Sequence | Main Risk |
|---|---|---|---|
| Timbering | Support excavation faces | Erect as you dig | Soil collapse |
| Formwork | Shape and support concrete | Prepare, erect, strike | Bulging or collapse |
| Scaffolds | Provide access at height | Erect top down | Falls from height |
| Shores | Support unstable structures | Install top down | Structural collapse |
How the Four Systems Work Together
The four systems often appear on the same site. For instance, a foundation project may use timbering for the trench, formwork for the footings, scaffolds for the walls, and shores for an adjacent building.
Moreover, each system depends on the others for safe access and sequence. Therefore, technicians must plan them together, not separately. Consequently, the site runs safely and efficiently.
Common Mistakes Across All Four Systems
Many temporary works failures result from avoidable errors. Therefore, avoid the following common mistakes.
- Starting work without reading the drawings.
- Using defective or undersized materials.
- Skipping the release agent on formwork.
- Erecting scaffolds without ties or braces.
- Installing shores from the bottom up.
- Removing temporary works before the permanent structure is ready.
- Releasing all supports at once.
- Ignoring inspection and maintenance.
- Neglecting PPE and housekeeping.
- Allowing untrained workers to perform temporary works.
Summary Table: Purpose and Key Points
| System | What It Supports | Critical Check |
|---|---|---|
| Timbering | Excavation faces | Member size and spacing |
| Formwork | Fresh concrete | Tightness and bracing |
| Scaffolds | Workers and materials | Ties and guard rails |
| Shores | Structures and walls | Sequence and tightness |
Conclusion
Temporary works in construction cover four essential systems: timbering, formwork, scaffolds, and shores. When technicians understand what each system does and how it must be installed, they protect workers and support efficient construction.
Moreover, the four systems often work together on the same site. Therefore, technicians must plan them as a whole. As a result, construction proceeds safely, and every worker returns home unharmed.
Frequently Asked Questions
What are temporary works in construction?
Temporary works in construction are structures and systems that support construction operations but do not form part of the finished building. They include timbering, formwork, scaffolds, and shores.
What is the difference between timbering and shoring?
Timbering supports excavation faces, while shoring supports structures and excavations that have become unstable. Moreover, shoring includes raking, flying, and dead shores.
Why is formwork a temporary work?
Formwork shapes and supports fresh concrete until it hardens. Therefore, workers remove it once the concrete gains sufficient strength, which makes it temporary.
How do scaffolds differ from shores?
Scaffolds provide access at height, while shores provide structural support. Consequently, they serve different purposes but often appear on the same site.
What is the most dangerous temporary work?
All temporary works carry risk, but dismantling is often the most dangerous stage. Therefore, technicians must release loads gradually and follow the reverse sequence.