---
title: "Why temporary construction; single and double scaffolding"
subject: "Building Technology"
chapter: 8
key: "semester_6/building_technology:scaffolding-single-double"
source: https://www.bctengineer.com/q/semester_6/building_technology/scaffolding-single-double
site: BCT Engineering
---

# Why temporary construction; single and double scaffolding

Building Technology · Chapter 8: Temporary construction

- Asked in: 2066 Jestha (old course), 4+6 marks
- Video: [Types of Scaffolding | Scaffolding | Building Construction | Civil Engineering](https://www.youtube.com/watch?v=e_2ZDfWLtN4) — SGK Online Education
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/scaffolding-single-double
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-8

## Question

Why temporary construction is necessary in building construction? Differentiate between single and double scaffolding with constructional details.

## Short answer

Temporary construction provides safe height access, supports walls, shapes concrete, and aids deep work. Single scaffolding has one row of standards 1.2-1.5 m from wall, putlogs fixed in wall holes; used for brickwork. Double scaffolding has two rows, putlogs on both ledgers, no wall holes; used for stone masonry and heavy work.

## Answer

#### Why temporary construction is necessary
- Gives workers and materials a safe, stable platform at height.
- Supports weak walls and trenches during work.
- Provides the shape for concrete until it hardens.
- Allows work on deep foundations and repair of old structures.
- Increases safety, speed and quality of work.

#### Single and double scaffolding

| Point | Single (brick layer's) | Double (mason's) |
|---|---|---|
| Standards | One row, 1.2-1.5 m from wall | Two rows: 0.2-0.3 m and 1.2-1.5 m from wall |
| Putlogs | One end in wall, other on ledger | Both ends on ledgers, not in wall |
| Hole in wall | Needed | Not needed |
| Used for | Brick masonry, plastering | Stone masonry, heavy work |
| Strength | Less rigid | More rigid, stronger |
| Cost | Cheaper | More expensive |

```text
  SINGLE                      DOUBLE
  wall |__ledger__            wall |  ledger  ledger
  wall |--putlog (in wall)    wall |==putlog on both==|
  wall |   standard           wall |  std      std
  wall |   standard           wall |  std      std
```
Constructional details: standards are fixed on sole plates, ledgers are lashed or clamped at 1.2-1.8 m height, braces (diagonal) are provided on the face and cross braces for stability, boards 40 mm thick are fixed on the putlogs, and guard rails and toe boards are provided.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which scaffold needs holes in the wall?
   A. Neither
   B. Double
   C. Both
   D. Single
   Answer: D. Single scaffold putlogs go into the wall; double does not. (Key point: Holes in wall)

2. In double scaffold the standards are at:
   A. 5 m
   B. 0.2-0.3 m and 1.2-1.5 m from the wall
   C. On the wall
   D. Only 1.2-1.5 m
   Answer: B. Two rows: the first close to the wall, the second further away. (Key point: Standards distance)

3. Double scaffold is used for:
   A. Trenches
   B. Plastering only
   C. Painting only
   D. Stone masonry and heavy work
   Answer: D. It is more rigid and avoids wall holes. (Key point: Use)

## Related in Building Technology

- [Double and cantilever scaffolding](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ascaffold-double-cantilever) — Building Technology, chapter 8
- [Types of temporary construction](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Atemp-construction-types-sketch) — Building Technology, chapter 8, asked 2×
- [Temporary construction, types and requirements](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Atemp-construction-types-requirements) — Building Technology, chapter 8
- [Types of temporary construction (list)](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Atemp-construction-types-list) — Building Technology, chapter 8
- [Single, double, multiple timber roofs; king post truss](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Atimber-roofs-king-post) — Building Technology, chapter 4, asked 2×
- [Roof covering; double and triple roofs](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aroof-covering-double-triple) — Building Technology, chapter 4

## Related in other subjects

- [Polymers in building construction](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Apolymer-properties-uses-building) — Civil Engineering Materials, chapter 10, asked 2×
- [Building near river bank; stop construction?](https://www.bctengineer.com/question.md?key=semester_8%2Fengineering_professional_practice%3Abuilding-on-river-bank-flood) — Engineering Professional Practice, chapter 7
- [Single and double handshaking](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Ahandshaking-single-double) — Microprocessor, chapter 4
- [Single vs double earth wire selection](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Asingle-double-earth-wire-criteria) — Transmission and Distribution System Design, chapter 3