---
title: "Why shoring; racking versus flying shore"
subject: "Building Technology"
chapter: 8
key: "semester_6/building_technology:shoring-racking-flying"
source: https://www.bctengineer.com/q/semester_6/building_technology/shoring-racking-flying
site: BCT Engineering
---

# Why shoring; racking versus flying shore

Building Technology · Chapter 8: Temporary construction

- Asked in: 2078 Chaitra, 2+4 marks
- Video: [What is shoring Types of Shoring | Raking Shores | Flying shores | Dead shores | Construction repair](https://www.youtube.com/watch?v=M98t5HHMRJU) — Real civil
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/shoring-racking-flying
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-8

## Question

Why is shoring necessary? Compare raking shores with flying shore.

## Short answer

Shoring is necessary to prevent collapse of weak, leaning, or cracked walls, support adjoining buildings during demolition or excavation, and carry loads during alterations or repairs. Raking shores use inclined rakers (60-70°) from ground to wall plate, requiring open ground space. Flying shores are horizontal members between two parallel walls, supported by needles and struts, keeping ground free and suitable for gaps up to 9 m.

## Answer

#### Why shoring is necessary
- A wall is bulging, leaning or cracked and may collapse.
- An adjacent building is being demolished, or an excavation is made nearby.
- The foundation of the building is weakened (settlement, flood, underpinning work).
- Alterations: removing a wall, opening or pier that carries load from above.
- Damage from an earthquake, fire or vehicle impact.

#### Raking shore versus flying shore

| Point | Raking shore | Flying shore |
|---|---|---|
| Position of members | Inclined (60-70 degrees) | Horizontal |
| Support from | Ground, outside the wall | The opposite wall |
| Touches ground | Yes (sole plate) | No; carried entirely by the two walls |
| Suitable when | A single wall, with open space beside it | Two parallel walls close together (up to about 9 m) |
| Components | Rakers, wall plate, needles, cleats, sole plate, braces | Horizontal shore, wall plates, needles, struts, straining pieces |
| Space needed | More on the ground | Less; ground kept free |
| Cost | Usually higher | Lower |

```text
 RAKING                        FLYING
  wall|\                    wall||=====shore=====||wall
  wall| \ raker             wall||  /         \  ||wall
  wall|  \                  wall||/ strut  strut\||wall
 _____|___\____ sole plate
```

## Related in Building Technology

- [Types of shoring; raking shore](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-raking) — Building Technology, chapter 8
- [Shoring types and flying shore](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-flying) — Building Technology, chapter 8, asked 2×
- [Objectives of shoring; dead shore](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-dead-shore) — Building Technology, chapter 8
- [Flying shoring with neat sketches](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aflying-shoring-sketch) — Building Technology, chapter 8
- [Shoring versus underpinning](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-vs-underpinning) — Building Technology, chapter 8, asked 2×