---
title: "Shoring versus underpinning"
subject: "Building Technology"
chapter: 8
key: "semester_6/building_technology:shoring-vs-underpinning"
source: https://www.bctengineer.com/q/semester_6/building_technology/shoring-vs-underpinning
site: BCT Engineering
---

# Shoring versus underpinning

Building Technology · Chapter 8: Temporary construction

- Asked in: 2079 Jestha, 2 marks; 2075 Bhadra, 1 marks (asked 2 times)
- Video: [Shoring , Underpinning & Scaffolding | Easy explain in 5 min](https://www.youtube.com/watch?v=2ba03P1wTnM) — NEXT STRUCTURE
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/shoring-vs-underpinning
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-8

## Question

Differentiate between shoring and underpinning.

## Short answer

Shoring provides temporary support to superstructure (walls, floors) using timber or steel rakers/props to prevent collapse during repairs. Underpinning permanently strengthens or deepens existing foundations using concrete, masonry, piles or grout to increase bearing capacity or reach firmer soil. Shoring is removed after use; underpinning becomes part of the permanent structure.

## Answer

| Point | Shoring | Underpinning |
|---|---|---|
| Meaning | Temporary support to a wall or structure | Strengthening or deepening of existing foundation |
| Purpose | Prevent collapse of walls, floors or roofs | Increase bearing capacity, carry more load, or reach firmer soil |
| Work done on | Superstructure | Foundation |
| Materials | Timber or steel (rakers, props) | Concrete, masonry, piles, grout |
| Duration | Temporary, removed afterwards | Permanent |
| Types | Raking, flying, dead | Pit, pile, pretest, grouting |

## Check yourself

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

1. Shoring is _____ while underpinning is _____.
   A. permanent; temporary
   B. temporary support; permanent strengthening of the foundation
   C. a foundation work; a superstructure work
   D. done with grout; done with timber only
   Answer: B. Shoring is temporary and removed afterwards; underpinning is permanent. (Key point: Nature of work)

2. Shoring acts mainly on the _____ and underpinning on the _____.
   A. foundation; superstructure
   B. roof; floor
   C. superstructure; foundation
   D. soil; water
   Answer: C. Shoring supports walls/floors/roofs above, whereas underpinning works on the foundation. (Key point: Work done on)

3. Which materials are typical for underpinning?
   A. Timber rakers and props
   B. Concrete, masonry, piles and grout
   C. Plywood and nails
   D. Bamboo
   Answer: B. Underpinning uses permanent materials like concrete, masonry, piles and grout; shoring uses timber or steel. (Key point: Materials)

## Related in Building Technology

- [Scaffolding, underpinning, shoring; underpinning methods](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aunderpinning-scaffold-shoring-terms) — Building Technology, chapter 8
- [Why shoring; racking versus flying shore](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-racking-flying) — Building Technology, chapter 8
- [Brick layer's scaffold and dead shoring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ascaffold-brick-layer-dead-shore) — Building Technology, chapter 8