---
title: "Causes of deterioration of stone"
subject: "Civil Engineering Materials"
chapter: 2
key: "semester_3/civil_engineering_materials:causes-deterioration-stone"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/causes-deterioration-stone
site: BCT Engineering
---

# Causes of deterioration of stone

Civil Engineering Materials · Chapter 2: Building Stones

- Asked in: 2081 Baisakh (new course), 1.5 marks; 2076 Chaitra, 2 marks; 2079 Bhadra, 2 marks; 2074 Asoj, 2 marks (asked 4 times)
- Video: [Deterioration of Stones](https://www.youtube.com/watch?v=56zsygZbszY) — Mounika Ganta
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/causes-deterioration-stone
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-2

## Question

What are the causes (factors) of deterioration of stones?

## Short answer

Stone deteriorates due to rain and moisture causing frost action and dissolution, acid gases (CO₂, SO₂), temperature changes leading to cracks, salt crystallization, wind abrasion, chemical reactions with sulphates/chlorides, vegetation growth, poor bedding, and fire. Proper selection and protection can mitigate these.

## Answer

Deterioration of stone is the loss of its strength, shape and appearance with time. Its main causes are:

1. **Rain and moisture:** water enters pores, dissolves minerals and causes frost damage and weakening of the stone.
2. **Atmospheric gases:** CO₂, SO₂ and acid fumes in polluted air form carbonic and sulphuric acids that attack limestone and sandstone (acid rain).
3. **Temperature variation:** daily and seasonal expansion and contraction cause cracks, particularly in stones made up of different minerals.
4. **Frost action:** water freezing in the pores expands by about 9% and splits the stone.
5. **Wind and abrasion:** wind-borne particles wear the surface.
6. **Crystallisation of salts:** soluble salts in the stone or in the ground water crystallise on the surface and spall the stone.
7. **Chemical action:** sulphates and chlorides from soil, sea water or mortar react with the stone.
8. **Vegetation and organisms:** roots, moss, lichens and fungi hold moisture and produce acids that corrode the stone.
9. **Poor selection and workmanship:** wrong bedding, porous stone, poor dressing or weak mortar.
10. **Fire and earthquakes** may also crack stone.

## Check yourself

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

1. Why are limestone and sandstone attacked in polluted air?
   A. Oxygen oxidises the stone
   B. Nitrogen dissolves the cement
   C. Dust melts the stone
   D. CO2 and SO2 form carbonic and sulphuric acids
   Answer: D. Atmospheric gases form acids that dissolve these stones (acid rain). (Key point: Acid rain)

2. How does frost damage stone?
   A. Water freezing in pores expands by about 9% and splits the stone
   B. Ice contracts and pulls the stone
   C. Frost dissolves the minerals
   D. Frost makes stone brittle by heat
   Answer: A. Expansion of freezing water in the pores exerts pressure that splits stone. (Key point: Frost action)

3. How do soluble salts deteriorate stone?
   A. They dissolve and strengthen the stone
   B. They crystallise on the surface and spall it
   C. They make the stone fireproof
   D. They only change colour
   Answer: B. Crystallising salts exert pressure and cause spalling. (Key point: Salt crystallisation)

## Related in Civil Engineering Materials

- [Deterioration and preservation of stone](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Adeterioration-preservation-stone) — Civil Engineering Materials, chapter 2, asked 2×
- [Methods of preserving stone](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Apreservation-of-stone) — Civil Engineering Materials, chapter 2, asked 4×

## Related in other subjects

- [Physical causes of concrete deterioration](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Aphysical-causes-deterioration) — Concrete Technology and Masonry Structure, chapter 6, asked 6×
- [Mechanical and physical causes of deterioration](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amechanical-physical-causes-deterioration) — Concrete Technology and Masonry Structure, chapter 6, asked 6×
- [Chemical causes of concrete deterioration](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Achemical-causes-deterioration) — Concrete Technology and Masonry Structure, chapter 6, asked 5×
- [Physical and chemical causes of deterioration](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Aphysical-chemical-causes-deterioration) — Concrete Technology and Masonry Structure, chapter 6, asked 5×