---
title: "Cement mortar versus lime mortar"
subject: "Civil Engineering Materials"
chapter: 6
key: "semester_3/civil_engineering_materials:cement-vs-lime-mortar"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/cement-vs-lime-mortar
site: BCT Engineering
---

# Cement mortar versus lime mortar

Civil Engineering Materials · Chapter 6: Mortar

- Asked in: 2076 Asoj, 2+1 marks
- Video: [Lime vs Cement: The better binder](https://www.youtube.com/watch?v=VKfMm8QavTU) — Aanandaa Permaculture Farm
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/cement-vs-lime-mortar
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-6

## Question

Define mortar and explain its engineering characteristics. Differentiate between cement and lime mortar.

## Short answer

Mortar is a plastic mixture of binder, sand and water for masonry and plaster. Good mortar has workability, bond, strength, water resistance and durability. Cement mortar is strong (5-10 MPa), sets quickly by hydration, and suits damp places. Lime mortar is weaker (1-2 MPa), sets slowly by carbonation, has better workability and is used for light interior plaster.

## Answer

**Mortar** is a plastic mixture of a binding material (cement, lime or mud), sand and water used for joining masonry units and for plastering and pointing.

#### Engineering characteristics
- Good workability and plasticity so it fills joints.
- Adequate bond with masonry units and sufficient compressive strength.
- Good water retentivity and impermeability.
- Appropriate setting time; no shrinkage cracks.
- Durable against weather and economical.

#### Cement mortar versus lime mortar
| Point | Cement mortar | Lime mortar |
|---|---|---|
| Binder | Portland cement | Fat or hydraulic lime |
| Strength | High (5-10 MPa and more) | Low (about 1-2 MPa) |
| Setting | Quick (30 min to 10 hr) | Slow (days) |
| Hardening | By hydration | By carbonation (with CO2) |
| Water resistance | Good in damp places | Fat lime poor; hydraulic lime fair |
| Workability | Less | Better |
| Cost | Higher | Lower |
| Use | RCC, load-bearing walls, foundations | Light structures, interior plaster |

## Check yourself

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

1. Lime mortar hardens by:
   A. Carbonation with CO2
   B. Hydration
   C. Evaporation only
   D. Boiling
   Answer: A. Cement mortar hardens by hydration. (Key point: Hardening)

2. Strength of lime mortar is about:
   A. 5-10 MPa
   B. 1-2 MPa
   C. 50 MPa
   D. 100 MPa
   Answer: B. Cement mortar is 5-10 MPa and more. (Key point: Strength)

3. Setting of lime mortar is:
   A. Quick (30 min)
   B. Instant
   C. Slow (days)
   D. 10 hours
   Answer: C. Cement sets in 30 min to 10 hr. (Key point: Setting)

## Related in Civil Engineering Materials

- [Mud mortar versus cement mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Amud-vs-cement-mortar) — Civil Engineering Materials, chapter 6
- [Merits and demerits of lime mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Alime-mortar-merits-demerits) — Civil Engineering Materials, chapter 6
- [Stepwise preparation of cement mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Astepwise-preparing-cement-mortar) — Civil Engineering Materials, chapter 6, asked 4×
- [Precautions while applying cement mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aprecautions-applying-cement-mortar) — Civil Engineering Materials, chapter 6, asked 3×
- [Steps of applying cement mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Asteps-applying-cement-mortar) — Civil Engineering Materials, chapter 6
- [Cement and mud mortar properties, uses](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-mud-mortar-properties-uses) — Civil Engineering Materials, chapter 6

## Related in other subjects

- [Detailed specification of cement sand mortar 1:4](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Adetailed-spec-cs-mortar-1-4) — Construction Management, chapter 12, asked 2×
- [Detailed specification of cement sand mortar 1:6](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Adetailed-spec-cs-mortar-1-6) — Construction Management, chapter 12, asked 2×
- [Preparing cement mortar by manual process](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-prep-manual) — Building Technology, chapter 3, asked 2×
- [Mortar properties; cement and sand for 10 cum](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-quantity-10cum) — Building Technology, chapter 3