---
title: "Precautions while applying cement mortar"
subject: "Civil Engineering Materials"
chapter: 6
key: "semester_3/civil_engineering_materials:precautions-applying-cement-mortar"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/precautions-applying-cement-mortar
site: BCT Engineering
---

# Precautions while applying cement mortar

Civil Engineering Materials · Chapter 6: Mortar

- Asked in: 2081 Baisakh, 2 marks; 2073 Shrawan, 2 marks; 2081 Kartik (new course), 2 marks (asked 3 times)
- Video: [4. Basics Of Plastering (English)](https://www.youtube.com/watch?v=18grjq1VYls) — Amrita Skills for Life
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/precautions-applying-cement-mortar
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-6

## Question

What precautions are to be taken (things to be considered) before/while applying ordinary cement mortar in construction?

## Short answer

Use fresh cement, clean sand, and potable water; measure proportions by volume correctly. Dry-mix first then add water on a clean platform and use within 30 minutes. Wet bricks or surfaces beforehand, keep joints thin and uniform, and cure with water for 7-10 days, avoiding extreme weather.

## Answer

Precautions before and during the application of cement mortar:

1. **Materials:** use fresh cement of the right grade (not lumpy), clean sharp sand free from silt, clay and organic matter, and potable water.
2. **Proportions:** measure the proportions by volume correctly, for example 1:3 to 1:6 as required by the job.
3. **Mixing:** mix dry first, then wet, on a clean, watertight platform; mix thoroughly until the colour is uniform. Do not use too much water.
4. **Time:** use the mortar within about 30 minutes of adding water; do not re-temper mortar that has started to set.
5. **Surface preparation:** clean and wet the masonry surface (soak the bricks in water) so it does not suck water from the mortar; rake out the joints so plaster adheres well.
6. **Joint thickness:** keep the joints uniform and thin (about 10 mm), and fully filled with mortar, with no hollows.
7. **Alignment:** check levels, plumb and lines while laying.
8. **Curing:** keep the work wet for at least 7 days (10 days for plaster); protect it from sun, wind, rain and frost in the early days.
9. **Weather:** avoid working in hot, dry or freezing weather without proper care.

## Check yourself

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

1. Before laying, bricks should be:
   A. Kept dry
   B. Heated
   C. Painted
   D. Soaked in water
   Answer: D. So they do not suck water from mortar. (Key point: Surface)

2. Curing period is at least:
   A. 7 days (10 for plaster)
   B. 1 day
   C. 1 hour
   D. No curing
   Answer: A. Protect from sun, wind, rain, frost. (Key point: Curing)

3. Joint thickness should be about:
   A. 50 mm
   B. 10 mm, uniform and full
   C. 2 mm hollow
   D. Variable
   Answer: B. No hollows. (Key point: Joint)

## Related in Civil Engineering Materials

- [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
- [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×
- [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
- [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
- [Cement mortar versus lime mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-vs-lime-mortar) — Civil Engineering Materials, chapter 6

## Related in other subjects

- [Microstructure of ordinary Portland cement](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amicrostructure-opc) — Concrete Technology and Masonry Structure, chapter 2
- [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×