---
title: "Preparing cement mortar by manual process"
subject: "Building Technology"
chapter: 3
key: "semester_6/building_technology:mortar-prep-manual"
source: https://www.bctengineer.com/q/semester_6/building_technology/mortar-prep-manual
site: BCT Engineering
---

# Preparing cement mortar by manual process

Building Technology · Chapter 3: Mortars & Masonry works

- Asked in: 2078 Chaitra, 4 marks; 2069 Bhadra, 4 marks (asked 2 times)
- Video: [How to mix cement mortar by hand DIY](https://www.youtube.com/watch?v=53GxFyGlJhU) — Sam Davies
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/mortar-prep-manual
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-3

## Question

Explain step by step procedure for preparing cement mortar by manual process (preparation of cement sand mortar 1:6).

## Answer

Manual mixing of cement mortar is done for small works, when a mixer is not available. For a **1:6 cement-sand mortar** (1 part cement to 6 parts sand by volume), the steps are as follows.

#### Materials and tools
Cement (OPC 43 grade), clean river sand (passing a 4.75 mm sieve, free from silt and organic matter), clean water; a watertight platform (masonry or steel sheet, 3 m × 3 m), shovels, trowels, a gauge box, buckets.

#### Procedure
1. **Measure the sand**: Measure the volume of sand with a gauge box (e.g. 6 boxes for 1 bag of cement; 1 bag of 50 kg = 0.035 m³).
2. **Spread the sand**: Spread the sand in a uniform layer, 150 to 200 mm thick, on a clean, hard platform.
3. **Add cement**: Spread the cement evenly over the sand.
4. **Dry mixing**: Mix the sand and cement with shovels, turning the heap over at least 3 times, until the mix has a uniform colour.
5. **Making a crater**: Form the dry mix into a ring with a hollow at the centre.
6. **Adding water**: Add water slowly into the centre, without letting it escape, using just enough to get a workable consistency (too much water weakens the mortar).
7. **Wet mixing**: Turn and re-mix 3 to 4 times with a shovel until the mortar is uniform and has the correct consistency.
8. **Use**: Use the mortar within 30 minutes of adding water (before the initial set). Hardened mortar must not be re-tempered; unused mortar is discarded.
9. **Cleaning**: Clean the platform and tools after use.
10. **Curing**: Cure the finished work for at least 7 days.

```text
 1. sand layer   2. + cement   3. dry mix
 ~~~~~~~~~~~~~   ===========   (turn x3)
 4. crater -> add water -> turn x3-4 -> mortar
```

## Check yourself

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

1. In manual mixing of mortar, the correct order is:
   A. Cement then water then sand
   B. Water first, then sand
   C. Spread sand, add cement, dry mix, make crater, add water
   D. Mix everything wet at once
   Answer: C. Dry mix until uniform colour, then add water in a crater. (Key point: Mixing order)

2. Mixed cement mortar should be used within:
   A. 5 hours
   B. 30 minutes
   C. One week
   D. 2 days
   Answer: B. Before initial set; hardened mortar must not be re-tempered. (Key point: Usage time)

3. 1:6 mortar means:
   A. 1:6 by cost
   B. 1 part cement to 6 parts sand by volume
   C. 6 parts cement to 1 sand
   D. 1 kg cement to 6 kg water
   Answer: B. Ratio is by volume of cement to sand. (Key point: Proportion)

## Related in Building Technology

- [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
- [Cement-sand plastering and its types](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aplastering-process) — Building Technology, chapter 9, asked 3×
- [Cement and sand for 100 m² plastering numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aplaster-100m2-1to6) — Building Technology, chapter 3, asked 2×
- [Cement and sand for 200 m² plastering numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aplaster-200m2-1to5) — Building Technology, chapter 3, asked 2×
- [Mortar for 10 m³ brickwork (1:4) numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-10m3-1to4) — Building Technology, chapter 3
- [First class brickwork in 1:6 mortar numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-first-class-1to6) — Building Technology, chapter 3

## Related in other subjects

- [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×
- [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×
- [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×