---
title: "Rate analysis: 12.5 mm plaster 1:5, per m²"
subject: "Estimating and Costing"
chapter: 4
key: "semester_7/estimating_and_costing:rate-plaster-12-5-1-5"
source: https://www.bctengineer.com/q/semester_7/estimating_and_costing/rate-plaster-12-5-1-5
site: BCT Engineering
---

# Rate analysis: 12.5 mm plaster 1:5, per m²

Estimating and Costing · Chapter 4: Analysis of Rates

- Asked in: 2081 Bhadra, 5 marks
- Video: [Rate Analysis of Plaster Work | Analysis of Rate for Plaster Work @CivilConstruction](https://www.youtube.com/watch?v=n8qR8FVY8Sw) — CivilConstruction
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/estimating_and_costing/rate-plaster-12-5-1-5
- Whole chapter: https://www.bctengineer.com/md/semester_7/estimating_and_costing/chapter-4

## Question

Prepare analysis of rate for 12.5 mm thick plaster with (1:5) cement sand mortar per 1 m².

## Short answer

Based on 20% wastage and 1.30 dry factor, dry mortar is 0.0195 m3/m2. For 10 m2, cement 0.936 bags and sand 0.1625 m3. Rate = Rs 433.39 per m2, including 15% overhead.

## Answer

#### Basis
12.5 mm thick plaster in cement mortar 1:5 on brick wall, worked for **10 m²** and divided by 10. Rates are **illustrative**.

#### Mortar quantity
- Wet volume per m² = 0.0125 m³; add 20% for filling uneven wall surface and wastage: 0.0150 m³.
- Dry mortar = 0.0150 x 1.30 = 0.01950 m³ per m².
- For 10 m²: dry mortar = 0.1950 m³; cement = 0.1950/6 = 0.03250 m³ = 46.8 kg = 0.936 bags; sand = 0.1625 m³.

#### Analysis (per 10 m²)
| Description | Qty | Unit | Rate (Rs) | Amount (Rs) |
|---|---|---|---|---|
| Cement (0.03250 m³) | 0.936 | bag | 900.00 | 842.40 |
| Sand (0.1625 m³) | 0.1625 | m³ | 2,500.00 | 406.25 |
| Mason (skilled) | 1.2 | md | 1,200.00 | 1,440.00 |
| Helper (unskilled, incl. water and scaffolding) | 1.2 | md | 900.00 | 1,080.00 |
| **Sub-total** | | | | **3,768.65** |
| Contractor's overhead and profit | 15% | | | 565.30 |
| **Total per 10 m²** | | | | **4,333.95** |

**Answer: Rate of 12.5 mm 1:5 plaster = 4,333.95 / 10 = Rs 433.39 per m²** (excluding VAT).

## Check yourself

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

1. Why is the wet mortar taken as 0.0150 m^3 per m^2 instead of 0.0125 m^3?
   A. 20% is added because dry mortar swells on mixing
   B. 20% is added for filling uneven wall surface and wastage
   C. The thickness is increased to 15 mm for 1:5 mortar
   D. It covers the contractor's overhead and profit
   Answer: B. The wet volume 0.0125 m^3 is increased by 20% for the uneven wall surface and wastage, giving 0.0150 m^3. (Key point: Allowance on mortar)

2. For 10 m^2 the dry mortar is 0.1950 m^3. How is the cement volume found for mortar 1:5?
   A. 0.1950/6 = 0.0325 m^3, since the ratio parts sum to 6
   B. 0.1950/5 = 0.039 m^3
   C. 0.1950 x 1/5 x 1.30 = 0.0507 m^3
   D. 0.1950/7 = 0.0279 m^3
   Answer: A. Cement is 1 part of 1+5 = 6 parts, so cement = 0.1950/6 = 0.0325 m^3. (Key point: Cement from dry mortar)

3. The total for 10 m^2 including 15% overhead and profit is Rs 4,333.95. What is the rate per m^2?
   A. Rs 4,333.95, as the rate is the total
   B. Rs 3,768.65 / 10 = Rs 376.87, as overhead is excluded
   C. Rs 4,333.95 x 10 = Rs 43,339.50
   D. Rs 433.39, by dividing the 10 m^2 total by 10
   Answer: D. The analysis is worked for 10 m^2 and divided by 10, giving Rs 433.39 per m^2, with overhead and profit included. (Key point: Final rate per m^2)

## Close variants set in other exams

- [Rate analysis: 20 mm plaster 1:4 per 100 m²](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-plaster-20mm-1-4) — Estimating and Costing, chapter 4, asked 3×
- [Rate analysis: 12 mm plaster 1:3 ceiling](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-plaster-12mm-1-3-ceiling) — Estimating and Costing, chapter 4, asked 3×

## Related in Estimating and Costing

- [Rate analysis: 12.5 mm plaster 1:3, per 100 m²](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-plaster-12-5-1-3-ceiling) — Estimating and Costing, chapter 4
- [Materials: 12 mm plaster 1:6 per 10 m²](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Amaterials-plaster-12mm-1-6) — Estimating and Costing, chapter 4
- [Rate analysis: 25 mm 1:2:4 concrete floor](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-cc-floor-25mm) — Estimating and Costing, chapter 4
- [Rate analysis: brickwork 1:6 per m³](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-brick-1-6-upper-floor) — Estimating and Costing, chapter 4, asked 2×
- [Rate analysis: 40 mm PCC 1:2:4 floor](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-pcc-1-2-4-floor-40mm) — Estimating and Costing, chapter 4
- [Rate analysis: 40 mm asphalt wearing coat](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-asphalt-wearing-coat-10m2) — Estimating and Costing, chapter 4

## 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×
- [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