---
title: "Construction of terrazzo flooring"
subject: "Building Technology"
chapter: 7
key: "semester_6/building_technology:terrazzo-flooring"
source: https://www.bctengineer.com/q/semester_6/building_technology/terrazzo-flooring
site: BCT Engineering
---

# Construction of terrazzo flooring

Building Technology · Chapter 7: Flooring

- Asked in: 2079 Chaitra, 5 marks; 2078 Poush, 4 marks; 2075 Baisakh, 3 marks; 2069 Bhadra, 5 marks (asked 4 times)
- Video: [How to Cast Insitu TERAZZO FLOORING Process |What is Terrazo Flooring | Terrazzo Flooring Cost](https://www.youtube.com/watch?v=c4K8Y6gBlMA) — Ian Construction
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/terrazzo-flooring
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-7

## Question

Explain the construction method of terrazzo flooring.

## Short answer

Terrazzo flooring uses cement and marble chips laid over a concrete base, ground and polished. Construction: lay concrete sub-floor, apply mortar bed, fix dividing strips, spread chip topping, cure 7-10 days, grind with coarse to fine stones, grout pinholes, polish with oxalic acid and wax.

## Answer

**Terrazzo** is a floor finish of cement and marble chips (aggregate) laid over a concrete base, ground and polished to a smooth, hard, attractive surface.

#### Materials
- Cement (white or grey, with colour pigments), marble chips 6-12 mm, sand/marble powder.
- Brass or glass dividing strips (3 mm thick, 40 mm deep).
- Oxalic acid and wax for polishing.

#### Construction method
1. **Base:** a concrete sub-floor (1:2:4, about 100 mm) is laid and levelled. Its surface is kept rough and cleaned, then wetted.
2. **Under layer:** a 25-30 mm cement-sand mortar (1:4) bed is spread and levelled while the base is still green.
3. **Dividing strips:** brass/glass/aluminium strips are fixed in the bed, in panels about 1 m x 1 m, with their tops at the finish level. They stop cracking and form patterns.
4. **Topping:** a mix of cement and marble chips (1:2 or 1:1.5 by volume; chips 6-12 mm), 6-12 mm thick, is spread in the panels, levelled and well rolled or pressed so the chips show on the surface.
5. **Curing:** cured under wet sand or gunny for 7-10 days.
6. **Grinding:** the surface is ground by a machine with carborundum stones: first coarse (No. 60), then medium (No. 120) and fine (No. 320), with water.
7. **Grouting:** pin holes are filled with a neat cement paste of the same colour and ground again.
8. **Polishing:** finally polished with oxalic acid powder and wax or polish.

```text
   Section
   ___ marble chip topping (6-12 mm)
   ~~~ cement mortar bed 1:4 (25 mm)
   ... PCC sub-floor 1:2:4 (100 mm)
   --- compacted brick soling / earth
   |brass strip| every ~1 m
```

Terrazzo is hard, durable, easy to clean, and is used in hospitals, schools and offices.

## Check yourself

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

1. What is terrazzo made of?
   A. Cement and brick chips left rough
   B. Cement and marble chips ground and polished
   C. Clay tiles with adhesive
   D. Timber boards on joists
   Answer: B. It is a cement-marble chip topping on a concrete base. (Key point: Terrazzo composition)

2. What is the purpose of the brass/glass dividing strips?
   A. To reinforce the base concrete
   B. To drain water
   C. To prevent cracking and form patterns
   D. To bond tiles
   Answer: C. Strips in panels of about 1 m x 1 m control cracks. (Key point: Dividing strips)

3. How is the surface ground?
   A. Fine first, then coarse
   B. Dry grinding with one grade
   C. Not ground, only trowelled
   D. Coarse (No. 60), then medium (No. 120), then fine (No. 320) with water
   Answer: D. Progressively finer carborundum stones are used. (Key point: Grinding order)

4. Why is grouting done after the first grinding?
   A. To fill pin holes with matching neat cement paste
   B. To add thickness
   C. To bond the base
   D. To remove oxalic acid
   Answer: A. Pin holes are filled and then ground again. (Key point: Grouting)

## Related in Building Technology

- [Terrazzo versus mosaic flooring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aterrazzo-vs-mosaic) — Building Technology, chapter 7
- [Construction of mosaic flooring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amosaic-flooring) — Building Technology, chapter 7, asked 2×
- [Construction of marble flooring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amarble-flooring) — Building Technology, chapter 7, asked 2×
- [Granite flooring, pros and cons](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Agranite-flooring-pros-cons) — Building Technology, chapter 7
- [Suspended ground floor; tile flooring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Asuspended-ground-floor-tile) — Building Technology, chapter 7
- [Flooring for low cost rural housing](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aflooring-low-cost) — Building Technology, chapter 7