---
title: "Suspended ceiling: types, fixing, construction"
subject: "Building Technology"
chapter: 9
key: "semester_6/building_technology:suspended-ceiling-fixing"
source: https://www.bctengineer.com/q/semester_6/building_technology/suspended-ceiling-fixing
site: BCT Engineering
---

# Suspended ceiling: types, fixing, construction

Building Technology · Chapter 9: Finishing works

- Asked in: 2081 Chaitra, 3 marks; 2072 Asoj, 4 marks; 2067 Asar (old course), 8 marks; 2066 Jestha (old course), 2.5 marks; 2065 Shrawan (old course), 4 marks; 2062 Poush (old course) (asked 6 times)
- Video: [How to Install a Drop Ceiling | Armstrong Ceilings for the Home](https://www.youtube.com/watch?v=6gSPccj2bbo) — Armstrong Ceilings for the Home
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/suspended-ceiling-fixing
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-9

## Question

Explain the types, functions and fixing (method of construction) of suspended (false) ceiling.

## Short answer

A suspended ceiling is hung below the structural slab via hangers and a grid of main and cross runners, holding gypsum, mineral wool, metal or timber panels. It conceals services, lowers ceiling height, improves acoustics and insulation, and provides fire resistance. Fixing: mark level, fix wall angle, suspend rods, level main and cross runners, lay panels and finish.

## Answer

A **suspended (false) ceiling** is a secondary ceiling hung below the main structural slab or roof by hangers, leaving a space between them.

#### Types
- **Gypsum board** (plasterboard) on a metal frame, with joints taped and painted.
- **Mineral fibre / acoustic tile** in a lay-in grid.
- **Metal panels** (aluminium, galvanised steel) such as strip, tile or grid.
- **Timber and plywood** panels.
- **PVC and fibre cement** boards for low cost.
- **Glass or plastic** panels for decoration.

#### Functions
- Hides services (ducts, pipes, wiring, AC).
- Lowers ceiling height for thermal, acoustic or lighting effect.
- Acoustic control and thermal insulation.
- Fire resistance and improved appearance.
- Allows easy access to services.

#### Fixing (construction)
1. **Marking:** the ceiling level is marked around the wall using a laser or water level.
2. **Perimeter channel:** wall angle (L-channel) is fixed to the wall at the marked level with screws.
3. **Hangers:** GI wire rods or threaded rods (about 6 mm) are fixed to the slab with anchor fasteners at 1.0-1.2 m spacing.
4. **Main runners (T-grid):** main channels are hung at 1.2 m c/c and levelled.
5. **Cross runners:** secondary runners are clipped between the main runners at 600 mm (or 400 mm) c/c.
6. **Boards or tiles:** panels are laid in the grid or screwed to channels; for gypsum boards, joints are taped, filled and painted.
7. **Finishing:** painting, fitting light fixtures, diffusers, and cleaning.

```text
   RCC slab ==========================
        |hanger        |hanger
        |              |
   -----+-main runner---+--------
        cross runner  |
   [tile][tile][tile][tile]
   wall angle at perimeter
```

## Check yourself

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

1. What is a suspended (false) ceiling?
   A. A secondary ceiling hung below the structural slab by hangers leaving a space
   B. A plaster coat on the slab
   C. A ceiling cast monolithic with the slab
   D. A timber floor
   Answer: A. It is hung below the main slab or roof, leaving a services space. (Key point: Definition)

2. Which is the correct start of the fixing sequence?
   A. Paint first, then fix runners
   B. Mark ceiling level, fix perimeter wall angle, then fix hangers to slab
   C. Hang main runners, then fix hangers
   D. Lay boards, then mark level
   Answer: B. Marking and wall angle come first, then hangers, main runners, cross runners and panels. (Key point: Fixing order)

3. What are the usual spacings of main and cross runners?
   A. Both 3 m
   B. Main 300 mm, cross 1.2 m
   C. Main runners 1.2 m c/c, cross runners 600 mm (or 400 mm) c/c
   D. Main 600 mm, cross 6 m
   Answer: C. Main channels hang at 1.2 m c/c, with secondary runners clipped between them at 600 mm or 400 mm. (Key point: Runner spacing)

4. Which function is NOT correct for a false ceiling?
   A. Acoustic control
   B. Allows easy access to services
   C. Hides services
   D. Carries the loads of upper floors
   Answer: D. A false ceiling is non-structural; it conceals services and improves acoustics and appearance, not carry floor loads. (Key point: Functions)

## Related in Building Technology

- [Purpose of suspended ceiling](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Asuspended-ceiling-purpose) — Building Technology, chapter 9, asked 2×
- [Suspended ground floor; tile flooring](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Asuspended-ground-floor-tile) — Building Technology, chapter 7

## Related in other subjects

- [True/false: auxiliary winding construction](https://www.bctengineer.com/question.md?key=semester_4%2Felectrical_machine%3Atf-auxiliary-winding-differs) — Electrical Machine, chapter 7
- [Equipment for concrete construction and functions](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Aconcrete-equipment-functions) — Construction Management, chapter 4