Suspended ceiling: types, fixing, construction

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.

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