What is a dropped ceiling?
A dropped ceiling is a ceiling that hangs below the structural soffit, meaning below the underside of the floor or the old ceiling above it. It is also called a false ceiling. In Dutch it is called a verlaagd plafond. The space between the dropped ceiling and the structural soffit is called the plenum. You can use it for pipes, ducts, spotlights and insulation.
Types of dropped ceiling
- Plasterboard ceiling: plasterboard on timber battens or metal profiles, then plastered or painted. Smooth and permanent, but to reach the services you have to cut a hole or plan access hatches in advance.
- Suspended ceiling system: loose ceiling tiles in a grid of profiles, hung from ceiling hangers. Every tile can be lifted, so the services stay accessible. Widely used in offices.
- Chilled or heated ceiling: a ceiling with pipes or panels used for cooling or heating.
- Stretch ceiling: a tensioned fabric or film.
- Boarded ceiling: timber or plastic boards on battens, widely used in the past.
Why lower a ceiling?
- To conceal pipes, ventilation ducts or an old, damaged ceiling.
- To fit recessed spotlights.
- To improve acoustics with sound-absorbing panels.
- To make a room that is too tall look lower and cosier.
Step-by-step plan for a plasterboard ceiling
- Decide on the height and mark it all round with a laser or spirit level.
- Fix perimeter profiles or perimeter battens to the walls.
- Hang the main profiles or battens from the structural soffit with adjustable hangers. Keep to the centre spacing specified by the board manufacturer.
- Install pipes and any insulation before closing up, and plan access hatches at taps, valves and junction boxes.
- Screw the boards at right angles to the profiles, with staggered joints.
- Finish the joints with joint tape and filler.
Points of attention
- Clear height: in the Netherlands, a habitable room in new build must be at least 2.6 m high; for alterations and existing buildings a lower limit of 2.1 m applies. If you are lowering a ceiling, check what remains. Dutch rules also set clear height requirements in a corridor (circulation route).
- Fire safety: if a fire-resisting or smoke-resisting wall does not continue up to the structural soffit, the separation leaks through the plenum. Continue the separation up to the structural floor.
- Moisture: in a bathroom, choose moisture-resistant boards and make sure the extract fan does not discharge into the plenum.
- Spotlights: some recessed spotlights get hot. Keep to the distance from insulation stated by the manufacturer.
Related terms
- Suspended ceiling system
- Plenum
- Ceiling hanger
- Plasterboard, gypsum board, gypsum fibreboard
- Raised access floor
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