Acoustic suspended ceiling

A second ceiling hung from the structural one on droppers, creating a service plenum above it and, below, a continuous or panelled surface. It absorbs noise, hides and gives access to the services, integrates lighting and diffusers, and can give the floor fire resistance. It is the element that «finishes» and equips rooms, from offices to public spaces.

The suspended ceiling is a secondary hung ceiling, fixed to the floor on adjustable droppers that carry a metal grid; to this are fixed panels (mineral fibre, metal, wood) or continuous boards (plasterboard). Between the two ceilings a plenum remains, the service space where pipes, ducts and cables run. It is an entirely dry system.

Unlike a wall, the ceiling works mainly by absorption: sound-absorbing panels (mineral fibre, wool, perforated metal with felt) capture the sound energy that strikes them, cutting the reverberation and background noise of the room. It is the key to acoustic comfort in offices, schools, restaurants and public spaces, where the problem is not (only) to insulate but to make speech intelligible.

The space above the ceiling houses lighting, ventilation, sprinklers, cables and ducts, keeping them hidden but reachable: modular panels lift out for maintenance, continuous boards have access hatches. The plenum sets the clear height and must be sized with the services; at the walls the ceiling can stop or continue over, according to the acoustic and fire needs.

The ceiling can contribute to the floor's fire resistance (a protective membrane) or, conversely, form a hidden path for smoke and flames in the plenum: so, where needed, it is compartmented and certified panels and grids are used. Droppers, grid and edges must be fixed to resist suction too and, in seismic areas, the horizontal actions.