Suspended ceiling is a type of finishing system that is suspended below the ceiling structure within a room or building. It can be hung from the ceiling or roof deck, which consists of structural load-bearing framing beams above and below the roof. Most suspended ceiling systems consist of steel bars and acoustic tiles, although other materials can be used as well. Metal suspension wires are used to suspend these systems anywhere from three inches to more than one foot (7.6 cm to 30.5 cm) below the surface.
These ceilings can be installed over existing drywall, exposed wood frames , steel joists, or even tiled ceiling finishes. In a typical suspended ceiling system, the tiles are supported by thin metal frames that run in a grid pattern across the room. Wall trim is attached to the wall around the entire perimeter of the room. The rest of the grille is suspended by suspension wires, although the ends of each grille section are attached to the edge of the wall for additional support.
The grid can be laid out in a 2″ x 4″ (122cm x 61cm) or 2″ x 2″ (61cm x 61cm) pattern depending on standard acoustic tile sizes. Recessed fluorescent lights are often used with these ceilings and are designed to fit into regular grid patterns. Heating and air conditioning grilles can be sold in standard tile sizes so they can also be fitted into a suspended ceiling grill.
Suspended ceiling offers many advantages over other types of ceiling structures. Since it is suspended below the surface, the interstitial space can act as an air chamber for ventilation. This space can also be used to hide pipes, ducts, and electrical wires. Because the tiles can be removed easily, the above-the-roof mechanical and electrical equipment can still be accessed for maintenance and servicing. Grid suspended systems are also relatively affordable and can be installed quickly and easily.
There are also a number of potential drawbacks that should be considered when choosing a suspended ceiling. Acoustic tiles tend to yellow over time and can make a room look old. They must be replaced regularly and are subject to staining and damage due to moisture or shock. Finally, since they are hung below the ceiling surface, they reduce the overall ceiling height inside the room. This is often considered unattractive, especially in rooms with already relatively low ceilings.