Suspended ceilings are hung from the ceiling joists with a metal grid. This creates a cavity between the joists and the ceiling where pipes, wiring, and duct work can be hidden. The cavity can also hold light fixtures, sprinkler heads, and other various electrical devices. The grid consists of a series of metal channels in the shape of an upside down T, suspended on wires from the overhead structure.
Suspended ceilings are much cheaper than carrying out extensive demolition and repair work, making them popular in many homes and offices. These ceilings are so easy to remove; therefore, renovation and redesign are much quicker. Suspended ceilings are available in wood, plastic, fiber, and other materials. Some panels also have an added degree of fire protection.