grid ceiling

A dropped ceiling is a secondary ceiling, hung below the main (structural) ceiling. It may also be referred to as a drop ceiling, T-bar ceiling, false ceiling, suspended ceiling, grid ceiling, drop in ceiling, drop out ceiling, or ceiling tiles and is a staple of modern construction and architecture in both residential and commercial applications.

A typical dropped ceiling consists of a grid-work of metal channels in the shape of an upside-down "T", suspended on wires from the overhead structure. These channels snap together in a regularly spaced pattern of cells. Each cell is then filled with lightweight ceiling tiles or "panels" which simply drop into the grid. The primary grid types are "Standard 1" (15/16 face), Slimline (9/16" grid), and concealed grid.

In the United States the cell size in the suspension grids is typically either 2 ft × 2 ft or 2 ft × 4 ft and the ceiling tiles are the same size. In Europe the cell size in the suspension grids is 600×600 mm, while the ceiling tiles are slightly smaller at 595mm x 595mm or 595mm x 1195mm.