One type of suspended ceiling is made up of Acoustic Ceiling Tiles (ACT) and a stick-built grid system. Sometimes called a lay-in ceiling, this type of system is versatile, durable, and cost effective. In addition, the ceiling tiles can be removed without damage to the system so that above ceiling items can be maintained. Seen throughout many commercial and institutional buildings, ACT is a popular ceiling material that now has a wide variety of aesthetic options.

Suspended Acoustic Ceiling Components

The diagram below identifies the major components of a suspended lay-in ceiling. The continuous main beam T shapes are suspended from the structure above by hanger wires. Shorter cross T segments connect to the main beam T shapes to make a rigid frame. Edge molding shapes are attached to the walls around the perimeter of the room. Finally, ceiling tiles are dropped into the grid to finish the ceiling.

Components of a Suspended Acoustic Lay-In Ceiling
Components of a Suspended Acoustic Lay-In Ceiling

Ceiling Grid T Shapes

The most commonly used T shapes are 15/16" wide; however, 9/16" wide T shapes are becoming more common. Suspended ceiling manufacturers also make a variety of shapes that offer aesthetic options to the designer. A stepped T shape is often used with tegular tiles to provide a ceiling with more depth. A reveal T shape provides a notch along the length of the grid that makes the T shapes recede more than a typical T shape.

Standard Ceiling Grid T Shapes   Stepped Ceiling Grid T Shape   Reveal Ceiling Grid T Shape

There are two common edge moldings used to terminate a ceiling grid at a wall. The standard shape is the Angle Molding. Also available is a Shadow Molding, which creates a shadow line along the edge of the room. Manufacturers also provide their own series of edge molding shapes.

Angle Edge Molding   Shadow Edge Molding

Ceiling Tile Materials and Design

Ceiling tiles come in an infinite variety of textures and designs. Most ceiling tiles are made from mineral fiber, but other materials are available, such as fiberglass. Mineral fiber tiles typically have a high Noise Reduction Coefficient (NRC), which means they are good at absorbing sound within a space to prevent echo or loud environments. While some tiles have a high Ceiling Attenuation Class (CAC), meaning they prevent sound from passing through the ceiling to another space, acoustic ceiling tiles are generally not used to provide privacy between spaces.

In addition to tile material, there are a wide variety of designs available. Tiles may have a rough appearance or a smooth appearance. Tiles may also have designs imprinted in them or other patterns scored into the tile. There are a few edge options that are typical, as shown below.

Square Edge Ceiling Tile   Tegular Edge Ceiling Tile   Beveled Tegular Edge Ceiling Tile   Concealed T or Shiplap Edge Ceiling Tile

Ceiling Tile Sizes

Ceiling tiles come in a wide variety of shapes and sizes. In addition to the standard tiles, custom tiles are available from most manufacturers. Ceiling tiles can be made in virtually any shape. Standard sizes are listed below in inches.

12" x 12" 12" x 24" 24" x 24"
24" x 24" 24" x 48" 24" x 60"
24" x 72" 30" x 30" 20" x 60"
30" x 60" 60" x 60" 48" x 48"

Seismic Considerations

For suspended ceilings in seismic zones, special considerations must be made. Some of these considerations include wider edge moldings, limits on size of ceiling or weight of ceiling, additional attachment requirements, additional bracing requirements, and additional inspection requirements.

Refer to to the codes of your jurisdiction for more detailed information.

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