Ceiling Attenuation Class (CAC)

Effectively Block Sound

Control sound transmission and ensure speech privacy in a variety of spaces.


What is CAC? Ceiling Attenuation Class is a measure for rating the efficiency of a ceiling system as a barrier to airborne sound transmission between adjacent closed spaces that share a common air plenum.

The higher the CAC rating, the better the performance. A ceiling system with a CAC less than 25 is very low performance, whereas a ceiling with a CAC of 35 or greater is considered high performance.

Application Considerations

CAC is important between closed spaces that need privacy, and from closed rooms to adjacent spaces, especially now as all types of interiors are being reconsidered. The ceiling plane is one of the single largest surfaces for integrating materials that can offset the noise created by additional hard surfaces or layout changes.

  • Private offices to corridors
  • Mixed plan offices
  • Healthcare offices and exam rooms to waiting areas
  • Classrooms to group learning areas

By selecting a ceiling with a high CAC value you can reduce noise traveling through the ceiling plenum – from an adjacent office, exam room or classroom, or from the floor above, no matter how your space may be configured.

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We can help select the right ceiling solution for your space.
Request speech privacy calculations for your space!

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