Ceiling Attenuation Class
- This is a rating value for the efficiency of the ceiling as a barrier to airborne sound transmission between adjacent rooms when the dividing wall doesn't connect with the structural ceiling.
- 35 is a typical CAC for offices.
- A ceiling system with a CAC < 25 is consider low performance, whereas one with CAC > 35 is high performance.
ASTM E1007 Field Measurement of Tapping Machine Impact Sound Transmission through Floor-Ceiling Assemblies and Associated Support Structures
ASTM E1111 Measuring the Interzone Attenuation of Ceiling Systems
ASTM E1414 Airborne Sound Attenuation Between Rooms Sharing a Common Ceiling Plenum
ISO 140, Part 9 Laboratory Measurement of Room-to-Room Airborne Sound Insulation of a Suspended Ceiling with a Plenum Above
Subjects: Noise & Vibration