Building codes stipulate minimum performance requirements regarding noise transmission through common interior walls and floor/ceiling assemblies that separate a dwelling unit from either a public area or an adjacent dwelling unit. In the 2018 International Building Code (IBC), two parameters are used to establish these minimum acoustical requirements: Sound Transmission Class (STC) and Impact Insulation Class (IIC). Compliance with these requirements may be demonstrated either through testing or through engineering analysis based on empirical test data from other similar assemblies. This presentation provides an overview of the new American Wood Council (AWC) empirical model which may be used for analysis of wood-frame floor/ceiling assemblies to estimate the code-regulated sound transmission parameters. A report titled Technical Report 15 – Calculation of Sound Transmission Parameters for Wood-Framed Assemblies, available at awc.org, provides the basis for the calculation-based analysis approach.

Learning Objectives:

1. Recognize the basic physics of sound transmission through and around floor/ceiling or wall assemblies in a building, and how this is perceived by occupants within the building.
2. Summarize the code provisions relating to sound transmission, and how compliance with these code provisions may be demonstrated.
3. Describe the scope of the AWC empirical sound transmission model, how it was developed, how it works, and how it was validated.
4. Evaluate how the model can be used to estimate sound transmission parameters in order to demonstrate code compliance and understand the scope and limitations of the model.

Funding provided in part by the Softwood Lumber Board.