Acoustic Lab Testing (ASTM E492-2016, ASTM E90-2016) of Multi-Family Residential CLT and MPP Wall and Floor Assemblies
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Date
2019-03
Authors
Van Den Wymelenberg, Kevin
Northcutt, Dale
Fretz, Mark
Stenson, Jason
Zagorec-Mark, Ethan
Journal Title
Journal ISSN
Volume Title
Publisher
Institute for Health in the Built Environment, University of Oregon
Abstract
The use of mass timber panels is becoming a popular choice for construction due to concerns about climate change, resource sustainability, the need for construction efficiencies and the human biophilic affinity for wood. Developed about three decades ago in Austria, panelized mass timber products have been used in Europe for some time but are now gaining market traction across North America and represent an opportunity for designers, developers, engineers and contractors. With this new design opportunity in North America comes jurisdictional code performance requirements that need to be demonstrated to building authorities in the United States. Among these are requirements for fire, seismic and acoustic testing. Acoustics standards in the United States are prescribed by various organizations, such as the International Code Council (ICC), Housing and Urban Development (HUD), American Nation Standards Institute (ANSI), American Society for Testing and Materials (ASTM) and Facility Guidelines Institute (FGI) and are codified by jurisdiction based on building typology. In addition to code requirements, the economics of occupant satisfaction and well-being play a role in project development. Economic studies have shown that consumers value spaces with higher acoustic quality and display a willingness to pay for the relief from unwanted noise.1 Furthermore, noise intrusion in places where people spend a majority of their time has been shown in a body of literature to effect cognitive function, disrupt sleep patterns, promote irritability, and provoke heart conditions.2 Therefore, in order for a housing project to perform, it must not only meet code requirements but also market expectations for high quality, acoustically separated living spaces.
The acoustic performance of mass timber panels is measured by two metrics: STC (sound transmission class) and IIC (impact insulation class). STC, for example, is how well a wall assembly acoustically separates two spatial volumes. IIC is a measurement of how well a floor dampens the sound transmission of an impact between two adjacent spatial volumes, be that a dropped object or footstep. For multifamily housing, the International Code Council (ICC) prescribes a wall and floor assembly performance standard to meet or exceed a STC rating of 50 in a lab test (ASTM E 90 )or 45 in field tests (ASTM E 336) and IIC rating of 50 in a lab test (ASTM E 492) or 45 in field tests (ASTM E 1007).3 Using industry standards such as ICC, HUD, ANSI, FGI as a starting point for designing a series of floor and wall assemblies we hope to find high performing cost-effective acoustic solutions for mass timber assemblies that can be readily adopted by design teams and jurisdictional authorities . In addition, this study aims to provide more third-party verified data on CLT + MPP acoustic performance and disseminate it into the public sphere.
Description
215 pages
Keywords
Multi-Family Residential Housing, Acoustic testing, timber, sound transmission class, impact insulation class