Mass timber aesthetics vs. acoustics

Mass timber has made a name for itself as a sustainable, aesthetically pleasing construction method valued by both designers and building occupants. With a structure comprised entirely of laminated or otherwise reinforced timber, the beauty and warmth of real wood are placed front and center within the built space in a world where steel and concrete have become the norm.

But as mass timber reaches new heights as an alternative and innovative construction method, there is still an underlying issue of acoustic control. Ironically, the aesthetic benefit of mass timber construction is its own undoing: Such wide-spanning assemblies of hard, reverberant wood create acoustic challenges unique to these types of structures, particularly around sound absorption and sound transmission.

Without a deliberate plan from the outset of a project to address these challenges in the design phase, the acoustic challenge of mass timber can impact acoustic comfort through excessive noise, leading to reduced occupant satisfaction.

Despite the challenge of balancing acoustics and aesthetics, there are solutions that can create harmony between the two within a mass timber structure, particularly concerning the floor/ceiling assembly.

Acoustics matter in mass timber

Acoustics between floors are measured by sound transmission class (STC), impact isolation class (IIC), and high-impact isolation class (HIIC) requirements. Lacking the necessary acoustical absorption, the exposed wood of mass timber transmits sound more easily, which makes it difficult to meet these code requirements in multi-family construction.

This is where you turn your focus to flooring solutions; adding mass to the floor in the form of poured concrete can improve STC, but it will have little effect on IIC. Additionally, the weight of traditional poured concrete can create structural issues, and its long curing times can delay construction schedules, costing both time and money.

Instead, opt for a poured gypsum underlayment, along with decoupling through sound mats and resilient layers. Poured gypsum cures faster than traditional concrete and enables the floor assembly to achieve high STC and IIC ratings with the incorporation of a sound mat between the gypsum and subfloor.

One way this type of installation can be achieved is through a combination of Levelrock® Brand SAM-N™ Supreme Series Sound Attenuation Mats, a premium sound mat engineered for mass timber, along with a poured gypsum Levelrock® Brand Floor Underlayment product according to the compressive strength required of the assembly. 

Suspended acoustical tile ceilings are among the most effective and are typically specified for controlling reverberation within the plenum space, but they are far from an ideal solution for mass timber. Specifying specialty ceiling products, like an acoustic baffles array, can offer both aesthetic cohesion and acoustic absorption for standout ceiling features that enhance rather than obscure the woodgrain while still managing the noise-reduction coefficient (NRC) and ceiling attenuation class (CAC) of the space.

This is where a system like Ceilings Plus Colortex Barz Direct-Mount PET Baffles can be effective. Not only are these baffles made from 100% recycled materials, they can mount flush to both walls and ceilings in a range of profiles and finishes, including woodgrain, to match the aesthetic goals of a project while offering excellent acoustic performance with an Array-NRC up to 1.00.

USG is committed to working together to find the right solution for your mass timber projects without compromising on acoustic comfort. Learn how at http://usg.com/MassTimber. 

USG has experience identifying sound solutions to help mass timber projects achieve their aesthetic and acoustic goals. In addition to the resources linked above, here are some recent projects showcasing the benefit of partnering with us for serious sound performance in mass timber:

Rhode Island School of Design North Hall

Center for Deaf and Hard of Hearing Youth

Julia West Housing

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