Enhancing the vibration performance of mass timber floors: Effects of non-structural components

Mass timber has gained significant attention as a sustainable construction material from developers, architects, engineers, and policymakers. Despite its advantages, mass timber floor systems are often perceived to have poor vibration performance, posing a challenge to their widespread adoption. This study presents the results of vibration tests conducted on a cross-laminated timber (CLT) residential floor during construction. The floor system features 7-ply CLT panels in a 3-span configuration, supported by cold-formed metal framing walls, with a span length of 27.75 ft (8.5 m). The findings reveal that the addition of non-structural components, including gypcrete topping and partition walls, significantly improves the floor’s dynamic performance. The installation of these components increased the resonant frequencies of the floor and added damping and generated new vibration modes. Analysis indicates that the completed partition walls act as elastic supports, effectively reducing the "dynamic" span length of the CLT panels, thereby increasing their natural frequency and minimizing vibrations. Furthermore, the added mass of the gypcrete topping contributed to additional vibration reductions. These findings provide valuable insights for optimizing CLT floor systems to address vibration concerns in vibration sensitive applications.