Laboratory measurements of lightweight floating floor systems on cross-laminated timber (CLT) slabs

Mass timber family of products (including cross-laminated timber - CLT) offer an alternative to fossil fuel-intensive materials for many applications and an opportunity to reduce the carbon footprint of the built environment. However, the use of mass timber in multi-family and commercial buildings presents unique acoustic challenges. Additionally, one of the most desired aspects of mass timber construction is the ability to leave a building's structure exposed as finish, which creates the need for asymmetric assemblies. This means that when speaking about floor/ceiling applications, preferentially any acoustical component should be installed on top of the assembly. To measure airborne sound reduction and impact noise isolation of lightweight floating floor systems and confirm CLT assemblies can provide satisfactory sound insulation, CDM Stravitec launched a testing campaign (done on Belgian Building Research Institute, institution recognized by application of the decree-law of the 30th of January 1947), where measurements were made considering several types of decouplers, such as: discrete bearings with multiple thickness and/or different void depth (filled in totally or partially with insulation material) and mats and strips placed between the CLT slab and different timber, cement and gypsum-based boards with and without use of the well-known constrained layer damping technique. This paper will present the findings of the test campaign.