Hollow-box timber floors are an efficient constructive option when long span is required. The industry has a strong interest in timber long span floors because they are a mean to make wooden constructions competitive in urban buildings and a wider range of building categories. Accurate knowledge of their acoustic properties is required to make these solutions attractive for the market and contribute to sustainable design choices. In the last years, we wrote several papers focusing on the sound insulation of hollow-box timber floors. Here, we present a consolidated summary of these papers with the aim of making the knowledge more readily available for the practitioners and the industry. We provide an overview of the parameters governing airborne and impact sound insulation in hollow-box timber floors. We present examples of how the available information can be used to adapt and optimize assemblies to meet different requirements. We discuss the constructive consequences of different choices, looking in particular at space requirements and the acoustic performance of the different solutions.