Deflection criteria for controlling timber floor vibrations: A 200-year evolution

Timber floor vibrations have long been a significant challenge in design and research, growing in importance with advancements in engineered wood products and the increasing use of mass timber panels. Since the publication of Thomas Tredgold's Elementary Principles of Carpentry in 1820, deflection limits have been essential in controlling excessive vibrations in timber floors, a practice that has evolved over 200 years. Despite updates to align with modern construction and timber engineering innovations, these criteria are often deemed insufficient for mass timber floor systems, underscoring the need for more rational analyses. This review examines the evolution of deflection criteria for timber floor vibrations and identify critical technical aspects for future design criteria, especially for mass timber floors. It highlights two distinct paradigms for floor vibrations: acceptability-based and perception-based. The deflection criteria, derived from acceptability-based studies, integrate three key factors: vibration source, transmission path, and occupant response (receiver), offering a practical and effective solution for controlling timber floor vibrations, despite being essentially empirical. In the future, a reliability-based approach is urgently needed to handle the significant uncertainties involved. Additionally, the human side of floor vibration serviceability equation has been least studied, emphasising the importance of recognising the variability and subjectivity of human responses. • This review traces the 200-year evolution of deflection criteria for controlling timber floor vibrations. • Advancements and shifts in deflection criteria are highlighted, providing insights into their effectiveness and limitations. • A detailed comparison of acceptability-based and perception-based paradigms was conducted. • Two problem-solving strategies for floor vibration were summarised.