EXPLICIT FIRE SAFETY FOR MODERN MASS TIMBER STRUCTURES - FROM THEORY TO PRACTICE

Abstract

A holistic methodology for explicit fire safety strategies for buildings with mass timber structures has been developed based on theoretical frameworks outlined in the literature and the current state of published research on the fire behaviour and safety of mass timber structures. This paper presents the four main pillars of this methodology: tenability for occupant evacuation; heating of the mass timber structure and loss of loadbearing capacity; external flaming; and assessment of the potential for self-extinction of the mass timber structure after burnout of the movable fuel load. The application of the methodology to three case study buildings showed the need for interdisciplinary collaboration throughout the design and planning of mass timber buildings. Engineering and design decisions including structural design options, the extent of exposure of the timber, façade type and construction and general building layout influence the resultant level of fire safety to an even greater extent for buildings utilising structural mass timber elements than for buildings with non-combustible structures. All practitioners collaborating on design projects with mass timber structural elements require a contemporary understanding of the persisting limitations around timber fire safety strategies and research as anyone whose work affects or limits the fire safety measures on such a project will carry a certain ethical or legal responsibility for the outcomes and consequences of a fire.