Performance criteria for the fire safe use of thermal insulation in buildings

Abstract

Building design can be considered as a multi-objective optimisation problem, in which many criteria are considered for determining the most favourable solution. The application of optimisation techniques requires the design criteria to be quantifiable, which sets the baseline for the application of performance-based designs. Sustainability has become the main driver in the built environment during recent decades, with energy efficiency becoming the foremost design criteria and appropriately quantified. By contrast, the approach taken for fire safety is much simplistic, relying on a series of prescriptions based on material classification and “pass–fail” criteria defined in standard fire tests. This results in deficiencies in identification of fire hazards and undermines any attempt at design optimisation. A redefinition of the failure criteria framework based on fundamental understanding of the material behaviour, including the heat transfer controlled processes governing the onset of pyrolysis, can provide a performance-based methodology for the fire safe use of insulation materials in buildings. The different hazards from insulation materials in fire are identified and a set of criteria are defined to identify likely failure modes. A series of highly instrumented large-scale experiments of a construction system involving a common combustible material are referenced to demonstrate the proposed methodology.