BRE IP2/17 PDF

Introduction

Flashover is a key and dramatic event that may occur during an enclosure or room fire. It marks the sudden transition from a localised fire to the ignition of all exposed flammable surfaces within the enclosure, creating conditions where life is no longer tenable. Analysis of fires in enclosures usually considers preflashover and post-flashover fire conditions separately, adopting different empirical and theoretical methods for each case.

The time to flashover is an important factor when determining the relative hazards that may occur during the development of a fire and how those hazards impact on escaping occupants, firefighting tactics and the structure of a building.