FE Analysis of Modular Woodburning Fireplace Fire with Gas Log Lighter in Determining Fire’s Cause

Determining the Correct Fire Cause

Abstract

A fire originated inside the chase1 (a vertical enclosure, usually constructed of wood, that houses and conceals a chimney) surrounding a modular fireplace system of a new residence, ultimately spreading and destroying the home. A lawsuit by the homeowner’s insurance company was later filed against the general contractor and framing subcontractor, alleging that improper clearances between the fireplace and chase framing caused the fire. The author was retained to perform a forensic engineering analysis of the origin and cause of the fire. An exemplar modular fireplace system and chase were constructed and instrumented, and more than 30 test burns were performed. Additional testing evaluated gas migration from the fireplace log lighter into flexible combustion make-up air ducting and the burning propensity of the ducting. The testing and analysis concluded that the cause of the fire was not improper clearances to the chase framing but improper installation of the combustion air kit facilitating a mediation of the case.