John A. Kennedy & Associates

Fire and Explosion Investigation Experts

Depth of Calcination Measurement In Fire Origin Analysis

P. Kennedy, K. Kennedy & R. Hopkins, 2003

Fire Patterns, Fire Investigation, Fire Science, Calcination, Fire Investigation Techniques

This is a report on a research project into the practical use of measurements of depth of calcination of room-fire exposed gypsum wallboard, under actual fire scene investigation conditions, to discover and illustrate movement and intensity fire patterns for fire origin determination. The work builds on the previously published research of Posey and Posey, 1983; McGraw and Mowrer, 1999; Mowrer, 2000; and Schroeder and Williamson, 2000 and the procedures outlined in NFPA 921.

ABSTRACT

This is a report on a research project into the practical use of measurements of depth of calcination of roomfire exposed gypsum wallboard, under actual fire scene investigation conditions, to discover and illustrate movement and intensity fire patterns for fire origin determination. The work builds on the previously published research of Posey and Posey, 1983; McGraw and Mowrer, 1999; Mowrer, 2000; and Schroeder and Williamson, 2000 and the procedures outlined in NFPA National Fire Codes component document NFPA 921-2001, Guide for Fire and Explosion Investigations, sections 4.12 through 4.12.4.

This research project was performed in conjunction with the 2002 National Advanced Fire, Explosion, and Arson Investigation Training Program cosponsored by the National Association of Fire Investigators (NAFI), the Eastern Kentucky University Fire and Safety Engineering Technology Program (EKU), and the National Fire Protection Association (NFPA).

The research was designed to illustrate and, if appropriate, support the system for measuring depth of calcination on fire exposed vertical gypsum wallboard and used in fire patterns analysis as recommended in NFPA 921.

The tests and data collection were conducted in March 2002 on full-scale room fire evolutions, using ten fire investigators of widely varying experience, from novices to full time professionals, to make and record depth of calcination measurements with no previous knowledge of the actual origins of the test fires.

Additional supplemental laboratory bench testing was conducted as background research into the loss of density of gypsum wallboard from heat exposure at the Forensic Fire Science and Technology Laboratories of John A. Kennedy and Associates.

Research test results were good, providing accurate and reproducible fire movement analysis and supporting the calcination measurement techniques, systems, and tools advocated by NFPA 921. Collected data was comparable among participants with widely varied fire investigation experience and after only minimal instruction and practice in the calcination depth measurement techniques and tools.

Read Full Paper (PDF)

Scroll to top