The Fire Protection Research Foundation (FPRF), the research affiliate of the National Fire Protection Association (NFPA) has set out to determine the impact of door gap sizes on preventing the spread of fire and smoke.

This summer, the Research Foundation worked with a Burnaby, British Columbia-based lab to conduct 20-minute- and 90-minute-rated single-swing and double-egress fire door tests in a controlled environment. The tests were performed to measure baseline results of fire-rated doors with the exact measurements allowed by NFPA 80, Standard for Fire Doors and Other Opening Protectives: three-quarters of an inch for the bottom gap and one-eighth of an inch for the vertical and top edges.

Although NFPA 80 has existed for more than 50 years, the parameters set within the standard have come into question in recent years, prompting organizations such as the American Society for Health Care Engineering (ASHE), which is a principal sponsor of the research, to advocate for a standard thoroughly backed by scientific evidence.

Doors in high-traffic hospitals are constantly in use and can suffer damage from contact with medical equipment and patient gurneys. Also, as buildings shift and settle, floors tend to sag over time causing gaps that sometimes only reach an additional one-sixteenth of an inch. This factor has made door gaps an easy target during compliance surveys and one of the most frequently cited deficiencies. For health care facilities, the issue is compounded when faced with hundreds and sometimes thousands of doors in the largest hospitals.

The baseline test sets the control to allow comparison of fire-rated doors with larger gap sizes for bottom gaps. The Research Foundation has moved to conducting these comparison tests and plans to publish its results at a future date, however a project summary of this ongoing research is available now.

Other sponsors of the research include: Builders Hardware Manufacturers Association, Hollow Metal Manufacturers Association, Steel Door Institute and the Window & Door Manufacturers Association.