As hospitals perform annual fire door inspections, they find that excessive gaps top the list of common deficiencies. Bringing excessive gaps into compliance can be challenging, as many factors such as frame installation, temperature and humidity may influence the behavior of a fire door. The challenge is compounded because there are limited products available to reduce gaps, in part because any product installed on a fire door to reduce gaps must be appropriately listed. 

To learn the technical basis behind fire door gap requirements in the National Fire Protection Association’s NFPA 80, Standard for Fire Doors and Other Opening Protectives, the American Society for Health Care Engineering (ASHE) helped sponsor a study on the “Influence of Gap Sizes Around Swinging Doors with Builders Hardware on Fire and Smoke Development,” by the Fire Protection Research Foundation. 

The first part of the study, conducted in 2018, consisted of a literature review of past editions of NFPA 80 to determine when allowable gap sizes were introduced. Computer modeling also was conducted to determine the influence of gap sizes on fire doors.

The literature review found that door gap requirements have been in NFPA 80 for many years. The dimension requirements remained unchanged until the 1990 edition, when a 1/16-inch over tolerance was established for steel doors. One of the important conclusions from the report is “technical committee records do not seem to show any supporting technical/scientific justification for the NFPA 80 clearance dimensions.”

The results of the modeling indicate that more extensive, full-scale testing should be conducted to accurately determine how gap sizes influence the behavior of fire doors during a fire. The experimental fire door tests were scheduled for the week of April 6, 2020, but were postponed due to the COVID-19 pandemic. The tests are tentatively rescheduled for this summer. Once testing is conducted, ASHE will evaluate the results and consider submitting proposals to revise gap size requirements in future editions of NFPA 80.

Access the NFPA study to learn more.