The minimum burn time for a fire door is typically 20 minutes. Fire doors are designed and tested for specific fire resistance durations, and 20 minutes is one of the common fire ratings for fire doors. Fire door ratings can vary, with 20, 30, 60, 90, and 120 minutes being some of the most common durations. These ratings indicate the amount of time the door is designed to withstand exposure to fire and heat without losing its fire resistance integrity.
A 20-minute fire-rated door (often denoted as FD20) can resist the spread of fire and smoke for 20 minutes, providing valuable time for building occupants to evacuate safely and for firefighters to respond to a fire emergency. The selection of a specific fire rating for a door depends on the building’s fire safety requirements, local building codes, and the unique needs of the building or occupancy.
