Understanding Fire Door Ratings: 60-Minute vs 120-Minute Explained

What Does a Fire Door Rating Actually Mean?

When you see a fire door labelled "60-minute" or "120-minute," that number refers to the duration for which the door assembly — door leaf, frame, hardware, and seals — can withstand fire and hot gases under standardised test conditions without allowing flames or smoke to pass through to the other side.

In India, fire door performance is governed by IS 3614 (Part I & II), which aligns with international standards like BS 476 Part 22. The test subjects the door to a furnace that follows a time-temperature curve, rising from ambient to approximately 945 °C over 60 minutes and to 1049 °C at 120 minutes.

60-Minute Fire Doors (FD60)

A 60-minute rated fire door provides one full hour of passive fire resistance. This is the minimum requirement specified by the National Building Code of India 2016 (Part IV) for most internal compartmentation doors in commercial and residential buildings up to a certain height. FD60 doors are suitable for:

• Stairwell enclosures in buildings up to G+7
• Corridors separating tenant units in offices and retail
• Plant rooms, electrical rooms, and UPS rooms
• Hotel room exit doors opening onto escape corridors

120-Minute Fire Doors (FD120)

A 120-minute rated door offers twice the protection and is mandatory in high-risk or high-rise scenarios. The NBC 2016 and local fire NOC requirements for buildings above 15 metres typically mandate FD120 for:

• Basement car park entrances connecting to main building
• Lift lobby enclosures in high-rise residential and commercial towers
• Fire escape stairwell doors in buildings above 24 metres
• Transformer rooms, generator rooms, and fuel storage areas
• Between occupancies of significantly different fire load density

IFES Product Range

Indian Fire Equipment Systems manufactures both FD60 and FD120 steel fire doors under ISI certification (IS 3614), tested at CBRI Roorkee. Our doors are supplied with intumescent seals, cold smoke seals, CE/ISI-marked hinges, and panic hardware as required. We offer single-leaf, double-leaf, and vision panel variants to suit architectural requirements without compromising fire rating.

Contact our technical team for a site-specific door schedule and specification assistance for your project.