Ever wondered about the unsung heroes of fire safety in your facilities? You may not think about it often, but fire doors are the difference between an accident and a tragedy. Today, we’ll be diving deep into the exciting world of fire-rated doors, what their ratings mean, why they’re important and some other helpful fire safety tips. From pedestrian doors to overhead variants and even counter gates, we’ve got you covered!

Fire Doors 101: What Makes a Door “Fire-Rated”?

These doors truly are superheroes in disguise. They are specifically designed and manufactured to resist the heat and stop the spread of fire for a designated period. In order for a door to be “fire-rated” it must go through a series of tests and then be certified by the manufacturer.

Fire endurance- The doors face intense heat reaching up to 1925 degrees F for a potential maximum rating of 180 minutes. If the door stays securely in its frame without any gaps and successfully contains the flames, it earns a certification of 20, 45, 60, 90, or 180 minutes.

Hose stream- Following the fire endurance test, the door faces the hose stream test, in which it’s blasted with water at 30 psi from a distance of 20 feet. It’s worth mentioning that most US building codes usually exempt 20-minute doors from this hose stream test.

Temperature rise- In specific scenarios, these doors don’t just act as barriers to fire but also prevent excessive heat transfer to safeguard building occupants during evacuations. These specialized doors, termed “temperature rise doors,” possess both an hourly rating and a temperature rise rating. The temperature rise ratings can be 250 degrees F, 450 degrees F, or 650 degrees F. This rating illustrates the maximum temperature increase, beyond the ambient, on the non-fire side during the initial 30 minutes of a standard fire test. Notably, a 250-degree F rating is seen as the most rigorous, thus fulfilling specifications even if they call for 450 or 650 degrees F.

Smoke and draft control- Certain doors, like 20-minute doors in corridors with fire resistance ratings or smoke barriers, might also undergo smoke infiltration tests as per UL 1784, the Standard for Air Leakage Tests of Door Assemblies and Other Protective Openings.

How do they withstand all of those tests? The materials they’re made of, including:

  • A core of fire-resistant material (like vermiculite, gypsum, or ceramic).
  • A layer that prevents heat transfer.
  • Seals that expand with heat, blocking the gaps around the door.
Fire Door

Decoding Fire Door Ratings

When you come across doors with ratings like 20, 45, 60, 90, or even 180, you’re essentially peeking into how many minutes that door can withstand a standard fire exposure. A ’90’ rating means the door offers resistance for up to 90 minutes. So, the higher the number, the longer your safety net! Keep in mind that the door fire rating must match the frame rating, if it doesn’t the rating is actually the lower of the two. Here’s a guide to better understand which doors should be used where:

Fire Rated Hollow Metal Door Pair Fire Labels
Description and Use Wall Rating Door and Frame Rating
Openings that separate buildings or divide a single building into designated fire areas 4 hours 180 minutes
Openings used in enclosures of vertical communication or egress through buildings (ex. stairwells) 2 hours 90 minutes
Door and frame assemblies that divide occupancies in a building 1 hour 60 minutes
Openings in corridors or room partitions 1 hour 45 minutes
Opening where there is potential for severe fire exposure from the exterior of the building 2 hours 90 minutes
Opening that has the potential for moderate to light fire exposure from the exterior of the building 1 hour 45 minutes
Opening in corridors where smoke and draft control is required 1 hour 20 minutes

Different Types of Fire Doors & Their Importance

At United Door and Dock we know how important safety is for a business, especially when it comes to something as potentially devastating as fire. The National Fire Protection Association (NFPA) mandates annual inspections and drop tests on all doors. To help keep the building you work in and the people in it safe, we offer preventative maintenance programs that include inspections as frequently as you need them! We also service and install all fire-rated doors, including:

These are the doors we typically see and use every day in our offices, plants, and buildings. When they’re fire-rated, they act as a secure barrier, giving people ample time to escape in emergencies.

Often used in large commercial or industrial settings, these doors are crucial for compartmentalizing fires. They’re designed to close automatically in the event of a fire, helping prevent its spread from one section of a facility to another.

Found in settings like commercial kitchens or service counters, these smaller doors protect openings from potential fire spread. They are compact yet robust barriers, keeping both staff and patrons safe.

Fire Overhead

The Critical Need for Fire Doors in Your Facility

In the United States, fire-rated doors are a requirement in commercial buildings by The National Fire Protection Association (NFPA), International Fire Code (IFC) and The International Building Code (IBC). Non-compliance can result in hefty fines and legal challenges. If that’s not enough, here are a couple of other important reasons you should have them:

Safety First: The primary benefit of these doors is the precious time they provide for evacuation. In a fire, every second counts, and these doors can be the difference between a safe escape and a tragic outcome.

Property Preservation: By containing a fire, these doors can save vast portions of a property from damage, saving businesses potentially millions in repair and replacement costs.

Additional Steps to Boost Your Facility’s Fire Safety

  • Smoke Alarms & Sprinkler Systems: They’re the first line of defense, providing early warnings and immediate response to fires.

  • Fire Extinguishers: While this seems like an obvious tip, fire extinguishers need to be in their designated locations and visible. Also note, extinguishers should be inspected annually for defects.

  • Routine Inspections: Regularly inspecting electrical systems, machinery, and fire exits ensures they’re always ready to serve in emergencies.

  • Training Sessions: Equip your staff with knowledge! Regular fire safety drills and educational sessions can be lifesavers.

  • Clear Signage: Ensure that all fire safety equipment and exits are clearly marked. In a crisis, clear signs can guide the way.

Closing Thoughts

Fire safety is one of those things we often take for granted until we’re faced with a real emergency. By understanding and investing in fire-rated doors, you’re not only ensuring compliance with regulations but also showing genuine care for the safety of everyone in your facility. While we hope this blog is a helpful guide, for more detailed information, always refer to local building codes and professional guidance when installing or maintaining fire doors. United Door and Dock is happy to assist in any questions you may have on how to keep your building safe in the event of a fire. Give us a call, email or check out the live chat to talk to one of our industry specialists.

Remember, when it comes to safety, it’s always better to be proactive than reactive. Here’s to creating safer spaces, one fire door at a time!


It’s recommended that they are inspected at least annually to ensure they function correctly and maintain their fire-resisting properties.

While painting is acceptable, it’s crucial not to alter the door, such as drilling unnecessary holes, which can compromise its fire-resistant properties. Always use compatible paint and ensure that any intumescent seals are not painted over.

Ideally, yes. They should be kept closed to prevent the spread of fire. However, if they’re held open for accessibility or ventilation, they should be fitted with a device that automatically closes them in the event of a fire alarm.

Fire exit doors are specifically designed for egress during emergencies and are usually found on building exteriors. Fire-rated doors are internal doors designed to resist the spread of fire within a building.


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