Commercial fire-rated doors slow the spread of fire and heat, allowing people to exit safely and keeping critical areas protected. These assemblies are tested in controlled fire conditions and rated for how long they can hold their structure.
Buildings use these systems to form protected paths and delay heat spread during the early minutes of a fire. Each assembly uses materials that react differently to rising temperatures, which helps the opening stay stable.
Codes such as National Fire Protection Association (NFPA) 80, NFPA 101, and the International Building Code assign fire ratings and define where these doors must be installed. These rules help protect stairwells, mechanical rooms, corridors, and shared openings between structures. The doors rely on tested components, including rated glass, treated cores, steel frames, and heat-responsive seals.
This guide explains how these doors operate within buildings, where they are required by code, and why their design and materials matter at each fire rating level. To schedule installation, inspection, or service for commercial fire-rated doors, call A 24 Hour Door National Inc. at (800) 884-4440.
What Is a Fire-Rated Door?
A fire-rated door blocks fire, smoke, and heat for a set amount of time, such as 20, 30, 60, or 90 minutes, so that people can exit and property stays protected. This type of door is tested in a fire chamber and must withstand the specified heat rating.
A fire-rated door matters in many buildings because it helps create fire barriers. These barriers divide sections of a building so fire stays in one area instead of moving through corridors or stairwells.
A fire door also supports safe evacuation. The door holds back heat long enough for people to move to protected areas. This gives emergency teams time to reach the source of the fire.
Where Fire Doors Are Required in Commercial Buildings
Fire doors are required in commercial buildings at stairwells, main corridors, openings between attached buildings, high-risk rooms, and elevator lobbies. In these buildings, fire or heat can spread between different parts.
The commercial buildings that need fire doors include:
• Stairwells: These shafts let fire rise fast, so a rated opening keeps the stairs safe for evacuation.
• Main corridors and entrances: Long hallways carry flames through large areas, so a rated door divides the space into smaller zones. Some sites use commercial fire-rated double doors here for wider passage.
• Openings between attached buildings: Shared walls or passages can spread fire from one structure to the next, so a rated barrier helps contain it.
• High-risk rooms: Electrical rooms, boiler rooms, and storage areas increase fire risk, so a rated opening helps keep early flames inside the room.
• Elevator lobbies: Smoke rises through elevator shafts, so a rated door helps slow it down from reaching upper levels.
Fire Rating Levels and What They Mean for Safety
Fire rating levels show how long a door can block flames and heat during a standard fire test. These levels include 20-, 45-, 60-, and 90-minute ratings used in commercial buildings.
Common fire rating levels include:
• 20-minute rating: Used in low-exposure areas. Slows the spread of the smoke during the first stage of a fire.
• 45-minute rating: Used in corridors and small rooms. Holds longer when the heat increases.
• 60-minute rating: Common in large commercial sites. Protects rooms with frequent use or higher occupancy.
• 90-minute rating: Used in high-priority areas such as stairwells or mechanical rooms. Holds longer when heat levels stay high.
• Exterior rated openings: Some commercial exterior door code requirements need a fire rating when local rules require a barrier between the building and nearby structures or property lines.
Code and Compliance Rules for Commercial Fire-Rated Doors
Commercial fire door compliance and codes explain how these doors must be built, installed, and maintained to withstand flames, smoke, and heat during a fire.
Here are the main code and compliance rules:
NFPA 80 fire-rated door requirements
• Clearance limits: Gaps must be 1/8 inch at the top and sides, and no more than 3/4 inch at the bottom.
• Required hardware: Only fire-rated hinges, closers, locks, and latches are allowed. No surface bolts or unlisted add-ons.
• Closing action: The door must close on its own and latch fully without manual force.
• Intumescent and smoke seals: Seals must stay in place and must not be painted over or removed.
• Field modifications: Only small changes like drilling for surface hardware are allowed. Anything larger needs listing agency approval.
• Label visibility: The fire rating label must stay readable at all times.
• Annual inspection: The assembly must be inspected once a year, and any deficiency must be repaired right away.
• Frame condition: Frames must have no holes, warping, or loose anchors.
• Glazing rules: Glass must be rated and match the door label. No substitutions.
• Self-closing device: The closer must shut the door completely every cycle.
International Building Code rules
• Rating tied to wall rating: A 1-hour wall needs a 1-hour fire door. A 2-hour wall needs a 1.5-hour fire door.
• Location-based ratings: Higher ratings are required for stairwells, shafts, and hazardous rooms.
• Glass limits: Fire protective glass may not exceed 100 square inches in 60 and 90-minute doors unless it is fire-resistant glass tested to American Society for Testing and Materials (ASTM) E119.
• Temperature rise limits: Some openings require temperature rise doors to reduce heat transfer.
• Door closers: Fire-rated doors must have closers unless specifically exempted.
• Labeling rule: Each door, frame, and glazing panel must show a permanent label from a testing agency.
Underwriters Laboratories (UL) and Intertek certification rules
• Permanent listing label: The door, frame, and glazing must show labels from UL, Intertek, or another listed agency.
• Matching assembly: All components must match the assembly tested by the lab.
• Hardware compatibility: Hinges, locks, closers, and glass must be listed to the same rating.
• No label removal: Labels cannot be painted over or covered by signage.
• Listing limits: The label defines the rating, test method, permitted glass size, and door type.
Americans with Disabilities Act (ADA) rules
• Clear width: Doors along accessible routes must provide a clear opening of at least 32 inches.
• Handle height: Operable parts must be between 34 and 48 inches above the floor.
• Opening force: Interior doors on accessible paths must open with minimal force, except where closers are required for fire rating.
• Maneuvering space: Adequate clearance must be provided on the push and pull sides of the door.
• No tight grasping or pinching: Handles must allow easy use without tight grasping or twisting.
• Local inspection rules: Many cities require annual fire door inspections. These inspections check for gaps, damaged seals, loose hinges, missing labels, or hardware that does not latch. Any problem that affects the fire rating must be repaired so the door can still block fire and smoke.
Closing and latching rules
• Automatic closing: The door must close fully without manual force.
• Latch engagement: The latch must hold the door closed under fire pressure.
• No wedges or props: If the door is blocked, it cannot protect the building from fire.
• Closing speed: The closer must not slam or stall and must shut the door at a controlled rate.
• Hold open rules: Only listed hold open devices may be used, and they must release during an alarm.
Materials Used in Fire-Rated Doors for Commercial Use
Fire-rated doors use materials such as metal panels, steel construction, wood cores, rated glass panels, intumescent seals, and fire-rated hardware.
These materials help the door resist flames, smoke, and heat during a fire test. Each material supports a different level of fire protection and must match the door’s fire rating label.
The materials used in fire-rated doors are the following:
• Metal panels
Metal panels hold up well under high heat. Many commercial doors use metal cores or metal skins because they do not bend or fail quickly in a fire. Metal helps keep the opening sealed so smoke and heat stay inside the fire area.
• Steel construction
Steel offers strong fire protection. Frames and door faces stay stable during long fire exposure. This material supports higher fire ratings used in stairwells or mechanical rooms.
• Wood cores
Wood cores are used when the door design needs a warmer look, such as in offices or hotels. These cores must be treated and tested to meet fire-rating requirements. The core is built to slow heat movement even though the material is natural.
• Rated glass panels
Commercial fire-rated doors with glass use tested panels that block flames for the rated time while allowing safe visibility. Codes and test results limit the size of the glass. This material is used when visibility is needed in corridors or doors near monitored areas.
• Intumescent seals
Seals made from heat-reacting material sit along the edge of the door or frame. When exposed to heat, these seals expand and fill small gaps. This keeps smoke from entering the next space.
• Fire-rated hardware
Hardware like closers, locks, and latches must match the door rating. It must stay attached and keep the door closed during heat exposure. These components are tested separately and labeled with their own ratings.
Key Components That Make a Fire-Rated Door Safe
The key components of a fire-rated door are the door leaf, frame, intumescent seals, rated glass, hardware, and the permanent label. They work together to block flames, smoke, and heat during a fire.
The components that keep the fire-rated door safe include:
• Door leaf
The door leaf is the main panel that swings or slides. It is built from tested materials that remain stable under heat exposure. Its structure slows heat transfer and keeps the opening sealed.
• Door frame
The frame holds the door leaf in place. Most commercial frames use steel because it stays strong when temperatures rise. A rated frame helps the door leaf keep its shape and stay aligned during a fire.
• Intumescent seals
These seals sit along the edge of the door or frame. They swell when heated and fill small openings. This helps stop smoke and hot gases from moving through gaps.
• Rated glass (if used)
Some doors include fire-rated glass. This glass is tested to handle heat while stopping flames and smoke. Code rules control the size and type of glass used.
• Permanent label
A rated door must have a visible label from a testing agency. The label shows the fire rating and the test used. It confirms that all parts of the assembly match the tested design.
• Fire-rated hardware
This hardware group includes the hinges, latch, lock, closer, and any listed operating parts. Each piece must hold its strength under high heat and keep the door closed so the assembly protects the opening as tested.
Inspection and Testing Guide for Fire-Rated Doors
Inspection and testing steps check the label, measure gaps, test the closer and latch, review the seals, inspect hardware, and confirm no damage that affects the fire rating.
The inspection steps that keep the door performing as tested include:
• Label check
Inspectors confirm the label is readable and shows the correct fire rating. A missing label means the door is not considered rated.
• Door alignment check
The door must close smoothly and sit square in the frame. Misalignment creates gaps that can let smoke pass into protected areas.
• Gap measurement
Inspectors measure the space around the edges. NFPA 80 allows only small gaps. Larger gaps reduce fire protection.
• Closer and latch test
The door must close on its own and latch tight. If it remains open or bounces back, it cannot block smoke or heat.
• Seal and gasket check
Seals must be in place with no damage. Missing or cracked seals cannot expand during heat.
• Hardware inspection
Hinges, locks, and handles must be tight and working. Loose hardware weakens the assembly and may fail in high heat.
• Hold open device test
If a door uses a hold-open device, it must release when the alarm system activates. A device that does not release removes all fire protection.
• Damage review
Inspectors look for holes, dents, or unapproved changes. Any change to the door leaf or frame can break the tested design.
Installation Guide for Commercial Fire-Rated Doors
Installation rules for fire-rated doors focus on correct placement, proper hardware, and accurate alignment so the door performs as tested.
Key installation steps include:
• Correct door selection
The door must match the fire rating required for the wall. A one-hour wall needs a matching one-hour opening. This rule comes from the International Building Code.
• Rated frame installation
Install a frame with the same rating as the door leaf. A mismatch lowers the fire resistance of the opening. The frame must be square and anchored to solid material.
• Clearance and gap control
The space around the edges must meet NFPA 80 limits. Small gaps help the door seal during a fire. Large gaps let smoke move into exit paths.
• Self-closing device setup
The closer must pull the door shut without help. A fire-rated opening loses its performance if it stays open. Test the closer after installation.
• Hardware placement
Hinges, locks, and handles must be rated and installed in the approved locations. Unrated parts weaken the assembly. Each piece must line up with the test instructions.
• Seal installation
Place intumescent seals and smoke seals in the correct spots around the frame. These seals expand during heat and fill open spaces, which helps keep smoke out.
• Label visibility
Keep the certification label readable. Paint or repairs must not cover it. The label shows the rating and confirms compliance.
Fire Door Checklist for Commercial Properties
A fire door checklist confirms a clear doorway and makes sure the door is never propped open. It also checks for a working closer, a firm latch, tight hinges, intact seals, a damage-free surface, and rated glass.
These safety checks help keep a rated opening ready for an emergency.
• The door is never blocked
Keep the doorway clear at all times. Boxes or carts weaken fire protection because the door cannot close.
• Door is never propped open
A fire-rated opening must stay closed unless it uses a listed hold-open device. A wedge or object removes all fire protection.
• Closer works properly
The closer must pull the door shut every time. If the door stays open or closes slowly, the part needs service.
• Latch holds firmly
The latch must click into place when the door closes. A loose latch allows smoke to enter the next room.
• Hinges stay tight
Loose hinges cause sagging and gaps. Inspect hinges for missing screws or movement.
• Seals stay intact
Intumescent and smoke seals must be clean and undamaged. Torn seals cannot expand in heat.
• Surface shows no damage
Look for holes, dents, or unapproved alterations. Damage breaks the tested design and lowers the fire rating.
• Glass panel remains rated
If the door includes glass, check that the panel and its frame match the label rating. Unrated glass cannot block heat or smoke.
Call A 24 Hour Door National Inc. for Commercial Fire-Rated Door Services
A-24 Hour Door National Inc. provides commercial fire-rated door services that help your building stay code-compliant and safe during a fire event. Our team installs, repairs, and inspects rated openings so they perform as tested when heat, smoke, or flames appear.
Our technicians understand NFPA 80, NFPA 101, and International Building Code requirements. This helps keep your openings aligned with local safety regulations.
We work with metal, steel, wood-core, and rated glass doors for hallways, stairwells, utility rooms, and other commercial spaces. We also service closers, hinges, locks, frames, seals, and latching systems. Each part must work for the opening to meet its fire rating.
We respond fast and finish the work with simple communication so your business can keep running. Call (800) 884-4440 to get commercial fire-rated doors near you.
Source Links
• NFPA
https://www.nfpa.org
• ADA Access Board
https://www.access-board.gov
• OSHA
https://www.osha.gov
• UL
https://www.ul.com
• Intertek Certification Directory
https://bpdirectory.intertek.com
• ICC
https://www.iccsafe.org
• ASTM International
https://www.astm.org
FAQs
How long does a fire-rated door protect a building?
A fire door protects a building based on its listed fire rating, which ranges from twenty minutes to ninety minutes or more. Longer ratings offer more time for evacuation and slow the movement of smoke and heat.
Can fire-rated doors include glass panels?
Fire-rated doors can include tested glass panels that match the door’s listed rating. The size and type of glass must comply with code requirements and the limits shown on the certification label.
Can a normal door be turned into a fire-rated door?
A normal door cannot be turned into a fire-rated door because it has not been tested to fire standards. Only listed and labeled openings with rated frames and hardware qualify.