Fire-Rated Door Installation Requirements

Fire-rated door assemblies must be installed in strict compliance with NFPA 80 (Standard for Fire Doors and Other Opening Protectives), the International Building Code (IBC), and the conditions of the door’s UL or WHI listing. Every component in the assembly—door, frame, hinges, closer, latch, glazing, and seals—must be listed and labeled for the required fire rating. Unauthorized field modifications, missing hardware, or incorrect clearances void the fire rating and create code violations that will be cited during inspection. This guide covers the complete installation requirements for 20-minute, 45-minute, 60-minute, 90-minute, and 3-hour (180-minute) fire-rated door assemblies based on publicly available code and standard requirements.

CDF Distributors ships complete fire-rated door and frame assemblies with all required labeled hardware. You can configure and order fire-rated assemblies online using CDF’s ProBuilder tool at cdfdistributors.com. For assistance selecting the correct fire rating and hardware for your project, call (855) 769-9895 or email sales@cdfdoors.com.

Understanding Fire-Rated Door Assemblies

A fire-rated door assembly is not a single product. It is a tested and listed system of components that, when installed together according to the listing, will resist the passage of fire and smoke for a specified duration. The assembly includes the door leaf, the frame, all hardware (hinges, closer, latch set, lock), any glazing, and any gasketing or edge seals. Every component must be individually listed and labeled, and the combination must conform to a tested assembly configuration.

Fire-rated door assemblies are tested to NFPA 252 (Standard Methods of Fire Tests of Door Assemblies), UL 10B, or UL 10C. The testing laboratory (UL, WHI, or Intertek) issues a listing that specifies exactly which components may be used together and how they must be installed. Deviating from the listing voids the fire rating.

Fire Rating Levels and Where They Apply

The IBC and NFPA 80 specify five standard fire-rating levels for door assemblies. The required rating depends on the fire-resistance rating of the wall in which the door is installed and the occupancy type of the building. The following table summarizes the five standard fire-rating levels and their typical applications.

Fire Rating Requirements by Wall Type

20-Minute	Corridor walls with a 1-hour fire-resistance rating in certain occupancy types. Smoke and draft control assemblies. Often required in office corridors, hotel guest room corridors, and educational occupancies.
45-Minute	Corridor walls with a 1-hour fire-resistance rating where the AHJ or local amendments require 45-minute doors instead of 20-minute. Common in healthcare corridors.
60-Minute (1-Hour)	Walls with a 1-hour fire-resistance rating in most occupancies. Stairwell enclosures in buildings 4 stories or fewer. Shaft enclosures with 1-hour rating.
90-Minute (1.5-Hour)	Walls with a 2-hour fire-resistance rating. Stairwell enclosures in buildings over 4 stories. Exit passageways. Fire barriers between occupancies.
3-Hour (180-Minute)	Walls with a 3-hour or 4-hour fire-resistance rating. Fire walls separating buildings. Occupancy separation walls in high-hazard areas. These assemblies require masonry or concrete frames; hollow metal drywall frames are not listed for 3-hour ratings.

The general rule from IBC Table 716.1 is that the door assembly rating must be at least 75 percent of the required wall rating, except for 1-hour corridor walls, which may use 20-minute doors. Always verify the specific requirement with the Authority Having Jurisdiction (AHJ) and the project’s code analysis.

Fire Door Labels: Identification and Preservation

The fire label is the single most important element on a fire-rated door assembly. It is the only evidence that the door, frame, and hardware have been tested and listed. Labels are applied by the manufacturer under the authority of the testing laboratory. The following requirements apply to label preservation during and after installation.

Every fire-rated door leaf must bear a permanent label from the listing agency (UL, WHI, or Intertek) on the hinge edge of the door.
Every fire-rated frame must bear a separate label, typically on the hinge jamb face or the head behind the door stop.
Labels must not be painted over, removed, or obscured. NFPA 80 Section 5.2.4 requires that labels remain legible and attached throughout the life of the assembly.
If a label is missing, illegible, or has been removed, the door no longer has a valid fire rating. The assembly must either be re-labeled by the listing agency or replaced entirely.
During installation, take care not to damage the label when handling the door leaf or applying finishes. If the door is field-painted, the label area must be masked off.

Field Modification Restrictions

Fire-rated doors are tested as complete assemblies under controlled conditions. Any modification not explicitly permitted by the listing voids the fire rating. NFPA 80 Section 5.1 and the UL listing conditions govern what can and cannot be done to a fire-rated door in the field. The following modifications are prohibited unless the listing specifically allows them.

Cutting, planing, or trimming the door leaf beyond the manufacturer’s allowance. Most listings permit no more than 3/4” total material removal from the height (top and bottom combined). Some listings prohibit any field cutting.
Adding or relocating hinge preparations, lock preparations, or closer reinforcements that are not part of the original listing.
Drilling holes through the door for surface-mounted hardware unless the hardware is listed for use on fire-rated doors.
Removing or modifying any factory-applied intumescent material, edge banding, or glazing stops.
Adding louvers or vision panels in the field unless the modification conforms to a listed field-modification kit from the door manufacturer and is performed by a licensed installer.
Applying surface-mounted kick plates, push plates, or pull plates that are not listed for use on fire-rated doors.

When in doubt about whether a modification is permitted, contact the listing agency or the door manufacturer before proceeding. An unauthorized modification discovered during inspection will result in the assembly being cited as non-compliant and may require full replacement.

Clearance and Gap Tolerances

NFPA 80 specifies strict clearance requirements between the door and frame. These clearances are critical because excessive gaps allow fire and smoke to pass through the assembly. Clearances that are too tight prevent the door from closing and latching properly. The following table lists the maximum allowable clearances per NFPA 80.

Maximum Allowable Clearances per NFPA 80

Door-to-Frame (Jambs)	1/8” (3.2 mm) maximum on hinge side and lock side
Door-to-Frame (Head)	1/8” (3.2 mm) maximum between top of door and head of frame
Meeting Edges (Pairs)	1/8” (3.2 mm) maximum between meeting edges of double doors, plus 1/16” if rabbeted meeting edges
Undercut (Bottom)	3/4” (19 mm) maximum between bottom of door and top of finished floor. If the listing specifies a lower maximum, the listing governs.
Steel Door Exception	For steel doors in steel frames, NFPA 80 permits up to 1/8” plus or minus 1/16” at the jamb and head.

Measure clearances with a gap gauge at the hinge side, lock side, and head of the frame after the door is hung and before final hardware adjustment. If any clearance exceeds the maximum, the installation must be corrected before the assembly can pass inspection. Shimming the frame, adjusting hinge placement, or replacing a door that has been over-trimmed may be necessary.

Required Hardware for Fire-Rated Door Assemblies

Every piece of hardware installed on a fire-rated door must be listed and labeled for the required fire rating. Using non-listed hardware on a fire-rated assembly voids the listing. The following hardware categories have specific requirements under NFPA 80 and the IBC.

Hinges

Fire-rated doors require steel hinges, typically bearing type. The minimum is three hinges for a standard-height door (up to 7’0”). Doors over 7’0” require an additional hinge for each additional 30 inches of height. Spring hinges are acceptable as the self-closing device on 20-minute assemblies only if listed for that application. Aluminum or brass hinges are not permitted on fire-rated assemblies.

Self-Closing Devices (Door Closers)

NFPA 80 Section 6.1.3 requires that every fire-rated door be self-closing. The door must close from any open position and latch automatically without human intervention. Acceptable self-closing devices include surface-mounted door closers, concealed closers, floor closers, and spring hinges (on 20-minute doors only). The closer must have enough force to fully close and positively latch the door.

Doors that are required to be held open during normal operations must use a listed electromagnetic hold-open device connected to the building’s fire alarm system. When the fire alarm activates, the hold-open device releases and the closer pulls the door shut. Non-listed hold-open devices (kick-down door stops, wedges, chains) are prohibited on fire-rated doors under NFPA 80.

Self-Latching Hardware

NFPA 80 Section 6.1.4 requires that fire-rated doors be self-latching. The latch bolt must project into the strike and hold the door in the closed position. Push/pull hardware without a positive latch does not meet this requirement. Roller latches do not meet the positive latching requirement of NFPA 80 and are not permitted on fire-rated doors.

The following latch types are acceptable on fire-rated doors, provided they are listed:

Cylindrical locksets with a deadlocking latch bolt
Mortise locksets with a deadlocking latch bolt
Rim or vertical rod exit devices (panic hardware) with fire exit hardware listing
Mortise exit devices with fire exit hardware listing
Surface bolt or flush bolt assemblies on the inactive leaf of a pair (with coordinator)

Exit Devices on Fire-Rated Doors

Exit devices (panic hardware) installed on fire-rated doors must bear a separate fire exit hardware listing in addition to the panic hardware listing. A standard panic device listed only to UL 305 is not acceptable on a fire-rated door. The device must also be listed to UL 10C for use on fire-rated assemblies. Fire exit hardware is marked with an additional label or stamp indicating the fire rating.

Door Coordinators for Pairs of Doors

When a pair of fire-rated doors is installed in a single frame with an overlapping astragal, a door coordinator is required. The coordinator ensures that the inactive leaf closes before the active leaf so that the astragal overlaps correctly and both doors latch. The coordinator must be listed for fire-rated applications.

Gasketing and Smoke Seals

Where required by code for smoke and draft control (S-labeled assemblies), intumescent or silicone-based gaskets must be installed on the frame stops or the door edges. These seals expand at high temperatures to fill clearance gaps. Smoke seals are required on all doors in smoke barrier walls (IBC Section 716) and on corridor doors where required by the occupancy chapter. The gasket must be listed as part of the fire-rated assembly.

Glazing Restrictions for Fire-Rated Doors

Vision panels in fire-rated doors are subject to strict limitations on size, glazing type, and framing. The glazing must be fire-rated and listed for the specific fire rating of the door assembly. The following table summarizes glazing restrictions by fire rating level.

Maximum Glazing Area by Fire Rating

20-Minute	No maximum glazing area limitation per NFPA 80 for doors in 1-hour corridor walls. Standard fire-rated glazing (wired glass or listed ceramic) is acceptable. Tempered glass alone is not fire-rated.
45-Minute	Maximum 1,296 square inches (typically one dimension cannot exceed 54”). Listed fire-rated glazing required. Wired glass, listed ceramics, or listed glass-ceramic products are acceptable.
60-Minute	Maximum 100 square inches per light unless listed fire-rated glazing with a hose stream rating is used, which allows up to 1,296 square inches.
90-Minute	Maximum 100 square inches per light of wired glass. Listed fire-rated glazing with hose stream rating may allow larger lights per the specific listing.
3-Hour (180-Minute)	Maximum 100 square inches per light of wired glass only. No vision panel exemptions. Very limited glazing options at this rating.

All glazing must be set in listed fire-rated glazing frames or stops. Field-cut glass is never acceptable. The glazing and framing must be part of the tested assembly configuration. Where wire glass is used, it must meet safety glazing requirements per CPSC 16 CFR 1201 or ANSI Z97.1 unless it is protected by a bar or other protective measure.

Step-by-Step Fire-Rated Door Installation

Step 1: Verify All Components Against the Listing

Before beginning installation, verify that every component matches the listing requirements. Check the following items against the project door schedule and the listing documentation.

Door leaf fire rating label matches the required rating (20-min, 45-min, 60-min, 90-min, or 3-hour).
Frame fire rating label matches the required rating.
Hinges are steel, bearing type, and listed for the fire rating.
Closer is listed for the fire rating and properly sized for the door weight and width.
Latch set or exit device bears a fire listing label matching the required rating.
Glazing (if present) is fire-rated for the required duration and does not exceed the maximum area allowed by the listing.
Gasketing or smoke seals are present if the assembly is required to be smoke-rated (S label).

Do not proceed with installation if any component is missing, damaged, or does not match the listing. Installing a mismatched component creates a non-compliant assembly.

Step 2: Install the Fire-Rated Frame

Install the fire-rated frame according to the frame manufacturer’s instructions and the conditions of the listing. Fire-rated frames have additional requirements compared to non-rated frames.

Drywall frames (up to 90 minutes) must be grouted or have steel stiffeners as required by the listing. Some listings require grout fill in the frame for ratings above 45 minutes.
Masonry frames (for 3-hour ratings) must be fully grouted in the wall with mortar as specified in the listing.
Verify that the frame is plumb, level, and square before proceeding. Fire-rated assemblies have very tight clearance tolerances (1/8” at jambs and head) that cannot be achieved if the frame is out of alignment.

Step 3: Hang the Door Leaf

Mount the fire-rated door leaf in the frame using the listed hinges. Follow these requirements during installation.

Install the correct number of hinges: minimum three for doors up to 7’0”, four for doors up to 8’0”, and one additional hinge for each additional 30”.
Ensure all hinge screws are installed. Empty screw holes on fire-rated hinges are a common inspection citation.
Verify that the door swings freely and closes completely into the frame rabbet without binding or dragging.
Check that the fire label on the hinge edge of the door is visible, legible, and undamaged.

Step 4: Verify Clearances

With the door hung, measure all clearances using a gap gauge. This step must be completed before installing the closer and latch hardware.

Hinge side: 1/8” maximum gap between the door edge and the hinge jamb.
Lock side: 1/8” maximum gap between the door edge and the strike jamb.
Head: 1/8” maximum gap between the top of the door and the head of the frame.
Undercut: 3/4” maximum between the bottom of the door and the finished floor. If the listing specifies a tighter tolerance, follow the listing.

If clearances exceed the maximums, determine the cause (frame out of plumb, door over-trimmed, incorrect door size) and correct before proceeding.

Step 5: Install the Self-Closing Device

Install the door closer according to the closer manufacturer’s template and instructions. The closer must be listed for the fire rating of the assembly.

Mount the closer on the door or frame as specified by the closer manufacturer. Surface-mounted closers are the most common type on fire-rated single doors.
Adjust the closing speed so the door closes completely from any open angle. NFPA 80 requires the door to close and latch from the fully open position.
Adjust the latching speed to ensure the latch bolt fully engages the strike. A door that swings closed but does not latch fails inspection.
If the door is required to be held open, install a listed electromagnetic hold-open device connected to the fire alarm system. Test the release function.

Step 6: Install Latching Hardware

Install the listed latch set, lockset, or exit device. Verify that the latch bolt positively engages the strike when the door closes.

The latch bolt must project fully into the strike pocket.
The strike must be properly aligned so the door does not have to be pushed or pulled to engage the latch.
For exit devices (panic hardware), confirm the device bears a fire exit hardware label in addition to the panic hardware listing.
For pairs of doors with an overlapping astragal, install the door coordinator and verify the correct closing sequence: inactive leaf first, then active leaf.

Step 7: Install Gasketing and Smoke Seals (If Required)

If the assembly requires an S (smoke) label, install the listed gasketing or smoke seals per the manufacturer’s instructions.

Intumescent seals are typically installed in a kerf in the frame stop or applied to the door edge.
Seals must run the full length of both jambs and the head without gaps.
Do not trim or splice gasketing unless the manufacturer’s instructions permit it.

Step 8: Final Inspection and Functional Testing

After all components are installed, perform a complete functional test of the assembly. This test mirrors the checks performed during NFPA 80 annual inspections.

Open the door to 90 degrees and release it. The door must close completely and latch without assistance.
Verify that the latch bolt is fully engaged in the strike.
Confirm that no light is visible between the door and frame at the jambs and head (except at the undercut).
Verify that all labels (door, frame, hardware) are visible, legible, and undamaged.
Confirm that no unauthorized hardware or modifications are present.
If the door is held open by an electromagnetic device, activate the fire alarm and confirm the door releases, closes, and latches.

Document the installation by recording the fire rating, listing agency, and serial numbers from the labels. This documentation will be needed for annual inspections.

What Voids a Fire Door Listing

A fire door listing can be voided by any condition that deviates from the tested assembly configuration. Once voided, the assembly no longer provides the rated fire protection and must be corrected or replaced. The following conditions void a fire door listing.

Missing or illegible fire label on the door, frame, or hardware.
Unauthorized field modifications (cutting, drilling, adding hardware not in the listing).
Non-listed hardware installed on the assembly.
Clearances exceeding the NFPA 80 maximums (1/8” at jambs/head, 3/4” undercut).
Door does not self-close and positively self-latch from any open position.
Glazing that is not fire-rated, exceeds the maximum area, or is installed in non-listed framing.
Door held open by non-listed devices (wedges, door stops, chains, hooks).
Holes, damage, or breakage in the door leaf or frame that compromise the fire barrier.
Missing or damaged gasketing on smoke-rated (S-label) assemblies.
Frame not securely anchored to the wall or visibly out of alignment.

Annual Inspection Requirements per NFPA 80

NFPA 80 Section 5.2 requires that fire door assemblies be inspected and tested annually. The building owner is responsible for ensuring inspections are performed. Inspections may be conducted by facility maintenance staff or a qualified third-party inspector. The following checklist summarizes the annual inspection requirements.

NFPA 80 Annual Inspection Checklist

No open holes or breaks exist in surfaces of either the door or frame.
Glazing, vision lights, and fire-rated glazing beads are intact and secure.
The door, frame, hinges, hardware, and noncombustible threshold are secured, aligned, and in working order.
No parts are missing or broken.
Door clearances do not exceed the maximums specified in NFPA 80.
The self-closing device operates correctly and the door closes from any open position.
The self-latching device operates and the latch bolt fully engages the strike.
If provided, the coordinator is operational and causes the doors to close in the correct sequence.
Auxiliary hardware items that interfere with the operation of the door are not installed.
No field modifications have been made to the door assembly that void the listing.
Gasketing and edge seals (where required) are intact.
The fire label on the door and frame is present and legible.

NFPA 80 requires that inspection records be maintained and available for review by the AHJ. Records must include the date of inspection, name of the inspector, and the disposition of each assembly (pass, fail, or corrective action required).

Tools and Materials for Fire-Rated Door Installation

Gap gauge: for measuring door-to-frame clearances at jambs, head, and undercut
4-foot level: for verifying frame plumb on jambs
2-foot level: for verifying frame level on the head
Tape measure: for verifying door dimensions and rough opening
Impact drill: for driving frame anchors and hardware screws
Phillips and Torx bits: for hardware installation per manufacturer specifications
Shims: for frame alignment and plumb adjustment
Closer template: provided by the closer manufacturer for correct mounting hole locations
Safety glasses: required PPE
Door label reference sheet: listing agency documentation showing required label locations

Common Fire-Rated Door Installation Mistakes

Avoid these errors, which are the most frequent causes of fire door inspection failures:

Installing non-listed hardware. Standard commercial hardware is not automatically acceptable on fire-rated doors. All hardware must bear a fire listing label.
Failing to verify clearances after installation. Even a properly sized door can have out-of-tolerance gaps if the frame is not plumb or the hinges are not properly aligned.
Using roller latches instead of positive-latching hardware. Roller latches do not meet the NFPA 80 self-latching requirement.
Propping fire doors open with wedges or non-listed hold-open devices. This is the single most commonly cited fire door violation in commercial buildings.
Over-trimming the door to address floor clearance issues. If the undercut exceeds 3/4”, the listing is voided. Address floor height issues at the floor, not the door.
Painting over the fire label. Mask the label area before applying any field-applied finish.
Omitting gasketing on smoke-rated assemblies. If the door schedule calls for an S label, the seals must be installed as part of the listed assembly.

Industry Standards Referenced

NFPA 80: Standard for Fire Doors and Other Opening Protectives
NFPA 252: Standard Methods of Fire Tests of Door Assemblies
IBC Chapter 7: Fire and Smoke Protection Features (Table 716.1)
UL 10B: Fire Tests of Door Assemblies
UL 10C: Positive Pressure Fire Tests of Door Assemblies
UL 305: Panic Hardware
ANSI/BHMA A156 series: Hardware standards for commercial doors
CPSC 16 CFR 1201 / ANSI Z97.1: Safety glazing requirements

Configure Your Fire-Rated Door Assembly

CDF Distributors’ ProBuilder tool allows contractors and facility managers to configure complete fire-rated door assemblies online. ProBuilder ensures that the door, frame, and hardware selections are compatible and carry matching fire ratings. ProBuilder displays only listed hardware options for the selected fire rating and provides instant pricing.

For assistance selecting the correct fire rating and components for your project, call (855) 769-9895 or email sales@cdfdoors.com. CDF’s sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.

Frequently Asked Questions

What is the maximum gap allowed between a fire-rated door and frame?

NFPA 80 allows a maximum of 1/8” (3.2 mm) between the door and frame at the jambs and head. The maximum undercut at the bottom of the door is 3/4” (19 mm). If the specific listing calls for tighter tolerances, the listing governs. Steel doors in steel frames are permitted 1/8” plus or minus 1/16”.

Can I cut or trim a fire-rated door in the field?

Most fire-rated door listings permit very limited field trimming, typically no more than 3/4” total from the height (top and bottom combined). Some listings prohibit any field cutting. Always check the listing conditions before trimming. Exceeding the allowed trim voids the fire rating and the door must be replaced.

Are roller latches acceptable on fire-rated doors?

No. NFPA 80 requires positive latching, meaning the latch bolt must project into the strike and hold the door closed. Roller latches, magnetic catches, and ball catches do not meet this requirement. A listed cylindrical lockset, mortise lockset, or fire exit hardware device is required.

What happens if the fire label is missing or painted over?

A fire-rated door without a legible, attached label has no valid fire rating. The assembly will fail inspection. The label cannot be replaced in the field. The original manufacturer or listing agency must re-label the door, or the door must be replaced. Prevent this by masking the label area before applying any field-applied finish.

Can I hold a fire-rated door open?

Fire-rated doors may only be held open using listed electromagnetic hold-open devices connected to the building’s fire alarm system. When the alarm activates, the device releases and the closer pulls the door shut. Kick-down stops, wedges, chains, hooks, and any other non-listed hold-open method are prohibited by NFPA 80.

How often must fire-rated doors be inspected?

NFPA 80 requires annual inspection and testing of all fire door assemblies. The building owner is responsible for ensuring inspections occur. Records of each inspection must be maintained and made available to the Authority Having Jurisdiction (AHJ) upon request.

What is the difference between a fire-rated door and a smoke-rated door?

A fire-rated door resists the passage of fire for a specified duration (20 minutes to 3 hours). A smoke-rated door (S label) includes gasketing to resist the passage of smoke at ambient temperature. Many applications require both ratings. An assembly with both a fire rating and an S label has been tested for both fire resistance and smoke leakage. The door schedule will specify whether an S label is required.

What fire rating do drywall frames support?

Hollow metal drywall wrap-around frames can be fire-rated up to 90 minutes. Assemblies requiring a 3-hour (180-minute) rating must use masonry or concrete frames. CDF Distributors fabricates fire-rated drywall frames for 20-minute, 45-minute, 60-minute, and 90-minute applications. Configure your fire-rated frame assembly using ProBuilder at cdfdistributors.com or call (855) 769-9895.

About This Guide

This installation guide is based on the publicly available requirements of NFPA 80 (Standard for Fire Doors and Other Opening Protectives), the International Building Code (IBC), and UL listing standards for fire-rated door assemblies. CDF Distributors provides this guide as a reference for contractors, facility managers, and code officials working with fire-rated door assemblies. CDF’s fabrication team ships fire-rated assemblies with all required labeled components from its Nashville, Tennessee facility.

This guide does not replace the specific listing conditions for any individual assembly. Always follow the listing documentation provided with the assembly and verify all requirements with the Authority Having Jurisdiction (AHJ). For questions about fire-rated door assemblies or to configure an order, contact CDF at (855) 769-9895 or sales@cdfdoors.com.

What Are the Requirements for Installing a Fire-Rated Door Assembly?