Basic Fire Door, Fire Door Frame, Transom/Sidelight Frame, and Window Frame Requirements

SDI 118-21

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Table of Contents

  1. Introduction
  2. Doors
  3. Glazing Materials
  4. Temperature rise doors
  5. Louvers
  6. Fire door frames
  7. Transom and sidelight assemblies
  8. Fire window frames (borrowed light)
  9. Fire doors with Builder’s Hardware
  10. Fire resistive frames
  11. Hardware – pairs of doors
  12. Product labeling
  13. Fire test methods
  14. Smoke and draft control
  15. Smoke barrier doors
  16. Field Labeling
  17. Field modifications
  18. Fire door inspections
  19. References

1. Introduction

Fire testing of doors, door frames, transom/ sidelight frames, window frames, glazing, and hardware and the resulting labeling programs granted by third-party testing agencies are complex subjects better understood when basic rules and guidelines are applied. The following information is based upon the requirements of the International Building Code.

Note: Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information.

2. Doors

The fire-protection classification of the wall into which the door is installed dictates the required fire-protection rating of the door. The location of the wall in the building and prevailing building codes establish the fire-protection rating requirements for the wall. Fire door assemblies are often required to also act as smoke and draft control barriers by the building code in addition to the specified fire-protection rating. For openings in a smoke partition, no fire-protection rating is required for the door assembly but the door cannot exceed the code’s maximum air leakage rate. The associated door fire-protection ratings are shown in Table 1.

Table of 7 fire door openings with illustration of opening style, wall rating, door and frame rating, and a description and use for each type

2.1 Hourly ratings

Steel fire doors are “rated” by the duration of time (in minutes or hours) that a door has successfully withstood exposure to fire test conditions. Hourly ratings include 1-1/2-hour (90 minute), 1-hour (60 minute), 3/4-hour (45 minute), and 1/3-hour (20 minute), with the maximum rating required of any swinging type fire door being 3-hour (180 minute). All doors have been subjected to a hose stream test, unless otherwise noted on the label.

2.2 Three-hour (180-minute) doors

A door with a three-hour fire-protection rating is usually required in walls that separate buildings or that divide a large building into smaller fire areas. The wall rating is four hours.

2.3 1-1/2-hour (90-minute) doors

Doors rated for 1-1/2 hours are required in 2-hour rated walls. These doors are commonly located in stairwells, or other enclosures of vertical passage through a building. They also occur in boiler rooms and in exterior walls that have the potential for severe fire exposure from the outside of the building.

2.4 One-hour (60 minute) doors

One-hour rated doors are used in occupancy separation walls, which are also one-hour rated.

2.5 3/4-hour (45 minute) doors

Doors with 3/4-hour fire-protection ratings are used in one-hour walls. A 3/4-hour rated door is required in walls of corridors and room partitions. A door with this rating may also be located in the exterior wall of a building subject to moderate fire exposure from the outside of the building.

2.6 1/3-hour (20 minute) doors

One-third-hour or 20 minute doors are used in one-hour walls. These doors are used for corridor applications and in other applications where smoke and draft control is a primary concern.

2.7 Doors tested without hose stream

Doors may be rated as 20 minutes without a hose stream. These doors have successfully passed a 20-minute fire test, with the omission of the hose stream test, and bear a label that specifically states “Twenty-Minute-Rating Tested Without Hose Stream.” These doors may be provided with vision lights only limited in size by the door manufacturer’s fire labeling procedure.

Assemblies identified as “Twenty-Minute-Rating Tested Without Hose Stream” should not be confused with 1/3-hour fire-rated doors, which have been tested in accordance with the standard fire test procedure that includes the hose stream test.

2.8 Smoke and Draft Control Door

Doors marked as smoke and draft control door assemblies will be used in smoke partitions with no fire resistance rating. These doors are used to control the passage of smoke from room to room where the partition must only provide smoke and draft control. The door and frame assembly with all hardware and gasketing are required to have a maximum leakage rate not to exceed 3.0 CFM/ft2 at 0.10 in. (0.9 m3/min./m2 at 25 Pa) of water. These assemblies will be indicated by a leakage-rated door assembly label. These assemblies must be tested in accordance with UL 1784 and installed in accordance with NFPA 105. For double egress doors used as cross corridor smoke barriers, please refer to Section 15.

2.9 Summary

Doors are typically rated for three-fourths of the rating of the surrounding wall: A 3-hour door is used in a 4-hour rated wall; a 1-1/2-hour fire door is used in a 2-hour rated wall; and a ¾-hour door is used in a one-hour rated wall. The exceptions are the 1-hour and the 1/3-hour rated doors which are typically used with onehour rated walls.However, a door with a higher fire-protection rating than the opening requires may also be specified. For example, a door rated for 3 hours may be used in a 1-1/2-hour opening. All requirements for the 3-hour rating, such as maximum glazing materials size, door size, and other restrictions for the higher rated door must be met.

3. Glazing Materials

A wide variety of glazing materials and glazing compounds are available for use in fire doors and frames. Wired glass that is 1/4″ (6.35 mm) thick was once the most common type of glazing in fire-rated assemblies but is generally prohibited for use in areas subject to human impact. For this reason, ceramic and other non-wired glazing materials, along with filmed wire glass, are now the most common types of glazing used in fire-rated assemblies. For glazing materials, the maximum exposed area per individual light, the minimum groove depth, glazing compound and the rating shall be as indicated in the individual manufacturer’s published listings. Consult the door and glazing manufacturers for the limitations of size, area and number of vision lights in a door.

The vision light kit or window frame used for glazing materials must be approved for use in a fire-rated door.

Two categories of glazing used in doors, door frames, transom/sidelight frames, and borrowed light frames are available as follows:

Fire-Protection-Rated Glazing – This glazing is evaluated for fire-protection ratings measured in minutes or hours in doors, door frames, and transom/sidelight frames in accordance with UL 10C or NFPA 252 and borrowed light frames in accordance with UL 9 or NFPA 257.

Fire-Resistance-Rated Glazing – Fire-resistance-rated glazing is designed to limit the temperature rise on the unexposed surface in accordance with UL 263 or ASTM E119. Performance is rated in terms of temperature rise on the unexposed face at increments of time (minutes or hours). This glazing may be used in Temperature Rise Doors, explained in the next section.

Fire protection and fire resistance glazing installed in fire doors and fire-rated windows that are subject to human impact shall meet applicable impact safety standards (e.g. – 16 CFR 1201, U.S. Consumer Product Safety Commission, “Standard for Architectural Glazing”).

The reader may also wish to review NFPA 80, Chapter 4, Glazing Material in Fire Doors for additional information on this topic.

The manufacturers’ listings for fire door, transom/sidelight frame, window frame, and glazing may be obtained through the listing agencies as follows:

Use the following link to access the UL “Online Certifications Directory”. Enter the “UL Category Code” indicated below for a listing of approved manufacturers or search by company name or product type. (link valid as of 7/13/2021)

  • Fire Door Manufacturers – GSYX or GSZN
  • Fire Door and Window Frame Manufacturers – GVTV
  • Glazing Manufacturers – KCMZ or CCET

Intertek Testing Services (Warnock Hersey)

Use the following link to access the Intertek “Listed Product Directories”. Enter keywords such as glass, glazing, fire door, fire door frame, fire window, or transom frame for a list of approved manufacturers. (link valid as of 12/14/2021)

4. Temperature rise doors

In certain applications, fire doors are required to minimize the transmission of heat from one side of the door to the other, as in the stairwell of a high-rise building or in horizontal exits. These doors are fire-resistance rated, as opposed to fire-protection rated. If the door can limit the transmission of heat for a period of time, people can safely pass below the floor of fire origin in a burning building. These doors are built with a core that is specifically designed to restrict the transmission of heat and are referred to as temperature rise doors.

In addition to the hourly rating, the fire door label will also state the temperature rise rating of the door. Temperature rise ratings are 250°F (139°C), 450°F (250°C), and 650°F(361°C), and the ratings indicate the maximum rise in temperature above ambient temperature measured on the unexposed surface (non-fire side) of the door during the first 30 minutes of the standard fire test. In some applications the International Building Code (IBC) requires a 450° F (250°C) temperature rise rating for doors, interior exit stairs and ramps, and exit passageways. The 250°F (139°C) temperature rise designation is the most stringent rating of the three, since itrequires the most limited rise in temperature. A 250°F (139°C) temperature rise door meets the requirements of specifications calling for a 450°F (250°C) or 650°F (361°C) temperature rise rating.

5. Louvers

Listed louvers are permitted in 1-1/2-hour and 3/4-hour fire doors where the louver is installed in accordance with the manufacturer’s listing. Louvers may not be used in 1/3-hour (20-minute) rated doors, or doors of other hourly ratings that may be part of a smoke and draft assembly. Doors with glass lights, or doors equipped with fire exit devices may not have louvers unless permitted by local building codes.

6. Fire door frames

Where a frame bears a recognized label qualifying it as a fire door frame without an indicated rating, it may support a 3-hour, a 1-1/2-hour, 1-hour, a 3/4-hour, 1/3-hour, or a 20 minute door. Some state and local building codes may require hourly ratings to be indicated on the certification label. Frames used in masonry walls may be used with a maximum 3-hour fire door, while frames used in drywall stud walls are intended to be used with a maximum 1-½-hour fire door. Consult individual fire door frame manufacturers listings for fire door frames that can be used in drywall stud walls with a maximum 3-hour rating. Unless otherwise stated in the manufacturer’s certification, grout or any other filler material is not required for fire-rated frames installed in either drywall or masonry walls for any hourly rating.

7. Transom and sidelight assemblies

Labeled door frames are available with transom areas, sidelight areas, or a combination of both. The transom and sidelight areas can be assembled with listed panel assemblies or listed glazing material. Frames with solid transom panel and/or side panels may be used in openings rated up to and including 3 hours. Transom and sidelight frames with labeled glazing material may be used in openings rated up to 1-1/2 hours. The maximum hourly rating, overall frame size, panel construction, and individual glazing material exposed areas for frame and glazing manufacturers may be obtained through the listing agencies as indicated in Section 3. Unless otherwise stated in the manufacturer’s certification, grout or any other filler material is not required for transom and sidelight frames installed in either drywall or masonry walls for any hourly rating.

The overall size of transom and sidelight frames is limited to the maximum size that a manufacturer has listed. Since the size may vary, it is important to consult the manufacturer when designing or writing specifications.

8. Fire window frames (borrowed light)

Fire window frames are labeled hollow metal glass light frames that are not attached to a door frame and are tested in accordance with NFPA 257 or UL 9. Individual glazing material exposed areas are not to exceed 1296 square inches (32.92 m2)and the dimension for width or height shall not exceed 54 inches (137.16 cm) unless otherwise tested. The maximum hourly rating, overall window size, and individual glazing material exposed areas for frame and glazing manufacturers may be obtained through the listing agencies as indicated in Section 3. Fire window frames are typically used in corridor walls and may be provided for masonry or drywall construction. Consult the frame manufacturer as to the ability to supply fire window frames for installation in drywall walls. Unless otherwise stated in the manufacturer’s certification, grout or any other filler material is not required for fire window frames installed in either drywall or masonry walls at any hourly rating.

9. Fire doors with Builder’s Hardware

Fire doors with builders hardware serve four main purposes:

  1. To function as a door at all times;
  2. to provide ready egress;
  3. to keep fire from spreading throughout the building; and
  4. to protect life and property.

To adequately perform these functions, a fire door must be equipped with labeled hardware for dependable operation. Proper hardware selections can be verified by consulting online listings published by UL LLC and Intertek. These listings identify hardware and other products that may be used in fire-rated assemblies. The information can also be accessed at the following links: (link valid as of 10/16/2020)

Search by type of hardware, company name, or UL Category Code such as GXHX or GYJT.

Intertek Testing Services (Warnock Hersey) (link valid as of 12/14/2021)

NFPA 80 provides requirements for installing fire doors, frames, and hardware in the building openings, as well as requirements for annual inspection, testing and maintenance.

9.1 Hinges

A labeled fire door must be hung on steel ballbearing-type or listed hinges. NFPA 80 allows the use of steel ball-bearing hinges without a listing. Steel hinges that meet the criteria of NFPA 80 have been proven to be adequate during a fire. There are certain hinge designs made of non-ferrous metals which may be used on fire doors in accordance with the listing information for the particular hinge but may result in a lower fire-protection rating.

Hinges with ball bearings are required in order to provide smooth operation and to minimize wear throughout the lifetime of the opening. Remember, a fire door must close in the event of a fire. Exception: Some manufacturers may provide doors with hinges that use other antifriction bearing surfaces if they meet the requirements of ANSI/BHMA A156.1.

NFPA 80 allows the use of standard weight (0.134 inch (3.4 mm) leaf thickness) 4-1/2″ (114.3 mm) steel hinges as a minimum on 1-3/4″ (44.45 mm) doors up to 4′-0″ (1.22 m) in width and 8′-0″ (2.44 m) in height. Doors over 8′-0″ (2.44 m) in height shall have heavy weight (.180 inch (4.6 mm) leaf thickness) 4-1/2″ (114.3 mm) hinges as a minimum. Some manufacturers have the capability of providing lighter weight hinges on doors over 8′-0″ (2.44 m) in height as part of a listed assembly. (Consideration should be given to larger hinge sizes for frequently used or heavy doors.)

9.2 Latching devices

Every swinging fire door must have a listed and labeled self-latching device. Dead bolts may be provided in addition to the latch bolt,except on doors in a means of egress, in which case interconnected locks may be used which simultaneously retract the dead bolt with the latch bolt. Dead bolts may not be used in place of latch bolts.

When selecting latching devices, it is important to use the correct length of latch bolt, a requirement that can vary with the door construction and the manufacturer’s listing. It is common for a pair of doors to require a longer latch bolt throw than a single door. The minimum latch bolt length that must be used for any given door is indicated on the fire door label.

An exception to latching for fire-rated openings is allowed by the IBC for double egress doors in corridors that are in a smoke barrier. State and local building code authorities may also allow latching to be omitted in certain openings. Consult individual manufacturers for labeling capabilities.

9.3 Fire exit hardware

Fire exit hardware devices may be used on labeled doors provided the door labeling specifically states “Fire Door To Be Equipped With Fire Exit Hardware.” This label indicates that the door has been properly reinforced for fire exit devices. Fire exit hardware used on doors that bear this label must pass a panic loading test in accordance with UL 305 and a cycling test in accordance with ANSI/BHMA A156.3 in addition to the standard fire test. The panic load test measures the structural capability of the door to allow the hardware to operate in a panic situation. The cycling test ensures that the hardware is durable and does not malfunction due to every day use.

Care must be taken when selecting exit devices for use on fire-rated doors, as some devices have been tested for panic applications only, and have not been fire tested. In addition, exit devices have size and hourly rating restrictions, and must be properly labeled and identified as fire exit hardware.

NFPA 80 provides additional guidance on use of other listed hardware in conjunction with fire exit hardware devices.

9.4 Closing devices

A properly sized closing device is the last of the “basic” fire door hardware requirements. A fire door must be in a closed and latched position to serve as a protective barrier in the event of a fire. For this reason, either listed ANSI/BHMA Grade 1 spring hinges or a listed door closer is required to ensure that the door will close properly.

Note: Per NFPA 80, the authority having jurisdiction may allow the closer to be omitted from the inactive leaf of a pair of doors for equipment rooms to allow the movement of equipment.

9.5 Hold open devices

Tests and investigations have proven that smoke and toxic gases are the main cause of death in fires. Listed closers with closer arms that are equipped with a fusible link (if allowed by the local Authority Having Jurisdiction) or a listed combination closer/holder shall be used. Mechanical hold-open only devices and hold-open only arms are not permitted on self-closing doors. Doors with surface closers equipped with a listed hold open device (e.g. electromagnetic release) also prevent the passage of the toxic
gases and smoke. These devices are activated by electronic detectors that sense smoke and/or the products of combustion.

10. Fire resistive frames

The assemblies detailed above in sections 8 and 9, where located in fire barriers, are limited to 156 square feet (14.49 square meter) in area or an aggregate width of 25 percent of the length of the wall. Where either of these parameters are exceeded, the opening protective must be tested in accordance with ASTM E119 or UL 263 and have a minimum fire-resistance rating not less than the fire-resistance rating of the wall. These are referred to as fire resistive frame assemblies as they limit the radiant heat transfer through the assembly in addition to the passage of flame.

11. Hardware – pairs of doors

Pairs of doors for rated openings have some unique hardware requirements.

11.1 Hinges and closing devices
Pairs of doors for labeled openings require steel, ball-bearing-type hinges or a listed continuous hinge. Closing devices are required on both leaves of a pair of doors except on mechanical equipment rooms where the closing device may be omitted from the inactive leaf, if acceptable with the authority having jurisdiction.

11.2 Latching hardware
11.2.1 Active leaf of pairs of doors
An active leaf of a pair of doors may require labeled fire exit hardware, or any labeled latch that shall be opened by one obvious operation from the egress side.

11.2.2 Inactive leaf of pairs of doors
Local codes may allow manual flush or surface mounted bolts to be used to secure the inactive leaf of pairs of doors being used as entrances to equipment rooms or similar situations. The IBC requires that the inactive leaf have no knob or other visible hardware that implies means of egress.

Labeled fire exit devices are mandatory for exits unless local authorities give specific approval for the use of labeled self-unlatching and latching devices, such as automatic flush bolts on the inactive leaf. The self-unlatching feature must work only when the active leaf is opened.

11.3 Double egress pairs
Double egress pairs of doors should only be provided with vertical rod fire-exit hardware devices on both leaves unless otherwise permitted by the code. The vertical rod devices may be either surface mounted or concealed.

11.4 Astragals
The application of astragals on pairs of doors depend upon the individual door manufacturer’s published listings. For pairs of doors that do require an astragal, the astragal shall project a minimum of 3/4-inch (19 mm) beyond the edge of the door to which the astragal is attached. Pairs of doors that are in a required means of egress may not be equipped with an astragal that inhibits the free use of either leaf. An overlapping astragal may not be used on pairs of doors swinging in the same direction with vertical rod exit devices on both leaves of the pair.

In some situations a coordinator may be needed to allow the inactive leaf to close before the active leaf. This ensures proper latching of pairs of doors. Some manufacturers are able to supply labeled pairs of doors with an open-back strike without an astragal, which eliminates the need for a coordinator.

12. Product labeling

There are several materials and attachment methods for fire labels that are approved by recognized labeling agencies. These include steel, brass, aluminum, and non-metallic materials such as mylar. Metal labels are attached with welds, rivets, drive screws, or adhesive. Non-metallic labels are either die-slit or tamper proof with an adhesive back. Once applied, any attempt to remove the label will indicate tampering. Embossed metal labels and embossments directly applied to doors and frames may be painted as long as the listing agency mark and all listing information is legible.

The mark of a labeling agency shall be provided on all labels applied to fire-rated doors and frames. The agency mark or manufacturer isn’t required to be the same on the door, frame, and hardware. Labels are located on the edge of a door between the top and middle hinges. Labels are located on the frame rabbet between the top and middle hinges. Labels may be located on the top of the door or head of the frame, or lock edge of door or face of door, if there is interference with hardware (e.g. electric power
transfer, continuous hinge, smoke seals) that would obscure the label.

Fire labels on doors and frames are not intended to survive a fire. The label is there to indicate that the opening is protected by a properly constructed steel door and frame.

13. Fire test methods

There are two primary fire test methods recognized by the IBC to establish the fire-protection ratings of doors. The first is ANSI/UL 10C and is referred to as a ‘positive pressure’ test. The second is, NFPA 252 and is required by the IBC to be conducted under positive pressure test conditions.

Fire doors may be specified by calling out the test method or by indicating that the product must meet a specific section of a model building code.

14. Smoke and draft control

Doors that open into corridors that are used for a means of egress may be required to have a smoke and draft control rating. Smoke and draft control assemblies are tested for air leakage per UL 1784 and NFPA 105 and fire-protection ratings as previously discussed.

14.1 Gaskets
Gaskets are typically required for doors to pass a smoke and draft control test. The requirement for a gasket also includes the meeting edges of a pair of doors. The gaskets used in a smoke and draft control assembly must be fire-rated and be listed for use in a smoke and draft control assembly. A bottom seal is not required for smoke and draft control assemblies.

14.2 Marking
The IBC requires smoke and draft control assemblies to have an identification mark of “S” which appears on the door label following the hourly rating. The frame doesn’t require the “S” mark to be present on the label.

15. Smoke barrier doors

The IBC includes a requirement for smoke barrier doors. These doors need to provide smoke and fire protection as previously described in this document. The IBC includes an exception for double egress doors that require that these doors have the same characteristics of a fire door except a fire-protection rating and self latching are not required. Double egress doors used in a smoke barrier are used in cross corridor applications.

16. Field Labeling

If a product or component does not have a certification acceptable to the Authority Having Jurisdiction (AHJ) or other vested party, field labelling can be performed by a testing and listing agency that is used by the manufacturer of the product or component under review.

17. Field modifications

If the product or component requires a field modification, the testing / listing agency that the product or component was listed with shall be contacted by the manufacturer and provided with a description of the proposed modification. If the agency determines that the modification does not affect the integrity and fire protection capabilities of the opening and provides written authorization, then field modifications may be performed. Any modification of a non-fire-rated door assembly to achieve a fire-protection rating must be conducted under label service (See Field Labeling) evaluation process.

18. Fire door inspections

The 2018 edition of the International Building Code and subsequent editions require fire door assemblies to be inspected after they are installed, in addition to the acceptance and annual requirements found in NFPA 80. Building owners must have a qualified individual inspect all components of the fire door assembly and document the results as outlined in NFPA 80. Any deficiencies noted during the inspection must be addressed with maintenance or component replacement, and a follow-up acceptance test performed.

19. References

  1. ANSI/BHMA A156.1-2016 Butts and Hinges
  2. ANSI/BHMA A156.3-2014 American National Standard for Exit Devices
  3. ASTM E119-2020 Standard Test Methods for Fire Tests of Building Construction and Materials
  4. NFPA 80-2019 Standard for Fire Doors and Other Opening Protectives
  5. NFPA 105-2019, Standard for Smoke Door Assemblies and Other Opening Protectives
  6. NFPA 252-2017 Standard Methods of Fire Tests of Door Assemblies
  7. NFPA 257-2017 Standard Methods of Fire Tests of Window and Glass Block Assemblies
  8. Underwriters Laboratories Standard for Safety ANSI/UL 9 Standard for Fire Tests of Window Assemblies, 8th Edition, July 2, 2009, revisions up to and including March 20, 2020
  9. Underwriters Laboratories Standard for Safety ANSI/UL 10B Standard for Fire Tests of Door Assemblies, 10th Edition, February 7, 2008, revisions up to and including May 4, 2020
  10. Underwriters Laboratories Standard for Safety ANSI/UL 10C Standard for Positive Pressure Fire Tests of Door Assemblies, 3rd Edition, May 27, 2021
  11. Underwriters Laboratories Standard for Safety ANSI/UL 263, Fire Tests of Building Construction and Materials, 14th Edition, June 21, 2011, revisions up to and including September 9, 2020
  12. Underwriters Laboratories Standard for Safety ANSI/UL 305, Standard for Panic Hardware, 6th Edition, July 12, 2012, revisions up to and including March 22, 2017
  13. Underwriters Laboratories Standard for Safety ANSI/UL 1784, Standard for Air Leakage Tests of Door Assemblies and Other Opening Protectives, 4th Edition, February 21, 2020
  14. International Building Code, 2018