Fire Doors From A to Z

June 2, 2014
Fire doors must be closed and latched at all times. Therefore door hardware must be installed on fire door which will fulfill specific requirements

Locksmiths install and service locks and other hardware on doors which are very likely to be labeled fire doors. Determining whether a door is a Fire door is the first step whenever repairing the door or installing hardware on it.

If a label is not visible on the door or frame, it does not release you from being responsible for supplying the appropriate hardware, making permitted repairs, or otherwise modifying the door consistent with its listing.

The fire label provides vital information about the door. Your goal should be to maintain or enhance the safety of your customer or building occupants, and also indemnify yourself against litigation. It involves more than simply providing fire rated hardware on the door “to be on the safe side” but it certainly is a good place to begin.

You are there because the customer called you, and if possible you should perform the work requested, leaving the site with a properly functioning door. When this is not possible, present a clearly documented transcript of what is going on with the opening, and understanding between you and the customer that deficiencies or unresolved issues will be diligently and quickly followed up.  Contacting the local authority having jurisdiction (LAHJ) or arranging an on-site meeting between the LAHJ, you the client might be good step towards safe, code-compliant conditions at the site, and establishing yourself as the security professional in this picture.

Doors: What Are They For?

Fire doors serve four main purposes:

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

There are different ratings for fire doors, and fire doors are constructed of different materials. Fire doors are supposed to be labeled, but you can’t assume that if there is no label on a door, it is not a fire door.

An interesting fact is that doors are 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 3/4-hour door is used in a one-hour rated wall.

One exception is that 1/3-hour rated doors are also used with one hour rated walls.

A higher rated door may be used. An example would be using a 3 hour door in a 2 hour wall. Even in a situation like this, the door hardware used on the door must be consistent with the door’s rating even though it is in a lower rated wall.

Why is this? Why is the rating for the door lower than the rating for the wall? The explanation is that it is presumed that the door will not have combustible materials piled up against it, while it is reasonable to assume combustible materials might be stored on a wall. Therefore the wall requires a higher level of fire resistance.

This leads to another important issue with fire doors; they must not be obstructed, blocked, bolted or otherwise disabled so that individuals cannot readily transgress.

Fire doors frames are not affected by the ratings and classifications that apply to doors. There are no hourly ratings for a basic fire door frame unless the labeling on the frame specifically states that the frame is rated for something less than 3 hours. If a frame bears a recognized label qualifying it as a fire door frame, it may support a 3-hour, a 1-1/2-hour, a 3/4-hour, or a 1/3-hour door

Fire doors and frames are considered Fire Door assemblies whose components have been tested together and supposed to have labels so that they may be readily identified as fire doors and what their ratings are. This is particularly helpful when replacing hardware so you are assured the hardware is appropriate for the door.

Door Hardware

Fire doors must be closed and latched at all times. Therefore door hardware must be installed on fire door which will fulfill certain requirements:

  • The door closes by itself
  • When it closes it latches
  • The door may be readily unlatched and swings to the open position.
  • The door will remain closed and latched during a fire to meet the extent of its rating

Latching devices must use the correct length of latch bolt. Pairs of doors to require a longer latch bolt throw than a single door.

Note: The minimum latch bolt length that must be used for any given door is indicated on the fire door label.

Building Codes require the use of exit devices on certain doors based on the occupancy and the location of the door in the building.

Not all fire doors are designed to be used with fire exit hardware. The fire door’s label must state: “Fire Door To Be Used With Fire Exit Hardware.” This label indicates that the door has been properly reinforced for fire exit devices.

Closing devices are required to cause a door to be self-closing and a properly sized closing device rated for the particular opening is a critical fire door hardware requirement.

In certain situations, fire doors may be held in the open position as long as they are held open with listed door holders which are connected to premises fire alarms so that the holders release and permit the door to close in the event of a fire alarm.

Usually in corridors, the hold-open provides for convenient passage through the building, but if fire or smoke is present, the doors can close to prevent the spread of products of combustion (smoke) and fire.

Most deaths in fires are caused by the toxic products of combustion created by the fire. The spread of fire is inhibited by closed and latched fire doors. For this reason, either spring hinges or a listed door closer is required. When the door has closed to the latched position, the closer has fulfilled its role as a protective device.

Restrictions On Field Modifications

Field modification of fire doors is limited by NFPA 80 to preparations for surface-applied hardware, function holes for mortise locks, holes for labeled viewers, installation of protection plates, and a maximum ¾-inch wood and composite door undercutting.  Holes drilled in the field are limited to 1-inch diameter, with the exception of cylinder holes which can be any size.  If holes are left in a fire door assembly when hardware is removed, those holes must be filled with steel fasteners or the same material as the door or frame.  There is also a fire door caulk now available for use in filling small holes in wood doors.  Other field modifications should not be made unless the doors are to be reinspected by a labeling agency.

NFPA 80 is the National Fire Protection Agency’s NFPA 80: Standard for Fire Doors and Other Opening Protectives

A Standard is an agreed way to do something. A Code is a law which is enforceable. NFPA 80 is a standard that is included in most building codes, and therefore treated as a law with respect to the requirements for fire doors.

Remember that requirements are minimum standards, and the AHJ has the final word regarding the interpretation and application of standards.

NFPA 80 sets forth a list of 11 items which must be inspected and must be in good repair in order for a door to be considered in compliance with the letter and intent of NFPA 80:

  • No open holes or breaks exist in surfaces of either the door or frame.
  • Glazing, vision light frames, and glazing beads are intact and securely fastened in place, if so equipped.
  • The door, frame, hinges, hardware and non-combustible threshold are secured, aligned, and in working order with no visible signs of damage.
  • No parts are missing or broken.
  • Door clearances at the door edge to the frame, on the pull side of the door, do not exceed clearances listed in 4.8.4 and 6.3.1.
  • The self-closing device is operating by verifying that the active door will completely close when operated from the full open position.
  • If a coordinator is installed, the inactive leaf closes before the active leaf.
  • Latching hardware operates and secures the door when it is in the closed position.
  • Auxiliary hardware items, which interfere or prohibit operation, are not installed on the door and frame.
  • No field modifications to the door assembly have been performed that void the label.
  • Gasketing and edge seals, where required, are inspected to verify their presence and integrity.

Read a more detailed article about these requirements, the Importance of Site Surveys, in the April 2014 issue of Locksmith Ledger or online at