Hollow Metal Door Hardware
Hollow Metal Door Fire Exit Hardware
Hollow metal doors are known for durability, security, and safety. The hardware used on any hollow metal door is dependent on whether the door is a fire door or not. This can easily be checked by looking at the fire label on the hinge side of the door. The fire label or construction label is typically right below the top hinge of the door and it states valuable information such as the fire rating in minutes. If there is no fire label and the door is not considered a fire label, then fire rated hardware is not necessarily required. However, if it is a fire rated door, any hardware that is replaced must be fire rated in order to maintain fire code compliance.
Fire Rated Door Hardware Requirements
Any fire door must either be self closing, automatic closing, or power operated. There are two exceptions to this:
- The International Building Code exempts communicating doors between hotel rooms from the self closing requirement.
- The NFPA 80 has an exception for the inactive leaf of a pair leading to a room not normally occupied by humans, if acceptable the AHJ (Authority Having Jurisdiction).
Self Closing Doors
Fire doors must be self closing. This is important because in the event of a fire, the fire door must be closed in order to deter the smoke and flames from reaching other parts of the building. To meet the self closing door requirements, a fire rated door closer or other closing device will suffice.
Hydraulic Door Closer
The standard and most popular choice is a heavy duty, fire rated door closer that is mounted at the top of the door and head of the frame. Each time the fire door is opened by a pedestrian, it gently closes shut.
Electronic Hold Open Mechanism
The International Building Code requires hold opens that are used in most fire door locations to be smoke activated. Automatic closing doors use an electric hold open device, often known as a magnetic hold open device. These devices are able to keep the door open using a magnetic hold function. Magnetic hold open devices are designed to be wired with fire alarms so that in the case of a fire, the magnetic hold open device will release the door and close.
Power Operated Doors (ADA Door Openers)
A power operated door opener is an electromechanical device designed to mount at the top of the door frame head. In recent years, due to ADA and touchless activation health industry concerns, power door openers have become extremely popular. Power door operators are designed to keep the door closed just like a hydraulic door closer in the event of a fire. What alot of people don't realize is that there is a huge number of non compliant power door operators on the market today. Fire rated power door operators due exist and they have the proper UL10C label to show it. That is the biggest indicator to quickly check if the door operator can be installed on a fire rated door. Fire rated power door operators all have an internal clock spring that winds up as the door opens. When the pedestrian passes through the door, power door opener spring unwinds closing the door. This is what makes power door openers compliant with UL10C, along with other factors. So as an example, in the event of a fire the power door opener will always close the door, even in the event of a fire. Non fire rated power door operators do not have an internal clock spring, since it is a cheaper manufacturing process. This is very dangerous because if the power goes out and there is a fire, if the power door opener was in the middle of an opening cycle, it will keep the door in that same position. Fire doors depend on the door being self closing to deter any kind of flames or smoke.
Any fire rated hollow metal door must have a positive door latch. So what do we mean by a positive latch? Every fire door must have an active latchbolt so that the door will latch closed in the event of a fire.
Hollow Metal Door Cylindrical Lock
So this means if the door has a cylindrical lock or even an exit device then there is a spring loaded latchbolt on the lock or exit device to ensure that the door will remain closed in the event of a fire. The minimum latch throw is not specified by recent editions of the NFPA 80.
Hollow Metal Door Electric Strikes
An electric strike is an electromechanical door strike that is installed in a door frame. An electric solenoid mechanism with the strike body allows the strike to release or lock depending on the voltage signal applied to it. Electric strikes come in a variety of models for use with cylindrical locks or rim exit devices. Electric strikes are also available with UL10C, compliant for use on fire rated doors. Electric strikes are typically used for security type doors and are interfaced with card readers, keypads, or power door operators to allow access for a select group of people or employees. For fire rated doors electric strike must be fail secure. A fail secure electric strike remains in the lock position in the event of a power outage. A fail safe electric strike is not permitted on fire rated doors. Fail safe electric strikes are unlocked in the even of a power outage which means it could easily unlatch a door in the event of a fire, which is not allowed. All fire rated electric strikes are interfaced in some way with a fire alarm system, so that the strike keeper will always be in the secured or locked position in the event of a fire.
Hollow Metal Door Fire Rated Exit Device
An exit device is a horizontal push pad locking device. It is designed to be mounted on the interior side of the door. When a pedestrian pushes on the push pad the latchbolt releases and unlatches, and the door can swing open. Exit devices are also known as crash bars, panic bars, push bars, etc. They were originally designed to address growing concerns with crowds inside of buildings. In the early days, doors didn't have exit devices, and sometimes in the event of a catastrophe groups of people found themselves trapped or trampled on because they could not figure out how to open the door quick enough. A fire rated exit device is designed specifically to be pushed against to release the door. Non fire rated device are known as panic devices. These devices typically have a dog down feature which allows the exit device to remain unlatched. Fire rated exit devices are not allowed to have the dogging feature. Why you might ask? Because all fire doors depend on latching closed in the event of a fire. Panic devices with the dog down feature mean that the door could be unlatched during a fire, which is unacceptable.
Hollow Metal Door Automatic Flushbolts
For fire rated door pairs, there is typically one active door panel and one non active door panel. Fire rated door pairs require positive latching automatic flush bolts or fir exit hardware. The exception would be for manual flush bolts for rooms that are not normally occupied by humans, such as a storage room or a mechanical room. However, that should always be checked with your Authority Having Jurisdiction (AHJ). Auxiliary fire pins may be used in place of a bottom bolt wit some automatic flush bolts. On fire rated doors there should be no hardware that would indicate an operable door such as a dummy lever or push bar.
Hollow Metal Door Coordinators
Door coordinators are used with fire rated door pairs that use automatic flush bolts. A door coordinator is a mechanical device mounted at the head of the door frame which makes the inactive door panel close before the active panel. Coordinators are very important because if the active door panel closes first, then the latchbolt on the lock or exit device will not latch properly, making it a hazard in the event of a fire.
Hollow Metal Door Astragals
An astragal is a type of weatherstripping used on door pairs. An astragal is designed to provide a seal for the gap between the two door panels. For fire rated doors overlapping astragals are not mandatory for every fire door, but maybe required by a manufacturer's listings. Fire rated door pairs should have a projection of approximately 3/4" when an astragal is required. Astragals cannot restrict egress. For astragals like the flat astragal or overlapping astragal a door coordinator will be required.
Hollow Metal Door Hinges
A door hinge is a pivot mechanism that attaches to the door and frame and allows the door to safely swing open or closed. For hollow metal doors, the standard hinge is a square 4.5" x 4.5" commercial ball bearing hinges. Door hinges must be a steel base material, ball beraing, or listed for use on a fire door. It is required to have 2 hinges for the first 60 inches of the door height, and one additional hinge for each 30 inches of door height. As an example, a standard 3'-0" x 7'-0" (36" x 84") door would have a total of 3 hinges, while a 3'-0" x 8'-0" (36" x 96") would have a total of 4 hinges. Spring hinges are allowed on doors, however they cannot exceed use on doors wider than 3 feet or taller than 7 feet high. The NFPA 80 (2013) allows for use of continuous hinges on hollow metal doors as long as the length of the continuous hinge is within 1 inch of the door height.
Hollow Metal Door Pivots
Although pivots on hollow metal doors are not an industry standard, they are still allowed. The hollow metal door can utilize a top and bottom pivot system. There must be 1 intermediate pivot for doors up to 90 inches in height. For doors over 90 inches height, there must be 1 additional intermediate pivot for each 30 inches of door height. If the hollow metal door only uses intermediate pivots with no top or bottom pivot then, there must be 2 intermediate pivots for doors up to 60 inches in height and 1 additional intermediate pivot for each 30 inches of door height.
Hollow Metal Door Gasketing and Weatherstrip
Gasketing or weatherstripping is a seal that is installed on the door or frame in order to prevent debris, wind, or pests from penetrating through the door way. Hollow metal door smoke and draft control doors must be tested for air infiltration in accordance with UL 1784. Maximum air leakage rate must be limited by the IBC to 3.0 ft^3/min/ft^2 of door opening. Hollow metal door gasketing is essentially required to limit air infiltration to this level. All gasketing and threshold products must be listed for use on fire doors. Bottom seals and thresholds are not required for fire doors in many locations.
Hollow Metal Door Protection Plates
A protection plate is metal sheet that is installed on the face of the door for increased armor to prevent damage. The most popular protection plates are kick plates, mop plates, or armor plates. The NFPA 80 limits the height of protection plates on fire doors. The plates must be mounted at the bottom 16" of the door and may be field installed with no label required. The protection plate may be installed under the label service (at the factory or in approved shop) as allowed by the manufacturer's listings. All field installed plates mounted above 16 inches of the door must be labeled for use on fire doors.
Hollow Metal Door Vision Lite
A vision lite is a glass window installed on a hollow metal door. The NFPA 80 has limitations on the size and type of glass used. If the door is fire rated, the vision lite must also be fire rated. The glazing is limited to the maximum area tested by the door or frame manufacturer and the glazing manufacturer. Each piece of glass must be identified with a label that is visible after installation. More information on hollow metal door vision lite kits is available in our vision lite kit section.
Hollow Metal Door Louver Kit
A louver is a vent installed on a hollow metal door. It is designed to offer ventilation. If the hollow metal door is fire rated, then the door louver must also be fire rated. Please see our section on door louvers for more information.