Door hardware 101: The basics of door hardware specifications

July 1, 2020

by Lori Greene, DAHC/CDC, CCPR, FDAI, FDHI

Photos courtesy Allegion[1]
Photos courtesy Allegion

Door hardware specifications can be confusing and tedious. Just the thought of having to recall door hardware terminology, code requirements, and best practices is overwhelming. Then, transferring that knowledge to work when designing commercial or institutional facilities with hundreds to thousands of openings, each including five to 10 pieces of hardware, seems like a monumental task.

To help the process seem a little less daunting, here is a reference guide explaining common terminology and hardware. There are four main steps to follow when specifying door hardware:

Hang the door

Typically, hinges are used to hang the door. There are a few basic types. Five-knuckle or three-knuckle are the common choices. Continuous hinges run the entire length of the door and are often used on exterior doors. It is important to consider the door width, thickness, weight, and clearance when choosing a hinge.

Pivots reduce stress on the frame by distributing the door weight throughout the floor and structure. Pivots are used when the door is heavy, design requires pivots, or it is an aesthetic preference.

In the author’s experience, hinges causing the most confusion are wide throw, swing clear, raised barrel, and anchor hinges.

Wide throw hinges

These hinges are used when extra clearance is needed behind a door. These are commonly utilized when a door needs to open 180 degrees and sit parallel with the wall, held open on a magnetic holder.

Swing clear hinges

These hinges are used to swing the door out of the clear opening of the frame when the door is open approximately 90 to 95 degrees. Swing clear hinges are most commonly used in hospitals.

Raised barrel hinges

For these hinges, the barrel is offset to one side instead of centered between the hinge leaves. This type of hinge is fairly rare, but it is used when the barrel of a standard hinge would interfere with a special frame condition or trim.

Anchor hinges

These are used as the top hinge for high-use or heavy doors. In addition to the standard hinge leaves, flanges are attached to the top of the door and the underside of the frame head. These hinges require a special door and frame prep, and are handled.

Secure the door

Understanding how to secure openings is an important step with a lot of pieces to the puzzle.

Locking hardware

It is easy to get overwhelmed when discussing lock functions as sometimes as many as 50 functions could be listed in a catalog. It is helpful to start with the following six basic functions that account for the vast majority of locks specified.

Passage set

Passage sets are used where doors do not need to lock. A latch bolt can be operated by a lever from either side at all times.

Privacy set

Privacy sets are used for spaces like restrooms or dressing rooms. They can be locked from the inside with a thumb turn or with a push button/turn for privacy, and they are typically unlocked from the outside using a tool rather than a key. There are several variations.

Storeroom lock

Storeroom locks are used when the outside lever should be locked at all times. A key is used to retract the latch bolt and open the door; when the key is removed the door is locked on the outside.

Entrance/office lock

These may be controlled by a key in the outside cylinder or by a thumb turn or push button/turn on the inside. The outside lever may be left in a locked or unlocked position.

Traditional classroom lock

Classroom locks are controlled by a key in the outside cylinder, which locks or unlocks the outside lever. The lock can be left in the locked or unlocked state by using the key, and there is no means of locking or unlocking the door from the inside. This function was originally designed for schools to prevent students from tampering with the lock, but most of the new institutions have classroom security locks, office function locks, storeroom locks, or electrified locks.

Classroom security lock

Classroom security locks allow control of the outside lever via key cylinders on both the inside and outside of the door. This allows a teacher to lock the classroom door during a lockdown without opening the door and possibly being exposed to an intruder in the corridor.

Mechanical locks

Tubular, cylindrical, mortise, deadbolt, and interconnected types of mechanical locks.

Tubular

Tubular locks have a center spindle assembly extending through the center of the lock body and latch, allowing for retraction of the latch when the lever or knob is rotated. While this type of lock is very common on interior doors and in residential applications, they are considered the least secure lock type.

Cylindrical

Cylindrical locks are sturdier and considered more secure than tubular locks. The latch bolt assembly interlocks with one side of the lock chassis, making it easier to install, replace, and rekey. Cylindrical locks are also available in different formats that provide various levels of security, all of which use the same type of key.

Mortise

Mortise locks are stronger and heavier than cylindrical locks, making them ideal for use in hospitals and schools. They require a pocket—the mortise—to be cut into the door where the lock is fitted. Mortise locks also provide a wide variety of choices for function, trim, key systems, and finishes.

Interconnected

An interconnected lock comprises two locks that are connected together, so operating the lever handle will retract both the latch bolt and deadbolt simultaneously. The latch set is either a cylindrical or tubular lock with a deadbolt above it. These locks are most commonly employed on dwelling unit entrance doors in multifamily buildings.

Deadbolt

Deadbolts are available with a single or double cylinder. The single-cylinder deadbolt operates by a key on the outside and a thumb turn on the inside. A double-cylinder deadbolt requires a key for unlocking on both sides of the door and cannot be used on doors required for egress, except in limited locations where specifically allowed by the adopted codes. In these cases, all criteria stated in the adopted code must be met.

Electrified hardware

Electrified hardware uses power to control the locking and unlocking of the door. Most electrified hardware is available in one of two functions: fail safe or fail secure. Fail safe and fail secure refers to the status of the secure side (key side, outside) of the door. Most electrified hardware allows free egress from the egress side (inside) of the door.

Low-energy automatic operators are used where a knowing act, such as a push button, is used to automatically open the door.[2]
Low-energy automatic operators are used where a knowing act, such as a push button, is used to automatically open the door.

Electronic locks

An electronic lock is controlled by a reader, such as a keypad, card reader, or biometric terminal. There are two main types of electronic locks.

Standalone locks and readers

Standalone electronic locks employ the same credential as networked locks. However, they are not connected to access control software, so they require the user to physically go to each lock to administer access rights and retrieve tracking information.

Networked locks

Networked electronic locks are connected to an access control system. They allow the system manager to easily change access rights and track movement throughout the entire facility from anywhere they are connected to the network.

Electromechanical locks

An electromechanical lock is an electrified lockset that can be controlled by a card reader, remote release, or other access control device. Most electromechanical locksets allow free egress at all times.

Electromagnetic locks

An electromagnetic lock is an electromagnet that mounts on the frame, with a steel armature mounted on the door. When power is applied to the magnet, it bonds to the armature, securing the door. Electromagnetic locks are only available in fail-safe mode. They unlock when power is removed.

Electric strikes

An electric strike replaces the regular strike for a lockset or panic hardware. It is used as part of an access control system to provide added security and convenience such as traffic control and remote release. An electric strike is typically paired with a storeroom function lockset or panic hardware, so access is controlled by the electric strike but egress is unaffected.

Fail safe versus fail secure

Fail-safe products are unlocked when power is removed. Power is applied to lock the door. Fail-secure products are locked when power is removed. Power is applied to unlock the door.

Here are some tips to keep in mind:

Readers

Just as a key fits a lock, a card, biometric, fob, or phone requires a reader. There are a number of options to choose from. In some cases, the lock and reader are combined into one unit. Readers can be contact-based, which requires the credential to be swiped or touched by the reader. They can also be contactless, requiring only a certain proximity or range to communicate. Biometric readers are also an option. These use unique human characteristics as the credential, such as the size or shape of the hand. The most secure reader options on the market, biometrics are more common in high-security applications, such as data centers, airports, banks, and government buildings.

When specifying a card reader, it is advisable to ensure it has the capacity to read all types of cards such as smart, proximity, and mag stripe. Specifying a multi-technology reader can eliminate the expense of installing new readers should credentials change down the road. In today’s market, it is also important to make sure the specified product is able to read credentials on a mobile device.

Panic hardware

Panic hardware—also known as exit devices, crash bars, panic bars, panic devices, or push bars—is designed to provide fast and easy egress to allow building occupants to exit safely in an emergency. These devices allow the exterior side of the door to be locked, while ensuring people can always exit from the interior. Consisting of a spring-loaded metal bar or touchpad mechanism fixed horizontally to the inside of an out-swinging door, it activates a mechanism that unlatches the door, allowing occupants to leave quickly. The National Fire Protection Association (NFPA) 101, Life Safety Code, and the International Building Code (IBC) both include requirements pertaining to panic hardware. It is important to remember local codes may be different.

Dogging is a feature employed in panic hardware to hold the touchpad or crossbar in a retracted position, thus allowing a door to operate in push/pull mode without latching. Mechanical dogging is not allowed for fire doors, so fire exit hardware will not have the ability to be mechanically dogged. Fire doors may be dogged electrically, as long as the latches project upon fire alarm to positively latch the door.

There are several types of panic hardware.

Touchpad

Touchpad panic hardware is mounted on the inside of the door and features an enclosed mechanism case with a touchpad to allow egress.

Crossbar

Crossbar panic hardware may be used for doors with large glass lites or where there is an aesthetic preference for the crossbar style. Available for both wide and narrow stile doors, they are ideal for environments demanding a traditional look that is durable enough to withstand rugged applications.

Recessed

Recessed panic hardware is embedded into the door in order to maintain a low profile with sloped end caps to deflect objects away from the door. This hardware is close to being totally flush with the door when depressed.

Rods versus cables

Vertical rod panic hardware has historically been manufactured with rods and latches to secure the door both at the top and bottom. Recently introduced exit devices utilize a concealed vertical cable instead of rods. Concealed vertical cable panic devices are more aesthetic and easier to install and maintain than traditional vertical rod devices.

Control the door

Controlling the door is the job of a door closer. The function of a door closer is not just to close the door, but also control the door in both the opening and closing cycles to prevent damage and injury caused by abuse, wind, or other factors.

Choosing a door closer involves the consideration of a variety of criteria. In addition to the closer’s performance in fire situations, other factors may include resistance to opening forces, control over the rate of closing, safety, durability, risk of vandalism, and aesthetics. Many codes and standards contain requirements for door closers, so it is important to reference all accessibility, fire, and life-safety requirements before specifying.

There are five basic types of door closers.

Surface-mounted closers

These closers mount at the top of the door and frame—either parallel arm mount (push side), regular arm mount (pull side), or top jamb mount (push side).

Floor closers

These closers mount in the floor, and the door is typically hung on pivots. Floor closers must be carefully coordinated with the floor construction and finish flooring for proper installation.

Concealed closers

Concealed closers are mounted in the frame head, or in the top rail of the door, when aesthetics are a concern.

High-security closers

High-security closers feature a vandal-resistant design for use where closers may be exposed to abuse or vandalism.

Electronic closers

Fire doors may not be held open mechanically, but electronic closers may be used on fire doors to hold the door open and automatically close the door when a signal is received from the fire alarm or smoke detector. A door with this type of closer is called automatic-closing, while a door closing each time it is opened is called self-closing.

Automatic operators

Low-energy automatic operators are used where a knowing act, such as a push button, is used to automatically open the door. They are required by code to open the door slowly and with a limited amount of force.

Electro-hydraulic systems

These are designed for manual opening applications where there is occasional need for automating the door to allow easier access for building occupants or to meet Americans with Disabilities Act (ADA) requirements. Electro-hydraulic operators combine a conventional heavy-duty door closer with a low-energy automatic operator.

Electromechanical systems

Designed for more frequent automatic use, these operators are often used on cross-corridor doors and other often-used openings in hospitals. These operators are mainly designed for applications where automatic operation is the primary need.

Pneumatically powered systems

These are great for use in areas where electrically operated devices are not convenient or permitted. The pneumatic operator consists of a heavy-duty door closer for manual operation and a pneumatic automatic operator to power the door when required. Power for the operator comes from the in-house air supply or for a compressor furnished with the operators. These operators are silent when the compressor is installed in a remote location, making them ideal for use in libraries, churches, hospitals, and laboratories.

Protect the door

Many products are available to protect the door, an important step in the specification process.

Plates

Protection plates, including mop plates, kick plates, stretcher plates, and armor plates, are used to protect a door from wear and tear. In institutional or high-abuse and high-use applications, it is best to specify the proper plates to help prevent damage.

Stops and holders

Door stops prevent doors from coming into direct contact with walls or other adjacent surfaces. Common stops include wall stops, floor stops, and overhead stops.

Overhead stops and holders should be used in locations where wall stops and floor stops are unsuitable. Some door closers are available with built-in stops, which work well for some applications, but the backcheck feature of a door closer is not a substitute for an auxiliary stop.

Gasketing and thresholds

Gasketing and thresholds may be used to restrict airflow, smoke infiltration, sound, light, and temperature. Gasketing is installed at the head and jambs of the door opening. Thresholds and sweeps are installed at the bottom of the door.

Conclusion

In the author’s experience, some architects and specifiers enjoy writing hardware specifications. Others could get overwhelmed by the amount of products, code requirements, and terminology that come with the territory. Whether you write your own specifications or work with an architectural hardware consultant, knowing the jargon for door hardware will help ensure your next project is safe and secure.

[3]Lori Greene, DAHC/CDC, CCPR, FDAI, FDHI, is the manager of codes and resources for Allegion. She has worked in the industry for more than 30 years, including more than 20 years as a hardware consultant writing specifications. Greene is a member of CSI, the Door and Hardware Institute (DHI), the International Code Council (ICC), the National Fire Protection Association (NFPA), and the Builders Hardware Manufacturers Association (BHMA) Codes and Government Affairs Committee. She also blogs at www.iDigHardware.com[4], which is celebrating its 11th anniversary this year. Greene can be contacted at lori.greene@allegion.com[5].

Endnotes:
  1. [Image]: https://www.constructionspecifier.com/wp-content/uploads/2020/06/00180_EDU_E_18x12_300.jpg
  2. [Image]: https://www.constructionspecifier.com/wp-content/uploads/2020/06/00064_HC_CEO_17x12_300.jpg
  3. [Image]: https://www.constructionspecifier.com/wp-content/uploads/2020/06/Lori-Greene-DAHC-768x999-1.jpg
  4. www.iDigHardware.com: http://www.iDigHardware.com
  5. lori.greene@allegion.com: mailto:lori.greene@allegion.com

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