Garage door installation—not to mention garage doors themselves—are surprisingly complex, especially if you’ve never investigated all the components and mechanisms that make it possible for a garage door to open and close smoothly. As a result, there is quite a bit of terminology around garage doors that is unfamiliar to the typical lay-person.
Are you wondering what an astragal or escutcheon could be, or confused about the difference between backroom and headroom? The garage door experts at Dodds Garage Doors have the answers to these questions and many more in this comprehensive glossary of garage door terms and definitions.
A
A-Frame: A supporting piece utilized to secure the torsion spring assembly of a vertical lift door to the wall located above the opening of the garage door.
Anodize: The process of electrolytically coating aluminum with an oxide layer for protection and/or decorative purposes.
Astragal: Weather stripping along the bottom of a garage door that seals the gap between the garage door and the floor.
B
Back Hangs: Vertical supports that are used to secure the horizontal track in place and prevent the door from shifting within the track.
Backroom: The amount of clearance required for garage door installation from the door to the back end of the horizontal track.
Bottom Bracket: A structural element fastened to the lowest section of a garage door with a lifting cable attached to it so the door can be raised and lowered. Also referred to as a bottom corner bracket.
Bracket-Mounted: A vertical track that is affixed to vertical jambs with angle brackets.
C
Cable: A flexible, multi-strand metal wire that attaches the counterbalance assembly to the bottom bracket.
Cable Drums: Grooved drums located on the torsion spring shaft. When the garage door opens, the lifting cables wind around the cable drums to prevent cable chafing or lapping when the door is opening and closing.
Cable Safety Device: A fixture that prevents a door from falling if the cable breaks.
Center Lift Cable: An extra lifting cable on the outside of garage doors for additional support with wider or heavier doors.
Clearances: The amount of headroom, sideroom and backroom required for a sectional garage door installation.
Cycle: The overall process of the garage door opening and closing. Starting from a closed position, the cycle is complete once the door has opened and then closed again.
D
Dead Load: A static load of weight with no movement.
Door Frame: A frame composed of two vertical jambs and a header that line the opening where the garage door is hung.
Double Car Garage Door: A garage door greater than 10 feet in width, designed to accommodate double-parking spots inside the garage.
Double-Thick Glass: A pane of glass that is thicker than the standard at about an eighth of an inch thick.
Duplex Spring: Two torsion springs with different diameters combined together by being telescoped within spring plugs.
E
Electric Opener: A garage door opener that utilizes electricity to complete the opening and closing cycle of a garage door.
Escutcheon: A crucial component of a lock set, serving as a supporting surface for the lock shaft, and is typically fixed in position by small screws referred to as escutcheon screws.
Extension Springs: Springs that are responsible for generating the lifting force as they stretch when the door is in motion, running from a pulley to the rear-track hanger.
Exterior Lock: A keyed lock mounted on the outside of a garage door that must be manually operated.
F
Ferrule: A metal cap or ring that is attached to a cable to create a secure loop or bottom at the end of the cable.
Flag Bracket: An L-shaped bracket that is used to connect the vertical and horizontal tracks together.
Flush Design: A style in which the garage door is flat, without grooves or indentations.
G
Galvanizing: The process of applying a zinc coating to steel to make it resistant to corrosion.
Garage Door Opener (GDO): The mechanism that opens or closes a garage door, typically operated by a remote control.
Gauge: A measurement of the thickness of steel. The higher the number of gauge, the thinner the piece of steel.
H
Header Seal: Weather stripping that runs along the top of a garage door opening to seal the gap between the header and the garage door.
Headroom: The space between the top of a garage door opening and the closest obstruction.
Heat Transfer: The natural process of the movement of thermal energy from a warmer place to a cooler place. The purpose of insulation is to prevent heat transfer through a garage door, window, wall or other type of surface.
High Cycle Springs: Counterbalance springs with greater durability and cycle lift capability, intended to support garage doors that have a high rate of usage.
Hinges: Mobile joints that are screwed in between sections of a garage door so the sections can “break” apart independently as the door moves from a vertical to a horizontal position.
Horizontal Track: A door guide and support assembly consisting of a track and an angle piece for reinforcement, serving to guide and support the door in the horizontal position.
I
Inclined Track: A tapered vertical track combined with edge hinges situated at a graduated height to ensure a secure, weather-resistant seal between the garage door and the jamb.
Inside Lock: A sliding, spring-loaded deadbolt lock on the inside of a garage door that must be manually operated.
Insulated Glass: Two panes of glass separated by a small air gap and sealed together at the edges of the panes to form a single unit with a space in between to improve insulation and resist heat transfer through the glass. Insulated glass cuts heat transfer by about half compared to non-insulated glass.
Insulation: Material that is capable of resisting heat transfer.
J
Jambs: The vertical portions of a door frame, typically made of wood or steel.
Jamb Seal: Weather stripping that runs along the vertical jambs to seal the gap between the jambs and the garage door.
Joint Seal: Weather stripping that covers the joint between garage door sections to help prevent heat transfer and air drafts.
L
Lift Clearance: The distance between the top of a garage door opening and the bottom of the horizontal tracks.
Lift Handle: A handle attached to the middle of the bottom section of a garage door to enable the door to be manually lifted.
Lite: A garage door panel that consists of a frame and glass or clear plastic glazing to allow natural light into the garage. The number of panels in a section determines the maximum quantity of lites that can be installed, and they may be doubled glazed to improve insulation.
Low Headroom: Additional hardware that enables garage door installation in a building with a minimal amount of headroom space, usually 16 inches or less.
M
Mounting Plates: Flat pieces of wood or steel that are affixed to the wall to accommodate chain hoists, spring shaft bearings and mountings.
Mullion: A narrow bar situated between two garage doors, typically used to carry wind load rather than vertical load.
Muntin: A small strip of material such as wood or metal that separates and supports panes of glass in a multi-pane window or lite.
O
Opening: The area of the open space in the wall of a garage that will be covered by a garage door once installation is complete.
Opening Height: The distance between the floor and the top of a garage door opening.
Opening Width: The distance between the vertical jambs of a garage door opening.
Overhead Garage Door: A garage door with hinged sections that rolls open and closed along vertical and horizontal tracks, so it is in a horizontal position parallel to the garage ceiling when open.
P
Pass Door: A small swinging door set in a garage door that allows people to pass in and out of the garage without opening the larger garage door structure. Also referred to as an access door or wicket door.
Pedestrian Door: An access door that is adjacent to a garage door rather than set into it like a pass door, for people to get in and out of the garage without using the garage door.
Perimeter Seal: A package of weather stripping for garage doors that includes the astragal, header seal and jamb seal.
Perimeter Wearstrip: To prevent rubbing, a vinyl or felt wearstrip is attached to the corrugated sheet door curtain. This can be placed either at the ends or drum locations.
Photo Sensors: Small sensors that are mounted on either side of a garage door a few inches above the floor. They cause a closing door to reverse direction if an obstruction is detected between the floor and the bottom of the closing garage door. Also known as photo eyes.
R
Radius: The curved section of the track facilitates the door’s transition from a vertical to a horizontal position, and vice versa. The curvature is measured in inches, determining the necessary headroom.
Rain Stop: A small step or rise at the edge of the garage floor below the garage door opening, usually about one inch higher than the outside ground or driveway, that prevents rainwater from seeping into the garage.
Roller Assembly: The combination of wheels or rollers, and axles that allow garage door sections to move along tracks.
Rollers: Wheels, typically made of either steel or nylon, that are attached to each section of a garage door to allow the section to roll along the vertical and horizontal tracks.
R-Value: An indicator of insulation materials’ thermal performance and heat resistance. Typically measured per inch of thickness, it represents the material’s ability to prevent heat transfer. Various factors, including density, thickness, and material type, influence the R-value. A higher R-value signifies a greater effectiveness in blocking heat transfer.
S
Safety Spring Containment: A supplementary cable that is employed alongside garage door extension springs to safeguard against potential damage or injury in the event of a spring breakage. This cable runs through the center of the spring and is securely fastened at both ends of the horizontal track.
Sideroom: The amount of space between each side of the garage door opening and the closest obstruction inside the garage or building.
Single Car Garage Door: A garage door that is less than 10 feet in width, to give access to a single parking spot inside the garage.
Spring Fittings: Two components that attach torsion springs to the torsion shaft: the stationary sleeve or spring retainer, and the winding cone or sleeve.
Strut: A support stiffener that boosts a door’s wind load capacities and minimizes deflection when the door is in a horizontal position.
T
Torsion Spring Counterbalance Assembly: All the necessary hardware components that work together to ensure the weight of the garage door is evenly distributed when it is opening and closing.
Torsion Springs: A spring that enables opening and closing functions for a garage door. The springs are mounted above the door on a shaft, where they turn the shaft so the cables attached to the shaft can lift and lower the garage door.
Track: Metal bars shaped like a channel that form a path for the rollers that move garage doors from a vertical to a horizontal position and vice versa.
V
Vertical Lift: A piece of hardware that enables a sectional garage door to open vertically along the wall above the opening without folding back into the building.
Vertical Track: A track assembly mounted to the jambs on either side of a garage door opening to support and guide a sectional door in the closed position when the door is vertical.
W
Winding Cone: A hardware component that converts tension to distribute the weight and make it manageable for the spring assembly.
Wind Load: A measurement of the force of the wind against a closed garage door.
Wire Glass: A pane of glass with wire mesh embedded into it that prevents the glass from shattering when broken.