Glossary
This glossary defines common technical terms related to residential systems, components, hardware, and performance. Use the A–Z navigation to jump to a letter or scroll through the full list.
Anchor
An anchor is a fastener used to secure hardware into masonry, concrete, or other solid substrates. It transfers loads from brackets or tracks into the supporting structure.
Angle Iron
Angle iron is an L‑shaped steel support used to mount tracks, operators, or bracing. Its shape provides rigidity and allows secure attachment to ceilings or walls.
Astragal
An astragal is a flexible seal installed along the bottom or edge of a moving panel to reduce air, water, and debris infiltration. It also cushions contact with the floor or frame.
Automatic Reversal
Automatic reversal is a safety feature that causes a moving system to reverse when it encounters an obstruction. It relies on force sensing, photo eyes, or both.
Backroom
Backroom is the horizontal distance from the opening to the nearest obstruction behind it. Adequate backroom is required for the system to fully open and store overhead.
Belt Drive
A belt drive uses a reinforced belt to transmit motion from the operator to the system. It typically runs more quietly than chain drives and requires less maintenance.
Bottom Bracket
The bottom bracket is a metal fitting near the lower edge of a panel where lift cables attach. It carries significant tension and must be properly installed for safe operation.
Brush Seal
Brush seal is weatherstripping made of dense bristles used to reduce drafts and dust around gaps. It allows flexible sealing without restricting movement.
Cable Drum
A cable drum is a grooved wheel that winds and unwinds lift cables as the system moves. Its size and groove profile match the height and weight of the assembly.
Cycle Rating
Cycle rating indicates how many open‑and‑close operations a component is designed to withstand. Higher cycle ratings mean longer expected service life.
Clearance
Clearance is the minimum space required around and above the system for tracks and hardware to move freely. It includes headroom, side room, and backroom.
Cladding
Cladding is an exterior layer applied over a structural panel to change appearance or improve durability. It may affect weight, insulation, and maintenance needs.
Dead Load
Dead load is the permanent weight of the system and its fixed components. It is used to size springs, supports, and structural members.
Direct Drive
Direct drive refers to an operator design where the motor moves the system directly without long chains or belts. It reduces moving parts and can lower noise.
Double Track
Double track uses two horizontal track levels to change how panels store overhead. It can reduce headroom requirements or alter the travel path.
Edge Seal
Edge seal is weatherstripping installed along vertical or horizontal edges to reduce air and water infiltration. It also cushions contact between sections and the frame.
Emergency Release
The emergency release disconnects the operator from the system for manual operation. It is essential during power outages or malfunctions.
Extension Spring
An extension spring stretches to provide counterbalance force as the system closes. It is typically mounted along the horizontal tracks.
Flush Panel
A flush panel has a flat exterior surface without raised or recessed patterns. It is common in modern or minimalist designs.
Force Setting
Force setting controls how much resistance the operator tolerates before stopping or reversing. Proper adjustment is critical for safety.
Frame
The frame is the structural opening into which the system is installed. It must be plumb, level, and strong enough to support hardware.
Gauge
Gauge refers to the thickness of sheet metal used in panels or hardware. Lower gauge numbers indicate thicker, stronger steel.
Glazing
Glazing is the glass or transparent material installed in window openings. It affects light, insulation, and appearance.
Guide Track
Guide track is the channel that rollers travel in as the system moves. It keeps panels aligned and supports their weight.
Headroom
Headroom is the vertical space between the top of the opening and the nearest obstruction. It is critical for tracks, springs, and hardware.
Hinge
A hinge connects adjacent sections and allows them to pivot as they follow the track. Different hinge sizes match specific track radii.
Horizontal Track
Horizontal track runs parallel to the ceiling and supports the system in the open position. It must be properly braced.
Impact Rating
Impact rating indicates how well a system withstands wind‑borne debris or physical impacts. Some regions require specific ratings by code.
Insulation
Insulation reduces heat transfer and improves energy efficiency. It is often described by R‑value and may also affect sound and rigidity.
Intermediate Section
An intermediate section is any panel between the top and bottom sections. It may include hinges, windows, or decorative features.
Jamb
Jambs are the vertical sides of the framed opening. Tracks and seals attach to them, and they must be structurally sound.
Jamb Seal
Jamb seal is weatherstripping installed along the vertical sides of the opening. It reduces drafts and water entry.
Keypad
A keypad is a control device that allows operation using a numeric code. It provides access without a remote or key.
Kicker
A kicker is a diagonal brace used to stabilize horizontal tracks or framing. It helps prevent movement or sagging.
Lift
Lift describes how the system transitions from vertical to horizontal travel. Common configurations include standard, high, and vertical lift.
Lift Cable
Lift cables connect the bottom brackets to the cable drums and carry the load as the system moves. They operate under high tension.
Low Headroom
Low headroom refers to installations with limited space above the opening. Special hardware allows operation in these conditions.
Manual Release
Manual release disconnects the operator from the system for hand operation. It is essential during power failures or service work.
Motor Housing
The motor housing encloses the operator’s motor and internal components. It protects them from dust and damage.
Mounting Bracket
A mounting bracket attaches tracks, operators, or hardware to the building structure. Proper fastening is critical for safety.
Operator
The operator is the powered device that opens and closes the system. It includes the motor, drive mechanism, and controls.
Opener Arm
The opener arm connects the operator’s moving trolley to the top section. It transfers pushing and pulling forces.
Overhead Clearance
Overhead clearance is the space above the open position of the system. It must be free of obstructions like pipes or lights.
Panel
A panel is an individual section that forms part of the full assembly. Panels vary in height, style, material, and insulation.
Photo Eye
Photo eyes are safety sensors that project an invisible beam across the opening. If the beam is interrupted, the operator stops or reverses.
Pitch
Pitch refers to the slope of the roof or ceiling above the system. It may affect track bracing and operator mounting requirements.
R‑Value
R‑value measures thermal resistance and indicates how well a material resists heat flow. Higher values mean better insulation performance.
Radius Track
Radius track is the curved portion of the track that transitions from vertical to horizontal. Its radius affects headroom and travel smoothness.
Roller
A roller is a wheel that rides inside the track and supports the panels. Roller material and bearing type influence noise and durability.
Section
A section is another term for an individual panel in a multi‑panel assembly. Sections pivot on hinges as they follow the track.
Sensor
Sensors detect conditions such as obstruction, position, or force. They provide input to the operator’s control system for safe operation.
Spring Cycle
Spring cycle refers to one complete open‑and‑close movement as it relates to spring life. Springs are rated for a set number of cycles.
Strut
A strut is a horizontal reinforcing member attached to a section. It increases stiffness and helps prevent sagging, especially on wide assemblies.
Thermal Break
A thermal break separates interior and exterior metal components with a less conductive material. It reduces heat transfer and condensation.
Torsion Spring
A torsion spring twists to provide counterbalance force. It is mounted on a shaft above the opening and stores energy as it winds and unwinds.
Track
Track is the metal channel that guides rollers and defines the system’s path. It must be aligned for smooth, quiet operation.
U‑Bar
U‑bar is a U‑shaped reinforcing member used to increase panel strength. It helps resist bending and improves performance under load.
UL 325
UL 325 is a safety standard governing operators and related controls. Compliance ensures required safety features and behaviors.
Weather Seal
Weather seal reduces air, water, and debris infiltration along edges or the bottom of the system. It also cushions contact with the floor.
Wind Load
Wind load is the force exerted by wind pressure on the exterior surface. Many regions require minimum wind load ratings by code.
Wrap‑Around Track
Wrap‑around track partially surrounds the roller for added guidance and retention. It improves stability and reduces the chance of derailment.