- Air permeability
- Air permeability is how much air leaks through a closed door at a set pressure difference. For industrial doors it is classified under BS EN 12426 in classes 0 to 6, where a higher class means less leakage. Good seals at the head, sides and bottom of a door improve the class, cutting draughts and heat loss. Where the property is tested, the manufacturer declares it on the Declaration of Performance. See: Insulated roller shutter doors Sectional overhead doors
- Approach gradient
- The approach gradient is the slope of the yard on the approach to a loading bay. A yard that falls towards the dock tilts the trailer, changing its bed height and pushing the top of the vehicle into the dock shelter, so the gradient affects leveller range, shelter size and door fit. It also decides where surface water collects, so drainage at the dock face matters on any sloping approach. See: Complete loading bays Dock shelters and seals
- Barrel
- The barrel is the steel tube above the opening that a roller shutter curtain coils around as the door opens. It turns on a shaft carried by bearings in the endplates, the steel brackets at each end that fix the door to the wall or guide rails. The motor or chain hoist drives the barrel, and on many shutters springs inside it help counterbalance the weight of the curtain. See: Industrial roller shutters Industrial door repairs
- BS 7273-4
- BS 7273-4 is the British Standard code of practice for the electrical actuation of mechanisms that release, unlock or open doors in a fire, including their interface with the fire detection and alarm system. It grades actuation as critical (Category A), standard (Category B) or indirect (Category C). It is widely used when designing how a fire shutter is released to close on an alarm signal. See: Fire shutters Fire shutter servicing and drop tests
- BS EN 12453
- BS EN 12453 is the standard for safety in use of power-operated industrial, commercial and garage doors and gates; the current UK edition is BS EN 12453:2017+A1:2021. It covers crushing and impact force limits, presence detection, monitoring of safety devices and protection if a suspension part fails. HSE notes that meeting the standard is not enough on its own to show legal compliance: a site-specific risk assessment is still needed. See: Door safety upgrades Door automation and controls
- BS EN 12604
- BS EN 12604 sets mechanical requirements and test methods for industrial, commercial and garage doors and gates; the current edition is BS EN 12604:2017+A1:2020. Since its 2017 revision the scope covers manually operated doors, with safety in use of power-operated doors dealt with by BS EN 12453. It sits alongside BS EN 13241, the product standard used for the Declaration of Performance. See: Industrial door installation
- BS EN 12635
- BS EN 12635 covered installation and use of industrial, commercial and garage doors and gates, setting out the information manufacturers should give installers and users, including instructions, maintenance and a log book. BSI lists the 2002+A1:2008 edition as withdrawn in December 2023, with EN 12453 and EN 12604 named as its replacements. Many existing manuals and specifications still refer to it. See: Industrial door installation Planned maintenance contracts
- BS EN 13241
- BS EN 13241 is the product standard for industrial, commercial and garage doors and gates. It sets out the performance characteristics a manufacturer declares, such as wind load resistance, thermal transmittance, air permeability and safe opening, and is the basis for the Declaration of Performance and CE or UKCA marking. Doors with fire or smoke control performance are assessed against BS EN 16034 as well. See: Industrial door installation
- BS EN 16034
- BS EN 16034 is the product standard for the fire resisting and smoke control characteristics of doors, including industrial doors and shutters, used together with BS EN 13241. Fire resistance comes from the manufacturer's tests and classification of the product, so it belongs to the tested design. A fire shutter has to be installed and maintained exactly as tested and certified for that performance to hold. See: Fire shutters Fire shutter servicing and drop tests
- Cable break device
- A cable break device is a safety catch on a sectional overhead door that stops the door falling if a lifting cable snaps or goes slack. It is usually fitted at the bottom brackets and locks into the track when cable tension is lost. A door that has tripped its cable break device should be left closed and inspected by an engineer before it is used again. See: Sectional overhead doors Industrial door repairs
- Centre drive
- A centre drive places the door's drive unit at or near the middle of the door rather than at one end, for example a motor mounted part-way along a roller shutter barrel or an operator on the centre line of a sectional door. It is chosen where there is too little side room beside the opening for an end-mounted motor, or where the manufacturer's design calls for it. See: Industrial door motor replacement Door automation and controls
- Chain hoist
- A chain hoist is an endless hand chain that turns a door's barrel or shaft through reduction gearing, so a heavy door can be raised and lowered by hand. It is used as the main operation on manual roller shutters and sectional doors, and is built into many industrial motors as the manual override for use during a power cut or fault. See: Industrial roller shutters Door automation and controls
- Curtain and laths
- The curtain is the moving part of a roller shutter, made of interlocking horizontal slats called laths that coil around the barrel. Laths may be single-skin steel or aluminium, double-skin and foam-filled for insulation, or perforated for light and airflow. Damaged laths can often be replaced individually, although heavy damage or corrosion may make a new curtain the better value. See: Industrial roller shutters Insulated roller shutter doors
- Cycle count
- A cycle count is the number of times a door has opened and closed, often recorded by the control panel. One cycle is a full opening and closing. Springs, cables, bearings and motors wear in proportion to cycles, and torsion springs are made for a rated number of them, so the count helps set service intervals and plan part replacement before a failure. See: Planned maintenance contracts
- Declaration of Conformity
- A Declaration of Conformity is the document in which the Responsible Person for a machine, such as a powered door, declares that it meets the essential health and safety requirements. In Great Britain it is issued under the Supply of Machinery (Safety) Regulations 2008. In Northern Ireland EU machinery rules apply, with the EU Machinery Regulation 2023/1230 applying directly from 20 January 2027. See: Door automation and controls Industrial door installation
- Declaration of Performance
- A Declaration of Performance is the manufacturer's statement of how a construction product performs against the characteristics in its product standard, which for industrial doors is BS EN 13241. It lists declared values such as wind load class, thermal transmittance and air permeability, and underpins CE or UKCA marking. It belongs to the manufacturer's product and is passed to the client at handover. See: Industrial door installation
- Direct drive motor
- A direct drive motor is a geared motor unit that fits straight onto the door's drive shaft or barrel end, with no separate drive chain between them. With fewer moving parts to wear or adjust, it is compact and quiet, and it usually includes limit switches, a brake and a manual override. It is a common choice on modern sectional doors and roller shutters. See: Industrial door motor replacement Door automation and controls
- Dock bumper
- A dock bumper is a rubber or steel-faced buffer fixed to the dock wall that absorbs the impact of a reversing vehicle, protecting the building, the leveller and the vehicle. Bumpers take repeated hits and wear down over time; once worn, vehicles strike the dock face and leveller directly. Checking and replacing bumpers is a routine part of loading bay servicing. See: Bollards and door protection Dock leveller and loading bay repairs
- Dock height
- Dock height is the height of the loading dock floor above the yard, set to match the bed height of the vehicles a site serves most often. The difference between dock height and each trailer's bed height is what a dock leveller has to bridge, so a site serving vans and large trailers from one dock needs a leveller with a wider working range. See: Complete loading bays Dock levellers
- Dock leveller
- A dock leveller is a powered platform, usually hydraulic, set into the dock floor that bridges the height difference and gap between the dock and a trailer bed, so forklifts and pallet trucks can drive straight on and off. A hinged or sliding lip, sometimes called the lip plate, rests on the trailer bed. Levellers are sized to the vehicles served and the loads carried. See: Dock levellers Dock leveller and loading bay repairs
- Dock lights
- Dock lights are lamps on adjustable arms mounted beside a dock door so they can be swung to shine into the trailer during loading. They help forklift drivers see the trailer floor, load and any damage inside an unlit vehicle. Modern units use LED lamps and are usually wired into the loading bay controls or a local switch. See: Complete loading bays
- Dock seal
- A dock seal is a set of compressible foam pads fixed around a dock door that the back of a trailer presses into, forming a tight seal around the vehicle. Seals give strong thermal sealing and suit sites where vehicles are a consistent size, but they wear from repeated compression and can restrict access to the full trailer width. See: Dock shelters and seals
- Dock shelter
- A dock shelter is a frame fitted around the outside of a dock door with flexible side and top curtains that close around the back of a docked vehicle, cutting draughts, heat loss and weather. Retractable shelters fold back if a vehicle strikes them. Inflatable shelters use fan-blown air bags to seal around the vehicle, suiting chilled or frozen goods and mixed vehicle sizes. See: Dock shelters and seals Complete loading bays
- Drop test
- A drop test is a test of a fire shutter's automatic closing, in which the shutter is released as it would be in a fire to check it closes fully and at a controlled speed. It normally includes testing the alarm release and fail-safe closing. Industry practice is a full service with drop test at least once a year, often every six months, as set by the fire risk assessment and manufacturer. See: Fire shutter servicing and drop tests Fire shutters
- Edge-of-dock leveller
- An edge-of-dock leveller is a compact leveller mounted on the face or edge of the dock, with no pit needed. It has a small working range, so it suits bays where trailer beds sit close to dock height, light-duty use or sites where a pit cannot be built. Where vehicle heights vary widely, a full pit leveller is usually the better fit. See: Dock levellers
- Emergency release
- An emergency release, or manual override, lets a powered door be opened or closed by hand when the power fails or the drive is faulty, for example by a hand chain, crank handle or brake-release cord. Workplace law requires powered doors to be operable manually where safety requires, unless they open automatically on power failure, so the release should be tested on every service. See: Door automation and controls Industrial door repairs
- Fail-safe closing
- Fail-safe closing is the way a fire shutter closes when it receives a fire alarm signal or, depending on the system, loses power. The holding device releases and the curtain descends under gravity, with a governor, a speed-limiting device, controlling the speed so it closes steadily. Because closing does not rely on the motor, it still works if the power supply fails during a fire. See: Fire shutters Fire shutter servicing and drop tests
- Frequency inverter
- A frequency inverter is an electronic motor controller that varies a door motor's speed by changing the frequency of its supply. It gives soft start and soft stop, so the door accelerates and slows gently, reducing wear on the drive, curtain and fixings, and it allows faster opening than closing. Some inverters also let a three-phase motor run from a single-phase supply. See: Door automation and controls Industrial door motor replacement
- Fusible link
- A fusible link is a heat-sensitive link that parts at a set temperature, releasing a fire shutter to close. On older or simpler shutters it may be the only release; on most modern installations the shutter closes on a fire alarm signal, with the fusible link as a back-up. Links are part of the tested product, so replacements should match the manufacturer's specification. See: Fire shutters
- Guide rails
- Guide rails are the vertical channels either side of an opening that the curtain of a roller shutter or high-speed door runs in. They keep the curtain aligned, often carry brush or rubber seals, and on some doors hold it against wind pressure. Because they sit at forklift height, they are often damaged, and guide-rail guards or bollards protect them. See: Bollards and door protection Industrial door repairs
- Heated frame
- A heated frame has electric heating cables built into the frame or seal area of a freezer door, keeping the seal line above freezing. Without heating, moisture in the air freezes on the seals, which can lock the door shut, tear the gaskets and spoil the seal. Heating faults are a common cause of freezer door problems, so they are checked on every service. See: Cold store and freezer doors
- Hold-to-run control
- Hold-to-run control, also called deadman control, moves a powered door only while the user keeps the button pressed; letting go stops the door straight away. The user has to be able to see the door while operating it. Because a person is in control throughout, hold-to-run usually needs fewer additional safety devices than impulse control, where users are trained. See: Door automation and controls Door safety upgrades
- Impact door
- An impact door is a double-acting door, made with tough plastic, rubber or reinforced panels, that is pushed open by trolleys, pallet trucks or people and swings closed behind them. Impact doors are common in food production, retail back-of-house and hospital service routes. Vision panels matter, because workplace law requires a door that can be pushed open from either side to give, when closed, a clear view of the space close to both sides. See: Impact traffic doors
- Impulse control
- Impulse control runs a powered door fully open or closed from a single press of a button, remote, pull cord or detector, without the user holding the control. Because the door can move while nobody is watching, it needs safety devices such as a safety edge, photocells or a light curtain, selected under BS EN 12453 and the site risk assessment. See: Door automation and controls Door safety upgrades
- Induction loop
- An induction loop is a wire loop cut into the floor in front of a door that detects metal vehicles such as forklifts passing over it and signals the door to open. Loops ignore pedestrians, which helps avoid unwanted openings on busy routes. They are often paired with high-speed doors and need the floor in good condition, since cracks can break the wire. See: Door automation and controls High-speed doors
- Interlock
- An interlock is a control link that stops one piece of equipment working until another is in a safe state. At loading bays it can stop the door opening until a vehicle is restrained, or stop the leveller working until the door is fully open. Interlocks can also stop two doors in an airlock opening at once. See: Complete loading bays Door automation and controls
- Leveller pit
- A leveller pit is the recess in the dock floor that houses a dock leveller, formed to the manufacturer's dimensions with steel edge angles to carry the frame. New pits need civil works and curing time before the leveller goes in. On replacements, the existing pit is measured at survey, and the pit may need adapting or a leveller designed to fit existing pits. See: Dock levellers Complete loading bays
- Light curtain
- A light curtain is a pair of vertical posts that create many infrared beams across the opening, detecting people or vehicles through the full height of a door. If any beam is broken, the door stops or reopens before contact. Light curtains give wider coverage than a single photocell and are widely used on high-speed doors and as a safety upgrade. See: Door safety upgrades High-speed doors
- LPS 1175
- LPS 1175 is the LPCB standard for the intruder resistance of doors, shutters and other building components. Under Issue 8 a rating combines a letter from A to H for the attack tools used in testing with a number for the minimum delay in minutes, for example A1 or H20. The rating belongs to the certified product, so it must be installed as certified. See: Industrial roller shutters Steel personnel and fire exit doors
- Photocell
- A photocell is an infrared beam across a doorway, between a transmitter and receiver or reflector, that stops or reverses a closing door when the beam is broken. It protects at one height only, so it is usually combined with a safety edge or replaced by a light curtain where people or vehicles of varying heights pass through. See: Door safety upgrades
- Planned preventive maintenance
- Planned preventive maintenance is servicing carried out on a fixed schedule to keep doors safe and catch wear before it causes a failure. The law sets no fixed interval, but industry practice treats at least one service every 12 months as a minimum, with more frequent visits for high-cycle doors, harsh environments or where the manufacturer's manual requires it. See: Planned maintenance contracts
- Pressure relief valve
- A pressure relief valve is fitted in the wall of a cold store or freezer to balance the air pressure inside and out. When warm air enters and cools after the door closes, the pressure inside drops, which can make the door very hard to open and strain the panels. The valve lets air in or out, and is usually heated to stop it freezing. See: Cold store and freezer doors
- PUWER
- PUWER is the Provision and Use of Work Equipment Regulations 1998, which apply in England, Wales and Scotland; Northern Ireland has PUWER (NI) 1999. They require work equipment, including powered doors used at work, to be maintained in efficient working order and good repair, and any maintenance log for machinery to be kept up to date. See: Planned maintenance contracts
- Radar activation
- Radar activation uses a microwave motion detector above a door to open it when a person or vehicle approaches. Detectors can be set to respond only to movement towards the door and adjusted for range, which cuts unwanted openings from passing traffic. Radar detects pedestrians as well as vehicles, so it suits mixed routes where an induction loop would miss people. See: Door automation and controls High-speed doors
- Responsible Person
- Responsible Person has two meanings for doors. Under the Supply of Machinery (Safety) Regulations 2008, it is the manufacturer or representative placing a machine on the market, often the installer who assembles or powers a door. Under the Regulatory Reform (Fire Safety) Order 2005 in England and Wales, it is the person with fire safety duties for premises. Scotland uses dutyholder; Northern Ireland guidance often says appropriate person. See: Door automation and controls Fire shutter servicing and drop tests
- Safety edge
- A safety edge, also called a sensitive edge, is a pressure-sensitive strip along the bottom rail of a powered door that stops and reverses the door when it touches an obstruction. Edges may be pneumatic, optical or electrical, and on modern systems the control panel monitors them so a fault is detected. They should be tested at every service. See: Door safety upgrades Industrial door repairs
- Sections
- Sections are the horizontal panels, hinged together, that form the leaf of a sectional overhead door. Industrial sections are usually double-skin steel filled with insulating foam, often 40 mm thick or more, and can include vision panels or a wicket door. The sections run on rollers in tracks and move up into the building, clear of the opening. See: Sectional overhead doors
- Self-repairing curtain
- A self-repairing curtain is a high-speed door's fabric curtain, usually PVC-coated polyester, designed to pull out of its guides when struck by a forklift and feed itself back in on the next cycle. It avoids most breakdowns from minor knocks. Fabric curtains can include clear vision strips and come in insulated versions for chilled areas. See: High-speed doors
- Service log
- A service log is the record kept for each door of inspections, servicing, repairs, modifications and test results, such as force measurements and safety device checks. It shows the door has been kept safe and in efficient working order, helps engineers spot repeat faults and should stay with the building when occupiers or contractors change. See: Planned maintenance contracts
- SMR 2008
- SMR 2008 is the Supply of Machinery (Safety) Regulations 2008. In Great Britain they apply to powered doors as machinery. Whoever assembles a powered door from components or converts a manual door to power usually becomes the Responsible Person, with duties covering a technical file, conformity marking, a Declaration of Conformity and user instructions. Northern Ireland follows EU machinery rules. See: Door automation and controls Industrial door installation
- Spiral door
- A spiral door is a high-speed door with rigid slats, often aluminium or insulated, that run into a spiral track above the opening instead of coiling tightly on a barrel. Because the slats do not rub against each other, they open very quickly with little wear. Spiral doors offer more security and insulation than fabric high-speed doors. See: High-speed doors
- Spring break device
- A spring break device is a safety catch on the spring shaft of a sectional overhead door that locks the shaft if a torsion spring breaks, stopping the door from falling. Springs can break without warning at the end of their cycle life. If the device has tripped, the door should stay out of use until an engineer replaces the spring and checks the door. See: Sectional overhead doors Industrial door repairs
- Strip curtain
- A strip curtain is a row of overlapping flexible PVC strips hung across a doorway that people and vehicles push through. It cuts draughts, heat loss, dust and flying insects while leaving the opening usable. Strips come in grades for low temperatures, welding screens and other uses, and they are replaced individually when they become scratched or brittle. See: PVC strip curtains
- STS 202
- STS 202 is a security test standard published by Warringtonfire, used to rate the burglary resistance of doors, shutters and other building products. Ratings run from BR1 upwards, with higher numbers resisting more determined attack. Like LPS 1175, the rating belongs to the certified product, and evidence is checked through the certification body and the manufacturer. See: Industrial roller shutters Steel personnel and fire exit doors
- Swing lip
- A swing lip is the hinged front plate on a dock leveller that swings out as the platform rises and rests on the trailer bed. It is simple and robust and suits most routine loading. Because the platform rises before the lip lowers, it gives less precise placement than a telescopic lip when the lip must land exactly on the trailer bed. See: Dock levellers
- Technical file
- A technical file is the set of documents a Responsible Person compiles to show a machine, such as a powered door, meets the essential health and safety requirements. It typically holds drawings, the risk assessment, standards applied, test results and instructions. Under the Supply of Machinery (Safety) Regulations 2008 it must be available to the authorities for at least 10 years from manufacture. See: Door automation and controls
- Telescopic lip
- A telescopic lip is a dock leveller lip that slides straight out under the operator's control, so it can be placed exactly on the trailer bed. It suits loading the last pallet row, vehicles with varying bed heights and sites where precise placement matters. It costs more than a swing lip but gives finer control and more reach. See: Dock levellers
- Thermal break
- A thermal break is an insulating barrier between the inner and outer metal parts of a door panel or frame, stopping heat travelling straight through the metal. It lowers the U-value and keeps the inner face warmer, which reduces condensation. Thermal breaks matter most in insulated sectional doors, cold store doors and doors to heated spaces. See: Insulated roller shutter doors Sectional overhead doors
- Torsion springs
- Torsion springs are coiled springs on a shaft that counterbalance the weight of a sectional door, and of many roller shutters, so a motor or person can lift it with little force. Each spring is designed for a rated number of cycles before it fails. Springs store a lot of energy, so only trained engineers should adjust or replace them. See: Industrial door repairs Sectional overhead doors
- Traffic lights
- Traffic lights at a loading bay are red and green signals that tell drivers outside and staff inside when it is safe to move, load or leave. They are often linked to the door, leveller and vehicle restraint. HSE notes that signals alone do not physically stop a vehicle moving, so they work most effectively combined with a restraint or other safe system of work. See: Complete loading bays
- U-value
- A U-value measures how much heat passes through a building element, in watts per square metre per kelvin; lower is better. In England, Approved Document L 2021 Volume 2 sets a limiting U-value of 1.3 W/m²K for vehicle access and similar large doors in buildings other than dwellings. Wales, Scotland and Northern Ireland have their own energy guidance. See: Insulated roller shutter doors Sectional overhead doors
- Vehicle restraint
- A vehicle restraint holds a vehicle at the loading bay so it cannot drive away early or creep forward during loading. Trailer creep is the gradual movement of a trailer away from the dock as forklifts drive on and off, which can open a dangerous gap. Restraints hook the rear under-run bar or lock a wheel, and are often interlocked with the door. See: Complete loading bays
- Vision panels
- Vision panels are clear glazed or polycarbonate windows set into a door leaf, such as sectional door panels, impact doors or perforated vision laths on shutters. They let people see traffic on the other side and bring in daylight. Workplace law requires doors that can be pushed open from either side to give, when closed, a clear view of the space close to both sides. See: Sectional overhead doors Impact traffic doors
- Wheel guides
- Wheel guides are steel guides or raised kerbs fixed in the yard either side of a loading bay that steer a reversing vehicle into the centre of the dock. Good alignment protects the door, shelter and leveller from glancing strikes and puts the trailer where the leveller lip can land squarely. They are often fitted with high-visibility markings. See: Complete loading bays Bollards and door protection
- Wicket door
- A wicket door is a pedestrian door built into the leaf of a larger door, such as a sectional, sliding or hangar door, so people can pass through without opening the whole door. A safety switch stops the main door moving while the wicket is open. Most wicket doors have a raised threshold, which can be a trip hazard and is not suitable for every route. See: Sliding and folding industrial doors Hangar and large-span doors
- Wind load class
- Wind load class rates a door's resistance to wind pressure under BS EN 12424, from class 0, no performance determined, to class 5. Classes 1 to 4 correspond to 300, 450, 700 and 1,000 pascals, with class 5 above 1,000 pascals. The manufacturer declares the class on the Declaration of Performance, and exposed or wide openings usually need a higher class. See: Sectional overhead doors Hangar and large-span doors
Last updated 19 October 2026.