Scaffolding & Construction Terminologies

Australian Scaffolds has created a scaffolding terminology glossary.


Access Gate

Means by which a person or vehicle can approach or leave a specific location, including walkways, platforms, stairways, ladders, roads and all provisions for safe entry and exit.

Access Hatch

A closed device which can be opened to provide access through a platform, roof or other similar structure.

Access Platform

A platform that is used, or primarily intended to be used, to provide access for persons, or for persons and materials, going to and from places of work, but does not include a working platform.

Accessory Scaffold

A fitting that is able to be attached to a structural member of a scaffold, or to join a structural member to something else.

Acrow Props

First made by the “Acrow” company these items are used for supporting mainly formwork in a vertical position but can be used raked and even horizontally. They consist of one steel tube sliding into another with a course screw and collar for adjustment. They have a square steel plate on each end to distribute the loads.

Adjustable Castor

A swivelling adjustable wheel attached to a scaffold.

Adjustable Prop

Structural scaffolding member loaded in compression that is capable of coarse and fine adjustment of its overall length.

A-Frame Scaffold

Frame trestles are commonly used by bricklayers, plasterers and painters, and for general fit out and finishing work. Typically used for the construction of residential dwellings from 1 to 4 storeys high.

Aluminium plank

Between 25mm and 100mm thick and at least 150mm wide, with its wide dimension horizontal, used as bearing surfaces, such as in walkways or maintenance access.

Aluminium Scaffold

Aluminium scaffolding is a temporary structure used to support people and material in the construction or repair of buildings and other large structures. It is usually a modular system of aluminium pipes or tubes.

Aluminium Trestles

A trestle (sometimes Tressel) is a rigid frame used as a support.


A device used to give stability to one part of a structure by securing it to another part, or to a separate structure capable of resisting the additional load, or to a suitable anchorage in the ground.

Anchor Bolt

Bolt firmly attached into rock or masonry or cast into concrete and with its threaded length projecting to secure structural members.

Anchor Masonry

A device used for fixing to masonry or concrete, which is inserted into a pre-drilled hole and expands upon tightening.

Arch Centering

Temporary framework or formwork, usually timber that masonry or concrete arches are built on top of.


Australian Standard – followed by a number which denotes a particular publication.

Authorised Person

A person is given the authority to perform specific tasks or grant permission for others to perform specific tasks.


A measure of a plane surface within defined boundaries: such as land, buildings or building elements. In scaffold terms, it would generally mean the area of scaffold being used e.g 1100 m2.

Auger Underpinning

The underpinning of foundations by drilling a series of auger holes under the foundations. By part filling with concrete it is possible to lift the foundation with hydraulic jacks, before totally filling with concrete.

B – Scaffolding Terminology

Back Propping

A process by which adjustable supports are placed to give support to the cast-in-situ concrete during the removal of the soffit formwork, which may also remain in a position to act as multi-storey shoring.

Backing Rails

Rails whose function is to transfer loads from infill panels to supporting posts.

Back Splice

A splice at the end of a fibre rope to prevent it from unlaying.

Bald Eye

An eye in a rope which is not protected by a thimble. It is also called a ‘soft eye’.


Concrete blocks or steel weights are used to act as ballast weights for cantilever towers and for scaffolds/towers. They can be attached to wire ropes which are fixed to the structure to provide greater stability.

Bamboo Scaffolding

Scaffolding made out of natural bamboo. Predominately used in third world countries.

Barge Boards

Plain or decorated sloping board fixed to a verge or projecting gable to conceal roof construction. A scaffold is often used for maintenance of boards.

Barrow Hoist

Modular transportable lifting device used to handle light loads.

Base Plate

A plate that distributes the load from a vertical load bearing member to the supporting structure.

Bay Extension Platform

A portion of a working platform that protrudes beyond the face of a scaffold, adjacent to a bay of an independent scaffold, forming an extension of that bay.

Bay Length

The horizontal distance between any two longitudinally adjacent standards or members, serving the purpose of standards, or the horizontal distance between any two longitudinally-adjacent support points on the cradle of a suspended scaffold.

Bay Width

The horizontal distance between the centres of any two transversely adjacent standards or members, serving the purpose of standards, including spurs or cantilevered beams, but does not include bay extension formed by platform brackets.

Beam Box

Hollow rectangular beam or girder made of steel, timber or prestressed concrete. Scaffolds are often tied to this component for rigidity.

Beam Clamp

A fitting designed for joining beam and tube. Also known as a gravlock coupler, beam coupler or girder clamp. Recommended for use in pairs.

Beam Formwork

Suspended formwork for the sides and soffit of a beam.

Beam I – (Also called I beam)

Beam with a cross-section in the shape of the letter I. Scaffold can be attached to I beam using beam / gravlock couplers.

Beam Needle

A beam which is inserted horizontally through a wall to provide temporary support to the wall above while the wall below is removed for alteration or underpinning. The needle beam is supported at the ends by and transfers loads to, a pair of dead shores (vertical shores) placed clear of the work.

Bearing (structural)

Contact area through which loads are transferred from one structural member to another.

Bearing area

An effective area over which a force is transferred to a supporting structural system.

Bearing Capacity

A load which soil or another supporting medium can safely carry without failure or unacceptably large settlement.

Bearing Pressure

Load on bearing surface divided by its area.

Bed Joint

The mortar between bricks. Scaffold ties should not use the bed joint as an anchor point.

Bill Of Materials (US)

Document for tendering, usually prepared in a standard form, comprising both a descriptive list of quantities of works and descriptions of material, workmanship and other matters required for construction works.

Bill Of Quantities (Australia)

Document for tendering, usually prepared in a standard form, comprising both a descriptive list of quantities of works and descriptions of material, workmanship and other matters required for construction works. It is based on the working drawings, specification and scheduled for that project. The bill of quantities is commonly prepared by a quantity surveyor to provide a uniform basis for competitive tendering or quotations by contractors and/or subcontractors.

Bird Cage Scaffold

Self-supporting scaffold, consisting of more than two rows of standards in both directions connected by ledgers and transoms.

Block and Tackle

A sheave block or blocks used with fibre rope.

Boatswain Chair

A suspended scaffold where the platform is a chair or similar device, suitable for use by one person.

Body Belt

A safety belt designed to be worn around the waist and which does not have shoulder straps or leg straps.

Bolt Expansion

Bolt with an expanding device which increases the diameter of the inner end to form a wedge grip.

Bolt Eye

Bolt with a screw thread at one end and a welded circle, or eye, at the other: used mainly to secure ropes.

Boom Hoist

Access equipment. A mobile scaffold platform that is raised and moved by an articulated boom Also known as a Cherry Picker.

Box Crib

A layout of squared timbers or similar concrete beams used as the lining of a shaft in mining and excavation work.

Brace diagonal

A member fixed to two or more members of a scaffold to increase the rigidity of the scaffold. Note: Braces are generally fixed diagonally.

Bracket (Scaffold)

The support that projects horizontally from a vertical surface. Also known as hop ups, stage brackets, console brackets.


Masonry unit that does not exceed 338mm in length, 225mm in width and 113mm in thickness. A scaffold can be fixed to brick.

Bricklayers Scaffold

A single row of standards with a single ledger, the putlogs are transoms – attached to the ledger at one end but integrated into the bricks at the other. Spacing is as general purpose scaffold and ties are still required.

Brick Guard

A meshed panel secured between a guardrail and toeboard and sometimes incorporating a kickplate.

Bridge Scaffold

Scaffold bridges are purpose designed that affords passage to pedestrians, animals, small vehicles and services above obstacles or between two points above the ground.

Bridge Deck Scaffold

The horizontal or slightly inclined structural floor of a scaffold bridge deck.

Bridge Suspension Scaffold

The main structural members of which are load tension/compression braces. Used to span larger distances.

Building Code

Sets out the minimum community standards in regards to health, safety and amenity in buildings and during the associated construction work.

Building Code Of Australia (BCA)

Uniform set of technical requirements and standards, related to structural sufficiency, fire safety, health and amenity, for the design and construction of building and structures throughout Australia

Buttress Bay

Projecting scaffold built as part of the main scaffold to resist lateral thrust. A buttress bay gives additional strength and stability to the scaffold. distribute superimposed loads and/or resists lateral thrust.

C – Scaffolding Terminology


A beam, structural member or similar which is anchored at one end and which is free at the other end.

Cantilever Builder Hoist

A builders’ hoist where the car, bucket or platform is cantilevered from and travels up and down externally to a face of, the support structure.

Cantilever Needle Beam

In underpinning. A cast in situ concrete beam usually sat on piles or concrete piers that pass through and supports a wall, or foundation from one side of the wall only.

Cantilever Platform Bay

A bay of scaffold that protrudes beyond the face of an independent scaffold or structure, forming a discrete bay in addition to any bays in the independent scaffold.

Cantilever Platform Materials Hoist

A powered builder’s hoist which has the lift platform cantilevered from the hoist tower. It moves materials only, up and down the face of a building or structure. Also called a ‘barrow hoist’.

Cantilever Scaffold

A scaffold that is supported by cantilevered load-bearing members.

Cantilevered Crane Loading Platform

A temporary loading bay cantilevered from the face of a building or structure to land or lift crane handled loads.


Load carrying carriage on materials and personnel hoist.


A wheel rotating on an axle fixed into a housing capable of being connected to the lower end of a standard for the purpose of supporting and moving a scaffold. Note: The housing may be fixed or may be capable of swivelling to allow the scaffold to be moved horizontally in any direction.

Castor Swivel

A wheel rotating on an axle fixed into a housing capable of being connected to the lower end of a standard for the purpose of supporting and moving a scaffold. Note: The housing may be fixed or may be capable of swivelling to allow the scaffold to be moved horizontally in any direction.

Cat Ladder

In Scaffolding and while working on steep roofs. A ladder that lays on top of the roof surface as an aid to walking and working on roof surfaces. Also known as a crawling board.

Catch Platform

A platform attached to a scaffold to contain debris falling from a working platform. Note A cantilevered portion of a catch platform is also called a fan.


Usually a 45deg. bevel to a 90deg.(both internal and external) corner in concrete.

Check Coupler

A right angle, swivel or parallel coupler that is fixed hard against a loadbearing coupler, to restrict or prevent slippage of that coupler along the tube.

Cherry Picker

Access equipment. A mobile scaffold platform that is raised and moved by an articulated boom Also known as a Boom Hoist.

Climbing Frame

An internal or external frame used to lift the crane from the tower sections of a tower crane for climbing up or down.

Closed Platform

A platform that is capable of being a working platform but is temporarily closed to any loading or access by persons in accordance with the installation design.

Column Clamps

Various methods of clamping and holding column formwork in position.

Column Formwork

Timber, steel or other materials used to form concrete columns.

Competent Person

A person suitably qualified adequately trained and appropriately experienced for the particular class or kind of work described.

Concrete Formwork

The materials that are used to keep wet concrete in the correct position until it has set. After a period of time, it is usually removed.

Containment Sheeting

Sheeting that encloses the outer facade of the scaffold to retain objects or particles within the scaffold.

Continuous Flight Augering

In basement excavation and shoring. Know also as CFA. A machine driven auger that drills holes and when withdrawn, grout or concrete is pumped into the hole through a hollow centre. When withdrawn fully A rebar cage is inserted into the wet concrete. The process is repeated many times to form a continuous shield or secant pile wall.

Coupler External Sleeve

Used for external connection of two tubes end-to-end. Provides a more secure joint.

Coupler Fixed

One piece design, easily replaceable bolts, connect horizontal or ledger tubes to standards. To be used in every position where the tube it secures under load.

Counter Weight

A weight or series of weights that counterbalance a scaffold against overturning.


That portion of a suspended scaffold that incorporates a suspended platform.


An appliance intended for raising and lowering a load and moving it horizontally, but excluding industrial lift trucks, earthmoving machinery, amusement structures, tractors, industrial robots, conveyors, building maintenance equipment, suspended scaffolds and lifts.

Crane Loading Platform

In high rise work. A temporary platform, usually cantilevered out from an upper floor, to enable a crane to land and remove material to the floor.


Squared timbers or concrete members used to provide support or used in a retaining wall.

D – Scaffolding Terminology

Debris Net

A fine mesh net usually laid over an industrial safety net in order to catch small light items of falling debris.

Derrick Crane

A slewing strut-boom crane with the boom pivoted at the base of a mast which is either guyed (guy derrick) or held by backstays (stiff-leg derrick). Can luff under load.

Double Raking Shore

A shore with two raking members, either steel or timber to support a larger and higher section of wall.

Double Roped Suspended Scaffold

A scaffold where the cradle is suspended using two hoists and two suspension ropes at each support point.


A crane fitted with a bucket or scoop which is thrown outwards and retrieved by a drag cable arrangement.

Drop Scaffold

A hung scaffold.

Dual Coverage

Work which can be performed by someone who holds either the appropriate class of rigging certificate or the appropriate class of scaffolding certificate, because the work is within the scope of both types of certificate.

E – Scaffolding Terminology

Earth Auger

An auger used for drilling circular holes in the ground. Usually, machine mounted and hydraulically driven.

F – Scaffolding Terminology

Fabric Formwork

Formwork that is formed out of various plastic and fabric materials. Not reusable, but cheap and quick to erect.


Triangular lengths of timber or plastic used to form chamfers in concrete.

Flying Shore

A horizontal shore between two buildings to give temporary support to one or both of them

Form Oil

A generally low viscosity oil that is easily sprayed onto ply or steel form surfaces to stop the concrete sticking to the forms. Also called release oil or release agent.


Usually, in 2400 x 1200 (8ft x 4ft) and either 12mm, 16mm or 18mm (1/2″, 5/8″, or 3/4″) thick this plywood are made by various manufacturers with strength, water resistance and finish being the main criteria. Both sides are usually coated with a hard smooth resin finish.

Formwork Bearers

Heavy sections of steel or timber supported on props or shores, used to support the joists in suspended slab construction.

Formwork Cleats

Short lengths of timber used to join other timbers together.

Formwork Joists

Horizontal members sat on top of the bearers in suspended slab formwork.

Formwork Soldier

A vertical structural support member in formwork.

Formwork Waler

A horizontal structural support member in formwork. Also called Wales or Waling. The same term carries over into timbering for trenches.

Fox Wedges, Folding Wedges

Pairs of timber wedges used for adjusting timber props and many other wedging and tightening operations.

H – Scaffolding Terminology

Hydrostatic Pressure

Wet concrete, especially under vibration acts like a liquid. In simple terms, the pressure on the formwork is greater as the concrete gets deeper.

K – Scaffolding Terminology


A member parallel to the shutter being supported, hard up against the shutter and fixed to the support. A member parallel to the shutter being supported but offset from the shutter to allow for the fixing of braces.

L – Scaffolding Terminology

Ladder Access

In Scaffolding. The provision of spaces and ladders to allow access to the different levels of the scaffold.

Ladder Hoist

A ladder frame used to hoist materials into upper floor windows and onto roofs.


A horizontal member supported on standards, on which the transoms are laid in tube and coupler work. In modular systems, they perform the function of stiffening the standards and maintaining the correct bay widths. Also, they are used as handrail and guard rail supports.

M – Scaffolding Terminology

Modular Panel Formwork

Various steel, steel and ply panels to simplify erection and to save material costs. The many more cycles of use than simple timber systems.

Modular Scaffolding

A system that uses prefabricated sections to make up modules of standard sizes. Strong but compact for transport.

N – Scaffolding Terminology


1.) A short strong piece of timber which goes through a hole in a wall and which, via props or shores on either side of the wall supports the wall for further work.
2.) A short timber or steel member which passes through a hole in the wall to support a scaffold etc.

Needle Beam

In underpinning. A cast in situ concrete beam usually sat on piles or concrete piers that passes through and supports a wall, or foundation.

Needle Raft Slab

In underpinning. An integrated raft slab and cantilever reinforced concrete needles sat on micro piles.

P – Scaffolding Terminology 

Permanent Formwork

Formwork that is left in place after the concrete is set. Examples are metal pan systems like “Bondek” that simply the forming of suspended slabs and because of their thickness and keying into the concrete also contribute to the strength of the slab, reducing rebar costs. Go to – Permanent Formwork page.

Poling Boards

In trench shoring. Vertical boards to the side walls of an excavation.

Preventative Shoring

The fixing of shoring and braces to building undamaged, but that could be put at risk by nearby excavation and other construction work.


In trench shoring. Short sturdy vertical lengths of timber that support the walers. Similar pieces in old timber-framed buildings.


A horizontal member used for fixing a scaffold to a wall or other part of the structure of a building to brace the scaffolding.

Putlog Scaffold

A scaffold that is half supported by the building structure, saving on standards etc. The horizontal equivalents of the transoms are known as putlogs and the are attached or built into the structure as the work progresses. Rarely used in modern construction.;

R – Scaffolding Terminology

Raking Shore

A shore that is leaning at an angle (on the rake) to support the side of a building or other structure. The shore takes any thrust from the walls to the ground.

Raking Shore Details

Details of the setting out and construction of timber rakers.

Rebar Cage

A made up cage of reinforcing steel main bars held in place by smaller bars.

Roof Edge Protection

In roofing the provision of temporary scaffolding edge guardrails to protect workers from accidentally stepping off the edge of a roof.

S – Scaffolding Terminology

Safety Mesh

Various forms of mesh, steel or fabric that is designed to stop tools or materials falling off the platforms.

Scaffold Brace

Sloping angled tubes that provides sideways and lengthways bracing.


A temporary work platform inside or on the face of a building to allow worker and materials access to work areas above the ground.

Scaffolding Stairs

In modular scaffold systems, flights of stairs at normal ratios and wide enough to give access to different levels for a few workers at a time.

Scissor Lift

Access equipment. A mobile scaffold platform. Also known as a scissor hoist because of the method of raising the platform.

Screw Jacks

Steel course square threaded fittings that fit into shoring systems or scaffold pipes to adjust the height and to distribute the load of the frames or scaffolding through large steel flat plates.

Secant Pile Wall

Also known as Tangent, Soldier and Contiguous pile walls. A grout or reinforced concrete retaining wall made by the CFA system.

Semicircular-Arch Centering

Larger centering for a semicircular arch.

Settlement Bolts

Large diameter bolts, iron bars or straps that pass through a building in order to support it against settlement or to secure it due to damage.


A single prop or brace that is used to support temporary work or an unsafe part of a structure. They are often subdivided into the following categories:- Dead shores acting vertically, raking shores at an angle and flying shores bracing horizontally.

Shore Frames

Shoring systems for formwork to support suspended slabs etc.


Using a number of shores to support a temporary construction element or to support an unsafe building or to temporarily support adjacent buildings when new construction is carried out.


A made up a reusable section of formwork or shuttering that could consist of timber and ply, or any number of steel, steel and ply, or other material. It is made once and used many times.

Single Raking Shore

A shore with only a single raking member, either timber or steel, aimed at a specific portion of a wall.

Sole Plates

Lengths of timber used as the base of rows of props and formwork shoring systems. Essential on the ground and the wider and heavier the better of soft ground. Used to fix the base of props etc. and also to spread the load.

Stair Formwork

The formwork for stairs is usually ply on timber, apart from jobs that have many repetitions or curves, in which case purpose made steel forms are used.


A long vertical tube or a shorter tube with welded fitments in modular systems. The main load-bearing members.

Steel Props

First made by the “Acrow” company these items are used for supporting mainly formwork in a vertical position but can be used raked and even horizontally. They consist of one steel tube sliding into another with a course screw and collar for adjustment. They have square steel plate on each end to distribute the loads.

Stripping Formwork

The removal of the formwork.


1.) In Stair Formwork. A timber or steel member sat on top of and bracing the riser forms in wide flights of concrete stairs.
2.) In Formwork. Any type of large stiffening member on the outside of formwork.
3.) In Tilt Slab Construction. Temporary steel or timber stiffeners as extra support to panels during erection. e.g. around openings or as legs to “L” shapes. ;

T – Scaffolding Terminology

Temporary Fencing

Fencing around a construction site or work area.

Tie Bolts

High tensile steel threaded rod system for tying wall forms etc. together. Consisting of a course, rounded thread for speed of use and easy cleaning. Large wing nuts, plate washers, spacer tubes and polythene cones. allows the rods to be completely removed from the wall and re-used many times.

Tie Wire

A malleable black wire that is used mainly for tying rebar, but has many other uses in formwork. The basic principle of tie wire is that when it is twisted in a tourniquet (tightening) fashion it does not untwist but remains tight even under load.

Tilt Edge Form

Purpose made extruded aluminium section suitable for tilt slab construction.

Tilt Props

Purpose made steel props or braces that temporarily hold tilt panels until they are secured.

Tilt Slabs

A form of concrete wall construction where flat slabs are made on site and lifted into position when the concrete has become strong enough to lift.

Timber Props

Vertical timber supports, posts or shores.

Timber Scaffolding

Scaffolding made out of sawn timber of lumber.

Toe Boards

Timber or steel boards fitted to a work platform to stop people slipping off the platform, or tools or materials being kicked off the platform. Also known as kicker boards.


A horizontal member supported on standards, on which the scaffold planks are laid. Also used as safety rails to end bays.

Transom Beam

In scaffolding. A beam spanning a wider gap between standards than normal. Usually where wider access is required at ground level for vehicles and equipment.

Transom Truss

In scaffolding. A beam spanning a wider gap between standards than normal. Usually where wider access is required at ground level for vehicles and equipment. In modular systems, they are deeper than transom beams and so have two attachment points at each end to the standards.

Trench Shoring

Usually, steel or aluminium frames braced with adjustable struts to support the sides of excavations during pipe laying etc.

Trench Timbering

The provision of timber supports in excavations and trenches to prevent the collapse of the earth sides. A method of making trenches safe to work in.

Tube and Coupler

In Scaffolding. An assembly of heavy walled scaffold tubes used as verticals, horizontals and angled braces held together by purpose-made bolted couplers.

U – Scaffolding Terminology


Strengthening sub-standard or weak foundations.

Underpinning Pressure Grout

The stabilisation and adding new support to weakened foundations by pumping at high pressure a grout mixture under the footing to fill up voids in the subgrade.

W – Scaffolding Terminology

Wall Formwork

Methods of formwork for walls can vary from proprietary steel/steel frame with ply, aluminium and all timber.

Wall Ties

There are various methods of tying wall forms together. Snap Ties, She Bolts, Tie Bars and even Tie wire.

Click here to check out Scaffolding Basics Terminology here.

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