Formwork Glossary

Arch Centering Temporary framework or formwork, usually timber that masonry or concrete arches are built on top of. 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. Back Propping The technique of stripping the formwork in a suspended slab while still keeping it supported. Bamboo Scaffolding Scaffolding made out of natural bamboo Beam Formwork Formwork for beams. This particular page shows a low tech all timber method of forming a perimeter beam to a suspended slab. 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 An angled member working in compression only. Used to stiffen, straighten or support shutters etc. Cantilever 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 from one side of the wall only. 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 a roof surfaces. Also known as a crawling board. Chamfer Usually a 45deg. bevel to a 90deg.(both internal and external) corner in concrete. Column Clamps Various methods of clamping and holding column formwork in position. Column Formwork Timber, steel or other materials used to form concrete columns. 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. 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 A machine driven auger that drills holes and when withdrawn, grout or concrete is pumped into the hole through a hollow center. When withdrawn fully A rebar cage is inserted into the wet concrete.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. 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. Cribbing Squared timbers or concrete members used to provide support or used in a retaining wall. Double Raking Shore A shore with two raking members, either steel or timber to support a larger and higher section of wall. Earth Auger An auger used for drilling circular holes in the ground. Usually machine mounted and hydraulically driven. Fabric Formwork Formwork that is formed out of various plastic and fabric materials. Not reusable, but cheap and quick to erect. Fillets 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. Formply Usually in 2400 x 1200 (8ft x 4ft) and either 12mm, 16mm or 18mm (1/2", 5/8", or 3/4") thick this plywood is 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 Heavier 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. 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. Kicker 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. 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. Ledger 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 hand rail and guard rail supports. 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. Needle 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. Needled Raft Slab In underpinning. An integrated raft slab and cantilever reinforced concrete needles sat on micro piles. 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. Preventive Shoring The fixing of shoring and braces to building undamaged, but that could be put at risk by nearby excavation and other construction work. Puncheons In trench shoring. Short sturdy vertical lengths of timber that support the walers. Similar pieces in old timber framed buildings. Putlog In scaffolding. A horizontal member used for fixing a scaffold to a wall or other part of a buildings structure 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. 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. 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. Scaffolding 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 though a building in order to support it against settlement or to secure it due to damage. Shore 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. Shoring 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. Shutter A made up 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. Standard 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. The have square steel plate on each end to distribute the loads. Stripping Formwork The removal of the formwork. Strongback 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. 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 principal of tie wire is that when it is twisted in a tournequet (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 Transom 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. Underpinning 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. 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