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Contractor Glossary of Terms

Common words and phrases used in the construction industry

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Additive alternate: An alternate bid that, if accepted, adds to the contract sum .

Air rights: The right to use the space above a piece of real estate.

Air space: A cavity or space in walls, windows, or other enclosed parts of a building between various structural members.

Allowance: In contract documents, an amount noted by an architect to be included in the contract sum for a specific item.

Alteration: Partial construction work performed within an existing structure; remodeling without a building addition.

Alternate bid: The amount to be added to or deducted from a base bid amount if alternate materials and/or methods of construction are required.

Anchorage: A secure point of attachment for lifelines, lanyards, or deceleration devices .

Anchored bridging: Steel joist bridging connected to a bridging terminus point.

Aquifer: An underground formation of sands, gravel, or fractured or porous rock that is saturated with water and that supplies water for wells and springs.

Assignment: Transferring the rights and duties under a contract from one party to another.

Axial: In a direction parallel to the long axis of a structural member .

Backcharge: Billings for work performed or costs incurred by one party that, under the contract, should have been performed or incurred by the party to whom billed.

Base bid: An agreed construction sum based on the contract documents.

Batter board: Temporary framework used to assist in locating corners when laying a foundation; also used to maintain proper elevations of structures, excavations, and trenches.

Bid: A formal offer by a contractor, in accordance with the specifications for a project, to do all or a phase of the work at a certain price in accordance with the terms and conditions stated in the offer.

Bid bond: A bond issued on behalf of a contractor that provides assurance to the recipient of the bid that, if the bid is accepted, the contractor will sign the contract and provide a performance bond. The bonding company is obliged to pay the recipient of the bid the difference between the contract’s bid and the bid of the next lowest responsible bidder if the bid is accepted and the contractor fails.

Bid opening: The actual process of opening and tabulating bids submitted at a prescribed bid date/time and conforming with the bid procedures.

Bid security: Funds or a bid bond submitted with a bid as a guarantee to the recipient of the bid that the contractor, if awarded the contract, will accept it.

Body belt: A strap with means both for securing it about the waist and for attaching it to a lanyard, lifeline, or deceleration device.

Body harness: Straps that may be secured about the person in a manner that distributes the fall-arrest forces over at least the thighs, pelvis, waist, chest, and shoulders with a means for attaching the harness to other components of a personal fall arrest system.

Boilerplate: Standardized or formulaic language in a contract .

Bolted diagonal bridging: Diagonal bridging that is bolted to a steel joist or joists.

Bonding company: A licensed firm willing to execute a surety bond, payable to the owner, securing a contractor’s performance on a contract either in whole or in part, or securing payment for labor and materials. Also known as a surety.

Breach of contract: A material failure to perform an act required by a contract .

Bridging clip: A device that is attached to the steel joist to allow the bolting of the bridging to the steel joist.

Bridging terminus: A wall, a beam, tandem joists (with all bridging installed and a horizontal truss in the plane of the top chord), or other element at an end or intermediate point(s) of a line of bridging that provides an anchor point for the steel joist bridging.

Builder’s risk insurance: Insurance coverage on a construction project during construction.

Building code: The legal minimum requirements established or adopted by a government agency for the design and construction of buildings Building envelope: The outer structure of a building .

Bull float: A tool used to spread out and smooth concrete.

Bullnose: Any material with a rounded edge, such as a concrete block, ceramic tile, brick, window sill, etc..

Buttress: A projecting structure of masonry or wood to support or give stability to a wall or building against horizontal outward forces.

Chase: A groove made in a wall or through a floor to accommodate pipes or ducts .

Choker: A wire rope or synthetic fiber rigging assembly that is used to attach a load to a hoisting device.

Cleat: A ladder crosspiece of rectangular cross section placed on edge upon which a person may step while ascending or descending a ladder.

Cold forming: The process of using press brakes, rolls, or other methods to shape steel into desired cross sections at room temperature.

Column: A load-carrying vertical member that is part of the primary skeletal framing system. Columns do not include posts.

Competent person: One who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees and who has authorization to take prompt corrective measures to eliminate them.

Connector: A device that is used to couple (connect) parts of a personal fall arrest system or positioning device system together.

Connector: An employee who, working with hoisting equipment, is placing and connecting structural members and/or components.

Constructibility: The ability to erect structural steel members without having to alter the over-all structural design.

Construction load (for joist erection): Any load other than the weight of the employee(s), the joists, and the bridging bundle.

Construction manager: An entity that provides construction management services, either as an advisor or as a contractor.

Controlled access zone: A work area designated and clearly marked in which certain types of work (such as overhand bricklaying) may take place without the use of conventional fall protection systems guardrail, personal arrest, or safety net to protect the employees working in the zone.

Controlled decking zone: (CDZ) An area in which certain work (for example, initial installation and placement of metal decking) may take place without the use of guardrail systems, personal fall arrest systems, fall restraint systems, or safety net systems and where access to the zone is controlled.

Controlled load lowering: Lowering a load by means of a mechanical hoist drum device that allows a hoisted load to be lowered with maximum control using the gear train or hydraulic components of the hoist mechanism. Controlled load lowering requires the use of the hoist drive motor, rather than the load hoist brake, to lower the load.

Controlling contractor: A prime contractor, general contractor, construction manager, or any other legal entity that has the overall responsibility for the construction of the project—its planning, quality, and completion.

Cost breakdown: A detailed summary of all the anticipated costs on a construction project .

Critical lift: A lift that (1) exceeds 75 percent of the rated capacity of the crane or derrick, or (2) requires the use of more than one crane or derrick .

Deceleration device: Any mechanism such as rope, grab, ripstitch lanyard, specially-woven lanyard, tearing or deforming lanyards, automatic self-retracting lifelines/lanyards.

Deceleration distance: The additional vertical distance a falling person travels, excluding lifeline elongation and free fall distance, before stopping, from the point at which a deceleration device begins to operate.

Decking hole: A gap or void more than 2 inches (5.1 cm) in its least dimension and less than 12 inches (30.5 cm) in its greatest dimension in a floor, roof, or other walking/working surface. Pre-engineered holes in cellular decking (for wires, cables, etc.) are not included in this definition.

Derrick floor: An elevated floor of a building or structure that has been designated to receive hoisted pieces of steel prior to final placement.

Double-cleat ladder: A ladder similar in construction to a single-cleat ladder but with a center rail to allow simultaneous two-way traffic for employees ascending or descending Double connection: An attachment method where the connection point is intended for two pieces of steel which share common bolts on either side of a central piece.

Double connection seat: A structural attachment that, during the installation of a double connection, supports the first member while the second member is connected.

Effluent: Treated sewage from a septic tank or sewage treatment plant .

Equivalent: Alternative designs, materials, or methods that the employer can demonstrate will provide an equal or greater degree of safety for employees than the method or item specified in the standard.

Erection bridging: The bolted diagonal bridging that is required to be installed prior to releasing the hoisting cables from the steel joists.

Extension trestle ladder: A self-supporting portable ladder, adjustable in length, consisting of a trestle ladder base and a vertically adjustable extension section with a suitable means for locking the ladders together.

Failure: Load refusal, breakage, or separation of component parts. Load refusal is the point where the structural members lose their ability to carry the loads.

Fall restraint system: A fall protection system that prevents the user from falling any distance. The system is comprised of either a body belt or body harness along with an anchorage, connectors, and other necessary equipment. The other components typically include a lanyard and may also include a lifeline and other devices.

Final interior perimeter: The perimeter of a large permanent open space within a building such as an atrium or courtyard. This does not include openings for stairways, elevator shafts, etc..

Fixed ladder: A ladder that cannot be readily moved or carried because it is an integral part of a building or structure. A side-step fixed ladder is a fixed ladder that requires a person getting off at the top to step to the side of the ladder side rails to reach the landing. A through fixed ladder is a fixed ladder that requires a person getting off at the top to step between the side rails of the ladder to reach the landing.

Footprint: The outline of a building on the ground, used in site planning .

Formwork: The total system of support for freshly placed or partially cured concrete, including the mold or sheeting (form) that is in contact with the concrete as well as all supporting members including shores, reshores, hardware, braces, and related hardware.

Girt (in systems-engineered metal buildings): A “Z” or “C” shaped member formed from sheet steel, spanning between primary framing and supporting wall material.

Guardrail system: A barrier erected to prevent employees from falling to lower levels .

Handrail: A rail used to provide employees with a handhold for support.

Headache ball: A weighted hook that is used to attach loads to the hoist load line of the crane.

Hoisting equipment: Commercially manufactured lifting equipment designed to lift and position a load of known weight to a location at some known elevation and horizontal distance from the equipment’s center of rotation. Hoisting equipment includes but is not limited to cranes, derricks, tower cranes, barge-mounted derricks or cranes, gin poles, and gantry hoist systems. A come-a•long (a mechanical device, usually consisting of a chain or cable attached at each end that is used to facilitate movement of materials through leverage) is not considered hoisting equipment.

Hole: A void or gap 2 inches (5.1 centimeters) or more in the least dimension in a floor, roof, or other walking/working surface.

Individual-rung/step ladders: Ladders without a side rail or center rail support. Such ladders are made by mounting individual steps or rungs directly to the side or wall of the structure.

Jacking operation: Lifting vertically a slab (or group of slabs) from one location to another for example, from the casting location to a temporary (parked) location, or from a temporary location to another temporary location, or to the final location in the structure during a lift-slab construction operation.

Job-made ladder: A ladder that is fabricated by employees, typically at the construction site, and is not commercially manufactured. This definition does not apply to any individual-rung/step ladders.

Ladder stand: A mobile, fixed-size, self-supporting ladder consisting of a wide, flat-tread ladder in the form of stairs. The assembly may include handrails.

Lanyard: A flexible line of rope, wire rope, or strap that generally has a connector at each end for connecting the body belt or body harness to a deceleration device, lifeline, or anchorage.

Leading edge: The edge of a floor, roof, or formwork for a floor or other walking/working surface (such as the deck) which changes location as additional floor, roof, decking, or formwork sections are placed, formed, or constructed.

Lifeline: A component consisting of a flexible line for connection to an anchorage at one end to hang vertically (vertical lifeline), or for connection to anchorages at both ends to stretch horizontally (horizontal lifeline), and that serves as a means for connecting other components of a personal fall arrest system to the anchorage.

Lift slab: A method of concrete construction in which floor and roof slabs are cast on or at ground level and, using jacks, are lifted into position.

Limited access zone: An area alongside a masonry wall that is under construction and that is clearly demarcated to limit access by employees.

Lower levels: Those areas to which an employee can fall from a stairway or ladder. Such areas include ground levels, floors, roofs, ramps, runways, excavations, pits, tanks, material, water, equipment, and similar surfaces. It does not include the surface from which the employee falls.

Low-slope roof: A roof having a slope less than or equal to 4 in 12 (vertical to horizontal).

Maximum intended load: The total load of all employees, equipment, tools, materials, transitted loads, and other loads anticipated to be applied to a ladder component at any one time.

Metal decking: A commercially manufactured, structural grade, cold rolled metal panel formed into a series of parallel ribs; for this subpart, this includes metal floor and roof decks, standing seam metal roofs, other metal roof systems, and other products such as bar gratings, checker plate, expanded metal panels, and similar products. After installation and proper fastening, these decking materials serve a combination of functions including, but not limited to: a structural element designed in combination with the structure to resist, distribute, and transfer loads, stiffen the structure, and provide a diaphragm action; a walking/working surface; a form for concrete slabs; a support for roofing systems; and a finished floor or roof .

Multiple lift rigging: A rigging assembly manufactured by wire rope rigging suppliers that facilitates the attachment of up to five independent loads to the hoist rigging of a crane.

Nosing: That portion of a tread projecting beyond the face of the riser immediately below .

Opening: A gap or void 12 inches (30.5 cm) or more in its least dimension in a floor, roof, or other walking/ working surface. For the purposes of this subpart, skylights and smoke domes that do not meet the strength requirements of €1926.754(e)(3) shall be regarded as openings.

Opening: A gap or void 30 inches (76 centi•eters) or more high and 18 inches (46 centi•eters) or more wide in a wall or partition through which employees can fall to a lower level.

Permanent floor: A structurally completed floor at any level or elevation (including slab on grade).

Personal fall arrest system: A system used to arrest an employee in a fall from a working level. A personal fall arrest system consists of an anchorage, connectors, and a body harness and may include a lanyard, deceleration device, lifeline, or suitable combination of these. The use of a body belt for fall arrest is prohibited as of January 1, 1998..

Point of access: All areas used by employees for work-related passage from one area or level to another. Such open areas include doorways, passageways, stairway openings, studded walls, and various other permanent or temporary openings used for such travel.

Portable ladder: A ladder that can be readily moved or carried .

Positioning device system: A body belt or body harness system rigged to allow an employee to be supported on an elevated vertical surface such as a wall, and work with both hands free while leaning backwards.

Post: A structural member with a longitudinal axis that is essentially vertical, that: (1) weighs 300 pounds or less and is axially loaded (a load presses down on the top end), or (2) is not axially loaded but is laterally restrained by the above member. Posts typically support stair landings, wall framing, mezzanines, and other substructures.

Precast concrete: Concrete members (such as walls, panels, slabs, columns, and beams) that have been formed, cast, and cured prior to final placement in a structure Project structural engineer of record: The registered, licensed professional responsible for the design of structural steel framing and whose seal appears on the structural contract documents Punch list: A list of work that requires correction or completion.

Purlin (in systems-engineered metal buildings): A “Z” or “C” shaped member formed from sheet steel spanning between primary framing and supporting roof material Qualified person: One who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work, or the project Reshoring: The construction operation in which shoring equipment (also called reshores or reshoring equipment) is placed as the original forms and shores are removed in order to support partially cured concrete and construction loads Riser height: The vertical distance from the top of a tread to the top of the next higher tread or platform/ landing or the distance from the top of a platform/ landing to the top of the next higher tread or platform/landing Rope grab: A deceleration device that travels on a lifeline and automatically, by friction, engages the lifeline and locks to arrest a fall Safety deck attachment: An initial attachment that is used to secure an initially placed sheet of decking to keep proper alignment and bearing with structural support members Safety-monitoring system: A safety system in which a competent person is responsible for recognizing and warning employees of fall hazards Self-retracting lifeline/lanyard: A deceleration device containing a drum-wound line which can be slowly extracted from or retracted onto the drum under minimal tension during normal employee movement and which, after onset of a fall, automatically locks the drum and arrests the fall Shear connector: Headed steel studs, steel bars, steel lugs, and similar devices that are attached to a structural member for the purpose of achieving composite action with concrete Shore: A supporting member that resists a compressive force imposed by a load Side-step fixed ladder: See Fixed ladder Single-cleat ladder: A ladder consisting of a pair of side rails, connected together by cleats, rungs, or steps .

Single-rail ladder: A portable ladder with rungs, cleats, or steps mounted on a single rail instead of the normal two rails used on most other ladders.

Snaphook: A connector consisting of a hook-shaped member with a normally closed keeper or similar arrangement which may be opened to permit the hook to receive an object and, when released, automatically closes to retain the object.

Specifications or specs: A narrative list of materials, methods, model numbers, colors, allowances, and other details that supplements information in blueprints and other working drawings.

Spiral stairway: A series of steps attached to a vertical pole and progressing upward in a winding fashion within a cylindrical space.

Stair rail system: A vertical barrier erected along the unprotected sides and edges of a stairway to prevent employees from falling to lower levels. The top surface of a stair rail system may also be a handrail.

Steel erection: The construction, alteration, or repair of steel buildings, bridges, and other structures, including the installation of metal decking and all planking used during the process of erection.

Steel joist: An open web, secondary load-carrying member of 144 feet (43.9 m) or less, designed by the manufacturer, used for the support of floors and roofs. This does not include structural steel trusses or cold-formed joists.

Steel joist girder: An open web, primary load-carrying member, designed by the manufacturer, used for the support of floors and roofs. This does not include structural steel trusses.

Steel truss: An open web member designed of structural steel components by the project structural engineer of record. For the purposes of this subpart, a steel truss is considered equivalent to a solid web structural member.

Steep roof: A roof having a slope greater than 4 in 12 (vertical to horizontal) .

Step stoolo (ladder type): A self-supporting, foldable, portable ladder, nonadjustable in length, 32 inches or less in overall size with flat steps and without a pail shelf, designed to be climbed on the ladder top cap as well as all steps. The side rails may continue above the top cap.

Structural steel: A steel member, or a member made of a substitute material (such as, but not limited to, fiberglass, aluminum, or composite members). These members include, but are not limited to, steel joists, joist girders, purlins, columns, beams, trusses, splices, seats, metal decking, girts, and all bridging, and cold-formed metal framing which is integrated with the structural steel framing of a building.

Systems-engineered metal building: A metal, field-assembled building system consisting of framing, roof, and wall coverings. Typically, many of these components are cold-formed shapes. These individual parts are fabricated in one or more manufacturing facilities and shipped to the job site for assembly into the final structure. The engineering design of the system is normally the responsibility of the systems-engineered metal building manufacturer

Tank: A container for holding gases, liquids, or solids.

Temporary service stairway: A stairway where permanent treads and/or landings are to be filled in at a later date.

Through fixed ladder: A fixed ladder that requires a person getting off at the top to step between the side rails of the ladder to reach the landing.

Toeboard: A low protective barrier that prevents material and equipment from falling to lower levels and which protects personnel from falling.

Tread depth: The horizontal distance from front to back of a tread (excluding nosing, if any).

Tremie: A pipe through which concrete may be deposited under water.

Unit price: A predetermined price for a measurement of quantity of work to be performed under a contract. The designated unit price would include all labor, materials, equipment, or services associated with item.

Unprotected sides and edges: Any side or edge (except at entrances to points of access) of a stairway where there is no stair rail system or wall 36 inches (.9 m) or more in height, and any side or edge (except at entrances to points of access) of a stairway landing or ladder platform where there is no wall or guardrail system 39 inches (1 m) or more in height.

Vertical slip forms: Forms that are jacked vertically during the placement of concrete.

Walking/working surface: Any surface, whether horizontal or vertical, on which an employee walks or works, including but not limited to floors, roofs, ramps, bridges, runways, formwork, and concrete reinforcing steel. Does not include ladders, vehicles, or trailers on which employees must be located to perform their work duties

Warning line system: A barrier erected on a roof to warn employees that they are approaching an unprotected roof side or edge and which designates an area in which roofing work may take place without the use of guardrail, body belt, or safety net systems to protect employees in the area.

Zoning: Governmental regulations on the use of privately owned land.