A
Accessory: A building product which supplements a basic solid panel building such as a door, window, light transmitting panel, roof vent, etc.
Agricultural Building: A structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other agricultural products. Such structures should not include: spaces meant for habitation or to be occupied, spaces in which agricultural products are processed, treated, or the possibility of being as a place of occupancy by the general public.
Aluminum Coated Steel: Steel coated with aluminum for corrosion resistance.
Anchor Bolts: Bolts used to anchor members to a foundation or other support.
Anchor Bolt Plan: A plan view drawing showing the diameter, location and projection of all anchor bolts for the components of the Metal Building System and may show column reactions (magnitude and direction). The maximum base plate dimensions may also be shown.
Approval Drawings: A set of drawings that may include framing plans, elevations and sections through the building for approval of the dealer.
ASD: Allowable Stress Design.
Assembly: A group of mutually dependent and compatible components or sub-assemblies of components.
Astragal: A closure between the two leaves of a double swing or double slide door.
Automatic Crane: A crane which when activated operates through a preset series of cycles.
Auxiliary Crane Girder: A girder arranged parallel to the main girder for supporting the platform, motor base, operator’s cab, control panels, etc., to reduce the torsional forces that such a load would otherwise impose on the main crane girder.
Axial Force: A force tending to elongate or shorten a member
B
Bar Joist: A name commonly used for Open Web Steel Joists
Base Angle: An angle secured to a wall or foundation used to attach the bottom of the wall paneling.
Base Plate: A plate attached to the bottom of a column, which rests on a foundation or other support, usually secured by anchor bolts.
Base Tube: See Cast in Place Base
Bay: The space between the main frames measured normal to the frame.
Beam: A member, usually horizontal, that is subjected to bending loads. Three types are simple, continuous, and cantilever.
Beam and Column: A Structural system consisting of a series of rafter beams supported by columns. Often used as the end fame of a building.
Bearing End Frame: See Beam and Column.
Bearing Plate: A steel plate that is set on the top of a masonry support on which a beam or purlin can rest
Bent: See Main Frame.
Bill of Materials: A list that enumerates by part number or description each piece of material or assembly to be shipped. Also called tally sheet or shipping list.
Bird Screen: Wire mesh used to prevent birds from entering the building through ventilators and louvers.
Blind Rivet: A small headed pin with expandable shank for joining light gauge metal. Typically it is used to attach flashing, gutters, etc.
Box Girder: Girders, trucks or other members of rectangular cross section enclosed on four sides.
Bracing: Rods, angles or cables used in the plane of the roof and walls to transfer loads, such as wind, seismic and crane thrusts to the foundation
Bracket: A structural support projecting from a structural member. Examples are canopy brackets, lean-to brackets, and crane runway brackets,
Bridge (Crane): That part of an overhead crane consisting of girders, trucks, end ties, walkway and drive mechanism that carries the trolley and travels in a direction parallel to the runway
Bridge Crane: A load lifting system consisting of a hoist, which moves laterally on a beam, girder or bridge which in turn moves longitudinally on a runway made of beams and rails
Bridging: Bracing or systems of bracing used between structural members
British Thermal Unit (BTU): The amount of heat required to raise the temperature of one pound of water by 1 degree Fahrenheit.
Building: A structure forming an open, partially enclosed, or enclosed space constructed by a planned process of combining materials, components, and subsystems to meet specific conditions of use.
Building Aisle: A space defined by the length of the building and the space between building columns.
Building Code: Regulations established by a recognized agency describing design loads, procedures and construction details for structures usually applying to a designated political jurisdiction (city, county, state, etc.).
Built-Up Roofing: A roof covering made up of alternating layers of tar and materials made of asphalt.
Built-Up Section: A structural member, usually an “I” shaped section, made from individual flat plates welded together.
Bumper: An energy-absorbing device for reducing impact when a moving crane or trolley reaches the end of its permitted travel, or when two moving cranes or trolleys come into contact.
Butt Plate: The end plate of a structural member usually used to rest against a like plate of another member in forming a connection. Sometimes called a splice plate or bolted end plate.
Bypass Girt: A wall framing system where the girts are mounted on the outside of the columns.
C
“C” Section: A member in the shape of a block “C” formed from steel sheet, that may be used either singularly or back to back.
Cab-Operated Crane: A crane controlled by an operator in a cab supported on the bridge or trolley.
Camber: Curvature of a flexural member in the plane of its web before loading.
Canopy: A projecting roof system that is supported and restrained at one end only.
Cantilever Beam: A beam supported only at one end with the other end free to move.
Capillary Action: That action which causes movement of liquids when in contact with two adjacent surfaces such as panel sidelaps.
Cap Plate: A plate located at the top of a column or end of a beam for capping the exposed end of the member.
Capacity (Crane): The maximum load (usually stated in tons) that a crane is designed to support.
Cast In Place Base: A continuous member imbedded in the edge of the foundation to which the wall panels are attached.
Caulk: To seal and make weather-tight joints, seams, or voids by filling with a waterproofing compound or material.
Chalking: When the paint finish on panels has a white powder film due to over exposure.
Channel, Hot Rolled: A member formed while in a semi-molten state at the steel mill to shape having standard dimensions and properties.
Cladding: The exterior metal roof and wall paneling of a Metal Building System. See also Covering.
Clip: A plate or angle used to fasten two or more members together.
Closure Strip: A strip, formed to the contour of ribbed panels and used to close openings created by ribbed panels joining other components, either made of resilient material or metal.
CMU: Concrete Masonry Unit. Generally, used to construct masonry walls
Cold Forming: The process of using press brakes or rolling mills to shape steel into desired cross sections at room temperature.
Collateral Loads: The weight of additional permanent materials required by the contract, other than the Building System, such as sprinklers, mechanical and electrical systems, partitions and ceilings.
Column: A main member used in a vertical position on a building to transfer loads from main roof beams, trusses, or rafters to the foundations.
Component: A part used in a Metal Building System. See also Components and Cladding.
Components and Cladding: Members which include girts, joists, purlins, studs, wall and roof panels, fasteners, end wall columns and endwall rafters of bearing end frames, roof overhang beams, canopy beams, and masonry walls that do not act as shear walls.
Concealed Clip: A hold down clip used with a wall or roof panel system to connect the panel to the supporting structure without exposing the fasteners on the exterior surface.
Connection: The means of attachment of one structural member to another.
Continuity: The terminology given to a structural system denoting the transfer of loads and stresses from member to member allowing the members to act as a single unit.
Continuous Beam: A beam having three or more supports.
Covering: The exterior metal roof and wall paneling of a Metal Building System.
Crane: A machine designed to move material by means of a hoist.
Crane Aisle: That portion of a building aisle in which a crane operates, defined by the crane span and the uninterrupted length of crane runway.
Crane Girder: The principal horizontal beams of the crane bridge that supports the trolley and is supported by the end tracks.
Crane Rail: A track supporting and guiding the wheels of a top-running bridge crane or trolley system.
Crane Runway Beam: The member that supports a crane rail and is supported by columns or rafters depending on the type of crane system. On underhung bridge cranes, the runway beam also acts as the crane rail.
Crane Span: The horizontal distance center-to-center of runway beams.
Crane Stop: A device to limit travel of a trolley or crane bridge. This device normally is attached to a fixed structure and normally does not have energy-absorbing ability.
Crane Support Column: A separate column that supports the runway beam of a top-running crane.
Curb: A raised edge on a concrete floor slab or in the roof for accessories.
Curtain Wall: Perimeter wall panels that carry only their own weight and wind load.
D
Damper: A baffle used to open or close the throat of ventilators. They can be operated manually or by motors.
Dead Loads: The dead load of a building is the weight of all permanent construction, such as floor, roof, framing, and covering members.
Design Professional: Any Architect or Engineer.
Diagonal Bracing: See Bracing.
Diaphragm Action: The resistance to racking generally offered by the covering system, fasteners, and secondary framing. Distortion of the overall roof, floor, or wall shape.
Door Guide: An angle or channel used to stabilize or keep plumb a sliding or rolling door during its operation.
Downspout: A conduit used to carry water from the gutter of a building.
Drift (Sidesway): Horizontal displacement at the top of a vertical element due to lateral loads. Drift should not be confused with Deflection.
Drift (Snow): The snow accumulation at a height discontinuity.
Drift Pin: A tapered pin used during erection to align holes in steel members to be connected by bolting.
E
Eave: The line along the sidewall formed by the intersection of the planes of the roof and wall.
Eave Canopy: A projecting roof system on the sidewall whose overhanging edge is supported at the building.
Eave Gutter: See Gutter.
Eave Height: The vertical dimension from finished floor to the top of the eave strut.
Eave Strut: A structural member located at the eave of a building that supports roof and wall paneling.
Edge Strip: The surface area of a building at the edges of the roof and corners of the walls where the wind loads on components and cladding are greater than at other areas of the building.
Effective Wind Area: The area used to determine the wind coefficient. The effective wind area may be greater than or equal to the tributary area.
Elastic Design: A design concept utilizing the a property of materials allowing for non-permanent shape distortion under a specified range of loading.
Electric Operated Crane: A crane in which the bridge, hoist or trolley is operated by electric power.
Electric Overhead Traveling Crane: An electrically-operated machine for lifting, lowering and transporting loads, consisting of a movable bridge carrying a fixed or movable hoisting mechanism and traveling on an overhead runway structure.
End Approach: The minimum horizontal distance, parallel to the runway, between the outer-most extremities of the crane and the centerline of the hook.
End Bay: The bays adjacent to the endwalls of a building. Usually the distance from the endwall to the first interior main frame measured normal to the endwall.
End Frame: A frame located at the endwall of a building that supports the loads from a portion of the end bay.
End Post: See Endwall Column.
End Stop: A device attached to a crane runway or rail to provide a safety stop at the end of a runway.
End Truck: The unit consisting of truck frame, wheels, bearings, axles, etc., which supports the bridge girders.
Endwall: An exterior wall that is parallel to the interior main frames of the building.
Endwall Column: A vertical member located at the endwall of a building that supports the girts. In post and beam endwall frames, endwall columns also support the rafter.
Endwall Overhang: See Purlin Extension.
End Zone: The surface area of a building along the roof at the endwall and at the corners of walls. (see Edge Strip)
Engineer/Architect of Record: The engineer or architect who is responsible for the overall design of the building project. The manufacturer’s engineer is not the Engineer of Record.
Erection Bracing: Materials used by erectors to stabilize the building system during erection, also typically referred to as temporary bracing.
Erection Drawings: Roof and wall erection (framing) drawings that identify individual components and accessories furnished by the manufacturer in sufficient detail to permit proper Erection of the Metal Building System.
Erector: A party who assembles or erects a Metal Building System.
Expansion Joint: A break or space in construction to allow for thermal expansion and contraction of the materials used in the structure.
Exterior Framed: A wall framing system where the girts are mounted on the outside of the columns.
F
Fabrication: The manufacturing process performed in a plant to convert raw material into finished Metal Building System components. The main operations are cold forming, cutting, punching, welding, cleaning and painting.
Facade: An architectural treatment, partially covering a wall, usually concealing the eave and/or the rake of the building.
Fading: Refers to the paint finish on panels becoming less vibrant of color.
Fascia: A decorative trim or panel projecting from the face of a wall.
Field: The job site, building site, or general marketing area.
Filler Strip: See Closure Strip.
Film Laminated Coil: Coil metal that has a corrosion resistant film laminated to it prior to the forming operation.
Fixed Clip: A standing seam roof system hold down clip that does not allow the roof panel to move independently of the roof substructure.
Fixed Base/Weak Axis: A column base that is designed to resist rotation as well as horizontal or vertical movement.
Fixed-Base vs Pinned-Based Columns Most experienced structural engineers will agree that it is rather difficult to achieve a full column-base fixity in metal building systems. Outside designers routinely assume the column bases to be pinned, that is, not transmitting any bending moments to the foundations. Unfortunately, not everybody remembers to put this assumption in writing with the contract documents. Without being “nailed down”, the pin-base assumption exists only in the minds of the specifying engineers. Manufacturers may feel free to propose a flagpole-type system with fixed-base design, which is a much cheaper solution for them. Since manufacturers do not see the added foundation costs, they may sincerely believe that the fixed-base solution is truly economical. By this time, however, the foundations may have already been designed with the pin-base assumption in mind and could be partially constructed by, or at least awarded to, a concrete contractor. Since the fixed-base column design results in an unanticipated bending moment applied to the foundations, a redesign is almost always required. At this point, the owner’s choice is between accepting a large change order from the foundation contractor or a protracted battle with the metal building manufacturer.
Flange: The projecting edge of a structural member ( e.g. the top and bottom horizontal projections of an I beam).
Flange Brace: A member used to provide lateral support to the flange of a structural member.
Flashing: The metal used to “trim” or cover the juncture of two planes of material.
Floating Clip: A standing seam roof system hold down clip that allows the roof panel to horizontally move independently of the roof substructure. Also known as a “Sliding Clip” or “Slip Clip”.
Floor Live Load: Those loads induced on the floor system by the use and occupancy of the building.
Flush Girts: A wall framing system where the outside flange of the girts and the columns are flush.
Footing: A pad or mat, usually of concrete, located under a column, wall or other structural member, that is used to distribute the loads from that member into the supporting soil.
Foundation: The substructure, which supports a building or other structure.
Framed Opening: Framing members and flashing which surround an opening.
Framing Plans: See Erection Drawings.
G
Gable: The triangular portion of the endwall from the level of the eave to the ridge of the roof.
Gable Overhang: See Purlin Extension.
Gable Roof: A roof consisting of two sloping roof planes that form a ridge and form a gable at each end.
Galvanized: Steel coated with zinc for corrosion resistance.
Gantry Crane: A crane similar to an overhead crane except that the bridge for carrying the trolley or trolleys is rigidly supported on one or more legs running on fixed rails or other run-way.
Girder: A main horizontal or near horizontal structural member that supports vertical loads. It may consist of several pieces.
Girt: A horizontal structural member that is attached to sidewall or endwall columns and supports paneling.
Glaze: The process of installing glass in windows and doors.
Glazing: Glass panes or paneling used in windows and doors.
Grade: The term used when referring to the ground elevation around a building.
Grade Beam: A concrete beam around the perimeter of a building.
Ground Snow Load: The probable weight of snow on the ground for a specified recurrence interval exclusive of drifts or sliding snow.
Grout: A mixture of cement, sand and water used to fill cracks and cavities. Sometimes used under base plates or leveling plates to obtain uniform bearing surfaces.
Gusset Plate: A steel plate used to reinforce or connect structural elements.
Gutter: A light gauge metal member at an eave, valley or parapet designed to carry water from the roof to downspouts or drains.
H
“H” Section: A steel member with a cross section in the shape of an “H”.
Hair Pin: “V” shaped reinforcing steel used to transfer anchor bolt shear to the concrete floor mass.
Hand-Geared (Crane): A crane in which the bridge, hoist, or trolley is operated by the manual use of chain and gear without electric power.
Haunch: The deepened portion of a column or rafter designed to accommodate the higher bending moments at such points. (Usually occurs at the intersection of the column and the rafter.)
Header: The horizontal framing member located at the top of a framed opening.
High Strength Bolts: Any bolt made from steel having a tensile strength in excess of 100,000 pounds per square inch.
High Strength Steel: Structural steel having a yield stress in excess of 36,000 pounds per square inch.
Hinged Base: See Pinned Base.
Hip: The line formed at the intersection of two adjacent sloping planes of a roof.
Hip Roof: A roof that is formed by sloping planes from all four sides.
Hoist: A mechanical lifting device usually attached to a trolley that travels along a bridge, monorail, or jib crane. May be chain or electric operated.
Horizontal Guide Rollers: Wheels mounted near the ends of end trucks, which roll on the side of the rail to restrict lateral movement of the crane.
Hot-Rolled Shapes: Steel sections (angles, channels, “S” shapes, “W” shapes, etc.) which are formed by rolling mills while the steel is in a semi-molten state.
I
“I”-Beam: See S shape.
Ice Dam: A buildup of ice which forms a dam at the eave, contributing to an excessive build-up of snow on the roof.
Impact Load: A dynamic load resulting from the motion of machinery, elevators, craneways, vehicles, and other similar moving forces.
Impact Wrench: A power tool used to tighten nuts or bolts.
Importance Factor: A factor that accounts for the degree of hazard to human life and damage to property.
Installation: The on-site assembling of fabricated Metal Building System components to form a completed structure.
Insulation: Any material used in building construction to reduce heat transfer.
Internal Pressure: Pressure inside a building.
J
Jack Beam: A beam used to support another beam, rafter or truss and eliminate a column support.
Jack Truss: A truss used to support another beam, rafter, or truss and eliminate a column support.
Jamb: The vertical framing members located at the sides of an opening.
Jib Crane: A cantilevered or suspended beam with hoist and trolley. This lifting device may pick up loads in all or part of a circle around the column to which it is attached.
Jig: A device used to hold pieces of material in a certain position during fabrication.
Joist: A light beam for supporting a floor or roof.
K
Kick-Out (Elbow) (Turn-Out): An extension attached to the bottom of a downspout to direct water away from a wall.
Kip: A unit of measure equal to 1,000 pounds.
Knee: The connecting area of a column and rafter of a structural frame such as a rigid frame.
Knee Brace: A diagonal member at a column and rafter intersection designed to resist horizontal loads.
L
Lean-to: A structure having only one slope and depending upon another structure for partial support.
Length: The dimension of the building measured perpendicular to the main framing from outside to outside of endwall girts.
Leveling Plate: A steel plate used on top of a foundation or other support on which a structural column can rest.
Lift (Crane): Maximum safe vertical distance through which the hook, magnet, or bucket can move.
Lifting Devices (Crane): Buckets, magnets, grabs and other supplemental devices, the weight of which is to be considered part of the rated load, used for ease in handling certain types of loads.
Light Transmitting Panel: Panel used to admit light.
Liner Panel: A metal panel attached to the inside flange of the girts or inside of a wall panel.
Live Load: Loads that are produced (1) during maintenance by workers, equipment, and materials, and (2) during the life of the structure by movable objects and do not include wind, snow, seismic, or dead loads. Also see Roof or Floor Live Load.
Load Indicating Washers: A washer with dimples, which flatten when the high strength bolt is tightened. The bolt tension can then be determined by the use of feeler gauges to determine the gap between the washer and the bolt head.
Longitudinal: The direction parallel to the ridge or sidewall.
Longitudinal (Crane): Direction parallel to the crane runway beams.
Louver: An opening provided with fixed or movable slanted fins to allow flow of air.
Low Rise Building: A description of a class of buildings usually less than 60′ eave height. Commonly, they are single story, but do not exceed 4 stories.
LRFD: Load and Resistance Factor Design.
M
Main Frame: An assemblage of rafters and columns that support the secondary framing members and transfer loads directly to the foundation.
Main Wind Force Resisting System: A structural assembly that provides for the overall stability of the building and receives wind loads from more than one surface. Examples include shear walls, diaphragms, rigid frames, and space structures.
Manufacturer: A party who designs and fabricates a Metal Building System.
Manufacturer’s Engineer: An engineer employed by a manufacturer who is in responsible charge of the structural design of a Metal Building System fabricated by the manufacturer. The manufacturer’s engineer is not the Engineer of Record.
Masonry: Anything constructed of materials such as bricks, concrete blocks, ceramic blocks, and concrete.
Mastic: See Sealant.
Mean Roof Height: Average height of roof above ground.
Metal Building System: A complete integrated set of mutually dependent components and assemblies that form a building including primary and secondary framing, covering and accessories, and are manufactured to permit inspection on site prior to assembly or erection.
Mezzanine: An intermediate level between floor and ceiling occupying a partial area of the floor space.
Mill Duty Crane: Cranes with service classification E and F as defined by CMAA.
Moment: The tendency of a force to cause rotation about a point or axis.
Moment Connection: A connection designed to transfer moment as well as axial and shear forces between connecting members.
Moment of Inertia: A physical property of a member, which helps define strength and deflection characteristics.
Monolithic Construction: A method of placing concrete grade beam and floor slab together to form the building foundation without forming and placing each separately.
Monolithic Pour: The placing of concrete in a monolithic construction.
Monorail Crane: A crane that travels on a single runway beam, usually an “S” or “W” beam.
Multi-Gable Building: Buildings consisting of more than one gable across the width of the building.
Multi-Span Building: Buildings consisting of more than one span across the width of the building. Multiple gable buildings and single gable buildings with interior columns are examples.
Multiple Girder Crane: A crane, which has two or more girders for supporting the lifted load.
O
Oil Canning: A waviness that may occur in flat areas of light gauge formed metal products. Structural integrity is not normally affected by this inherent characteristic; therefore oil canning is only an aesthetic issue. Oil canning is not a cause for rejection of the material.
Open Web Steel Joists: Lightweight truss.
Order Documents: The documents normally required by the Manufacturer in the ordinary course of entering and processing an order.
Outrigger: See Auxiliary Crane Girder.
Overhanging Beam: A simply supported beam that extends beyond its support.
Overhead Doors: See Sectional Overhead Doors.
P
Panels: See Cladding.
Panel Notch: A notch or block out formed along the outside edge of the floor slab to provide support for the wall panels and serve as a closure along their bottom edge.
Pan Panel: A standing seam panel, which has vertical sides and has no space between the panels at the side laps.
Parapet: That portion of the vertical wall of a building that extends above the roofline.
Parts and Portions: See Components and Cladding.
Peak: The uppermost point of a gable.
Peak Sign: A sign attached to the peak of the building at the endwall showing the building manufacturer.
Pendant-Operated Crane: Crane operated from a pendant control unit suspended from the crane.
Personnel Doors: doors used by personnel for access and exit from a building.
Pick Point: The belted part of panel bundles where the bundle is to be lifted.
Piece Mark: A number given to each separate part of the building for erection identification. Also called mark number and part number.
Pier: A concrete structure designed to transfer vertical load from the base of a column to the footing.
Pig Spout: A sheet metal section designed to direct the flow of water out through the face of the gutter rather than through a downspout.
Pilaster: A reinforced or enlarged portion of a masonry wall to provide support for roof loads or lateral loads on the wall.
Pinned Base: A column base that is designed to resist horizontal and vertical movement, but not rotation.
Fixed-Base vs Pinned-Based Columns Most experienced structural engineers will agree that it is rather difficult to achieve a full column-base fixity in metal building systems. Outside designers routinely assume the column bases to be pinned, that is, not transmitting any bending moments to the foundations. Unfortunately, not everybody remembers to put this assumption in writing with the contract documents. Without being “nailed down”, the pin-base assumption exists only in the minds of the specifying engineers. Manufacturers may feel free to propose a flagpole-type system with fixed-base design, which is a much cheaper solution for them. Since manufacturers do not see the added foundation costs, they may sincerely believe that the fixed-base solution is truly economical. By this time, however, the foundations may have already been designed with the pin-base assumption in mind and could be partially constructed by, or at least awarded to, a concrete contractor. Since the fixed-base column design results in an unanticipated bending moment applied to the foundations, a redesign is almost always required. At this point, the owner’s choice is between accepting a large change order from the foundation contractor or a protracted battle with the metal building manufacturer.
Pin Connection: A connection designed to transfer axial and shear forces between connecting members, but not moments.
Pitch: See Roof Slope.
Plastic Design: A design concept based on multiplying the actual loads by a suitable load factor, and using the yield stress as the maximum stress in any member, and taking into consideration moment redistribution.
Plastic Panels: See Light Transmitting Panels.
Ponding: 1) The gathering of water at low or irregular areas on a roof.
2) Progressive accumulation of water from deflection due to rain loads.
Pop Rivet: See Blind Rivet.
Porosity: The measurement of openings in buildings, which allow air to enter during a windstorm.
Portal Frame: A rigid frame so designed that it offers rigidity and stability in its plane. It is generally used to resist longitudinal loads where other bracing methods are not permitted.
Post: See Column.
Post and Beam: A structural system consisting of a series of rafter beams supported by columns. Often used as the end frame of a building.
Post-tensioning: A method of pre-stressing reinforced concrete in which tendons are tensioned after the concrete has reached a specific strength.
Power Actuated Fastener: A device for fastening items by the utilization of a patented device that uses an explosive charge or compressed air to embed the pin in concrete or steel.
Pre-tensioning: A method of pre-stressing reinforced concrete in which the tendons are tensioned before the concrete has been placed.
Pre-Painted Coil: Coil of metal, which has received a paint coating.
Press Brake: A machine used in cold-forming metal sheets or strips into desired sections.
Pre-stressed Concrete: Concrete in which internal stresses of such magnitude and distribution are introduced that the tensile stresses resulting from the service loads are counteracted to a desired degree; in reinforced concrete the pre-stress is commonly introduced by tensioning the tendons.
Primary Framing: See Main Frame.
Prismatic Beam: A beam with a uniform cross section.
Public Assembly: A building or space where 300 or more persons may congregate in one area.
Purlin: A horizontal structural member that supports roof covering and carries loads to the primary framing members.
Purlin Extension: The projection of the roof beyond the plane of the endwall.
R
Rafter: The main beam supporting the roof system.
Rail (Crane): See Crane Rail.
Rails (Door): The horizontal stiffening members of framed and paneled doors.
Rake: The intersection of the plane of the roof and the plane of the endwall.
Rake Angle: Angle fastened to purlins at rake for attachment of endwall panels.
Rake Trim: A flashing designed to close the opening between the roof and endwall panels.
Rated Capacity (Crane): The maximum load (usually in tons), which a crane is designed to support safely.
Reactions: The resisting forces at the column bases provided by foundations that hold a structure in equilibrium under a given loading condition.
Reinforcing Steel: The steel placed in concrete as required to carry the tension, compression and shear stresses.
Remote-Operated Crane: A crane controlled by an operator not in a pulpit or in the cab attached to the crane by any method other than pendant or rope control.
Retrofit: The placing of new metal roof or wall systems over deteriorated roofs or walls.
Rib: The longitudinal raised profile of a panel that provides much of the panel’s bending strength.
Ribbed Panel: A panel, which has ribs with sloping sides and forms a trapezoidal shaped void at the side lap.
Ridge: The horizontal line formed by opposing sloping sides of a roof running parallel with the building length.
Ridge Cap: A transition of the roofing materials along the ridge of a roof; sometimes called ridge roll or ridge flashing.
Rigid Connection: See Moment Connection.
Rigid Frame: A structural frame consisting of members joined together with moment connections so as to render the frame stable with respect to the design loads, without the need for bracing in its plane.
Rolling Doors: Doors that are supported at the bottom on wheels that run on a track.
Roll-Up Door: A door that opens by traveling vertically and is gathered into a roll suspended some distance above the floor.
Roof Covering: The exposed exterior roof surface consisting of metal panels.
Roof Live Load: Loads that are produced (1) during maintenance by workers, equipment, and materials, and (2) during the life of the structure by movable objects which do not include wind, snow, seismic or dead loads.
Roof Overhang: A roof extension beyond the endwall or sidewall of a building.
Roof Slope: The tangent of the angle that a roof surface makes with the horizontal, usually expressed in units of vertical rise to 12 units of horizontal run.
Roof Snow Load: The load induced by the weight of snow on the roof of the structure.
Runway Beam: See Crane Runway Beam.
Runway Bracket: A bracket extending out form the column of a building frame, which supports the runway beam for top-running cranes.
Runway Conductors: The main conductors mounted on or parallel to the runway, which supplies electric current to the crane.
S
“S” Shape: A hot rolled beam with narrow tapered flanges.
Sag Member: A tension member such as rods, straps or angles used to limit the deflection of a girt or purlin in the direction of its weak axis.
Sandwich Panel: A panel used as covering consisting of an insulating core material with inner and outer metal skins.
Screw Down Roof System: A screw down roof system is one in which the roof panels are attached directly to the roof substructure with fasteners that penetrate through the roof sheets and into the substructure.
Scupper: An opening in a gutter or parapet system, which prevents ponding.
Sealant: Any material that is used to seal cracks, joints or laps.
Secondary Framing: Members that carry loads from the building surface to the main framing. For example – purlins and girts.
Seaming Machine: A mechanical device that is used to close and seal the side seams of standing seam roof panels.
Sectional Overhead Doors: Doors constructed in horizontally hinged sections. They are equipped with springs, tracks, counter balancers, and other hardware, which roll the sections into an overhead position clear of the opening.
Seismic Load: The lateral load acting in any direction on a structural system due the action of an earthquake.
Self-Drilling Screw: A fastener that combines the function of drilling and tapping.
Self-Tapping Screw: A fastener that taps its own threads in a predrilled hole.
Shear: The force tending to make two contacting parts slide upon each other in opposite directions parallel to their plane of contact.
Shear Diaphragm: See Diaphragm Action.
Shim: A piece of steel used to level base plates or align columns or beams.
Shipping List: See Bill of Materials.
Shop Primer Paint: The initial coat of primer paint applied in the shop. A temporary coating designed to protect the steel during shipping and erection until the building exterior and interior finish coverings have been installed. This coating may or may not serve as a proper prime coat for other finishing paints.
Shot Pin: See Power Actuated Fastener.
Side Lap Fastener: A fastener used to connect panels together above their length.
Sidesway: See Drift (Sidesway).
Sidewall: An exterior wall, which is perpendicular to the frames of a building system.
Sidewall Overhang: See Eave Canopy.
Sill: The bottom horizontal framing member of a wall opening such as a window or louver.
Simple Connection: See Pin Connection.
Simple Span: A term used in structural design to describe a beam support condition at two points which offers no resistance to rotation at the supports.
Single Slope: A sloping roof in one plane. The slope is from one sidewall to the opposite sidewall.
Siphon Break: A small groove to arrest the capillary action of two adjacent surfaces. (Anti- Capillary Groove).
Sister Column: See Crane Support Column.
Slide Door: A single or double leaf door, which opens horizontally by means of sliding on an overhead trolley.
Sliding Clip: A standing seam roof system hold down clip, which allows the roof panel to thermally expanded independently of the roof substructure.
Slope: See Roof Slope.
Snow Drift: See Drift (Snow).
Snow Load: See Roof Snow Load.
Snug Tight: The tightness of a bolt in a connection that exists when all plies in a joint are in firm contact.
Soffit: A material, which covers the underside of an overhang.
Soil Bearing Pressure: The load per unit area a structure will exert through its foundation on the soil.
Soldier Column: An intermediate column used to support secondary structural members; not part of a main frame or beam and column system.
Spacer Strut (Crane): A type of assembly used to keep the end trucks of adjacent cranes on the same runway beams a minimum specified distance apart.
Span: The distance between two supports.
Specification (Metal Building System): A statement of a set of Metal Building System requirements describing the loading conditions, design practices, materials and finishes.
Splice: A connection in a structural member.
Spreader Bar: Elongated bar with attached hooks and/or chains used from a crane to lift long sections of panels, or structural members such as rafters.
Spud Wrench: A tool used by erectors to line up holes and to make up bolted connections; a wrench with a tapered handle.
Square: The term used for an area of 100 square feet.
Stainless Steel: An alloy of steel, which contains a high percentage of chromium to increase corrosion resistance. Also may contain nickel or copper.
Standing Seam: Side joints of roof panels that are arranged in a vertical position above the roofline.
Standing Seam Roof System: A roof system in which the side laps between the roof panels are arranged in a vertical position above the roofline. The roof panel system is secured to the roof substructure by means of concealed hold down clips attached with screws to the substructure, except that through fasteners may be used at limited locations such as at ends of panels and at roof penetrations.
Stiffener: A member used to strengthen a plate against lateral or local buckling.
Stiffener Lip: A short extension of material at an angle to the flange of cold formed structural members, which adds strength to the member.
Stiles: The vertical side members of framed and paneled doors.
Stitch Screw: A fastener connecting panels together at the sidelap.
Straight Tread Wheels: Crane wheels with flat-machined treads and double flanges, which limit the lateral movement of the crane.
Strain: The deformation per unit length measured in the direction of the stress caused by forces acting on a member. Not the same as deflection.
Stress: A measure of the load on a structural member in terms of force per unit area.
Strut: A member fitted into a framework, which resists axial compressive forces.
Stud: A vertical wall member to which exterior or interior covering or collateral material may be attached. May be either load bearing or non-load bearing.
Suspension System: The system (rigid or flexible) used to suspend the runway beams of underhung or monorail cranes from the rafter of the building frames.
Sweep: The amount of deviation of straightness of a structural section measured perpendicular to the web of the member.
T
Tapered Members: A built up plate member consisting of flanges welded to a variable depth web.
Tapered Tread Wheels: End truck wheels with treads which are tapered; the large diameter being toward the center of the span.
Tensile Strength: The longitudinal pulling stress a material can bear without tearing apart.
Tension Forces: Forces acting on a member tending to elongate it.
Thermal Block: A spacer of low thermal conductance material that is installed between the purlin and roof insulation, to prevent energy loss.
Thermal Conductance, (C-Factor): The time rate of heat flow through unit area of a body induced by unit temperature difference between the body surfaces. Units are BTU / (Hour x ft 2 x degree F) [Imperial system] or Watts / (m 2 x degree C) [SI system]. See Thermal Resistance.
Thermal Conductivity, (K-Factor): The time rate of heat flow through unit thickness of a flat slab of a homogenous material in the perpendicular direction to the slab surfaces induced by unit temperature gradient. Units for K are (BTU x in) / (hour x ft 2 x degree F) or BTU/ (hour x ft x degree F) [Imperial System] and Watts / (m x degree C) [SI System]. See Thermal Resistivity.
Thermal Resistance (R-Value): Under steady conditions, the mean temperature difference between two defined surfaces of material or construction that induces unit heat flow through unit area. Note: Thermal resistance and thermal conductance are reciprocals. To obtain the U-Factor, overall thermal transmittance, R-Value for materials and/or combinations of materials must first be evaluated. U-Factor is then the reciprocal of the sum of these individual R-Values.
Thermal Resistivity: Under steady conditions, the temperature difference between parallel surfaces of a slab (large enough so there is no lateral heat flow) of unit thickness that induces unit heat flow through unit area. Note: Thermal resistivity and thermal conductivity are reciprocals. Thermal resistivity is the R-Value of a material of unit thickness.
Thermal Transmittance (U-Factor): The time rate of heat flow per unit is under steady conditions from the fluid on the warm side of a barrier to the fluid on the cold side, per unit temperature difference between the two fluids. To obtain, first evaluate the R-Value and then compute its reciprocal.
Through-Fastened Roof System: A roof system in which the roof panels are attached directly to the roof substructure with fasteners, that penetrate through the roof sheets and into the substructure.
Through Ties: Reinforcing steel, usually in the concrete, extending from one column pier to the other column pier, tying the two columns of a rigid frame together to resist thrust.
Thrust: The horizontal component of a reaction usually at the column base.
Tie: A structural member that is loaded in tension.
Ton: 2,000 pounds.
Track: A metal way for wheeled components; specifically, one or more lines of ways, with fastenings, ties, etc., for a crane way, monorail or slide door.
Translucent Panels: See Light Transmitting Panels.
Transverse: The direction parallel to the main frames.
Tributary Area: The area directly supported by the structural member between contiguous supports.
Trim: The light gauge metal used in the finish of a building, especially around openings and at intersections of surfaces. Sometimes referred to as flashing.
Trolley (Crane): The unit carrying the hoisting mechanism.
Trolley Frame (Crane): The basic structure of the trolley on which are mounted the hoisting and traversing mechanisms.
Truss: A structure made up of three or more members, with each member designed to carry a tension or compression force. The entire structure in turn acts as a beam.
Turnout: See Kick-Out.
Turn-of-the-Nut Method: A method for pre-tensioning high strength bolts. The nut is tightened an additional amount from the Snug Tight position, corresponding to a few blows of an impact wrench or the full effort of a man using an ordinary spud wrench. The amount of rotation required depends on the bolt diameter and length.
Twist Off Bolts: Bolts with a segment, which shears off at a predetermined torque during bolt tightening. These bolts utilized a specially designed wrench for proper installation.
U
Uplift: Wind load on a building, which causes a load in the upward direction.
V
Valley Gutter: A heavy gauge gutter used for multi-gabled buildings or between buildings.
Vapor Barrier: Material used to retard the flow of vapor or moisture to prevent condensation from forming on a surface.
Ventilator: A roof mounted accessory, which allows the air to pass through.
W
“W” Shape: A hot rolled I-shaped member with parallel flanges generally wider than “S” shapes.
Wainscot: Wall material, used in the lower portion of a wall that is different from the material in the rest of the wall.
Walk Door: See Personnel Door.
Wall Covering: The exterior wall surface consisting of panels.
Weak Axis/Fixed Base: A column base that is designed to resist rotation as well as horizontal or vertical movement.
Fixed-Base vs Pinned-Based Columns Most experienced structural engineers will agree that it is rather difficult to achieve a full column-base fixity in metal building systems. Outside designers routinely assume the column bases to be pinned, that is, not transmitting any bending moments to the foundations. Unfortunately, not everybody remembers to put this assumption in writing with the contract documents. Without being “nailed down”, the pin-base assumption exists only in the minds of the specifying engineers. Manufacturers may feel free to propose a flagpole-type system with fixed-base design, which is a much cheaper solution for them. Since manufacturers do not see the added foundation costs, they may sincerely believe that the fixed-base solution is truly economical. By this time, however, the foundations may have already been designed with the pin-base assumption in mind and could be partially constructed by, or at least awarded to, a concrete contractor. Since the fixed-base column design results in an unanticipated bending moment applied to the foundations, a redesign is almost always required. At this point, the owner’s choice is between accepting a large change order from the foundation contractor or a protracted battle with the metal building manufacturer.
Web: That portion of a structural member between the flanges.
Web Stiffener: See Stiffener.
Wheel Base: Distance from center-to center of the outermost crane wheels.
Wheel Load: The vertical forces without impact produced on a crane ok wheel bearing on a runway rail or suspended from a runway beam. Maximum wheel load occurs with the crane loaded at rated capacity and the trolley positioned to provide maximum vertical force at one set of wheels.
Width: The dimension of the building measured parallel to the main framing from outside to outside of sidewall girts.
Wind Bent: See Portal Frame.
Wind Column: A vertical member designed to withstand horizontal wind loads, usually in the endwall.
X
X-Bracing: Bracing system with members arranged diagonally in both directions to form an “X”. See Bracing.
Z
“Z” Section: A member cold formed from steel sheet in the approximate shape of a “Z”.
Zinc-Aluminum Coated: Steel coated with an alloy of zinc and aluminum to provide corrosion resistance.