300 E. Richey
(575) 746-2412
304 E. Wood
(575) 887-9000
1900 E. Poe
(575) 623-5555
2741 81st St. (Phone sales only)
(806) 744-7092



A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X – Y – Z 


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 structure shall not include habitable spaces, spaces in which agricultural products are processed, treated or packaged; nor shall an agricultural building be 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: Approval drawings may include framing drawings, elevations and sections through the building as furnished by the manufacturer for approval of the buyer. Approval by the buyer affirms that the manufacturer has correctly interpreted the overall contract requirements for the metal building system and its accessories, and the exact location of accessories in the building.

AISI: The American Iron and Steel Institute

AISC: The American Institute of Steel Construction

AISE: American Iron and Steel Engineers

Architectural Drawing: A drawing which shows the plan view and/or elevations of the finished building for the purpose of showing the general appearance of the building, indicating all accessory locations.

ASCE: American Society of Civil Engineers

ASD: Allowable Stress Design

Assembly: A group of mutually dependent and compatible components or subassemblies 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. Automatic Welding: A welding operation utilizing a machine to make a continuous, unbroken weld.

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 load would otherwise impose on the main crane girder.

Auxiliary Loads: All specified dynamic live loads other than the basic design loads which the building must safely withstand, such as cranes, material handling systems, machinery, elevators, vehicles, and impact loads.

Awning Window: A window in which the vent or vents pivot outward about the top edge giving the awning effects.

AWS: American Welding Society

Axial Force: A force tending to elongate or shorten a member

Back to the Top


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 base of a column which rests on the foundation or other support, usually secured by anchor bolts

Base Tube: See “Cast in place Base”

Bay: The space between frame center lines or primary supporting members in the longitudinal direction of the building.

BBC: Basic Building Code

Beam and Column: A primary structural system consisting of a series of rafter beams supported by columns, often used as the end frame of a metal building system.

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: Primary member of a structural system

Bill of materials: A list of items or components used for fabrication

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 used to attach flashing, gutter, etc…

Block or Board Thermal Insulation: Rigid or semi rigid thermal insulation performed into rectangular units.

BOCA: Building Officials and Code Administrators International Inc.

Bonded Roof: A roof which carries a written warranty with respect to weathertightness for a stipulated number of years.

Box Girder: Girders, trucks or other members of rectangular cross-section enclosed on four sides.

Brace Rods: Rods or cables used in roof and walls to transfer loads such as wind loads, and seismic and crane thrusts to the foundation. (also used to plumb buildings but not designed to replace erection tables)

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 wall or column on which to fasten another structural member. Examples are canopy brackets, lean to brackets, and runway brackets.

Bridge Crane: A load lifting system consisting of a hoist which moves laterally on a bean girder, or bridge which in turn moves longitudinally on a runway made of beams and rails. Loads can be moved to any point within a rectangle formed by the bridge span and runway length.

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.

Builder: A party who, as routine part of his business, buys Metal Buildings Systems from a manufacturer for the purpose of resale.

Building: A structure forming an open, partially enclosed, or enclosed space structured 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 asphalt materials

Built-Up Section: A structural member, usually an “I” shape 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 girts are mounted on the outside of the columns.

Back to the Top


“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 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 having a free end and fixed end.

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: The maximum load (usually stated in tons), which 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 the 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 “C” shaped 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 primary member used in a vertical position on a building to transfer loads from main roof, beams, trusses, or rafters to the foundation.

Component: A part used in a Metal Building System. See also “Components and Cladding”.

Components and Cladding: Members that include girts, purlins, studs, wall and roof panels, fasteners, end wall columns and end wall rafters or bearing en d frames, roof overhang beams, canopy beams, and masonry walls when acting as other than 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 to 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 as if there were no connections.

Continuous Air Barrier (CAB): Special materials and/or assemblies that meet certain criteria for air infiltration as well as having all joints and penetrations sealed. By keeping the internal and external environments separate, CABs enhance energy efficiency and are required by newer energy efficiency building codes and standards.

Continuous Beam: A beam having three or more supports.

Continuous Insulation: Insulation that runs continuously over structural members and is free from significant thermal bridging.

Cool Roof: Refers to an outer layer or exterior surface of a roof that has high solar reflectance and high emittance and reduces heat gain into a building.

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: The portion of a building aisle in which a crane operates, defined by the crane span and the uninterrupted length of crane runaway.

Crane Rail: A track supporting and guiding the wheels of a bridge crane or trolley system. On under hung cranes, the crane rail also acts as the runway beam.

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 under hung 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, which supports the runway beam of a top running crane.

Curb: A raised edge on a concrete floor slab or roof accessory.

Curtain Wall: Perimeter wall panels which carry only their own weight and wind load.

Back to the Top


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.

Deflection: The displacement of a structural member or system under load.

Design Loads: Those loads specified in building codes published by Federal, State, County or City agencies, or in owners’ specifications to be used in the design of a building.

Design Professional: Any Architect or Engineer

Diagonal Bracing: See Bracing

Diaphragm Action: The resistance to racking generally offered by the covering systems, fasteners, and secondary framing.

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 (sideways): 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.


Back to the Top


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 that is supported and restrained at one end only.

Eave Gutter: See “Gutter” Eave Height: The vertical dimension from finished floor to the top of the eave strut.

Eave Strut: A structural member at the eave to support roof panels and wall panels. It may also transmit wind forced from roof bracing to wall bracing.

Edge Strip: The surface area of a building at the edges of a roof and at the wall intersections 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 proportional behavior of materials when all stresses are limited to specified allowable values in the elastic range.

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.

Emissivity: A material’s ability to release absorbed energy.

End Approach: The minimum horizontal distance, parallel to the runway, between the outermost 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 which 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 which is parallel to the interior main frame of the building.

Endwall Column: A vertical member located at the endwall of a building which supports the girts. In post and beam endwall frames, endwall columns also support 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.

Engineer/Architect of Record: The Engineer or Architect that is responsible for the overall design of the building project. The manufacturer’s engineer is not the Engineer of Record.

Erection: The on-site assembling of fabricated Metal Building System components to form a completed structure.

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 column

Back to the Top


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 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 the wall.

Fenestration: Windows or other panels of glass; their numbers and location.

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 which does not allow the roof panel to move independently of the roof substructure.

Fixed Base: A column base that is designed to resist rotation as well as horizontal or vertical movement.

Flange: The projecting edge of a structural member.

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 which allows the roof panel to move independently of the roof substructure. Also known as “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 the member into the supporting soil.

Force: The action of one body to another body which changes or tends to change its state of rest or motion. A force may be expressed in pounds (Newton), kips, or other similar units and may act in any one of the following ways:

Compression Force: A force acting on a body tending to compress the body, (pushing action)
Shear Force: A force acting on a body which tends to slide one portion of the body against the
other portion of the body. (sliding action)
Tension Force: A force acting on a body tending to elongate the body. (sliding action)
Torsion Force: A force acting on a body which tends to twist the body.

Foundation: The substructure which supports a building or other structure.

Framed Opening: Frame work (headers and jambs) and flashing which surround an opening in the wall or roof of a building; usually for field installed accessories such as overhead doors or powered roof exhausters.

Framing: The primary and secondary structural members (columns, rafters, girts, purlins, brace rods, etc.) which go together to make up the skeleton of a structure to which the covering can be applied.

Framing Drawings: Plans and erection instructions which identify all individual parts in sufficient detail to permit the proper erection and installation of all parts of the metal building system furnished by the seller (also known as erection drawings)

Back to the Top


GRAIN GROWTH – The increase in the size of grains making up the microstructure of steel such as may occur during heat treatments.

GRAIN REFINEMENT – Reducing the crystalline of grain structure by heat treating, or by a combination of heat treating and mechanical working.

GRAIN STRUCTURE – The type of crystalline structure as observed by eye or under the microscope.

GRAPHITIZING – Annealing gray cast iron so that most of the carbon is transformed to the graphitic condition. Controlled by increasing silicon and by thermal treatment.

Return to top


“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

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 which rises by inclined planes from all four sides of a building. The line where two adjacent sloping sides of a roof meet is called the hip.

Hood (Door): The metal flashing used over exterior slide door track along the full length of the door header to protect the tracks from weather and to conceal them for aesthetic purposes.

Hoist: A mechanical lifting device usually attached to a trolley, which travels along a bridge, monorail or rib 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.

Back to the Top


“I” Beam: See “S” shape.

Ice Dam: A buildup or ice which forms a dam on the roof covering along the eave of the building.

ICBO: International Conference of Building Officials.

Impact Load: A dynamic load resulting from the motion of machinery, elevators, crane ways, vehicles, and other similar moving forces. See auxiliary 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.

Insulated Metal Panel (IMP): Comprised of two single-skin metal panels and a non-chlorofluorocarbon (non-CFC) polyisocyanurate foamed-in-place core.

Insulation: Any material used in building construction to reduce heat transfer.

Internal Pressure: Pressure inside a building which is a function of wind velocity, and number and location of openings.

Back to the Top


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 a column to which it is attached.

Jig: A device used to hold pieces of material in a certain position during fabrication.

Joist: Light beam for supporting a floor or roof.

Back to the Top



Kick–out (elbow) (turn-out): An extension attached to the bottom of a downspout to direct water away from the wall.

Kip: A unit of measure equal to 1,000 pounds (4.4 KN)

Knee: The connecting area of a column and a 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.

Back to the Top


Lean-to: a structure such as a shed, having only one slope or pitch 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 (cranes): 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 Panels: Panels used to admit light. Refers to either transmitting panel or wall 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”.

Loads: Anything that causes a force to be exerted on a structural member. Examples of different types are Dead Load, Impact Load, Roof Live Load, Seismic Load, Wind Load, Crane Load, Collateral Load and Auxiliary Load

Loading Indicating Washers: A washer with dimples which flatten when the high strength bolt is tightened. The bolt tension can be then determined by the use of feeler gages to determine the gap between the washer and the bolt head.

Longitudinal: The direction parallel to the ridge of the 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

Back to the Top


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, which 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: Caulking or sealant normally used in sealing roof panel laps.

MBMA: Metal Building Manufacturers Association

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.

Metal Building Fiber Glass Insulation: A grade of fiberglass insulation blanket specifically manufactured for lamination to a vapor retarder.

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 connection members.

Moment of Inertia: A physical property of a member, which helps define strength and defection 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 a “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.

Back to the Top


Oil Canning: A waviness that occur in flat areas of light gauge, formed metal products. Structual 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: Light weight 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”

Back to the Top


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 which extends above the roof line.

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: A door used by personnel for access to 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.

Pin Connection: A connection designed to transfer axial and shear forces between connecting members, but not moments.

Pitch: The peak height of a gabled building divided by its overall span.

Plastic: Design: a design concept based on multiplying the actual loads by a suitable load factor, using the yield stress as the maximum stress in any member, and taking into consideration moment redistribution.

Plastic Panels: See “Translucent Light 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.

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 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 fastened items by the utilization of a patented device, which 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 tendons are tensioned after the concrete has reached a specific strength.

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 desire 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 which supports roof covering and carries loads to the primary framing members.

Purlin Extension: The projection of the roof beyond the plane of the endwall.

Back to the Top


R-value: A measure of the ability to resist heat flow through a material.

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.

Reaction: The resisting forces at the column bases holding the 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 system over deteriorated roofs or walls.

Rib: The longitudinal raised profile of a panel that provides much of the panels 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 which run on a track.

Roll-Up doors: A door that opens by traveling vertically.

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 a structure by movable objects and 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 horizontal, usually expresses in units of vertical rise to 12 units of horizontal run.

Roof Snow Load: That load induced by the weight of snow on the roof of structure.

Runway Beam: See “Crane Runway Beam”

Runway Bracket: A bracket attached to 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.

Back to the Top


“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: See insulated metal panel.

Screw Down Roof System: A system in which the roof panels are attached directly to the roof substructure with fasteners, which penetrate through the roof sheets and into the substructure.

Scupper: An opening in a gutter or parapet system, which prevents ponding.

Sealant: Any material, which is used to seal cracks, joints or laps.

Secondary Framing: Members, which 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 which combines the function of drilling and tapping.

Self Tapping Screw: A fastener which taps its own threads in a predrilled hole.

Shear: The force tending to make two contracting 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.

Shop Primer Paint: The initial coat of primer paint applied in the shop. A temporary coating designed to protect the steel for limited amount of time until it is in the dry. “This coating may or may not serve as a proper prime coat for other finishing paints.

Shot Pin: See “Power Fastener”

Side Lap Fastener: A fastener used to connect panels together at their side lap.

Sidewall: An exterior wall which is perpendicular to the frames of a building system.

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.

Single Span: A building or structural member without intermediate support.

Siphon Break: A small groove to arrest the capillary action of two adjacent surfaces. (Anti-Capillary Groove).

Sister Column: See “Crane Support Column”

Skylight: A roof accessory to admit light, normally mounted on a curbed framed opening.

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 move independently on 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.

Solar Reflectivity (SR): Solar reflectivity or reflectance is the ability of a material to reflect solar energy from its surface back into the atmosphere. The SR value is a number from 0 (zero) to 1.0. A value of 0 indicates that the material absorbs all solar energy and a value of 1.0 indicates it is all reflected. ENERGY STAR requires SR testing of both new and aged roof products. New products must have an SR value of 0.25 or higher for steep slope (above 2:12) roofing and an SR value of 0.65 or higher for low slope (2:12 or less) roofing. Aged testing takes three years to complete, so not all products that meet the initial requirements are qualified. For more information, please visit

Solar Reflectance Index (SRI): The Solar Reflectance Index is used to determine compliance with LEED requirements and is calculated according to ASTM E 1980 using values for reflectance and emissivity. To meet LEED requirements, a roofing material must have an SRI of 29 or higher for steep slope roofing (above 2:12 and an SRI value of 78 or higher for low slope roofing (2:12 or less) For more information, please visit

Soldier Column: An intermediate column used to support secondary structurals; 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 Systems): 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 sq. ft.

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 roof line.

Standing Seam Roof System: A roof system in which the side laps between the roof panels are arranged in a vertical position above the roof line. 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 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 under hung 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.

Back to the Top


Tapered Members: A built up plate member consisting of flanges welded to a variable depth web.

Tapered Tread Wheels: End truck wheels with treads that 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 Drift: Thermal drift occurs when the R-value decreases as insulation material ages and wind wash occurs with or without thermal variance. Most thermal drift occurs within the first 30 days of the life of foam plastic insulations. However, insulated metal panels do not experience thermal drift due to the metal exterior and interior skins.

Thermal Block: A spacer of low thermal conductance material that is installed between the purlin and the roof insulation, to prevent energy loss.

Thermal Bridging: A thermal bridge is an assembly or component in a building envelope that transfers heat at a significantly higher rate than the surrounding insulated area.

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 ft2xdegree F) (Imperial System) or watts/(m2 x degree C) (SI System). See “Thermal resistance”.

Thermal Conductivity (K-factor): A measure of a material’s ability to transfer heat per unit thickness (BTU-in/hr-ft2- °F). See “Thermal Resistivity”.

Thermal Resistance (R-value): Under steady conditions, the mean temperature difference between parallel surfaces of a slab (large enough so there us no lateral heat flow) of unit thickness that induces unit heat flow through unit area. Note: Thermal Resistance and thermal conductance are reciprocals.

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-value): Measures the amount of heat conducted through a material. It is evaluated by first evaluating the R-value and then computing the reciprocal.

Through-Fastened Roof System: A roof system in which the roof panels are attached directly to the roof substructure with fasteners which 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 fasteneds, ties, etc… for a crane way, monorail or slide door.

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 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 turned 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 being a function of 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.

Back to the Top


Uplift: Wind load on a building which causes a load in the upward direction.

Urban Heat Island: According to the U.S. Environmental Protection Agency (EPA), urban heat islands (UHIs) consist of urban and suburban temperatures that are 2°F to 10°F warmer than nearby rural areas due to the inability to cool because of modification of the land surface by urban development and waste heat generated by energy usage.

Back to the Top


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 that allows the air to pass through.

Back to the Top


X-Bracing: Bracing system with members arranged diagonally in both directions to form an “X”. See “Bracing”.

“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.

Back to the Top