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 that supplements a basic solid panel building such as a door, window, skylight, ventilator, etc.

Agricultural Building –  A structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products. Such structure shall not include habitable or occupiable 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 Bolt Plan – A plan view drawing showing the diameter, location and projection of all anchor rods 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.

Anchor Bolts – See Anchor Rods.

Anchor Rods – The term “anchor rod” is used for threaded rods embedded in concrete to anchor structural steel. The term “rod” is intended to clearly indicate that these are threaded rods, not structural bolts, and should be designed as threaded parts using the material specified in the latest edition of AISC. The embedded end of the rod may be secured in the concrete by means of a head, threading with a nut on the end, a hook orother deformation, by welding to reinforcing steel or other means.

ANSI – American National Standards Institute

Approval Drawings – A set of drawings that may include framing plans, elevations and sections through the building for approval of the buyer.

Apron Flashing – A flashing located at the juncture of the top of the sloped roof and a vertical wall or steeper-sloped roof.

Architectural Panel – Any panel that has a primary purpose of the aesthetic enhancement of a building or structure.

ASTM – American Society for Testing and Materials.

Astragal – A closure between the two leaves of a double swing or double slide door.

Auxiliary Loads – Dynamic live loads such as those induced by cranes and material handling systems.

Bar Joist – A name commonly used for “Open Web Steel Joists” typically used for mezzanine framing.

Base Angle – An angle secured to a wall or foundation used to attach the bottom of the wall paneling.

Base Flashing – The lower flashing component of a two component metal flashing detail. The component flashing details are often used either for expedience or to allow differential thermal movement between building elements or accessories.

Base Plate –  A plate attached to the bottom of a column that rests on a foundation or other support, usually secured by anchor rods.

Base Girt – A continuous member imbedded in the edge of the foundation to which the wall panels are attached.

Batten Seam –
– A metal panel profile attached to and formed around a wood or metal batten,
– A metal panel profile that imitates the traditional batten seam system but omits the wooden batten.

Bay – The space between the main frames.

Beam – A member, usually horizontal, that is subjected to bending loads. There are three types, 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 frame of a building.

Bearing End Frame – See “Beam and Column”

Bearing Frame Endwall (BFEW) – See “Beam and Column”

Bill of Materials – A list that enumerates by part number or description each piece of material or assembly to be shipped.  Also called a shipping list.

Bird Screen – Wire mesh used to prevent birds from entering the building through ventilators and louvers.

Blanket (batt) Insulation – A layer or sheet of flexible fiberglass thermal insulation.

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.

Bridging – Bracing or systems of bracing used between structural members.

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 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.).

Building Envelope –  The elements of a building that enclose conditioned spaces through which thermal energy is capable of being transferred.

Building Type – There are two types of Buildings “Stand Alone” buildings and “Attachment” buildings. Stand Alone – A Stand Alone building is any building in a project that does not attach to any other building in the same project. The first building entered in a new project is always a Stand Alone building because there are no other building to which it could attach. A Stand Alone building can be added to the project and located so that it does not interfere with other buildings in the project.  Attachment – An Attachment is a building which will attach to any other building in the project.  An attachment can be a Lean-to, single slope or gabled building.  Attachments can be made Endwall-to-Endwall, Sidewall-to-Sidewall, Endwall-to-Sidewall or Sidewall-to-Endwall.  The frames of an attachment that is a lean-to must line up with the columns lines of the building to which it attaches.  Any other building type can attach to another building anywhere along the wall to which it attaches.

Built-Up Section – A structural member, usually an I-shaped section, made from individual flat plates welded together.

Butyl Tape – A common abbreviation for polyisobutylene-isoprene polymer sealant tape used between metal roof panel and flashing joints.

Bypass Girt – See “Exterior Framed”.

“C” Section – A member formed from steel sheet in the shape of a block “C”, that may be used either singularly or back to back.

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 a fixed end.

Caulk – See “Sealant”.

Caulking – Filling the joints, seams or voids between adjacent units with a sealant in order to make them weather tight.

Channel, Hot Rolled – A C-shaped member formed while in a semi-molten state at the steel mill to a shape having standard dimensions and properties.

Cladding – The exterior metal roof and wall paneling of a Metal Building System. See also “Components and Cladding”.

Clip – A plate or angle used to fasten two or more members together.

Closure Strip – A resilient strip, formed to the contour of ribbed panels and used to close openings created by ribbed panels joining other components.

Coil Coating – The application of a finish to a coil of metal sheet using a continuous mechanical coating process.

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 foundation.

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

Connection – The means of attachment of one structural member to another.

Continuous Beam – A beam of variable geometry passing over two supports with overhang on one end or passing over three supports.

Contract Documents – The Documents that define the material and work to be provided by a Contractor or the General Contractor for a Construction Project.

Coping – The covering piece on top of an exposed wall or parapet usually made of metal, masonry or stone. It is often sloped to shed water back onto the roof.

Counterflashing – Formed metal or elastomeric flashing secured on or into a wall, curb, pipe, rooftop unit, or other surface, to cover and protect the upper edge of the base flashing and its associated fasteners from exposure to the weather.

Covering – See “Cladding.”

Damper – A baffle used to open or close the throat of ventilators.

Dead Load – The weight of the Building System construction consisting of members such as framing and covering.

Deck – A flat structural element that is fastened to the roof framing members, typically corrugated metal sheets or plywood. It acts as the substrate for non-structural roof panels.

Deflection – The displacement of a structural member relative to its supports due to applied loads. Deflection should not be confused with “Drift”.

Design Loads – The loads expressly specified in the contract documents that the Metal Building System is designed to safely resist.

Design Professional – The Architect or Engineer responsible for the design of a Construction Project.

Diagonal Bracing – See “Bracing”.

Diaphragm Action – The resistance to racking generally offered by the panels, fasteners, and members to which they are attached.

Double Lock Standing Seam – A standing seam in which the female component of the seam is wrapped and folded approximately 360 degrees around the male seam component. (The male component is interlocked and usually folded 180 degrees). See “Standing Seam”.

Downspout – A vertical conduit used to carry runoff water from a scupper, conductor head or gutter of a building to a lower roof level, or to the ground or storm water runoff system.

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.

Drip Edge –  A metal flashing, with an outward projecting lower edge, intended to control the direction of dripping water and to protect underlying building components.

Eave – The line that is usually parallel to the ridge line formed by the intersection of the planes of the roof and wall.

Eave Gutter – See “Gutter”.

Eave Height – The vertical dimension from finished floor to the eave.

Eave Strut – A structural member located at the eave of a building that supports roof and wall paneling and may act as a strut to transfer bracing loads to frames.

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 “End Wall Column”.

Endwall – An exterior wall that is parallel to the interior main frame of the building.

Endwall Column – A vertical member located at the endwall of a building that supports the girts. In beam and column end frames, endwall columns also support the beam. Also referred to as a “Wind Column”

Endwall Overhang – The projection of the roof beyond the plane of the endwall.

Endwall Type – Refers to the type of framing that is used at and endwall.

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.

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.

Exterior Framed – A wall framing system where the girts are mounted on the outside of the columns.

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.

Façade – An architectural treatment, partially covering a wall, usually concealing the eave and/or the rake of the building.

Fading – Any loss of initial color intensity.

Fascia – A decorative trim or panel projecting from the face of a wall.

Filler Strip – See “Closure Strip”.

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 – 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 – See “Trim”.

Floating Clip – See “Sliding Clip”.

Floor Live Load – Those loads induced on the floor system by the use and occupancy of the building.

Flush Frames – 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 that supports a building or other structure.

Framed Opening – Framing members and flashing that surround an opening.

Framing Plans – See “Erection Drawings”.

Gable – The triangular portion of the endwall from the level of the eave to the ridge of the roof.

Gable Overhang – See “End Wall Overhang”.

Gable Roof – A roof consisting of two sloping sides that form a ridge and a gable at each end.

Gage – The distance between adjacent lines of fasteners along which pitch is measured, or the distance from the back of an angle or other shape to the first line of fasteners.

Galvalume® – A proprietary trade name for a coating, used over sheet steel, that is composed of an aluminum-zinc alloy for corrosion protection.

Galvanized – Steel coated with zinc for corrosion resistance.

Gauge – The thickness of sheet metal.

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.

Grade – The term used when referring to the ground elevation around a building.

Ground Snow Load – The probable weight of snow on the ground for a specified recurrence interval exclusive of drifts or sliding snow.

Gutter – A light gauge metal member at an eave, valley or parapet designed to carry water from the roof to downspouts or drains.

“H” Section – A steel member with a cross section in the shape of an “H”.

Hair Pin – “V” shaped reinforcing steel used to transfer shear in the anchor rods to the concrete floor mass.

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 column and rafter.)

Header – The horizontal framing member located at the top of a framed opening.

Hem – The edge created by folding metal back on itself.

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.

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.

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” Beam – See “S” Shape.

IBC – International Building Code.

Importance Factor – A factor that accounts for the degree of hazard to human life and damage to property.

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

Jack Beam – A beam 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.

Joist – Light beam for supporting a floor or roof.

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.

Lap Joint – A joint where one roof panel or flashing segment overlaps another.

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 end wall to end wall.

Liner Panel – A metal panel attached to the inside flange of the girts or inside of a wall panel.

Live Load – See “Roof or Floor Live Load”.

Longitudinal – The direction parallel to the ridge or sidewall.

Louver – An opening provided with fixed or movable, slanted fins to allow flow of air.

Main Frame – An assemblage of rafters and columns that support the secondary framing members and transfer loads directly to the foundation.

Mansard – A steep sloped (almost vertical) real or mock roof element on the perimeter of a building. Originated by the French architect, Francois Mansart.

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 typically not the Engineer of Record.

Masonry – Anything constructed of materials such as bricks, concrete blocks, ceramic blocks, and concrete.

Mastic – See “Sealant”.

MBMA – Metal Building Manufacturers Association.

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.

Miter – The joint produced by joining two diagonally cut pieces, or the act of making such a cut.

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.

NAIMA – North American Insulation Manufacturers Association.

Neoprene – A synthetic rubber (polychloroprene) used in liquid-applied and sheet-applied elastromeric roof membranes or flashings. Also once used as gasketing material beneath the head of metal screw fasteners (although most now use EPDM).

Oil Canning – A waviness that may occur in flat areas of light gage, formed metal products. Structural integrity is not normally affected by this inherent characteristic and therefore is only an aesthetic issue.

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.  OSB, and should not be used in roofing applications.

Overhead Doors – See “Sectional Overhead Doors”.

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.

Panels – See “Cladding”.

Parapet – That portion of the vertical wall of a building that extends above the roof line.

Peak – The uppermost point of a gable.

Peak Sign – A sign attached to the peak of the building at the endwall identifying the building manufacturer.

Personnel Doors – A swinging door used by personnel for access to and exit from a building.

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.

Pinned Base – A column base that is designed to resist horizontal and vertical movement, but not rotation.

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

Pittsburgh Lock Seam – A method of interlocking metal sheets where each of two sheets are folded with two 180° bends.

Pop Rivet – See “Blind Rivet”.

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 – See “Beam and Column”.

Pre-Painted Coil – Coil of metal that has received a paint coating.

Primary Framing – See “Main Frame”.

Purlin – A horizontal structural member that supports roof covering.

Rafter – The main beam supporting the roof system.

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.

Reactions – The resisting forces at the column bases holding the structure in equilibrium under a given loading condition.

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 that 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 Board Insulation – Typically, a rigid polyisocyanurate or polystyrene foam insulation.

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 – Single or multiple leaf doors that open horizontally and are supported at the bottom on wheels that run on a track.

Roll-up Door – A door that opens by traveling vertically.

Roof Assembly – All roof/ceiling components of the building envelope that are horizontal or sloped at an angle less than 60 degrees from horizontal.

Roof Covering – The exposed exterior roof surface consisting of panels.

Roof Curb – See “Curb, Roof”

Roof Jack – 1. A synthetic rubber boot or collar that is used to seal around round roof projections. (Also see “Flashing Collar”.) 2. A metal bracket used to support toe-boards on steep-slope roofs.

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 and do not include wind, snow, seismic or dead loads.

Roof Overhang – A roof extension beyond the end wall or side wall of a building.

Roof Seamer – A machine that crimps or folds adjacent edges of standing seam metal roof panels together, to form a seam.

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 – That load induced by the weight of snow on the roof of the structure. Usually obtained by taking a fraction of the “Ground Snow Load”.

R-value (Thermal Resistance) – The reciprocal of the U-factor (thermal transmittance). Units of R and h•ft2/Btu. Higher R-values indicate a material’s ability to resist more heat flow.

“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.

Screwed Down Roof System – See “Through-Fastened Roof System”.

Scupper – An opening in a gutter or parapet wall that allows excess water to escape.

Sealant – A single-or multi-component polymeric or bituminous-based material used to weatherproof construction joints where moderate movement is expected. The material comes in various grades: pourable, self-leveling, non-sagging, gun grade, and tapes.

Seam – 1. The joint (sidelap) area formed by connecting two adjacent roof panels. 2. A joint formed by mating two separate sections of material.

Seaming Machine – A mechanical device that is used to close and seal the side seams of standing seam roof panels.

Secondary Framing – Members that carry loads from the building surface to the main framing. For example– purlins and girts.

Sectional Overhead Doors – Doors constructed in horizontally hinged sections. They are equipped with springs, tracks, counter

Seismic Load – The lateral load acting in any horizontal direction on a structural system due to the action of an earthquake.

Self Drilling Screw – A fastener that combines the functions of drilling and tapping.

Self Tapping Screw – A fastener that taps its own threads in a predrilled hole.

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.

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

Side Wall – An exterior wall that is perpendicular to the frames of a building system.

Side Wall Overhang – See “Roof Overhang”.

Sill – The bottom horizontal framing member of a wall opening such as a window or door.

Sill Angle – See “Base Angle”.

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 wall to the opposite wall.

Single Standing Seam – A standing seam that utilizes one overlapping interlock between two panels.

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 that opens horizontally by means of sliding on an overhead trolley.

Slope – See “Roof Slope”.

Snow Drift – See “Drift (Snow)”.

Snow Load – See “Roof Snow Load”.

Soffit – A material that covers the underside of an overhang.

Soffit Vent – A pre-manufactured or custom-built air inlet located in the soffit of a roof assembly.

Soldier Column – An intermediate column used to support secondary structurals; not part of a main frame or beam and column system.

Span – The distance between supports of beams, girders, or trusses.

Specification (Metal Building System) – A statement of a set of Metal Building System requirements describing the loading conditions, design practices, materials and finishes.  A tool used by erectors to line up holes and to make up bolted connections; a wrench with a tapered handle.

Stainless Steel – An alloy of steel that 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 drainage plane of the panels or flashings.

Standing Seam Roof System – A standing seam roof system is one 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 at ends of panels and at roof penetrations.

Stiffener – 1. A member used to strengthen a plate against lateral or local buckling. Usually a flat bar welded perpendicular to the longitudinal axis of the member.  2. A formed shape in a metal panel that reduces the effect of oil canning in the panel’s flat area.  Sometimes called “stiffener rib”.

Stiffener Lip – A short extension of material at an angle to the flange of cold formed structural members, which adds strength to the member.

Stitch Screw – A fastener connecting panels together at the sidelap.

Strut – A member fitted into a framework that resists axial compressive forces.

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

Tensile Strength – The longitudinal pulling stress a material can bear without tearing apart.

Thermal Block – A thermal insulating material that is placed between the metal building roof and the compressed insulation over the purlins. Also known as a “thermal spacer block”.

Through-Fastened Roof System – A through-fastened roof system is one in which the roof panels are attached directly to the roof substructure with fasteners which penetrate through the roof sheets and into the substructure.

Translucent Light Panels – Panels used to admit light.

Transverse – The direction parallel to the main frames.

Trapezoidal Panel – A panel configuration whose edge profile forms an open geometric form, roughly in the shape of a trapezoid.

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. Often referred to as flashing. When contrasted, “trim” is generally more decorative, while “flashing” serves more as functional weatherproofing.

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”.

Underlayment – A secondary waterproofing sheet material installed between the substrate and the roof panels, usually used in hydrokinetic roof construction. Some types may be self-adhering.

Uplift – 1. See “Wind Uplift” 2. Upward force at a column base caused by applied building loads or building geometry.

Valley – An architectural detail created where two roof planes intersect, usually having ridge lines at right angles to  each other.

Valley Gutter – A channel used to carry off water from the “V” of roofs of multi-gabled buildings.

Vapor Barrier – Material used to retard the flow of vapor or moisture to prevent condensation from forming on a surface.

Vent – An opening designed to exhaust air, heat, water vapor or other gas from a building or a building component to the atmosphere.

Ventilation – The process of supplying or removing air by natural or mechanical means to or from any space.

Ventilator – An accessory usually used on the roof that allows the air to pass through.

“W” Shape – A hot rolled member with parallel flanges.

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 or other material.

Web – That portion of a structural member between the flanges.

Web Stiffener – See “Stiffener”.

Width – The dimension of the building measured parallel to the main framing from sidewall to sidewall.

Wind Bent – See “Portal Frame”.

Wind Column – A vertical member designed to withstand horizontal wind loads.

Wind Load – The load caused by the wind from any horizontal direction.

Wind Uplift – The differential pressure resulting from the deflection of wind at roof edges, roof peaks or obstructions, causing a drop in air pressure immediately above the roof surface. This pressure, combined with “Internal Pressure”, produces an upward force on the roof components. In “Built-Up Roofing”, wind uplift may also occur because of the introduction of wind pressure underneath the membrane and roof edges, where it can cause the membrane to balloon and pull away from the deck.

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 shape of a “Z”.

Zinc-Aluminum Coated – Steel coated with an alloy of zinc and aluminum to provide corrosion resistance.