Glossary of Steel Building Terms

Accessory
A building product or component that supplements a basic solid panel building, such as a door, window, skylight, ventilator, light transmitting panel, roof vent, etc.

ACI (American Concrete Institute)
The leading authority and resource worldwide for developing and distributing standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials.

Active
(Metallurgy) A metal that will corrode in the presence of moisture and a "noble" metal (See Galvanic Action).

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 where agricultural products are processed, treated,d or packaged, nor shall the general public occupy a farming building.

AISC (American Institute of Steel Construction)
Not-for-profit technical institute and trade association that serves the structural steel design community and construction industry.

AISE (Association of Iron and Steel Engineers)
Professional organization for iron and steel engineers.

AISI (American Iron and Steel Institute)
It plays a lead role in developing and applying new steels and steelmaking technology and advances the case for steel as the lead construction material in the marketplace.

Aluminum
A corrosion-resistant metallic element. Aluminum alloy coated sheet is often used for metal roofing and wall panels.

Aluminum Coated Steel
Steel coated with aluminum for corrosion resistance.

Anchor Bolts/Anchor Rods
Bolts or threaded rods set in concrete used to anchor structural members to a foundation or other support. Usually, it refers to the bolts at the bottom of all columns and door jambs. The term "rod" is intended to clearly indicate that these are threaded rods, not structural bolts.

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, the length and width of the foundation, column reactions (magnitude and direction), and minimum base plate dimensions.

ANSI (American National Standards Institute)
Organization that oversees the creation, promulgation and use of thousands of norms and guidelines that directly impact businesses.

Anodic
Concerning metal and galvanic response, when two metals are connected in an electrolyte, they will form a galvanic cell, with the higher metal in the galvanic series being the anode. The anodic metal, being more "active" oxidizes first, thus protecting the cathodic metal from corrosion.

Approval Drawings
A set of drawings that may include framing plans, elevations and sections through the building for approval of the buyer. Approval by the buyer affirms that the manufacturer has correctly interpreted the overall contract requirements.

Architectural Drawing
A drawing that shows the plan view and/or elevations of the finished building to show the general appearance of the building, indicating all accessory locations.

ASCE (American Society of Civil Engineers)
Provider of technical and professional conferences and continuing education, the world's largest publisher of civil engineering content, and an authoritative source for codes and standards.

ASD (Allowable Stress Design)
Design philosophy used by civil engineers that says the stresses in a structure due to service loads do not exceed the building's elastic limit.

Assembly
A group of mutually dependent and compatible components or sub-assemblies of components.

ASTM (American Society for Testing and Materials)
An international standards organization that develops and publishes technical standards for a wide range of materials, products, systems, and services.

Astragal
A closure between the two leaves of a double swing or double slide door used to close the joint.

Automatic Crane
A crane which when activated operates through a pre-set cycle or cycles.

Automatic Welding
A welding procedure utilizing a machine to make a 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 Hoist
A supplemental hoisting unit, usually designed to handle lighter loads at a higher speed than the main crane hoist.

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.

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

Bar Joist
A name commonly used for "Open Web Steel Joists."

Barrel Vault
A semi-cylindrical shaped roof.

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, 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 Tube
A continuous member imbedded in the edge of the foundation to which the wall panels are attached.

Batten
A strip of wood common to non-structural panels that is used to support the vertical ribs of adjacent metal panels.

Batten Cover
A separate strip of metal is used to cover the wood batten and join the vertical ribs of adjacent metal panels on either side of the batten.

A strip of formed metal is used to span the void area and join the vertical legs of adjacent metal panels.

Batten Seam
A metal panel profile is 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 frame centerlines or primary supporting members in the longitudinal direction of the building.

Bay-End
The distance between the centerline of the first interior frame to the inside of the endwall panel.

Bay-Interior
The distance from centerline to centerline of two interior columns.

Bay-Spacing
The distance between bays - typically either 25' or 30'.

BBC (Basic Building Code)
Conditions a structure must pass before a permit is granted. (See BOCA)

Beam
A primary member, usually horizontal, that is subjected to bending loads. There are three types: simple, continuous, and cantilever.

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 Frame Endwall (BFEW)
See "Beam and Column" or "Bearing Hot Rolled."

Bearing Hot Rolled
Also referred to as a Bearing End Frame or Bearing Frame Endwall (BFEW). A structural system consists of hot rolled rafter beams supported by hot rolled columns connected by a series of pinned connections. Often used as the end wall framing of a building.

Bearing Plate
A steel plate that is set on the top of a masonry support on which a beam or purlin can rest.

Bead Mastic
Sealant furnished in a continuous roll, normally used for sealing roof panel laps.

Bent
See "Main Frame."

Bermuda Seam
A metal panel featuring a stepped profile. The panel runs perpendicular to the slope of the roof.

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.

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

Blind Rivet
A small-headed pin with an expandable shank for joining light gauge metal. Typically used to attach flashing, gutter, etc. Also referred to as Pop Rivet.

Block or Board Thermal Insulation
Rigid or semi-rigid thermal insulation preformed into rectangular units.

BOCA (Building Officials and Code Administrators International, Inc.)
An organization that developed and maintained model building codes until it was incorporated into the International Code Council in 1994.

Bonded Roof
A roof that carries a written warranty with respect to weather-tightness 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, seismic and crane thrusts to the foundation. (Also often used to plumb buildings but not designed to replace erection cables.)

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 crane runway brackets.

Brake
A machine used to bend, fold or form sheet metal.

Bridge (Crane)
That part of an overhead crane consisting of girders, trucks, end ties, walkway and drive mechanism which carries the trolley and travels in a direction parallel to the runway.

Bridge Crane
A load lifting system consisting of a hoist that moves laterally on a beam, 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
A structural member is used to give weak axis stability to joists, purlins, or systems of bracing used between structural members.

British Thermal Unit (BTU)
That amount of heat required to raise the temperature of one pound (0.45 kg) of water by 1° F (0.56° C).

Builder/Contractor
A party who, as a routine part of his business, buys the Metal Building System from a manufacturer for the purpose of resale. A general contractor or sub-contractor responsible for providing and erecting metal building systems.

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 apply 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: Any building in a project that does not attach to any other building in the same project.

Attachment: A building which will attach to any other building in the project (e.g., lean-to, single slope, or gabled building).

Built-Up Roofing
A roof covering made up of alternating layers of tar and asphaltic materials or layers (plies) of organic or synthetic fabric.

Built-Up Section
A structural member, usually an "I" 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.

Button Punch
A process of indenting two or more sheets of metal that are pressed against each other to prevent slippage between the metal.

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

Bypass Girt
See "Exterior Framed."

By-Framed Girts (or By-Pass)
Girts which overlap outside column flange to form a continuous member.

"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.

Cab-Operated Crane
A crane is controlled by an operator in a cab supported on the bridge or trolley.

Camber
A predetermined curvature is designed into a structural member to offset the anticipated deflection when loads are applied.

Canopy
Any overhanging or projecting roof structure with the extreme end usually unsupported.

Cantilever
A projecting beam that is supported and restrained at one end only.

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) 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.

Cathodic
With regard to metal and galvanic response, cathodic metals are lower (and more noble) in the galvanic series. (May be protected from oxidation by more anodic metals).

Caulk/Caulking
To seal and make weather-tight the joints, seams, or voids by filling with a waterproofing compound or material.

Centerline to Centerline of Runway Beams
The span of a crane system. Also referred to as Centerline to Centerline of Rail.

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.

Chalking
When the paint finish on panels has a white powder film due to over exposure.

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

Cleat
A sheet metal strip used in concealed fashion to secure panels or flashing that permits some limited degree of thermal response.

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

Clip-Angle
An angle used for fastening various 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.

CMAA (Crane Manufacturers of America Association)
An independent trade association in the United States that helps promote the standardization of cranes and uniform quality and performance.

CMRC (Cool Metal Roofing Coalition)
Organization promoting the benefits of cool metal roofing.

CMU (Concrete Masonry Unit)
Generally, used to construct masonry walls.

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. See our cold-formed steel building article for more details.

Cold Rolled
The process of forming sheet steel into desired shapes on a series of rollers at ambient room temperatures.

Collateral Load
All specified additional dead loads other that the metal building framing, such as sprinklers, mechanical and electrical systems, 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
For wind load considerations, members that do not qualify as part of a Main Wind Force Resisting System. They include girts, joists, purlins, studs, wall and roof panels, fasteners, end wall columns and end wall rafters of bearing end 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 on the exterior surface.

Conditioned Space
Cooled space: an enclosed space within a building that is cooled by a cooling system whose sensible output capacity is greater than or equal to 5 Btu/h·ft of floor area.

Heated space: an enclosed space within a building that is heated by a heating system whose output capacity is greater than or equal to 5 Btu/h·ft of floor area.

Semi-heated space: an enclosed space within a building that is heated by a heating system whose output capacity is greater than or equal to 3.4 Btu/h·ft of floor area but is not a conditioned space.

Conduction
The transfer of heat through a material or construction.

Conductor Head
A transition component between a through-wall scupper and downspout used to collect and direct run-off water.

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

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 of variable geometry passing over two supports with overhang on one end or passing over three supports.

Continuous Girt or Purlin
Girt or purlin that overlaps at columns or frames to form a continuous member.

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

Continuous Ridge Vent
10′ long roof ventilator located along roof peak line.

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.

Contract Documents
The documents which define the responsibilities of the parties involved in the sale, supply and erection of a metal building system. Such documents normally consist of a contract and specifications. Plans may be included.

Convection
The heating of the air that passes over a hot surface.

Cool Roof Color
The color coating on or self color of the roofing material gives it a high solar reflectance and a high thermal emittance. See our metal building colors article for more.

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.

Cooling Degree Day (CDD)
The difference in temperature between the outdoor mean temperature over a 24-hour period and a given base temperature. For example, using a base temperature of 65° F a day with 85° F mean temperature has 20 CDD (85-65=20). The annual Cooling Degree Days are the sum of the degree days over a calendar year.

Coped Flashing
A sheet metal flashing, cut or formed to the contour of ribbed panels and used to close openings created by ribbed panels joining other components.

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.

Copper
A natural weathering metal used in architectural metal roofing; typically used in 16 or 20 oz. per square foot thickness (4.87 or 6.10 kg/square meter).

Corner Column
A corner column (usually a "C" shape) is located at the corner of a bearing frame endwall.

Corner Trim
Preformed color sheet metal trim used to close the junction of side and endwall sheets.

Cornice
A decorative finish or flashing that accents the top of a wall, or the juncture of a roof and wall.

Counter Flashing
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
The exterior roof and wall covering for a metal building system.

CPO (Change Order)
Work that is added to or deleted from the original scope of work of a contract, which alters the original contract amount and/or completion date.

Crane
A machine designed to move material by means of a hoist.

Crane Aisle
This is the section of the building serviced by the crane. The aisle length can run the length of the building (perpendicular to frames) or it can run across (parallel to frames).

Crane Class
CMAA has established six categories of crane service classification as a guide for determining the service requirements of a specific crane application:

• Class A (Standby or infrequent use)
• Class B (Light Service)
• Class C (Moderate Service)
• Class D (Heavy service)
• Class E (Severe service) (Mill Duty)
• Class F (Continuous severe service) (Mill Duty)

Crane Control Type
The method by which the crane is controlled.

Crane Girder
The principal horizontal beams of the crane bridge which supports the trolley and is supported by the end tracks.

Crane Rail
A track supporting and guiding the wheels of a 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, a runway beam also acts as 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 is normally attached to a fixed structure and does not have energy-absorbing ability.

Crane Support Column
A column that sets under the runway beam and next to the frame column with bracing to the frame column for lateral support.

Crane System Type

• Top Running (TRE) (Top Running Electric)
• Underhung (UHE) (Underhung Electric) – Typically crane capacities up to about 15 tons
• Monorail – Typically crane capacities up to about 10 tons

CRRC (Cool Roof Rating Council)

Organization that rates and lists cooling properties of roofing products.

Curb

A raised edge on a concrete floor slab or skylight.

Curb, Roof

An element used to raise a wall, flashing or accessory item above the drainage plane of a roof.

Curtain Wall

Perimeter wall panels, which carry only their own weight and wind load.

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

Dead Load
The weight of the structure itself plus any permanent stationary loads.

Dealer
A metal building company that sells on behalf of the building manufacturer.

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 or system under load.

Design Loads
Those loads are specified in building codes published by Federal, State, County, or City agencies or in owner specifications for use in building design.

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

Dew Point Temperature
The temperature at which water vapor condenses in cooling air at the existing atmospheric pressure and vapor content. Cooling air below the dew point will cause condensation.

Diagonal Bracing
Diagonal bracing is a critical structural component in metal buildings that provides lateral stability and enhances the structure's overall integrity. It consists of diagonal members, typically made of steel rods, angle iron, or cables, that connect two points within the building frame

Diaphragm Action
The covering system, fasteners, and secondary framing generally offer the resistance to racking.

DIY (Do It Yourself)
Building, modifying, or repairing something without the help of a professional.

Direct Tension Indicator
See "Load Indicating Washer".

Door Guide
An angle or channel guide used to stabilize or keep plumb a sliding or rolling door during its operation.

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.

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.

Drift Pin
A tapered pin used during erection to align holes in steel members to be connected by bolting.

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 along the sidewall formed by the intersection of the planes of the roof and walls.

Eave Canopy
A roof extension beyond the sidewall of building. May also be cantilevered below the eave.

Eave Gutter
Diagonal bracing is a critical structural component in metal buildings that provides lateral stability and enhances the overall integrity of the structure. It consists of diagonal members, typically made of steel rods, angle iron, or cables, that connect two points within the building frame

Eave Height
Eave height, in metal building construction, is a crucial measurement that defines the vertical distance from a specific reference point to where the roof meets the wall of the building. Typically, it’s measured from the bottom of the base plate or finished floor level up to the intersection where the underside of the roof meets the outside edge of the sidewall. This measurement is essential for determining overall building height, door opening clearances, interior space, and storage capacity. It’s important to note that eave height should generally be at least 2 feet higher than the tallest door opening. Understanding and specifying the correct eave height is critical for ensuring your metal building meets your functional requirements and complies with local building codes. When discussing eave height with manufacturers or contractors, it’s advisable to clarify the exact measurement points due to some variations in definition across the industry.

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

Eave Strut Gusset
A small gusset shop-welded to main frame on RF and BC buildings to support eave struts and afford alignment with by-framed girts.

Eave Trim
Trim used to close off top of sidewall panels in lieu of eave gutter.

Edge Strip
The surface area of a building at the edges of the roof and at the wall intersections where the wind loads on components and cladding are greater than at other areas of the building.

Edge Venting
The practice of providing regularly spaced or continuous openings along a roof edge or perimeter, used as part of a ventilation system to dissipate heat and water vapor.

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 crane's outermost extremities and the hook's centerline.

End Bay
The bays adjacent to the endwalls of a building. Usually, the distance from the endwall to the first interior mainframe is measured parallel to the ridge.

End Frame
A frame at the endwall of a building to support the roof load from one-half the end bay.

End Post
An end wall column is a vertical structural member located at the building’s end wall. These columns support the end wall and roof system, transfer loads to the foundation, and serve as attachment points for girts and wall panels. Typically spaced 20-25 feet apart, end wall columns are made of cold-formed steel or built-up material, depending on the building’s requirements. Their design and placement are critical for ensuring proper load distribution and overall structural stability of the metal building.

End Stop
Bumpers or wheel stops attached to the end of the crane runway to prevent the crane from driving off the end of the runway.

End Truck
The unit consisting of truck frame, wheels, bearings, axles, etc., which supports the bridge girder(s) and allows movement along the length of the runway structure.

End Wall
An endwall in metal building construction is an exterior wall perpendicular to the ridge of the building. It typically features a rising line where the walls meet the roof, and the height of the wall changes. On a gabled building, the endwall is where the peak of the roof is visible, while on a single-slope building, it shows the wall sloping from a high to low side. Endwalls determine the building’s width and often include components like endwall posts and rafter beams to provide structural support and stability.

End Wall Column
A vertical member located at the endwall of a building which supports the girts. In beam and column end frames, endwall columns also support the beam.

End Wall Overhang
The projection of the roof past the end wall.

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 who is responsible for the overall design of the building project. The manufacturer's engineer is typically not the Engineer of Record.

EPDM (Ethylene Propylene Diene Monomer)
A Synthetic thermoset rubber that is popular for membrane roofing and flashings, and as gasketing material for the head of weather sealing screw fasteners.

Erection
The on-site assembling of fabricated components to form a complete 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.

Expansion Cleat
A cleat designed to accommodate thermal movement of the metal roof panels.

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.

Fabrication
The manufacturing process is 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
Any loss of initial color intensity.

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

Felt
A flexible sheet manufactured by the interlocking of fibers through a combination of mechanical work, moisture and heat.

Fenestration
Windows or other panes of glass; their number and location.

Ferrule
A small metal sleeve is placed inside a gutter at the top. In residential applications, a spike is nailed through the gutter into the fascia board to hold the gutter in place. The ferrule acts as a spacer in the gutter to maintain its original shape.

Field
The uninterrupted principal area of a roof, exclusive of edges, accessories, and other flashing areas.

Filler Strip
See "Closure Strip".

Film Laminated Coil
Coil metal that has a corrosion-resistant film laminated to it prior to the forming operation.

Finial
Gable closure at ridge.

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

Fixed Clip
A standing seam roof system hold down clip that does not allow the roof panel to move independently of the roof substructure.

Flange
The projecting edge of a structural member.

Flange Brace
A bracing member used to provide lateral support to the flange of a beam, girder, or column.

Flashing
A sheet metal closure which functions primarily to provide weather-tightness in a structure and secondarily to enhance appearance.

Flashing Collar
A counterflashing used to cover and/or seal the top of a pipe flashing or other small base flashing at penetrations through the roof.

Floating Clip
See "Sliding Clip".

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

Flush Framed
A wall framing system where the outside flange of the girts and columns are flush.

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.

Force
The action of one body on 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. (pulling 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. See our steel building foundation page for more details.

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).

FS (Fuel Surcharge)
Fee on delivery that accounts for the rise of gas prices.

FTB (First Time Builder)
Someone with little or no experience in steel building projects.

G90
A typical coating weight for galvanized metal sheet. Equates to 0.90 oz. (26g) of zinc per square foot, measured in both front and back surfaces. Other coating weights are G30 and G60.

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 ridged roof that terminates in gables.

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

Galvanic Action
An electrochemical reaction between dissimilar metals in the presence of an electrolyte.

Galvanic Series
A ranking of metals from most anodic (active) to most cathodic (noble):

• Magnesium (most active/anodic)
• Zinc
• Cadmium
• Aluminum
• Steel (plain)
• Cast iron
• Lead
• Tin
• Brasses
• Copper
• Bronzes
• Titanium (most noble/cathodic)

Galvanized
Steel coated with zinc for corrosion resistance.

Gantry Crane
A crane similar to a top running crane except one side of the bridge is supported by one or more gantry legs that ride on a rail attached to the floor, while the other side's end truck rides on a runway beam.

Gauge
The thickness of sheet metal or 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.

Girder
A main horizontal or near horizontal structural member that supports vertical loads. It may consist of several pieces.

Girt
A secondary horizontal structural member attached to sidewall or endwall columns to which wall covering is attached and supported horizontally.

Glare
The reflection of sunlight that can impair vision and create an annoyance. Glare of a coated surface is controlled by the sheen. Low Sheen = Low Glare.

Glaze or Glazing
The process of installing glass 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 carrying an exterior wall.

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. Often 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 channel member is installed at the eave of the roof to carry water to the drains or downspouts.

"H" Section
A steel member with an "H" cross section.

Hair Pin
"V" shaped reinforcing steel used to transfer shear in the anchor rods 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 connection of column and rafter).

Haunch Brace
A diagonal member from the intersection of the column and rafter section of the rigid frame to the eave member to prevent lateral buckling of the haunch.

Header
A horizontal framing member over a door, window, or other framed opening.

Header Trim
Trim used above a wall opening.

Heating Degree Day (HDD)
The difference in temperature between the outdoor mean temperature over a 24-hour period and a given base temperature. For example, using a base temperature of 65° F a day with 50° F mean temperature has 15 HDD (65-50=15). The annual Heating Degree Days are the sum of the degree days over a calendar year.

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. Some examples are ASTM A-325 and A-490.

High Strength Steel
Structural steel having a yield strength in excess of 36,000 pound per square inch.

Hinged Base
See "Pin Connection".

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.

Hoist
A mechanical lifting device usually attached to a trolley, which travels along a bridge, monorail, or jib crane. May be chain or electric operated.

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.

Horizontal Guide Rollers
Wheels mounted near the ends of end trucks that roll on the side of the rail to restrict lateral movement of the crane.

Hot-Rolled Shapes
Steel sections (angles, channels, H beams, etc.) which are formed by rolling mills while the steel is in a semi-molten state.

Hydrokinetic
Metal panel systems that are designed to "shed water" are referred to as hydrokinetic. Hydrokinetic roof details are typically devoid of sealant and rely on water to freely shed over the joints. Hydrokinetic roof details are not to be used on roof slopes below 3:12.

Hydrostatic
Metal panel systems that are designed to withstand being submersed in water for a period of time are called hydrostatic panels. Hydrostatic roof details rely on sealant to keep water from infiltrating the joints and seams. Hydrostatic roof details can be used at almost any roof slope (1/4:12 minimum).

"I" Beam
An I-beam is a structural member with an I-shaped cross-section, consisting of two horizontal flanges connected by a vertical web. Typically made of structural steel, I-beams are designed to efficiently carry heavy loads while minimizing material use. They are widely used in construction for building frames, bridges, and other large structures due to their excellent strength-to-weight ratio and ability to resist bending and shear forces.

IBC (International Building Code)
Model building code established by the US, and developed by the International Code Council.

ICBO (International Conference of Building Officials)
International Conference of Building Officials.

Ice Dam
A build up of ice which forms a dam on the roof covering along the eave of the building.

IECC (International Energy Conservation Code)
A model code for establishing minimum design and construction requirements for energy efficiency.

Impact Load
An assumed dynamic load resulting from the motion of machinery, elevators, craneways, vehicles and other similar moving forces.

Impact Wrench
An electric or pneumatic device used to tighten nuts on bolts.

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

Insect Screen
Wire mesh used to prevent insects from entering the building through ventilators, louvers, or other openings.

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. See our insulation page for more.

Internal Pressure
Pressure inside a building caused by wind acting on the building porosity.

Jack Beam
A beam used to support another beam or truss and eliminate a column support.

Jack Truss
A truss used to support another truss or beam and eliminate a column support.

Jamb
The vertical framing members located at the sides of an opening.

Jib Crane
A cantilevered boom or horizontal beam with hoist and trolley. This lifting machine 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.

Joistmaster
ARCO long-bay structural system, composed of built-up frames and long-span joists.

Joist
A member, usually horizontal, that is subjected to bending loads. There are three types, simple, continuous, and cantilever.

Kick-Out (Elbow)
A lower downspout section is used to direct water away from a wall.

Kip
A unit of measure equal to 1,000 pounds (4.4 kN).

Knee
The connecting area of a column and rafter of a structural frame, such as a rigid frame.

Knee Brace
A diagonal brace is designed to resist horizontal loads, usually from wind or moving equipment. This member normally has the lower end connected to a column and the upper end connected to an eave strut.

Knee Cap
A metal cover trim that fits over a panel rib or seam area after it has been cut and bent at a fascia break detail.

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

Lean-To
A structure such as a shed, having only one slope or pitch and depending upon another structure for partial support.

LEED (Leadership and Energy Environmental Design)
A green building certification program that recognizes best-in-class building strategies and practices.

Length
The dimension of the building measured perpendicular to the main framing from end wall to end wall.

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. Also referred to as "Hook Height".

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 Panels
Panels used to admit light. They are normally of the same configuration as the metal roof or wall panels, and installed in the same plane.

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".

Load Indicating Washers
A washer for high-strength bolts in which pre-tension load can be measured as a function of the amount of compression on raised portions of the washer.

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
• Auxiliary Load

Longitudinal
The direction parallel to the ridge.

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

LRFD (Load and Resistance Factor Design)
Newer method of steel design that requires examination of several load combinations corresponding to service, fatigue, strength and extreme event limit states.

LTL (Less Than Truckload)
A shipment that does not require a 48-foot or 53-foot flatbed trailer.

Main Frame
Primary structural members made up of columns and rafters or trusses, which support the secondary framing.

Mansard
A tilted fascia system mounted to the roof, outside the steel line, and above the roof line to form a decorative fascia appearance and hide the roof line.

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.

MBDA (Metal Building Dealers Association)
See SBA.

MBMA (Metal Building Manufacturers Association)
An organization that promotes the design and construction of metal buildings and metal roofing systems.

Metal Building Fiberglass 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 between two members that transfers the moment from one side of the connection to the other side, and maintains, under the application of load, the same angle between the connected members that existed prior to the loading. Also, a connection that maintains continuity.

Moment of Inertia
A physical property of a member, which helps define strength and deflection characteristics.

Monolithic Construction
A method of pouring concrete grade beam and floor slab together to form the building foundation without forming and pouring each separately.

Monorail
A single rail support for a material handling system. Normally a standard hot-rolled I-beam.

MS-Multi-Span
More than one building tied together; multiple gable buildings.

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 posts are examples.

Mullions
A vertical member connects two windows located side by side. Trim piece between the roll up doors on a mini warehouse.

NBC (National Building Code)
The building code published by the American Insurance Association and used in many localities in the United States.

Newton
SI unit of measure for force (N).

Nibbler
An electric hand tool used to cut steel roof or wall sheet openings.

O

OEM (Original Equipment Manufacturer)
A company that can make a product internally or uses other fabricators based on their own specifications.

OSHA (Occupational Safety and Health Association)
Federal agency charged with the enforcement of safety and health legislation.

Panel
A roof or wall panel.

Parapet
That portion of the vertical wall of a building that extends above the roof line at the intersection of the wall and roof

Partition
An interior wall, not necessarily load-bearing, that extends from floor to ceiling or roof of a building.

Pascal
SI unit of measure for pressure (Pa).

Peak
The uppermost point of a gable.

Peak Sign
A sign mounted at the peak of the roof, usually between the endwall and the first interior frame.

Penetration
Any object passing through the roof membrane.

Permanent Loads
Loads in which variations over time are rare or of small magnitude. All other loads are variable loads.

Pier
A concrete foundation of rectangular cross section, larger than a normal foundation, designed to support heavily concentrated loads.

Pilaster
A column of masonry, usually rectangular in cross section, projecting from a wall.

Pin Connection
A connection designed to allow rotation but not translation.

Pitch
The slope of a roof expressed as the ratio of vertical rise to horizontal run.

Pitch Pan
A flanged metal sleeve placed around a roof penetration and filled with grout or mastic to seal the opening.

Plan View
The view of an object or building as seen from above looking vertically downward.

Plastic
The ability of a material to deform permanently without rupture.

Plastic Design
The design of structural members using fully plastic stress distribution.

Plate
A flat, rolled steel product.

Plenum
A space between a suspended ceiling and floor or roof above that can be used for HVAC ductwork and electrical and communications wiring.

Plumb
Exactly vertical or true.

Plywood
A flat panel built up of sheets of wood veneer called plies, united under pressure by a bonding agent to create a panel with an adhesive bond between plies as strong as or stronger than the wood.

Point Load
A concentrated load at a point on a member.

Polyester
A resin used as a coating for painted metal panels.

Pop Rivet
See "Blind Rivet".

Portal Frame
A rigid frame with wind columns added at the sidewall to reduce sidewall deflections.

Post
A vertical framing member.

Pre-engineered
A building or building product that has been designed to meet a wide range of loading and spanning conditions.

Pre-Galvanized
Steel sheet that has been galvanized prior to forming into roof or wall panels.

Pressure Plate
A component of some standing seam roof systems that bears down on the roof panel seam to hold it in place.

Primary Framing
The main load-carrying members of a structural system.

Primer
A coating is applied to inhibit the corrosion of bare metal.

Projected Area
The area of a building surface as seen in an elevation view.

Purlin
A horizontal structural member that supports roof covering.

Purlin Lap
The overlapping of purlins at a frame flange.

Purlin Roll
The rotation of purlins from their vertical axis due to unbalanced loading.

R-Value
A measure of thermal resistance or the ability of a material to resist heat flow. The higher the R-value, the greater the insulating properties of the material.

Racking
The ability of a building to resist horizontal loads such as wind or seismic forces.

Radius
The length of a line from the center of a circular curve to any point on the curve.

Rake
The intersection of the plane of the roof and the plane of the gable.

Rake Angle
A structural member at the intersection of the sidewall and endwall used to support endwall panels.

Rake Trim
A flashing designed to close the opening between the roof and endwall panels.

Rated Load
The maximum load which may be lifted by a crane under normal operating conditions.

Reactions
The loads at the base of a structure that resist the effects of applied loads.

Reinforcing Steel
Steel rods or wire embedded in concrete to absorb tensile and shearing stresses.

Relative Humidity
The ratio of the amount of water vapor in the air compared to the amount required for saturation at the same temperature. It is usually expressed in percent.

Return
The termination point of a sloped roof panel at its lowest edge.

Ridge
The horizontal line at the junction of the upper edges of two sloping roof surfaces.

Ridge Cap
A transition of the roofing materials along the ridge of a roof. Sometimes called ridge roll or ridge flashing.

Rigid Connection
A connection designed to hold two or more members together while maintaining the initial angle between them.

Rigid Frame
A structural frame consisting of members joined together with rigid (or moment) connections so as to render the frame stable with respect to the design loads, without the need for bracing in its plane.

Roll Former
A machine that progressively forms flat steel coil stock into a desired panel profile.

Roll Up Door
A sectional overhead door that rolls up and stores on a shaft above the door opening.

Roof Covering
The exposed exterior roof surface consists of panels.

Roof Live Load
Those loads are induced by the building's use and occupancy, not including wind, snow, seismic, or dead loads.

Roof Pitch
The slope of a roof is expressed as the ratio of vertical rise to horizontal run.

Roof Slope
See "Roof Pitch".

Roof Snow Load
The vertical load induced by the weight of snow is assumed to act on the horizontal projection of a structure's roof.

Roof System
A system of structural and non-structural elements that provides weather protection and resistance to various loads.

Run of Slope
The horizontal distance from the eave to a point directly under the ridge. Half the span for a symmetrical gable roof building.

Runway Beam
The member that supports the crane rail along which the crane travels.

"S" Shape
A standard hot rolled steel section having the nominal shape of the letter "S".

Sag Member
A tension member used to limit the deflection of a girt or purlin in the direction of the weak axis.

Sag Rod
See "Sag Member".

Sandwich Panel
See "Insulated Metal Panel".

SBA (Systems Builders Association)
Formerly known as MBDA. Organization of metal building contractors and erectors.

SBCCI (Southern Building Code Congress International)
Organization that developed and maintained the Standard Building Code.

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

Scupper
An opening in a wall or parapet that allows water to drain from a roof.

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

Secondary Framing
Purlins, girts, struts, bracing and other members supporting the roof and wall systems.

Section Modulus
A measure of the bending strength of a structural member.

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 which combines the functions 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 contacting parts slide upon each other in opposite directions parallel to their plane of contact.

Shear Diaphragm
A roof or wall system designed to transfer lateral loads to the main framing.

Shear Wall
A wall designed to transfer lateral loads to the foundation or other lateral force resisting elements of the building.

Sheet
A flat rolled product that is cut to length.

Shipping List
See "Bill of Materials".

Shoring
Temporary supports used to hold members in place until they are strong enough or braced to support themselves.

Sidelap
The overlapping of two adjacent panels along their sides.

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

Simple Span
A term used in structural analysis to describe a support condition for a beam, girt, purlin, etc., which offers no resistance to rotation at the supports.

Single Slope
A sloping roof in one plane.

Single Span
A building or structural member without intermediate support.

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

Slide Door
A manually operated door that opens horizontally by means of sliding on an overhead trolley.

Sliding Clip
A roof panel clip that attaches to the panel seam and allows the roof panel to move independently of the roof substructure.

Sloped Glazing
Glass or transparent/translucent panels installed at a slope, typically in roofs.

Snow Drift
The accumulation of snow on the lower levels of a roof due to wind or the configuration of the roof.

Soffit
The underside covering of any exterior overhanging section of a roof eave.

Soil Bearing Capacity
The allowable load which may be safely supported by the soil.

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

Specification
A detailed enumeration of requirements for a Metal Building System.

Splice
A connection in a structural member.

Stainless Steel
An alloy of steel which contains a high percentage of chromium. Also may contain nickel or copper. Characterized by its resistance to corrosion.

Standing Seam
Side joints of roof panels that are arranged in a vertical position above the roof line.

Steel Line
The line along which the outer flanges of the columns of a Metal Building System are located.

Stiffener
A member used to strengthen a plate against lateral or local buckling. Usually a flat bar welded to the plate.

Stiffener Lip
A short extension formed at an angle to the flange of a structural member to provide increased strength.

Strain
The change in length of a body, expressed as a percentage of the original length, due to an applied force.

Stress
The force acting across a unit area in a solid material in resisting the separation, compacting or sliding that tends to be induced by external forces.

Strut
A member fitted into a framework, which resists axial compressive forces.

Stud
A vertical wall member to which exterior or interior covering or sheathing is attached.

Suction
A partial vacuum resulting from wind loads on a building which cause a load in the outward direction.

Superimposed Load
Any load which is applied to a structure other than its own weight.

Symmetrical
Having a shape which is identical on both sides of a dividing line or plane.

Taper
A gradual change in the depth of a structural member.

Teflon
A trademark for polytetrafluoroethylene, a low-friction plastic material.

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

Tension
The result of forces which tend to pull a body apart.

Thermal Block
A strip of rigid insulation, usually foam plastic, used to reduce heat flow through a roof system at the structural supports.

Thermal Conductance (C)
The rate of heat flow through a material or construction.

Thermal Conductivity (k)
The rate of heat flow through a homogeneous material exactly 1" thick.

Thermal Expansion
Change in dimension of a material as a result of temperature change.

Thermal Resistance (R)
The ability of a material to retard heat flow.

Thermal Spacer
See "Thermal Block".

Thermal Transmittance (U)
The rate of heat flow through a material or construction. The inverse of thermal resistance (R).

Through-Fastened System
A roof or wall system where the panels are attached directly through the panel to the substructure.

Thrust
A force that acts in a direction parallel to the ground surface.

Tie
A structural member that works in tension.

Tilt-Up
A concrete wall that is poured horizontally and tilted into its final position.

Top Running Crane
An overhead crane that runs on rails mounted on top of support beams.

Torque
A twisting force about a point or axis.

Translucent
Admitting and diffusing light so that objects beyond cannot be clearly distinguished.

Transmission
The passing of heat or light through a material.

Transverse
The direction parallel to the main frames of a building.

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.

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.

Turnkey
A project in which the contractor is responsible for the entire scope of work, including design, construction, and commissioning.

UBC (Uniform Building Code)
A model building code that was used primarily in the western United States.

UL (Underwriters Laboratories)
An independent product safety certification organization.

Uniform Load
A load of constant intensity distributed over a surface.

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

V
Valley
The internal angle formed by the intersection of two sloping roof planes.

Valley Gutter
A channel used to carry off water from the valley of a roof.

Vapor Barrier (Retarder)
A material used to retard the flow of vapor or moisture to prevent condensation from forming on a surface.

Variable Loads
Loads not classified as permanent loads.

Vent
An opening designed to convey air, heat, or vapor from inside a building or a confined space to the atmosphere.

Vertical Lift Door
A door that opens vertically with the door panels stacking one above the other.

Vestibule
An enclosed entrance projecting into or recessed into the side of a building.

Wall Covering
The exterior wall surface consisting of panels.

Wall, Bearing
A wall that supports any vertical load in addition to its own weight.

Wall, Non-Bearing
A wall that supports no vertical load other than its own weight.

Wall, Partition
An interior wall that extends from floor to ceiling or roof.

Web
That portion of a structural member between the flanges.

Web Member
A secondary structural member interposed between the top and bottom chords of a truss.

Weld
The process of uniting two pieces of metal by heating the edges until they fuse together.

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

Wind Uplift
The upward force exerted by wind traveling across a roof.

Wire Rope
A rope made of twisted strands of wire.

"X" Bracing
Diagonal bracing in the shape of an "X".

Y
Yield Point
The stress at which a material exhibits a specified deviation from the proportionality of stress to strain.

Yield Strength
The stress at which a material exhibits a specified limiting deviation from the proportionality of stress to strain.

Z
"Z" Section
A member cold-formed from steel sheet in the shape of a "Z".

Zee
See "Z" Section.

Zinc
A metallic element used as a protective coating for iron or steel.