Metal Building Basics

ANCHOR BOLTS Bolts used to anchor structural members to a foundation or other support. Typically refers to the bolts at the bottom of all columns and door jambs.

AUXILIARY LOADS All specified dynamic loads other than the basic design loads which the building must safely withstand, such as cranes, material handling systems and impact loads.

BASE ANGLE An angle secured to the foundation or to the top of a wall used to secure the bottom of the wall panels.

BAY The distance between frame center lines, measured in the longitudinal direction of the building.

BEARING FRAME An end frame utilizing corner columns, endwall columns, channel or hot-rolled rafter beams, which is designed to support one half of the end bay.

BY-PASS FRAMING A wall framing system where the girts are mounted on the
outside of the columns.

COLD FORMING The process of utilizing press brakes or rolling mills to shape and form steel into desired shapes at room temperature.

COLLATERAL LOADS All specified additional loads other than the metal building, such as sprinkler systems, mechanical and electrical, and ceilings.

DIAPHRAGM ACTION The resistance to racking provided by the panels, fasteners, and members to which they are attached.

EAVE The line along the sidewall of a building formed by the intersection of the
planes of the roof and sidewall.

EAVE STRUT A structural member located at the eave of a building which
supports both roof and wall panels.

ENDBAY The bay adjacent to the endwall of the building. Typically measured from the outside of the endwall girts to the centerline of the first interior main frame.

END FRAME The frame at the endwall of a building designed to support the roof load of one half of the endbay.

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

FIXED BASE A column base that is designed to resist rotation as well as horizontal and vertical movement.

FOOTING A pad of concrete beneath a column, wall or other structural member, that is designed to distribute the loads from that member into the supporting soil.

FOUNDATION The substructure which supports a building or other structure.

FRAMED OPENING Framing members (headers and jambs) and flashing which surround an opening in a wall or roof of a building for field installed accessories such as overhead doors, windows, louvers, or roof mounted heating/cooling units.

GABLE The triangular area of the endwall above the level of the eave to the ridge of the roof.

GAGE The numerical designation for the thickness of the steel.

GALVALUME Steel coated with a zinc-aluminum alloy for corrosion resistance.

GIRT A horizontal structural member that is attached to sidewall or endwall columns and supports the panel system.

HAIR PIN “V” shaped reinforcing steel used to transfer anchor bolt shear to the
concrete floor mass.

HAUNCH The deepened portion of a column or rafter designed to accommodate the higher bending moments at such points.

KIP A unit of measure equal to 1,000 pounds. A term used by design engineers.

KNEE The connecting area of a column and rafter of a structural frame. More
commonly referred to as the haunch.

LEAN-TO A structure having only one slope and relying on another structure for
support on either the highside or the lowside.

LENGTH The dimension of the building measured perpendicular to the main frames, measuring from outside of endwall to outside of endwall.

LINER PANEL A metal panel attached to the inside flange of the girts or the inside panel of an insulated sandwich panel.

LIVE LOAD The weight imposed on the building structure during the erection process and during routine maintenance.

LOADS Forces that specifically designed for during the engineering process. The common examples listed below are in alphabetical order, not in order of importance.
     Auxiliary Load          Roof Live Load
     Collateral Load         Roof Snow Load
     Crane Load              Seismic Load
     Dead Load               Wind Load

MAIN FRAME The combination of rafters and columns that support the secondary framing members and transfer loads directly to the foundation.

OIL CANNING A waviness that can occur in flat areas of sheeting or trim. The
structural integrity is not affected by this inherent characteristic.

PEAK The uppermost point of a gable.

PIECE MARK A number given to each separate part of the structure for erection identification.

PIER A concrete structure designed to transfer vertical load from the base of a
column to the foundation.

PORTAL FRAME A rigid frame structure designed such that it provides rigidity and stability in its plane. It is used to resist longitudinal loads when X-bracing is not permitted.

PURLIN EXTENSION The projection of the roof purlins beyond the plane of the endwall to provide an overhang.

RAFTER The main beam supporting the roof system.

RAKE ANGLE An angle fastened to the top of the purlins at the rake for attachment of endwall panels.

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.

ROOF LIVE LOAD Loads that are imposed upon the structure during erection of the building or during maintenance, either by workers, equipment, or materials.

ROOF SLOPE The angle generated by the comparison between the roof surface and the theoretical finished floor of a building.  Typically expressed in inches of vertical rise to 12 inches of horizontal run.

ROOF SNOW LOAD The load imposed on the roof of a building by the weight of snow.

SCREWED DOWN ROOF Any roof system that utilizes a panel which requires
screws to penetrate the panel for attachment to the structural system. This is the most economical system available.

SECONDARY FRAMING Members designed to transfer loads imposed on the
building surface to the main frames.  Examples would include purlins, girts, flange, braces, headers, jambs, and other miscellaneous framing.

SIDEWALL An exterior wall that is perpendicular to the frames of the building,
the walls that are parallel to the ridge.

STANDING SEAM PANEL A type of roof panel that has side laps designed vertically to prevent water penetration. This type of panel does not utilize fasteners, screws for attachment to the structure, thereby eliminating or greatly reducing the opportunities for roof leaks, but rather uses concealed clips for attachment to the
structural system.

UPLIFT The forces acting on the building in an upward direction, caused by wind passing around and over the building.

WIDTH The dimension of the building measured across the building from outside of eave strut to outside of eave strut, from sidewall to sidewall.

WIND LOAD The load imposed on the building by wind from any horizontal direction.

• Introduction
• Design Loading & Codes
• Primary Framing
• Secondary Framing
• Covering Systems