Pre-engineered Steel Building System

Pre-engineered steel building systems from Western Steel are designed around primary framing, secondary structural members, and bracing components engineered to meet each project’s requirements. These integrated components provide the structural framework for commercial and industrial buildings, with design options that accommodate different layouts, spans, and load requirements.

Pre-engineered Steel Building System

We Are SolutionCentric.®

Pre-engineered Steel Building System

Pre-engineered steel building systems from Western Steel are designed around primary framing, secondary structural members, and bracing components engineered to meet each project’s requirements. These integrated components provide the structural framework for commercial and industrial buildings, with design options that accommodate different layouts, spans, and load requirements.

Pre-engineered Steel Building System

We Are SolutionCentric.®

Understanding Pre-Engineered Metal Building Structures & Components

Also known as: Pre-eng building, Prefab Building, Metal Building, Metal Building Kit, Metal Building System, Steel Building Kit, Steel Building System
Diagram of a steel building framework with labeled components such as purlins, columns, and bracing.

Pre-engineered Steel Building Diagram

Bay Spacing – Each space or interval between the rigid frames.

Sidewall Column – Main member used in vertical support position to transfer loads from main purlins or rafters into the foundation.

Eave Height – Vertical dimensions from finished floor to eave.

Eave Purlin – Structural member located at the eave of a building that supports roof and wall paneling and may transfer bracing loads to frames.

Endwall – Exterior wall that is parallel to the interior rigid frame.

Endwall Column – Vertical member located at the endwall of a building that supports the girts.

Girt – Horizontal structural member that is attached to sidewall or endwall columns to support paneling.

Girt Clips – Connection clips used to attach the back side of a panel to a structural beam.

Ridge – Horizontal line formed by opposing sloping sides of a roof running parallel with the building length. Generally the highest point of building without parapet walls.

Rigid Frame – Structural frame consisting of members joined together with moment connections to render the frame stable with respect to the design loads, without the need for bracing in its plane.

Roof Purlin – Horizontal structural member that supports roof covering.

Sidewall – Exterior wall that is perpendicular to the frames of a steel building system.

Primary Framing Options for Pre-Engineered Steel Building Systems

Primary frames are designed for full bay loading and span the width of a building. For the pre-engineered systems these primary members are typically I-beams. Frame systems include clear-span, multi-span and lean-to frames in tapered or straight format. Each steel frame system is custom engineered to meet specifications and local building codes.

Tapered Frames vs. Straight Frames: The tapered frame is generally used in column free applications from 40’ to 250’. The straight column rigid frame is designed for maximum efficiency of interior space. Building widths up to 250’ are available with the option of straight columns instead of tapered columns. Lean-to structures are also available for future expansion or additional space if the original main structure had been designed to support the additional load of a lean-to.

Crane Buildings: Crane buildings are complex PEMB or hybrid structural building systems consisting of the crane with trolley and hoist, crane rails, and crane runway beams, structural supports, stops and bumpers.

3D illustration of a simple, modern table without a tabletop.

Gable Clear Span Primary Frame

Clear span frames are column-free interiors that provide the space required for material handling and crane systems. Common uses include warehouses, manufacturing facilities, aircraft hangars, arenas, and indoor sports complexes. Clear Span Frame can also be single slope.
3D rendering of an L-shaped metal bracket or shelf support on a white background.

Single Slope Clear Span Frame

Single Slope Clear Span Frame is great for providing unbstructed interior space without columns in the center of the structure. Single Slope Clear Span frames are often pair with parapet walls.
Simplified line drawing of a three-legged table structure without a tabletop.

Multi-span Primary frames

Multi-span frames are used for wide buildings that are supported by using the minimum number of columns. Common uses include manufacturing plants, warehouses, and retail stores. By strategically placing columns in the interior of the structure, there could be substantial cost savings as it would decrease the size of the ibeam and decrease the amount of steel used.
3D rendering of an L-shaped metal bracket or shelf support on a white background.

Lean-To Primary frames

A lean-to frame typically has a single slope profile and straight sidewall columns and must be supported by an attachment to another frame.

Bracing Systems

Bracing transfers seismic and wind loads from endwalls and sidewalls to the foundation. It is necessary in every pre-engineered building system.
Illustration of a 3D impossible object with grey bars and red strings.

Rod Bracing

(also called X-bracing) is a tension-only bracing system. It may be located in the roof and walls of a building between frame members, transferring longitudinal forces to the foundation.
3D schematic of a blue warehouse rack with a partial transparent view showing internal structure.

Portal Bracing

When bracing must occur in locations where doors or other accessories would interfere with rod-bracing, a portal frame may be used. A portal frame is comprised of two columns and a rafter made of built-up material and is attached to the web of the sidewall columns.

Flange/Cable Bracing

Structural members that attach purlins, girts, and eave struts to primary structural members. They are used to prevent the main frame from twisting or buckling laterally under the load. Flange braces can also be very useful as an erection aid to align the purlins and eave struts. Purlin bracing is an angle that connects the bottom flange of adjoining purlins to prevent purlin roll.

Diagram showing components of a steel structure with labeled parts: purlins, roof beam, and flange brace.
Technical illustration of a cable secured by an eyebolt and wire wrap.

Frequently Asked Questions

The main components typically include primary frames, columns, rafters, roof purlins, wall girts, roof and wall panels, and structural bracing. The exact configuration depends on the building design and project requirements.

A pre-engineered steel building system combines engineered structural components that work together to support the roof and walls and transfer loads to the foundation. The components are designed according to the building’s dimensions, intended use, and applicable design requirements.
Primary framing consists of the main structural frames, including columns and rafters. Secondary framing includes components such as roof purlins and wall girts, which support roof and wall panels and transfer loads to the primary structure.
Bracing helps stabilize the building and transfer applicable wind, seismic, and other lateral forces through the structural system to the foundation. The type and location of bracing depend on the building’s engineering design.
Yes. Pre-engineered steel building systems can be configured with different framing arrangements, dimensions, roof designs, and building features to meet project requirements. Customization depends on the structural design, site conditions, and applicable building codes.

Understanding Pre-Engineered Metal Building Structures & Components

Also known as: Pre-eng building, Prefab Building, Metal Building, Metal Building Kit, Metal Building System, Steel Building Kit, Steel Building System
Diagram of a steel building framework with labeled components such as purlins, columns, and bracing.

Pre-engineered Steel Building Diagram

Bay Spacing – Each space or interval between the rigid frames.

Sidewall Column – Main member used in vertical support position to transfer loads from main purlins or rafters into the foundation.

Eave Height – Vertical dimensions from finished floor to eave.

Eave Purlin – Structural member located at the eave of a building that supports roof and wall paneling and may transfer bracing loads to frames.

Endwall – Exterior wall that is parallel to the interior rigid frame.

Endwall Column – Vertical member located at the endwall of a building that supports the girts.

Girt – Horizontal structural member that is attached to sidewall or endwall columns to support paneling.

Girt Clips – Connection clips used to attach the back side of a panel to a structural beam.

Ridge – Horizontal line formed by opposing sloping sides of a roof running parallel with the building length. Generally the highest point of building without parapet walls.

Rigid Frame – Structural frame consisting of members joined together with moment connections to render the frame stable with respect to the design loads, without the need for bracing in its plane.

Roof Purlin – Horizontal structural member that supports roof covering.

Sidewall – Exterior wall that is perpendicular to the frames of a steel building system.

Primary Framing Options for Pre-Engineered Steel Building Systems

Primary frames are designed for full bay loading and span the width of a building. For the pre-engineered systems these primary members are typically I-beams. Frame systems include clear-span, multi-span and lean-to frames in tapered or straight format. Each steel frame system is custom engineered to meet specifications and local building codes.

Tapered Frames vs. Straight Frames: The tapered frame is generally used in column free applications from 40’ to 250’. The straight column rigid frame is designed for maximum efficiency of interior space. Building widths up to 250’ are available with the option of straight columns instead of tapered columns. Lean-to structures are also available for future expansion or additional space if the original main structure had been designed to support the additional load of a lean-to.

Crane Buildings: Crane buildings are complex PEMB or hybrid structural building systems consisting of the crane with trolley and hoist, crane rails, and crane runway beams, structural supports, stops and bumpers.

3D illustration of a simple, modern table without a tabletop.

Gable Clear Span Primary Frame

Clear span frames are column-free interiors that provide the space required for material handling and crane systems. Common uses include warehouses, manufacturing facilities, aircraft hangars, arenas, and indoor sports complexes. Clear Span Frame can also be single slope.
3D rendering of an L-shaped metal bracket or shelf support on a white background.

Single Slope Clear Span Frame

Single Slope Clear Span Frame is great for providing unbstructed interior space without columns in the center of the structure. Single Slope Clear Span frames are often pair with parapet walls.
Simplified line drawing of a three-legged table structure without a tabletop.

Multi-span Primary frames

Multi-span frames are used for wide buildings that are supported by using the minimum number of columns. Common uses include manufacturing plants, warehouses, and retail stores. By strategically placing columns in the interior of the structure, there could be substantial cost savings as it would decrease the size of the ibeam and decrease the amount of steel used.
3D rendering of an L-shaped metal bracket or shelf support on a white background.

Lean-To Primary frames

A lean-to frame typically has a single slope profile and straight sidewall columns and must be supported by an attachment to another frame.

Bracing Systems

Bracing transfers seismic and wind loads from endwalls and sidewalls to the foundation. It is necessary in every pre-engineered building system.
Illustration of a 3D impossible object with grey bars and red strings.

Rod Bracing

(also called X-bracing) is a tension-only bracing system. It may be located in the roof and walls of a building between frame members, transferring longitudinal forces to the foundation.
3D schematic of a blue warehouse rack with a partial transparent view showing internal structure.

Portal Bracing

When bracing must occur in locations where doors or other accessories would interfere with rod-bracing, a portal frame may be used. A portal frame is comprised of two columns and a rafter made of built-up material and is attached to the web of the sidewall columns.

Flange/Cable Bracing

Structural members that attach purlins, girts, and eave struts to primary structural members. They are used to prevent the main frame from twisting or buckling laterally under the load. Flange braces can also be very useful as an erection aid to align the purlins and eave struts. Purlin bracing is an angle that connects the bottom flange of adjoining purlins to prevent purlin roll.

Diagram showing components of a steel structure with labeled parts: purlins, roof beam, and flange brace.
Technical illustration of a cable secured by an eyebolt and wire wrap.

Frequently Asked Questions

The main components typically include primary frames, columns, rafters, roof purlins, wall girts, roof and wall panels, and structural bracing. The exact configuration depends on the building design and project requirements.

A pre-engineered steel building system combines engineered structural components that work together to support the roof and walls and transfer loads to the foundation. The components are designed according to the building’s dimensions, intended use, and applicable design requirements.
Primary framing consists of the main structural frames, including columns and rafters. Secondary framing includes components such as roof purlins and wall girts, which support roof and wall panels and transfer loads to the primary structure.
Bracing helps stabilize the building and transfer applicable wind, seismic, and other lateral forces through the structural system to the foundation. The type and location of bracing depend on the building’s engineering design.
Yes. Pre-engineered steel building systems can be configured with different framing arrangements, dimensions, roof designs, and building features to meet project requirements. Customization depends on the structural design, site conditions, and applicable building codes.
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