Components of Metal Buildings

Posted by CDMG Team on Apr 24, 2019 11:08:11 AM

Structural Pieces Within a Steel Building Kit

Anytime we are introduced to something new there is a learning curve. There are new words to learn, new concepts to understand, and new ideas to master.

This holds true for constructing pre-engineered metal buildings.

To help you get familiar with the various components of metal buildings, or to help you out if you’ve hit a wall during construction, we have compiled an informative list of metal building components and their purposes

Whether you have constructed buildings for years or are tackling your first DIY building project, Steel Building Construction uses unique terms to identify building pieces and parts.

Use this guide to metal building components to prepare for your upcoming design consultation, better understand your ongoing construction project, or simply familiarize yourself with the terminology involved in metal building construction.

What's Included in a Metal Building Kit?

Steel building kits include all of the instructions, materials, components, and fasteners necessary to erect your building. 

Pre-engineered buildings are designed for simple, straightforward construction.Metal Building Structure Components

Some buyers opt for do-it-yourself construction and may get together with a few friends to erect the building together. The size and magnitude of the building will often determine if the DIY option will work for you.

Others choose a metal building supplier that offers Project Management services or hire a project manager separately.

Regardless of whether you hire a construction manager or tackle the project yourself, each metal building kit is comprised of the same basic components to create a durable, functional final product.

Steel Building Dimensions

So let’s start with the basics.

The dimensions of a pre-engineered metal building are measured by length, width, and eave height.

It is important to keep in mind that the height of your building is measured to the top of the eaves, not to the peak of the roof.

Steel buildings are measured from the outside, rather than from the interior square footage as you might expect in house measurements.

Read how steel can get you a new building at a lower price than you've thought. 


Pre-Engineered Metal Building Structural Components

Foundation & Floor Line

Metal buildings are secured onto a poured concrete foundation.

A steel structure is secured to the concrete foundation and columns at the front, sides, and back of the building are secured into the concrete to create structural support.

Corner Columns

Corner columns are erected vertically into the four corners of the concrete foundation to support each corner of the building.

The two corner columns at the front of the building and the two corner columns at the back of the building connect overhead to Endwall Rafters that create the roof pitch.

The Endwall Rafters are the main steel ceiling rafters that create the roof pitch at the front and back of the building. 

Eave Struts

In addition to connecting to the endwall rafters, corner columns also connect to eave struts which run the length of the building horizontally. The eave struts are the main metal beams that support the length of the building along the roof, providing support to the roofing and siding.

The corner columns, endwall rafters, and eave struts essentially form an outline of the metal building that serves as the building’s main structural support. 

Endwall Columns & Endwall Rafters

Endwall columns add structural support to the front and back of the building. Endwall columns are located at the ends of the metal building and are secured vertically into the concrete foundation at the ground and the endwall rafters overhead.

Endwall columns connect to the endwall rafters higher up on the roof pitch than the corner columns. Endwall columns connect toward the middle of the endwall rafter, rather than at the ends like the corner columns.

These columns reduce the span of the endwall girts to carry the designed wind load.

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Frame Columns & Frame Rafters

Frame columns provide additional structural support to the sides of the building and are secured into the poured concrete foundation vertically.

Frame columns connect overhead to frame rafters which support the roof at the center of the building along the eave struts.

Sidewall Girt

Sidewall girts and endwall girts are horizontal members that add additional structural integrity.

Sidewall girts span the length of the building horizontally and connect to a corner column at the front and back of the building and the frame columns in-between.

Girts are required to support the building siding.

Endwall Girt

The endwall girt functions the same as the sidewall girt but is located at both ends of the metal building.

Endwall girts span horizontally across from one corner column to the other at the ends of the building. Endwall girts attach to corner columns and endwall columns.

Rod Braces/Cross Bracing

Rod braces are the members that form an X between columns and between rigid frame rafters to provide structural integrity. Braces are secured to the columns along the sidewalls and across the roof.

Braces are used to transfer the loads applied to the building to the concrete foundation.

Metal Building Roof Components

Roof Pitch

The roof pitch refers to the angle at which the roof slopes. The lowest slope available on a metal building is a 1/2":12 and is nearly flat.

A higher roof pitch is 4:12 and is much steeper of a slope.

The roof pitch is normally dictated by design, materials provided, or as-needed for aesthetics.


Purlins are the metal beams that run the length of the building to provide structural support for the roofing.

Ridge Cap & Ridge Vent

The ridge cap covers the peak of the roof, where two angles meet. The ridge vent is located on the roof of the building above the metal roofing and takes the place of the ridge cap.

The ridge vent allows for ventilation. Industrial Metal Building Erection

Eave Trim & Gable Trim

Eave trim and gable trim refer to the metal trim that lines the eaves on the roof for weather-proofing and visual appeal. Eave trim is made up of sheet metal like that of the exterior panel sheets used for walls in metal buildings.

Eave trim refers specifically to the sides of the building and gable trim refers to the eaves at the ends of the building along the roof peak, or gable.

Gutters & Downspout

The gutters and downspout on a metal building ensure proper drainage and prevent water damage to the concrete foundation. Proper drainage also protects against erosion beneath the concrete foundation. 

Gutters span the length of the building to collect rain runoff water along the edge of the roof at the eaves.

The gutters carry rainwater the corners of the building where a downspout drains the water to the ground away from the building foundation.

Steel Building Kit Exterior Components

Framed Opening Jamb & Framed Opening Header

The framed opening jamb provides structural support on each side of the space designated for mechanized or manual overhead doors, other large doors, louvers or duct openings.

The framed opening header provides overhead support at the top of the space.

Door Head Trim & Jamb Trim

Door head trim and jamb trim are used on the exterior of the building to give the jamb an attractive, finished look.

Walk Doors

The walk door is simply an entrance/exit door. These can be installed anywhere in a metal building and are often attached to a sidewall girt at the top of the door jamb for structural support.


Like doors, windows can be placed anywhere in a steel building and can be supported by a sidewall girt. 

Intuitive Pre-Engineered Steel Building Construction

Pre-engineered steel building construction involves several elements of construction, but once you become familiar with the process, it is relatively simple.

After all, there aren’t many building types that can be constructed in hours to days with little to no specialized skills.

Contact CDMG for Your Next Steel Building Project!

If you are interested in a new steel building construction, the experienced professionals at CDMG are a great resource to get started.

With decades of metal building kit experience, CDMG offers industry expertise combined with multi-discipline engineering and construction services to construct your building according to your exact specifications.

Click the button below to speak with one of our expert sales representatives.

Get Started On Your Metal Building Project Today With CDMG

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Topics: metal buildings