Building X Bracing and Portal Frames Basics

metal building bracing

Required Bracing and Door Locations

During the design process of your building, bracing is required in order for your building to be engineered to withstand lateral loads.  No point in having your beautiful new building to slant!

X-Bracing Standards

X-Bracing cables are the standard bracing required in at least 1 of your typically equally spaced Bays across the width and down the length of your building and set with steel columns at these spacings.

 Across the width, also known as the gable ends, Bays can range from 5′ to 28′ in size. 

Down the length, Bays range from 10′ to 30′ measures, set by steel columns at those measures.

metal building x bracing endwall
Typical design for 40’ wide Endwall would be 2@20’ with 1 Bay X-Cable Braced,
steel building sidewall x bracing
Typical design for 60’ long Sidewall would be 2@30, with 1 Bay X-Cable Braced,

Non-Expandable Endwall or Portal Frame is Required When...

Some folks like to have large framed openings for roll up doors across the width or length of their building.

For example:

steel building Endwall no X-brace
If you want a large door in each Bay, a Non-Expandable Endwall frame is needed to secure the lack of X-Bracing here.
metal building sidewall portal frame bay 1
A Portal Frame would be used in lieu of X-Cable Bracing in Bay 1 or 2, if you desire each of 2 Bays of 30' to have a framed opening.

IMPORTANT:  Keep in mind  that while most Roll Up Doors require 22″ – 26″ of clearance overhead and on the sides, Portal Framing and 1:12 roof pitch may be in the way, causing slightly higher building heights or steeper pitches to be considered.

Alternative Bay Spacings Available

Depending on the size of your building, and the Framed Openings you would like in your design, it is possible to stagger the Bay widths and still use X-Bracing.

metal building sidewall x bracing 10 foot bay 3
Shown here are 2 Bays at 25' and 1 Bay at 10'

In Summary

Portal Framing costs a bit more since the steel is beefed up to support your openings when X-Bracing is waived.

However, your design choices would be worth it if you want large overhead doors along the entire length or width of your building.  

Again, keep in the mind the general clearances required (noted above) for installed overhead doors…and ALWAYS order EXACTLY what you want for your building design!

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Guaranteed Savings:

  • Minimum $500 – $1,000 savings – Average savings is 15% below market rates…

  • plus one ADDITIONAL  feature more than any other offer

Our Terms:

  • 40′ x 60′ x 14′ – 80’x 100′ x 14′ with at least 2 roll up doors, roof & wall insulation included – minimum savings $500.

  • 80’x 100′ x 16′ or larger with at least 2 roll up doors, roof & wall insulation included – minimum savings $1,000.

  • Competitor’s quote must be dated within 2 weeks of the current date.

  • Competitor’s quote must be the same size structure, smae specifications, and accessories included as offered by us.

  • Competitor’s quote must be received by us before customer purchases from us.

  • Competitor’s building must be fabricated from an AISC (Amercian Institute of Steel Construction) certified facility in order to compare equal manufacturing standards.

Low Complexity Defined

We specialize in Low Complexity building design orders.

High complexity building quotes are done on a case by case basis.
What is considered Low complexity:

  • Size: 100 x 500 x 30 max, strictly square or rectangular

  • Roof Pitch: 1:12 through 4:12

  • Endwall & Sidewall Extensions with soffits: 1’ – 5’

  • All Snow & Wind Load Codes Available

  • Partitions and accessories (walk doors, windows, skylights, roll up doors, vents and insulation) available.

If you have questions about whether or not your building is Low or High Complexity, please call  1-800-593-4012

The Basics of Steel Building Codes

In summary, you should be familiar with the following codes prior to building purchase:

  • Snow Load/ Wind Speed
  • Wind Exposure, Example: Exposure B or C
  • Governing Code, Example: IBC 2009, 2014 or 2015
  • Current website prices reflect IBC 2015, Wind Exposure B – Call your local building department to confirm your requirements prior to ordering.

Roof Snow Load Codes/ Wind Speed Code

  • On the website, you will select from the Codes listed in the drop-down menus in Option 1, 2 or 3.
  • Please contact your local building department or Google codes for your zip code.
  • Choose codes from our list that meet or exceed your requirements for accuracy in pricing online:

Roof Snow/ Wind Speed

 0  lb. S/L/130 mph  

 0  lb. S/L/150 mph

 4  lb. S/L/115 mph

 20 lb. S/L115 mph

 30 lb. S/L 115 mph

 40 lb. S/L/115 mph

 60 lb. S/L/115 mph

More About Roof Snow Loads – Pound per Square Foot

Typical snow loads in the United States can range from 4  to 60+ lbs per square foot depending on precipitation. Obviously, in warmer climates there are 0 lb minimum snow load requirements, whereas, in colder states where snow and ice hardly have a chance to thaw before the next storm, roof snow loads can be greater than 60 lbs per square foot.  In addition, snow tends to drift and accumulate heavier in some spots than others, which is why snow loads are a factor in addition to the standard dead loads of a building.

More About Wind Codes – Miles per Hour

Wind load is also determined by patterns of climate local to your building site. Wind speed codes range from 0 mph to over 160 mph winds.

Wind, unlike snow, will affect different portions of the building not limited to only the roof.  The wind’s effects on your steel building structure will vary depending on your building design and how it sits on your property.  During the software designing process, strength factors are determined by building height, the size and number of large framed openings, and even the location of those openings.

Wind Exposure

Also in relation to wind is the exposure of your building. Exposure B or C is site-specific.  For example, in gusty areas, your local building department may require Exposure C if there are no windbreaks provided by your surroundings, such as trees or neighboring buildings. Wind exposure also affects how snow tends to drift and accumulate on your building structure.

Contact Your Local Building Department Early for Governing Codes, such as IBC – 2015

While your metal building broker will ask you to confirm these codes per your local building department, the MBS (design and pricing software used by your broker) will recall default minimums when the representative enters your building site ZIP code.  In many occasions, the local building department will ask you for higher than minimum requirements and dictate which building code year governs these specifics. For example, IBC 2015 or NCBC 2014 (International Building Code for year 2015, or North Carolina Building Code for year 2014, etc.)  

In summary, contact your local building department to get specific governing year code, roof snow requirement, wind speed requirement, and the wind exposure requirement specific to your building site address and ZIP code.  

If you want more education regarding other loads your building is designed for, please click to read “What’s Important About Steel Building Codes”  to learn more.