Training NameTraining DateRegistration URL
Virtual Training Day - December 17th
12/17/2021 10:30:00 EST

WI 141604 – SMDE: Additional issues with Beam Stability Factor


When designing rectangular members in MiTek Structure/Supply (such as EWP or dimensional lumber), additional issues have been discovered in the Beam/Lateral Stability Factor.

The following issues will be addressed in a software update:

  • The update released on January 12, 2022 included a fix so that the Job Setting to use the multi-ply width or a single ply width worked as expected.  
    • Since that update, MiTek identified an issue where the software incorrectly fails many longer spans due to Slenderness Ratio.
    • If the Unbraced Length of either the top or bottom of the beam is set to "Continuous," the program assumes both top and bottom are continuous.
    • Prescriptive rules that are used to bypass the calculation of the Beam Stability Factor and simply set to 1.0 are not using the Job Setting properly.

In addition to these issues, the Beam Stability Factor (CL in the US, Kin Canada) will be added to the member report to help troubleshoot the values used in the calculation of Positive Moment and Negative Moment 

Note that, while the issues noted above only affect US designs, the changes to the member reports are being made in both the US and Canada .

  • This issue does not affect the design of trusses.
  • This issue does not affect the design of Boise Cascade products.
    • Boise products are designed by an engine provided by Boise Cascade.



Action Plan

A fix will be applied through a software update in the following versions.   Upgrading to one of these versions is required for proper shear design.

  • 8.5.0 Update 19
  • 8.5.1 Update 14
  • 8.5.2 Update 13
  • 8.5.3 Update 7
  • 8.6.0 Update 2

The updates listed above are expected to be released on or around March 30, 2022.

If you are using a version earlier than 8.5.0, MiTek recommends upgrading to one of the versions listed above.

Reported By

Jobs from the field.

Steps to Initiate

Designing EWP products by clicking “Design Member” command.


There are no known workarounds.