Retrofitting of Existing Buildings with Steel Joists

October 9, 2019 @ 12:30 pm – 2:00 pm


Bruce Brothersen, PE, SE


Walter Worthley, PE, SE
Valley Joist

Handout and registration emails for this session will be sent to SE University companies on Friday, October 4th.

Session Description:

Evaluation and modification of joists may be required for many reasons: building renovations, field deviations, additional loads, and more. SJI’s Technical Digest No. 12 “Evaluation and Modification of Open Web Steel Joists and Joist Girders” addresses how to evaluate existing joists and Joist Girders for changes to the original loads and then how to modify the joists and Joist Girders to adequately carry the required loading.

This SE University session will review information from the technical digest, with examples of joists needing to be retrofitted. The discussion will then move to methods and examples evaluating existing open web steel joists and Joist Girders for revised loading conditions. Finally, common options will be presented for modifying these joists and Joist Girders.

Learning Objectives:

  • Show an example of joists that can be retrofitted and an example where joists should not be retrofitted.
  • Identify the key characteristics of in place joists.
  • Demonstrate how to determine who the original manufacturer was and whether they can provide any additional documentation.
  • Show how to verify the original design loads and evaluate the joist for the new loads.
  • Give several methods and practices to modify existing joists to increase the load carrying capacity.
  • Provide details that are commonly used to increase the load carrying capacity of a joist component.