Hello everyone,
This is a modelling question:
How do you explain Open Web Steel Joists (OWSJ) to Tally?
Thank you!
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I’m interested in this question. I haven’t used Tally for this, but I have done an external calculation with a material takeoff for steel tonnage multiplied by the GWP value from the 2022 Steel Joist Institute Industry-Wide EPD.
I’d be careful using the Tally numbers. Tally suffers from having to work with what Revit exports - Open Web Steel Joists are unfortunately not well reported in the Revit models, as they contain 3d geometry that’s not well defined through a single profile extrusion. We typically get a weight estimate from the structural engineer and apply the GWP values we use internally for steel (we base ours off of EC3, but the steel joist institute EPD would be a good choice as well).
When we did use Tally, we found that the none of the models matched our structural engineer’s assumptions. This could be modeling errors, although some quick tests suggest it’s more of an issue with the reporting. Ultimately, we decided it was quicker to ask the engineer than to try and fix modeling habits across the company.
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