by Dennis Collin
Revit users often ask why concrete and structural columns and beams do not automatically join, even when they have the same structural material set in their respective families.
Fig. Object seam lines highlighted.
One way to fix this problem is to use the Switch Join order feature that was introduced in the Revit 2020 release. Choose the multiple switch option to be able to change the join behaviour at both ends of the beam.
Selecting the respective beams and columns will present the geometry lines as expected.
Fig. Note the correctly joined beams and columns after the Switch Join command has been applied.