# Does it make any difference if I model a flush beam as a "Rib" or as a "Result Beam"?

Yes, it does, because this affects the stiffness of the entire structure.

When entering a flush beam as a "Rib," you will add the stiffness of the defined rectangular cross-section to the area of the line.

However, you have to only define the integration width for the result beam. The entered rectangular cross-section does not affect the stiffness of the entire structure, but is only applied as a design cross-section in the add-on modules (for example, RF‑CONCRETE Members).