the bigger question is,,what type of base for the post support do you have.
are you going to need to open up a slab and pour new 2′ pads with rebar in them or are you going to have to put more support in a wood floor with posts under than area.
is the beam,, steel or engineered wood.
and i’m guessing no snow load either.
so lets say about 10 feet to be safe without knowing the exact criteria of the buildings construction.
and support with 6″ by 6″ posts.easy to cover with some type of fancy wood skin or round column.