In my shop there are two W 32 x 16 steel beams. The weight of the beam is 32 lbs per foot, the beam height is 16 inches. The span between the beams is made by 2 x 8 's.
The engineer said I could use one beam in the center. That would have had to be a W 18 x 36, the span would have been made with 2 x 10's. It was cheaper and took up less space to use two beams.
I did not leave anything to chance, I let the engineer do the math and sign the plan. If you are going to shoot from the hip on the beam size, go heavier to be safe..
