I have a house that was built with steel I beam supports in the basement. I want to change the bathroom in the basement as well as move the laundry room to the 1st floor. How do I change the plumbing when there are steel I beams every 16 inches?

You fit the plumbing around the beam layout. For example, run the drains parallel with the run of the beams. What is sitting on the beams? A picture would help.

Post a photo or drawing with dimensions for better visual

Milo