Its been ages since I posted but I need your help.
Background info: In my shop I have a 5x12 (actual size) 15' free span wood beam that supports2x10 2nd story floor joists on both sides. I noticed a small crack/split starting at a knot a few months ago and now its growing so I put up a temporary support post in the middle of my work area. It's time to fix the problem: I have a 6"x6" 15 lbs per ft H-beam that I intend to put under the wood beam and support by 6x6 posts at each end. If I mount the H-beam on its side, I gain 3" overhead clearance vs flange side up. But what does this do to the load bearing of the H-beam.? If it reduces it by say 10% then no problem. But if it reduces it by 75% its not worth the height gain and may not meet my floor load needs.
My question: What's the distributed load bearing of a 6x6 15lb/ft H-beam in normal orientation and what is it when turned 90 degrees???????? If I mount it on its side I would weld a plate on both ends to tie the web and flanges together and I can constrain the sides (flanges) from side buckle by the wood beam (with shims) above and welded struts below.