"Christian McArdle" wrote in message
et...
when I looked into this for my loft I found the best method of saving
the most headroom was to span steel beams with wood inserts across the
longest length, and suspend wooden joist from them

I'm not sure I quite get this. Could you explain in more detail?

Would a simple floating T&G floor be sufficient? Is there any need to
attach
the floor to the joists?

There was a Grand Designs where they glued the floor to steel beams. I
remember it because the glue didn't stick.