I probably should have provided more info. Here is the situation: this is a large, one story, commercial building...about 65,000 sq. ft. There is a small mezzanine in one corner...about 1200 sq ft. The main space has about a 20' ceiling and many columns, steel bar joists, etc. It seems like you're creating another normal floor with "open below" for the non-mezzanine area. Is there another way or is this it? Thanks.
Mark