But seriously- calling upon the collective knowledge of the forum. This isn't a real difficult problem to solve.
The house is 180 years old. The floor joists are pitch pine and floors are heart pine. The joists are 3x6 spaced 2' on center. I'm amazed that they have held up as well as they have. The rooms upstairs are all fairly short spans except the living room, which spans 15'6"x17'6". The room below that is 15'6"x14'6", so there is a stone wall resting under part of that upstairs span.
All I want to do is build a laminated beam 12"x6"x15'6" and run it down the middle of the joists to divide the load and stiffen up that upstairs floor. The ceiling is plywood wainscoting trimmed with crown moulding. I really don't want to pull all that down. My thought is to build a bracket to support the beam and have it galvanized and powder coated. Use a trim saw to trim out only the wainscoting where the beam goes, trim away the crown moulding, and set the beam, then trim it out with a small piece of moulding to cover any gap along the ceiling.
Any objections? The walls on either end of the beam are 16" thick stone masonry construction, and the support would be lag bolted into that. I really do not want a support post because it interferes with furniture placement. Do the joists need to be mechanically tied to the beam, or can they just rest on the beam?
The floor is only sagging a tiny bit, and it's not terribly springy, but certainly it could be more stiff. So I guess I'm saying this doesn't really need to support a lot of load- just help out what is already there.
Crude sketch- bracket would be designed a bit more decorative than this, with decorative ends like these http://www.leevalley.com/US/wood/pag...=1,71685,73945
image.jpg