Ideas/Suggestions on livingroom remodel

[Movover]

In Garage Journal style my wife wanted to install new laminate floor of course that turned into well i might as well open the outside walls and insulate the totally empty spaces and lets change the front door because if we just put the floor down we will never tear it out to do the walls right well that was a few weeks ago.

Fast forward to today, we took down the ceiling drywall and the one internal wall because why have half the room new drywall and the other side really old rough drywall to my surprise the 2nd floor is 2x6 on a 24" on center and is a span of about 21.5' with a double 2x6 in the center to break the span to 11' each side! well its been like this for 60+ years and been fine but I am thinking it should be addressed, my wife would like to keep the flat ceiling so I can brace and cut that double 2x6 out and replace it with 3-1.75x7.25 gluelam and then add 2x6 in between the joists to make it a 12" on center. Am I overthinking this? I have attached a quick layout as best I can quickly sketch

Edit" There is a full bedroom over this room

 

[6768rogues]

It sounds grossly deficient.
Sizing of floor joists takes into account how much deflection there will be under full design load. Typically there is a factor of 1/360, where the floor will deflect one inch for every 360 inches of span and it is acceptable. Roofs are more like 1/180. That is why walking on a roof produces more bounce and deflection than walking on a floor.
All that said, a problem I see in your diagram is that two framing members in the middle are carrying somewhere in the neighborhood of 8 framing members of the same size. That is not adequate. Good practice does not support 8 with 2. Your glue lam beam will be better. It is sized larger, so will you have it stick down? Ask the lumber yard to have it engineered by the manufacturer/provider. I give them the rundown and they size it accordingly. Remember that the ends of that beam need to be adequately supported all the way down to a footer. Attach the joists to the beam with brackets and proper fasteners.
Is there a lot of bounce when you walk on the floor above? It is probably adequate to hold the load above as long as it is not excessive, but the problem will be bounce when you walk on it.
Are there any walls on that area above that need to be supported?
If the decking is adequate, you could sister joists to the existing ones rather than putting new ones between the existing joists.
I would put blocking at the half span on each side to try to stiffen the floor. When joists bend, the top is in compression and the bottom is in tension, so they try to even out by rotating. Blocking will prevent movement and stiffen the assembly.
By the way, when my house was gutted I insulated between the first and second floors and all the inside walls. Insulation is cheap. It keeps the bedrooms upstairs cooler and reduces noise transmission.

 

[Muzzy]

It's not clear from the pictures (at least to me), but are those rough cut hardwood?

 

[Richard Cranium]

They look to be rough cut.

 

[Movover]

It sounds grossly deficient.
Sizing of floor joists takes into account how much deflection there will be under full design load. Typically there is a factor of 1/360, where the floor will deflect one inch for every 360 inches of span and it is acceptable. Roofs are more like 1/180. That is why walking on a roof produces more bounce and deflection than walking on a floor.
All that said, a problem I see in your diagram is that two framing members in the middle are carrying somewhere in the neighborhood of 8 framing members of the same size. That is not adequate. Good practice does not support 8 with 2. Your glue lam beam will be better. It is sized larger, so will you have it stick down? Ask the lumber yard to have it engineered by the manufacturer/provider. I give them the rundown and they size it accordingly. Remember that the ends of that beam need to be adequately supported all the way down to a footer. Attach the joists to the beam with brackets and proper fasteners.
Is there a lot of bounce when you walk on the floor above? It is probably adequate to hold the load above as long as it is not excessive, but the problem will be bounce when you walk on it.
Are there any walls on that area above that need to be supported?
If the decking is adequate, you could sister joists to the existing ones rather than putting new ones between the existing joists.
I would put blocking at the half span on each side to try to stiffen the floor. When joists bend, the top is in compression and the bottom is in tension, so they try to even out by rotating. Blocking will prevent movement and stiffen the assembly.
By the way, when my house was gutted I insulated between the first and second floors and all the inside walls. Insulation is cheap. It keeps the bedrooms upstairs cooler and reduces noise transmission.

Thank you for all the information, the floor does not really bounce unless the kids are jumping off the bed or playing rough, otherwise it seems to be ok. There are knee walls about 3-4 feet in on each end but nothing else in the spanned area.

The wood is rough cut not a clue on species. A guess would be hemlock possibly?

They have options for 7-1/4 and 9-1/4 LVL which would require a bump in the ceiling. I called the Local lumber yard this morning and they will come out and size me the correct beam and look to make sure the point loads are correct

The current "beam" is lacking support on both ends and I am planning to address that. One side is over the big beam and metal lally column in the basement but only held up with 1 2x4, the other-side is right on the edge of the window and has also 1 2x4 but not quite on center

The blocking sounds like a great idea, tie the whole floor together.

I thought about insulating the upstairs from the down, I did the bathroom this way so when people go in to take a shower its not heard in the bedroom that is on the other side