19' span floor joist options for 2nd level other than I-joists?

[river place]

After having plans for the 1.5 story for several years we're finally on our way and just completed having the on grade slab poured for a 20'x48' 1.5 build.
I will be posting images soon of progress and a model of the design.

The house is basically broken up into two halves at the center (24' mar) with a wall that has an offset 4 ft opening on on side and a 6 ft opening centered on the second floor.  The 1st floor wall is approx 9' tall with the 2nd floor at 10ft.  The total sidewall height is 12ft so will be using 2x6x12 16oc for balloon studs. The west side 24' long section has internal walls so no issue with using 2x12 for joists for 2nd floor and it also contains the stairwell to the 2nd floor.

My question on joists is for the east side of the build. The plan is to have a 8' deep x 16' sitting area at the far end and a 3' wide bridge way to connect the sitting area to the west end of the house at the center point.  The floor area to the right and left of the bridge way will be open floor except for joints joist running perpendicular supporting the bridge way and connecting the two 12' high side walls.  The joist will be exposed so trying to avoid using I joists.   The 2nd floor will be covered with 7/8 advantech which could support up to 32" oc for joists.   no ceiling in this section so joists are visible.
Would it be best to use LVLs or open parallel trusses under the sitting area and bridge as I don't believe doubling 2x12s to span 19' would be enough?

Thanks

[Nate R]

https://www.awc.org/codes-standards/calculators-software/reversecalc

Douglas Fir 2x10s or 2x12s might be an option depending on grade, spacing, etc.

Looks like 24" oc would be OK with 2x12 select structural at 19 feet, assuming 30 psf loading live, 10 dead.

[akwoodchuck]

I'd use glulams...

[Don_P]

I'd like to see some framing drawings, from bottom to top.

[river place]

Don,

I'm working on finishing up the drawings but will not complete until after the first of the year. 

My main concern has been how to handle the wall to ceiling/loft connection.  I would like to have the loft wall be 2 ft tall at the outside wall and have an internal wall 3.5 ft high wall to allow for more insulation and having a shorter wall seems useless as regards to usable space.

If I use the plan truss design it still looks like I need to used a continuous wall stud up to 12ft (10 ft high loft floor) instead of a 2ft platform wall on the loft floor.

[Don_P]

From what you are describing I believe you need a structural ridge beam.

[siliconengineers]

you need structural ridge beam ......