My home is a 2 story home, built in 2003. There is one section in the home that was left open to above with approximately a 20' ceiling in this case. This is over the living/dining areas of the home and it is a substantial amount of space. I would like to fill in that space to expand the second story.
Now, I know that I need to get my plans approved not only by a structural engineer but also the city and I will do that. However, I am drawing the plans myself so I just want to make sure what I have is reasonable first.
The home has existing engineered wood products, for example the second story existing area is supported by wood I-beams that are 11-7/8" deep. So, I am trying to match that. Here is what I have and I just want to know if this is reasonable. I used software provided by Weyerhauser (although Roseburgh, LP and the like all have similar software) to put in all my specs and it says "Passed" but I just can't wrap my head around the fact that all of the I-Beam joists can hang from one engineered beam and support all of them, along with the second story I am adding.
Note, when I did the calcs, I over specified the loads (live, dead and deflection) above and beyond what code calls for.