2 cars on a Second-Floor garage. Looking for Structural Engineer advice

[Timco]

I'd just use the "15X (X=people) x 200Y (Y=lbs) = Z (Z=car) " base line. It's in the Dr Nick Rivierra Engineering From Home manual they sent me.

So, if 15 "average" people per car desired can stand there, you're good to go.

[Nine8Six]

I'd like to think that our good'ol Chinese concrete is far superior than the one Springfield, NJ was built on

Funny bit is not a single calc is the same. Some result indicate that I'll kill everyone on the first floor, some other formulas tells me I can even add up a third car. Calculating concrete psi/sq, force/pressure, beam loads + then taking into consideration the spacing between reinforcement steel rods in both floor and support pillars, etc etc... it really gets out of my hands lollll (there is the idiot factor also mind you).

Not a 'structural' engineer and can't pretend to be for that kind of set-up.

I'm really trying to save me the embarrassment (and money) before I bring this plan over a real firm specialized into feasibility simulation - as in legal ($$$). Advice taken from our local gov Bldg Code Officer who seems to back off on the idea (expected). Nobody wants to tell me "yea, go ahead". Half-hilarious :/

HELP!