I have an add on that is 24'x30' two story that i have built with steel. I want a cathederal floor downstairs so I have built floor trusses from 2x4X14ga. Rec. tubing and put 5ft on center, they are 24' long, 32in tall on ends and 8in. in middle, and fish plated. On top of that I have 3in. c-purlin standing up at 16in. on center with 3/4in. t&g OSB as subfloor. It seems strong but i have no idea of load rating and I can more if needed at this point. Any ideas?