fire rated assemblies 1

[Trypod2]

what is my fire rated assembly where I used open web steel joists, metal form deck, 4" thick 4000lb concrete decking. I will have a standard suspended acoustic tile ceiling below. Can someone help me

 

[Ron]

You are on the low end of the scale with respect to the joists. They are essentially unprotected, since the dropped ceiling offers little.

To gain fire resistance, you will need to add spray-applied fireproofing to the joists, or install a "hard ceiling" with fire-rated gypsum board.