Duct and lighting penetrations in a fire-rated floor truss system

[Shams Gannon]

I'm looking at using a UL-L558 No.4 (1hr) floor assembly in a stacked duplex and have a question on the penetration requirements. This project is in Austin Texas.

We're using 16" floor trusses, which I understand prohibit ceiling dampers. Am I still allowed to run exhaust vents (bathroom fan, hood) through the cavity? Where do I find the requirements for light penetrations?

Is it possible to have a fur-down with this system, say for ducting? Would there need to be a separation between the floor cavity and the fur-down?

Thanks!

 

[Yankee Chronicler]

As a start, do you understand the definitions of and the difference between a through penetration and a membrane penetration?

 

[Shams Gannon]

As a start, do you understand the definitions of and the difference between a through penetration and a membrane penetration?

Yes

 

[steveray]

Where do I find the requirements for light penetrations?

Is it possible to have a fur-down with this system, say for ducting? Would there need to be a separation between the floor cavity and the fur-down?

Thanks!

IBC 714

I had one building where they kept the rating tight at the floor ceiling assembly, put all their ducting under it with another finished ceiling below and pretty much avoided any rated penetrations....