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Re: Roof Construction - 1 hour fire rating

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>I am designing a Type II construction building under SBCCI building code. 
>Type II construction in SBCCI is non-combustible for all the UBC designers. 
>The roof of the building is hipped with a 4:12 pitch and about a 64 feet
>span.  The framing will be steel bar joists clear spanning between the
>exterior walls.  To create the slope the bar joists will have a stepped top
>chord, like a wood truss roof.  My question has to do with fire rating.  I
>need a 1 hour rated roof assembly.  Can anybody answer the following:
>  1. The UL Directory shows flat roof in their diagrams.  Can I use the UL
>systems on a sloping top chord and horizontal bottom chord/ceiling roof
>assembly?  Is there anything special that has to be done to the system to use
>it on a sloped roof?
>  2. The roof assembly must be non-combustible.  Ideally I would like to use
>asphalt shingles.  Is there a roof construction assembly which allows asphalt
>shingles?  I donÕt want to use fire retardant treated plywood.  Is there a
>way to get combustible plywood in the system?  Am I stuck with metal roofing?
>Thanks for your help.
>Richard Lewis, P.E.
>Missionary TECH Team
>The service mission like-minded Christian organizations
>may turn to for technical assistance and know-how.
I have done projects which used the UL, the minimum truss depth 
typically has to be 18 inches min. as specified in the UL.
Have also done with cold formed light gage trusses.  The truss manfr.
was able to obtain a letter from UL with the same 18 inch min. depth.

LG Lindell PE
Phx AZ