# Metal Deck Roofing System



## wangpengtju (Jun 28, 2016)

Hello there,

Good evening! Did anyone ever work on a 3" metal deck roofing system? I am trying to verify couple things listed. Many thanks!

A. For UL assembly 505 (1.5 hour rated) and 523 (1 hour rated), can 2" gypsum concrete sitting atop gypsum board/metal deck be switched to 2"-light-weight concrete on top of the foam insulation?

B. Can 5" min./8" max. foam (iso...) insulation achieve R value of R-30?

C. Per specs-required drainage slope of 1:48 min., 12' span of slope will be the maximum. To get the roof cheaper and easier to install, it seems better to layout the drainage plan with 24'x24' squares. However, to run down spot through the dray wall/plumbing chases below, the roof drainage pipes will have to run horizontally above the roof level ceiling. Does that matter?


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