I am trying to build a custom roof in wizard mode. It should have an EPDM
membrane, ?? polyiso cover board, R-20 rigid insulation, and metal deck (24?
spacing). I am not able to specify the metal deck in the layer-by-layer
construction dialog, and it seems to be throwing off my overall R-value
dramatically. I would just build the roof using wizard menu options (where I
can specify a metal deck), but there is no EPDM option for the exterior (or,
it seems, rubber of any kind).

Is there a way to either a) get the metal deck into the layer-by-layer
construction or b) get a rubber surface from the default menu options? I
would like to do as much as possible in wizard mode to save time, but does
this sound like a problem that has to be solved in detailed mode?

Ben Pressman

Project Engineer