Panelized Residential Roof System. II: Hygrothermal Performance and Architectural Details

Abstract

The design of insulated metal roof panels that meet both the structural and hygrothermal performance requirements for a conditioned attic/roof system is presented. The two panel designs, referred to as the truss core and the stiffened plate, are fabricated from steel-web plates laser welded to steel face sheets and a separate, polyurethane foam insulating layer. The truss core includes an exterior (roof side) and interior (attic side) face sheet, whereas the stiffened plate includes only an interior face sheet. This presentation extends the work presented in a previous paper, which focused on design of the structural component of the panels, to the design of complete panel assemblies that include foam insulation and finish layers. Design for hygrothermal performance of the panels and architectural details for panel-to-panel, ridge, soffit, and gable end-wall joints are provided. Both panels offer options for conventional roof finishes as well as a metal finish. Use of the stiffened-plate panel is restricted to sites with lower wind and snow loads and is preferred for dry climates. The truss-core panel, which is lighter and capable of longer spans, is suitable for a wide range of climates and architectural styles.