Monopoly Roof Assembly with Nail Base Panels - GreenBuildingAdvisor

Energy-Smart Details Monopoly Roof Assembly with Nail Base Panels Monopoly framing is a great way to improve airtightness and get the insulation where it works best, on the outside By Christi Weber | April 8, 2026 More Energy-Smart Details A Perfect Enclosure: Aligning Continuity, Clarity, Durability, and Beauty Wildfire Resilience: A Window Install That Works in a WUI Zone Wildfire Resilience: Wall-to-Roof Connection Navigating Construction Documentation The monopoly roof (aka the chainsaw retrofit for remodels) is a wall to roof assembly that eliminates rafter tails in order to wrap a WRB & air barrier continuously from the wall sheathing onto the roof sheathing. This is one of a few good ways to achieve an airtight assembly where a wall and roof meet. While there are already some nice examples of this method here on GBA, these particular details explore how it can be done using nail base panels.What are nail base panels?Nail base panels are prefabricated roof (or wall) panels that adhere OSB sheathing to polyisocyanurate, extruded polystyrene (XPS), expanded polystyrene (EPS), or graphite polystyrene (GPS) foam board. These panels are available in various thicknesses and R-values and are used where continuous insulation over the structural sheathing is desired.When adding foam insulation to the exterior of a roof, you need another layer of sheathing on top of it to fasten the roofing. In a typical built-up system, you would lay the foam sheets first and then take a seco...