Reduce heat loss by up to 90% while preventing mold growth where rooftop connections penetrate rooftop insulation.
Uninsulated rooftop connections for parapets, HVAC units, solar equipment and other structures penetrating the roof insulation layer act like cooling fins, creating a thermal bridge between the cold exterior structure and the warm interior steel or concrete structure that supports it, exposing the developer to short and long term problems.read more
Because of their load-bearing requirement, conventional rooftop connections are designed as exterior extensions of steel or concrete structures that penetrate through the heavily insulated rooftop. As such, they create a thermal bridge in the otherwise continuous insulation of the rooftop, rapidly conducting heat away from interior structures, through the insulation layer and into the exterior environment.
For decades, wasted heat from uninsulated rooftop connections, balconies and canopies, was considered unavoidable in concrete and steel high rise buildings in North America.
Because these buildings also leaked air profusely, interior humidity levels equalized with low exterior humidity levels (typically 18 to 25%) during winter months. Forced hot air surrounding cold penetrations immediately below the roof insulation further ensured that interior humidity remained too low to reach dew point, form condensation or support mold growth.
Modern buildings wrapped in airtight vapor barriers require less heat and retain more moisture from evaporation and human off-gassing, producing interior humidity levels of 35% to 50% (typical) during winter. While this humidity increase benefits energy efficiency and human comfort, it also allows the interior air to reach dew point, form condensation and support mold growth where cold rooftop penetrations connect to warm concrete or steel structures on the interior side of the building envelope.
Mold can grow on the inside face of sheetrock, studs and insulation years before it becomes visible on interior ceilings and walls adjacent to the rooftop, exposing the developer to remediation and liability costs.
A Structural Thermal Break from Schöck North America is a fabricated longitudinal assembly the same approximate width as the insulated building wall that creates a structural insulated-foam break between the exterior portion of a structural penetration and the interior structure that supports it, to minimize thermal conductivity between the two masses, while optimizing load-bearing capacity.
Structural thermal breaks for concrete parapet connections continue the rooftop insulation through the bottom of the parapet to prevent heat loss through the parapet, while transferring moments and shear forces, as well as compressive forces from the parapet back to the roof structure.
Structural thermal breaks for steel-to-steel rooftop connections – such as HVAC and solar equipment connections – are equipped with flanges and bolts for fastening to steel beams or joists on the interior side, and on the exterior side to steel rooftop penetrations.