Parapet Walls with Thermal Control Layerfrom Adam Kimble
If you are familiar with Schock Isokorb® you may associate it with products that limit thermal bridging in the wall portion of the building envelope in such areas as balconies or canopies. These solutions provide a continuous insulation layer in the vertical plane of the wall. As we look at the building envelope in a holistic approach, we can focus on other problematic areas that can be resolved with additional Isokorb® products.
Parapet walls, much like balconies, are thermal bridges that allow conductive materials to transfer energy through the thermal barrier. The two differ, as balconies are typically added as an aesthetic, giving the appearance of an extended living space within a unit, yet parapet walls are designed as part of the structural integrity of the building.
Parapet walls are designed to resist variable wind pressure differences, protecting mechanical units and other roof assemblies mounted on top of buildings. As an integral part of the building structure, parapets can prove problematic in many forms, such as: lateral failure, membrane failure, water intrusion, and improper water drainage. Therefore, when considering all of these possible setbacks, continuity of thermal insulation may be a secondary thought. The current, traditional practice to remedy such problems is to wrap the parapet with insulation. However, this application could become complicated in areas where the parapet wall is adhered to insulation, and the insulation is adhered to the roofing membrane.
As Yogi Berra once said, “In theory, there is no difference between theory and practice. In practice, there is.”
View pdf of traditional Parapet without thermal breaks for cast-in-place concrete
Parapets with Continuous insulation
Isokorb® structural thermal breaks can be the alternate solution that provides continuous insulation in plane with the roof insulation layer. The Isokorb® Type A for cast in place parapets solution circumvents the unnecessary need for wrapping insulation around the perimeter of the parapet wall by creating an insulation layer below the parapet connecting to the exterior wall insulation. This solution is beneficial for the delta between theory and practice, as well as areas that could be difficult to wrap with insulation, such as curtain walls that extend to the top of the parapet wall.
The cast in place solution is provided with hair pin bars cast in the roof slab horizontally and vertically at the boundary area where the parapet wall will be located. Once the roof slab is placed with the Isokorb® Type A, the parapet wall can be cast, and then the remaining roof detail assemblies can be installed.
The Isokorb® Type A solution provides a structural wall able to withstand lateral forces and an in-plane insulation layer, eliminating the need to include insulation around the perimeter of the parapet as part of the membrane detail.
View pdf of Parapet with Isokorb thermal breaks for cast-in-place parapets.
The Isokorb® Type A brings an integrated approach to roofing insulation, limiting potential maintenance issues and ensuring continuity of the vertical and horizontal insulation layers, which results in reduced heat transmittance and energy costs.
Visit the Schöck North America website for more information about structural thermal breaks for concrete and steel connections. Explore the full range of Isokorb® products for balcony, canopy, steel beam, exposed slab edge, parapet and rooftop connections.
Considering structural thermal breaks for an upcoming project? Have a Schöck Engineer call you to answer your specific design questions.