Masonry Shelf Angle

Masonry veneer walls need shelf angles and tie-backs, which provide important thermal bridges and can significantly lower a wall’s R value, making it challenging to comply with energy code requirements. The continuous insulation of the wall assembly is broken by shelf angles, which send the masonry load back to the edge of the building’s structural steel or concrete slab, resulting in a linear thermal bridge.

By enabling insulation to travel behind the steel angle and eliminating the impacts of a continuous thermal bridge, the shelf angle can be linked to the structure at discrete, uniformly spaced points, such as plate “blades,” to increase the U value of a masonry wall assembly. To support the cantilevered load, greater geometries and more material are needed when building the shelf angle outwards.

Improving Wall Assembly Efficiency

Alternatively, Armatherm™ FRR structural thermal break material can be used as a thermal break inside the insulating layer just beneath the masonry shelf angle. The linear transmittance (heat loss) of the shelf angle connection is greatly decreased thanks to the Armatherm™ thermal break. To further lessen the impacts of thermal bridging, rigid, metal flashing used as waterproofing can be replaced with a non-conductive, self-adhered membrane.