The Garland Company, a full-service roofing manufacturer and building envelope solution provider based in Cleveland, Ohio, announced the newest addition to its KEE-Stone family of thermoplastic roofing membranes: KEE-Stone HP. This membrane incorporates the industry's highest-quality ketone ethylene ester, Elvaloy™ HP, for superior flexibility, strength, and chemical and UV resistance.

KEE-Stone HP is a premium fleece-backed thermoplastic membrane designed as the cap sheet in a multi-ply hybrid system incorporating Garland-approved modified bitumen base sheets. KEE-Stone HP meets and exceeds the ASTM D6754 certification, the standard specification for KEE-based sheet roofing. Garland is the sole ASTM D6754 manufacturer harnessing the power of the HP Elvaloy polymer in its formulation. Julie Anne Geyer, Director of R&D for Garland, notes, "The 'HP' in KEE-Stone HP signifies high performance, a testament to the robust formulation, which delivers unparalleled weather, fire, and chemical resistance.”

The high-performance quality and durability of KEE-Stone HP's robust polymer compound and high tensile strength polyester scrim provides superior longevity. The HP Elvaloy functions as a polymeric plasticizer, remaining locked in the membrane even with harsh environmental exposure. In contrast, the typical liquid plasticized membranes are vulnerable to migration and subsequent cracking and crazing under comparable conditions. Furthermore, KEE-Stone HP  contains a novel blend of fire retardants, providing superior fire resistance, achieving a 3:12 Class A fire rating for a non-combustible deck and a 2:12 Class A fire rating for a combustible deck in a hybrid assembly. KEE-Stone HP's bright white surface, robust polymer compound, and advanced chemistry resist the damaging effects of the sun to protect the building and its occupants. The membrane can be either hot-applied or cold-applied and is backed by a forty-year warranty.

Geyer explains that "the bright white finish reflects harmful UV rays away from the building, providing a much cooler roof surface, minimizing solar absorption and reducing the energy needed to cool the structure. This membrane's solar radiative properties are among the highest of any membrane listed with the Cool Roof Rating Council (CRRC)."