On Monday, the Garland Company announced the newest addition to its KEE-Stone family of thermoplastic roofing membranes: KEE-Stone HP. The new membrane incorporates ketone ethylene ester, Elvaloy HP, for “superior” flexibility, strength, and chemical and UV resistance.

KEE-Stone HP is a fleece-backed thermoplastic membrane designed as the cap sheet in a multi-ply hybrid system incorporating Garland-approved modified bitumen base sheets, the company said in a March 11 news release. 

Garland said its KEE-Stone HP exceeds ASTM D6754 certification, the standard specification for KEE-based sheet roofing, and Garland is the sole ASTM D6754 manufacturer harnessing the power of the HP Elvaloy polymer in its formulation. 

"The 'HP' in KEE-Stone HP signifies high performance, a testament to the robust formulation, which delivers unparalleled weather, fire, and chemical resistance,” said Julie Anne Geyer, director of Research and Development for Garland,

The Cleveland-based manufacturer said the high-performance quality and durability of KEE-Stone HP's robust polymer compound and high tensile strength polyester scrim provides superior longevity. Garland said the HP Elvaloy functions as a polymeric plasticizer, remaining locked in the membrane even with harsh environmental exposure. In contrast, the company noted how typical liquid plasticized membranes are vulnerable to migration, cracking, and crazing under comparable conditions. Furthermore, KEE-Stone HP contains a new 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, polymer compound, and chemical design resist the damaging effects of the sun, protecting the building and its occupants. The membrane can be hot-applied or cold-applied and is backed by a 40-year warranty.

"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,” Geyer said. “This membrane's solar radiative properties are among the highest of any membrane listed with the Cool Roof Rating Council [or CRRC]." 

For more information, visit garlandco.com.