Flex Elvaloy

A Superior Roofing System for High Performance, Durability & Energy Savings


Roofing system


Flex membranes coated with DuPont’s Elvaloy KEE (ketone ethylene ester) provide state-of-the-art performance for thermoplastic single ply roofing systems. Elvaloy KEE, unlike liquid plasticizers, does not migrate out of the membrane, keeping it flexible, workable and tough from the day the roof is installed, even in extreme climates. Its remarkable physical and chemical properties make Flex Elvaloy KEE thermoplastic single ply membranes the ideal choice for roofing systems that are tougher than the elements.

Flex membranes based on Elvaloy KEE are ideal for mechanically attached, fully-adhered, ballasted and green roof applications. All membranes are reinforced and are available with smooth backing or fleece backing. Specify Flex Elvaloy KEE with confidence… DuPont Elvaloy KEE makes the difference.

Flex Elvaloy


  • Only thermoplastic single ply system type completely compatible with asphalt
  • White reflective Cool Roof surface reflects heat, significantly reducing air conditioning costs
  • Remains flexible and workable indefinitely, even in extreme environments
  • High resistance to chemicals, air conditioning coolants, jet fuels, restaurant grease, UV light, airborne bacteria, acid rain and industrial pollutants
  • Tough and resistant to tearing by workmen, tools and equipment
  • Installation options include adhered, mechanically attached, RhinoBond and V2T Vented system
  • Qualifies for LEED™ credits
  • Easy to weld with wider hot air welding window
  • Easy to clean, and are unharmed by the harshest cleaning agents
  • Environmentally-friendly, contains no volatile organic compounds (VOC’s)
  • Allows you to directly cap smooth BUR to minimize tear-off labor and debris disposal cost
  • Can be either fully-adhered or mechanically attached
  • Proven performance in the toughest climates and environments
  • Ideal for use with green roof systems
  • Perfect for below-grade waterproofing
  • Available as smooth-backed or fleece-backed single ply membranes in rolls up to 10’ wide