Procedure for flashing a new curb installed on an existing warranted roof.
NOTE: Koppers must be notified in writing regarding any proposed additions or modifications to a Koppers warranted roofing system prior to commencement of the work.
  1. Spud gravel approximately 24 inches (610mm) wide around perimeter of roof area to be removed.
  2. Cut and remove BUR and insulation to deck.
  3. Install envelope at cut edge of existing roof using two plies of organic felt or one ply of Polyester Base Flashing in Flash-On 441.
  4. Install equipment curb and secure to deck.
  5. Install 4 inch cant strips set in Flash-On 441 or steep asphalt.
  6. Install four plies of felt (same as roof membrane) to top of cant in Coal Tar Type I. Plies should be feathered onto the existing roof with a minimum 3 inch (76mm) overlap.
  7. Install appropriate Koppers flashing specification followed with metal counterflashing.
  8. Top pour and gravel completed areas.
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