DensDefy® Transition Membrane

An impermeable, self-adhered sheet designed for use as a rough-opening flashing and transition membrane for connecting dissimilar materials to maintain air and moisture barrier continuity.

Documents and Resources

Product Details


  • 25-mil composite impermeable membrane
  • Comprised of 16 mils of butyl adhesive and 9 mils of HDPP facer
  • Bonds to most surfaces, such as glass mat gypsum sheathing, poured concrete, masonry, steel and wood-based substrates
  • Ideal for:
    • Drift or control joints
    • Vertical expansion joints
    • Gaps greater than 1”
    • Transitions between dissimilar materials
  • Primerless application allows for faster installation time
  • May be exposed to normal weather conditions for up to 12 months
  • Backed by a Georgia-Pacific limited warranty
  • AAMA 711 Certified

Product Size and Packaging


  • 6” wide x 75’ long; 8 rolls per case
  • 9” wide x 75’ long; 4 rolls per case
  • 12” wide x 75’ long; 4 rolls per case Available as individual rolls on Amazon