Liquid Flashing

Liquid Flashing

Liquid Flashing

Why MajorSeal™ Liquid Flashing?

MajorSeal™ Liquid Flashing offers an alternative to traditional flashing technology to waterproof difficult flashing conditions. MajorSeal™ Systems combine MajorSeal™ Liquid Flashing and RoofMate™ Flashing Fabric to form a durable, redundant flashing membrane. Available in a convenient, easy-to-use kit, MajorSeal™ Liquid Flashing is a VOC-compliant, one-part moisture-curing grey polyether sealant. 


  • One Part:  No special tools or mixing required
  • Less Waste:  Open pouches can be sealed for reuse; fewer pot-life concerns
  • VOC Compliant:  Less than 25 grams/liter at 240°F and solvent free
  • Non Slumping:  On vertical surfaces
  • Quickly Coatable:  Coating can happen in 24 hours
  • Versatile:  Can be installed in temperatures ranging from 30°F (1.1°C) – 100°F (37.8°C)
  • No shrinkage:  Due to high solids moisture cure  


The MajorSeal™ Liquid Flashing System is used to waterproof irregularly shaped penetrations, low parapet walls, at door thresholds, in lieu of pitch pans, and at virtually any application where more traditional flashings are not practical. 


MajorSeal™ Liquid Flashing is easy to install. Compatible substrates include concrete, masonry (uncoated block and brick), wood, EFIS, and granule-surfaced BUR and SBS cap sheets. In addition, MajorSeal™ Liquid Flashing is compatible with most metals (excluding Kynar® coated metals and copper). MajorSeal™ Liquid Flashings cure in humid or dry climate conditions and may be installed at temperatures ranging from 30°F (1.1°C) to 100°F (37.8°C). Do NOT use on APP or single-ply membranes. MajorSeal™ Liquid Flashing is designed for use with hot asphalt or heat-welded applications.

Contact Technical Services at 1-800-ROOF-411 if there are questions on compatible substrates or application method. MajorSeal™ flashings require either the addition of Mineral Shield™ granules to ensure long-lasting waterproofing protection after the application of mineral granules or GAF coating. See application instructions for details.  


Product Properties

*Weather dependent; varies greatly by temperature and humidity.
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