Mastic for Asphalt Coated Flashing


Sandell Trowel Mastic is a cut-back asphalt, containing long-fibered material, manufactured in proper consistency for easy application. Sandell Trowel Mastic performs well over a wide range of temperature and weather conditions.

  • Provides a strong, flexible waterproof barrier with excellent adhesion
  • Asphalt Mastic allows for expansion or contraction caused by temperature fluctuations or building movement


  • 5 gallon pails
  • 30 oz. tubes

Sandell Trowel Mastic must NOT be used with non-asphaltic flashing products (e.g. Textroflash, Mighty-Flash, Copper Fabric NA & SA, etc.) or H&B Air Barrier Products.