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P E R F O R M A N C E   S I L I C O N E S   |   W O M A N   O W N E D

NovaFlash Butter Grade Mastic is an exceptionally versatile mastic and roof sealer designed for use on a variety of membranes and coated roofs.

The smooth finish of NovaFlash allows coating over flashing, and can even be “painted on”. This butter grade mastic can be applied with a trowel for high-build applications or a stiff-bristled brush for low-build applications. Designed for applications that require a lower thickness and less density than NovaPatch Fiber Reinforced Mastic, NovaFlash Butter Grade Mastic cures quickly and provides immediate waterproofing for short-term, long-term, and emergency repairs.

  • Rain safe in 1 hour (70°F/50% RH)
  • 100% silicone rubber
  • Solvent-free
  • Ponding water resistant
  • No hardening, chalking, crazing, or cracking
  • 5 year limited warranty
  • Made in USA
  • Proposition 65
  • Sulphur Free
  • UV Resistant
  • VOC Compliant
How to Buy
  • Applications

    Typical uses include: Rough areas of SPF, drain bowls, and under and around rooftop-mounted equipment.

  • Details

    NovaFlash Butter Grade Mastic is an excellent repair material for many roofing substrates. It is also an excellent repair material for direct-to-metal repairs, spray polyurethane foam, smooth built-up and smooth modified bitumen, granulated modified bitumen, aged single-ply roof membrane, flashings, fasteners, and drains.

    • Wide temperature application range: -20°F to 160°F (-29°C to 71°C)
    • Wide temperature performance range: -40°F to 400°F (-40°C to 204°C)
    • Easily applied by trowel up to 1/2″ thick on vertical or horizontal surfaces
    • Excellent adhesion and hang
    • Professional grade


    To Use:

    Surface must be clean and free of all dust, rust, residues, foreign matter, and all contaminants (chalk, grease, wax, etc.) that may cause loss of adhesion. Remove rust and scale from metal by wire brushing. Sweep area thoroughly to remove all dust, dirt, and other foreign matter that would interfere with a good bond. Scrub accumulated residue on low areas with detergent and rinse thoroughly. Surface must be dry and frost-free. Sealant adhesion should be tested on each different substrate prior to use. To test adhesion, apply sealant and allow to cure thoroughly. Then, pull one end to test adhesion strength.

    Repair cracks, breaks, tears, and holes by applying 1/8″ to 1/2″ thick with a trowel, putty knife, or stiff-bristled brush. Thicker application results in better performance and longer sealant life. Sealant can be applied over old silicone coating or sealant which has cured (following cleaning instructions above). Work the sealant into the damaged area and spread it 2” to 4” beyond, feathering the edges. Check to see that no voids have been left in patched areas. If so, apply more sealant and allow to set up before coating. NovaFlash Butter Grade Mastic is tack-free in about 1 hour and fully cured in about 48 hours (dependent on weather conditions, such as temperature and humidity).

    Clean hands with waterless hand cleaner. Equipment may be cleaned before sealant cures with mineral spirits.

    Not recommended for application at temperatures below 10°F or if rain is expected within 1 hour of application. DO NOT THIN. Keep container covered and sealed. Material left exposed to the atmosphere may begin to cure and form a skin on the surface. If this occurs, remove the skin and use the rest. DO NOT MIX PRODUCT.

  • Packaging and Lead Times
    This product is available in the following formats:
    • 1 gallon pail

    Lead times are:
    • 10 business days
  • Specifications
    • Product Specifications
      Appearance Viscosity Extrusion Rate
      1/8” Orifice @ 50 psi
      Skin Over Time
      3/8” @ 50% RH & 77°F
      Through Cure
      3/8” @ 50% RH & 77°F
      Mastic Paste (Various Colors) -- -- 5 – 15 minutes 48 hours
    • Typical Properties
      Slump (Flow) Specific Gravity Tensile Strength
      ASTM D412
      ASTM D412
      Tear Resistance
      ASTM D624
      Shore Hardness
      ASTM D2240
      Service Temperature Application Temperature Adhesion
      ASTM D903
      Peel Strength
      STM C974
      Green Strength
      ASTM C1135
      Joint Sealant Designation
      ASTM C920
      No Slump 1.25 – 1.55 120 – 170 psi 500 – 700% 30 – 35 pli 20 minimum -40°F to 400°F (-40°C to 204°C) -20°F to 160°F (-29°C to 71°C) Metal: 10 – 14 pli SPF: 10 – 14 pli -- -- --
    • Industry Specifications
  • Downloads
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