VFI®-630 Acrylic Flashing Grade

VFI-630 Acrylic Flashing Grade is a water-based elastomeric roof mastic. It is specifically engineered as an easy-to-use, extremely low VOC product that can be applied to substrates with a brush or trowel. It cures in high builds to completely seal roof penetrations, gaps, and areas around parapet walls and HVAC systems. VFI-630 is also applied to screw heads and fasteners to provide strength, flexibility, and leak protection to the entire roof. It has excellent adhesion to most surfaces and can be recoated with many types of fluid-applied roof coatings.

VFI-630 Acrylic Flashing Grade from VFI is a water-based roof mastic that seals abnormal roof areas to provide leak-free protection.

Features & Benefits

  • Water-based elastomeric – higher tensile strength makes it more durable when faced with severe impact
  • Superior hang – hangs on high pitches and vertical surfaces without sagging
  • Multipurpose – can adhere to a variety of substrates in multiple roof restoration systems
  • VOC-compliant content – exceeds EPA standards for VOCs
  • High build - cures up to ½ inch in a single coat, completely sealing areas with high leak potential
  • Easy to apply – even though it is thicker, it is just as easy to lay down with a brush, trowel, or small roller

Instructions for Use:

Surface Preparation

Make any necessary repairs to the structural components of the roof, including drains, gutters, flashing, penetrations, etc. Surfaces must be clean and free of oils, films, dirt, and debris that could affect adhesion. Power wash the roof to remove any other contaminants. More extensive substrate preparation will depend on the substrate and the application method. Since VFI-630 is one part of a roof restoration system, it should be applied to the substrate and allowed to cure before additional coatings are applied.


Bring VFI-630 Acrylic Flashing Grade to a minimum temperature of 65°F before use. During the application process, the temperature must be between 50°F – 120°F until the mastic has fully cured. Rain and moisture will affect adhesion, so do not start applying if either is present.

Using a brush or trowel, apply VFI-630 up to ½ inch thick on hard-to-reach areas and areas that need watertight protection. Check specifications for required wet and dry film thickness. VFI-630 can repair most penetrations and protrusions without extra reinforcement. Use the mastic to fill in stress cracks smaller than ¼”, then apply extra material up to one inch around each side of the crack. Cover exposed mechanical fasteners with VFI-630 and seal the fastener base to the roof.


Tools and equipment used to apply VFI-630 can be cleaned with water. If the material has cured, clean the equipment with mineral spirits.


*Always read the safety data sheet before working with chemicals

Use chemicals only as directed and for their intended purpose. Do not dispose of chemicals down the drain. Most chemicals must be disposed of as hazardous waste.

PPE to avoid all unnecessary exposure:

  • Eye protection – wear safety glasses and any additional eye protection as necessary
  • Hand protection – wear chemically resistant protective gloves (nitrile, butyl, or neoprene)
  • Skin and body protection – wear suitable protective clothing
  • Respiratory protection – in case of insufficient ventilation, wear suitable respiratory equipment. Respirator selection must be based on known or anticipated exposure levels, the hazards of the product, and the safe working limits of the selected respirator

Product Limitations

  • Incompatible materials – none known
  • Conditions to avoid – heat
  • Chemical stability – stable under normal storage conditions
  • Reactivity and hazardous reactions – no dangerous reaction known under normal use
  • Hazardous decomposition products – may include, and are not limited to, oxides of carbon

Potential Health Hazards

  • May cause respiratory tract irritation.
  • May cause stomach distress, nausea, or vomiting if swallowed.
  • May cause skin irritation and sensitization: redness, drying, defatting, and cracking of the skin.
  • May cause eye irritation: discomfort, pain, redness, swelling, excess blinking & tear production.

*If you are experiencing any of these symptoms, seek medical advice or attention. Call a poison control center or doctor if swallowed.

Application Methods:

  • Chip Brush
  • Brush
  • Trowel

Available Packaging:

  • 5 Gallon
  • 2 Gallon
  • 1 Gallon