SmartFlash ONE is a one-part, seamless, durable liquid applied polyurethane bitumen waterproofing resin.  It is designed for flashing new or existing penetrations and construction details within low-slope modified bitumen and/or built-up roofing (BUR) roofing systems.  SmartFlash ONE is also a durable, long-term repair solution for flashings or cracks within a steep slope asphalt shingle roof.  SmartFlash ONE membranes form full closure to irregular flashings and penetrations of every imaginable shape, and eliminate the need for pitch pockets on low-slope penetration details.  SmartFlash ONE, when cured, virtually becomes part of the substrate.

SmartFlash ONE delivers one-part labor efficiency with two-part performance.

Applied with no need for primer or A + B component mixing, contractors can work quickly without fear of the product setting up too fast or going to waste.  Unused resin may be resealed and used on future projects.  These application benefits are realized without compromising quality.  The SmartFlash ONE formula delivers stress resilience and UV stability backed by up to 20 years of warranty coverage, which is in line with the coverage afforded to two-part solutions.

SmartFlash ONE is available in Flash Packs, 1G (comes in carton with two 1G pails) and 5G pails.  SmartFlash ONE Polyester Reinforcement is included with the Flash PacK and sold separately in cartons with sixteen 6" x 100' rolls.

Technical Information

SmartFlash ONE is a one-part, seamless, durable liquid applied polyurethane bitumen waterproofing resin.  SmartFlash ONE may be applied when the ambient temperature is 40ºF-95°F (5°C-35°C).  Refer to SmartFlash ONE Safety Data Sheet (SDS) before handling.

  Flash Pack 1 Gallon 5 Gallon
Yield/Coverage 17 sq.ft.1 17 sq.ft.1 85 sq.ft.1
Thickness (Dry)   42 mils1
Pot Life   > 2 hours at 68°F (20°C)
Dry Time (Second Coat   2 hours at 68°F (20°C)
Dry Time (Rainproof)   2-12 hours at 68°F (20°C)
Cure Time   3 days at 68°F (20°C)

1Assumes two coats

Store containers in a cool, well-ventilated area, out of direct sunlight and away from humidity, heat and ignition sources.  Keep storage areas clear of combustible materials.  No smoking near storage area. Tightly seal all partially used containers.

Test Description Test Method Value
Peak Load, psi (MPa) ASTM D412 368 (2.5)
Elongation at Peak Load, % ASTM D412 67.2
Tear Resistance, lbf ASTM D 903 23.0
Water Vapor Transmission, perms ASTM D1653 11
Shore A Hardness ASTM D 2240 74
Low Temperature Flexibility, °F (°C) ASTM D 5147 -15 (-26)

* Data is represented by average values, unless noted otherwise


SmartFlash ONE is designed for use on bituminous low-slope roof systems or asphalt shingles; not for use with single-ply membranes such as TPO, PVC or EPDM.

  • Wear protective latex gloves during application.  Resin adheres to skin and is difficult to remove.
  • Apply when the ambient temperature is 40°F and rising
  • Apply with a brush, roller or squeegee
  • Do not dilute or thin

Prepare substrate to ensure the surface is free of debris, moisture or contaminants.  Apply resin at a rate of two (2) gallons per 100 ft2 or 30 wet mills. Primer is not required2. Immediately embed polyester reinforcement into wet resin.  NOTE: For repair applications, center polyester over crack and exceeding the crack or hole by 3" on all sides. Saturate polyester reinforcement at a rate of two (2) gallons per 100 ft2 or 30 wet mills, ensuring that the polyester reinforcement is completely embedded and covered.  Allow to dry.  Apply a finish application of resin at a rate of two (2) gallons per 100 ft2 or 30 wet mils. If granular aesthetic is desired, broadcast granul4es into the finish coat before the surface forms a skin.

2Primer not required for APP or SBS-Modified Bitumen Substrates or BUR Substrates set in Hot Asphalt; Primer required for BUR Substrates set in Coal Tar; SmartFlash ONE is not approved for use on substrates not listed herein.

Clean Up: Clean tools using petroleum solvents such as mineral spirits.  Cured resin may be disposed of in standard landfills.

For Construction Details and Specs Click Here

Warranty Details

When SmartFlash ONE is utilized for flashing as a component of an installation of a CertainTeed asphaltic low-slope roof system, SmartFlash ONE flashing details assume the warranty duration and coverage of the overall roof system, up to 20 years. Please download an overview of these warranty options for details.

When SmartFlash ONE is utilized as a stand-alone product, outside of a new asphaltic low-slope roof system, CertainTeed offers 10-year no-leak limited warranty coverage. Click to register a SmartFlash ONE stand-alone warranty

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