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Modified Bitumen lasts longer

Modified Bitumen (Mod Bit) is replacing the old BUR (built up roofing)

Many buildings that have flat or low-sloping roofs are topped with built-up roofing, which is made from an asphalt sheeting that is applied in layers. Built-up roofing also is known as tar and gravel roofing, as the roofing surface is coated with a layer of gravel, tar paper and bitumen.

Built-up roofing can have a life expectancy of roughly 20+ years depending on weather conditions.


System Benefits: Mod Bit

  • Elevator portability for high-rise building projects

  • Reinforced membranes offer long-term, watertight integrity you can count on

  • Minimal disruption to building operations and the environment

  • White cap sheets will help meet Green Roofing standards 


Fast Installation

Modified Bitumen roofing systems install quick and clean to a wide range of substrates. Choose the system to achieve the greatest performance with the least disturbance to your customer.


Versatile Cap Sheets

APP Torch Cap Sheet is available in both granulated or smooth along with Self-Adhering Cap Sheet options (APP or SBS). Ideal for new construction and retrofit installations.


Attractive Roofs

Granule surface cap sheets are available in 10 popular colors. We also offer an APP Torch S (smooth non-granulated) cap sheet. Light-colored surfaces have been shown to reflect the sun’s rays reducing energy costs.



High-quality compounds used in the manufacturing process allow for easy cutout and tie-in repairs. Products are available in both torch and self-adhering.


APP Torch (Granulated or Smooth)

The classic choice for outstanding long-term performance and durability. Thicker membrane boasts superior weatherability and puncture resistance.


Self-Adhering Mod Bit (SBS or APP)

“Dual compound” reinforced membranes with proprietary adhesive formulation on the bottom surface. Patented SEALLap® & FASTLap® engineering provides stronger, more reliable seams and end laps.

Common Types
  • SBS

  • APP

Common Applications
  • Conventional

  • Inverted

Manufacturing Method

Modifiers are added to standard roofing asphalt to replace plasticizers removed during the distillation process. Bitumen is reinforced with fiberglass or polyester fiber matting in order to increase durability and strength.

The two most common types are SBS and APP. The use of SBS (styrene-butadiene-styrene) increases the flexibility of the membrane and allows it to have stronger expansion and contraction capabilities. APP (attactic polypropylene) increases the aging ability of the roof system. SBS is often the more popular system as the synthetic rubber additive increases the products flexibility.

Application Method

Modified bitumen roof systems can be installed with the common torch method, asphalts, or cold adhesives. A standard SBS modified bitumen roof system is a two-ply system applied in rolls that overlap the edge of the previous roll.

  • Very durable

  • Weather resistant

  • Easy to repair

  • Factory manufactured rolls are easier to install and ensure quality control

  • Flexible, expands and contracts

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