Built-Up Bitumen

Pound for pound, the toughest & strongest roofing system

Developed over 50 years ago, this roofing membrane is composed primarily of polymer-modified bitumen sheets that when applied can create an impermeable uniform system. This roofing system is primarily made up of asphalt and is installed in alternating layers of roofing felt and hot asphalt to “build up” the superior waterproofing ability. Modified bitumen is produced in a factory controlled environment and due to

this regulated setting provides the sheet tremendous strength and durability while also maintaining a unique flexibility. In addition, the asphalt has been modified with a polymer to create plastic or rubber like properties. These modifiers provide increased resistance to brittleness, cold temperatures and increased elasticity and strength.

Modified Bitumen roofs are usually installed as a two ply system and are always fully adhered. There are numerous surfacing options for this system which include a factory applied mineral surface and gravel surface, including “cool roof” coatings which are highly-reflective to save on building cooling costs. Mineral-surfaced products are typically furnished with white granules, but are also available in designer colors to compliment the building design. The typical life span for these systems is about 10 to 20 years.


  • Superior waterproofing abilities
  • Broad range of application methods
  • Wide choice of top-surfacing, including “Cool Roofing” options
  • With insulation, provides an even better-performing building component
  • Resistant to UV Light
  • Flexible in extreme temperatures

To learn more about how much a built-up bitumen roof would cost on your building, Request a Quote from CORE Solar & Roofing Systems.