Commercial - Modified Bitumen

Modified Bitumen roofing systems create watertight barriers

Modified Bitumen perform for many years at a time due to the multiple layers. When built-up, these layers of bitumen exhibit exceptional resistance to conductivity of heat between the exterior and interior of the building. This generates noticeable reduction in heating and cooling costs. The thermoplastic polymers used in the modified bitumen make it more fire resistant as well. The technology employed in creating this roofing system makes it affordable and easy to get.

Modified Bitumen was first developed and utilized in Europe in the 1960s. This membrane is manufactured in uniform sheets comprised primarily of polymer-modified bitumen reinforced with one or more plies of fabric, or ply sheets. The fabrication can include polyester, glass, or a combination of the two. When applied in roofing, the finished version may be comprised of several sheets of modified bitumen and asphalt to create a uniform matrix.



When used in conjunction with a thermoplastic polymer, APP (Atactic Polypropylene), a uniform matrix is created within the modified bitumen sheets. This matrix increases the bitumen's resistance to ultraviolet (UV) light, increases its flexibility in extreme temperatures, and increases its resistance to water penetration. This added resilience and enhanced durability under extreme conditions makes modified bitumen a prime choice when there may be movement or deflection of the underlying deck of a roof.


We Are Trusted Professional Roofers

Western Pacific Roofing has been installing roofing for over 70 years and has evolved to become one of the most experienced roofing contractors in the state of California. This longevity has only been possible due to our employees' commitment to the relationships they have built with our clients over the years.


Companies We Work With

We are proud to have been entrusted to work on projects with the following brands.