Is modified bitumen roof good?

flat black bitumen roof

Expert roofing for your commercial building

Modified Bitumen, an asphalt-based roof coating, is a cousin to BUR (Built-up-Roof). Both are designed for flat or low slope roof buildings in Europe. They have been used in Canada and the United States since the mid-1970s. The two are applied differently; both have benefits that make them desirable to building owners with various modified bitumen types of application. 

BUR is mopped on a roof in a hot form, and Modified Bitumen can be “mopped” on in a hot form or installed with a cold process adhesive.  In recent years, using polymers in a particular combination that is applied to the underside, rolls or sheets of modified Bitumen are created for installation now. 

A release paper is removed from the sheets of modified Bitumen as the contractor rolls it out, and it adheres to the roof substrate. The usual associated risks are eliminated using this method that often takes place when hot asphalt and torches are used. It is a VOC way to install a modified bitumen roof, making it more environmentally friendly. 

What does modified bitumen mean?

Modified Bitumen is a popular choice of roofing material for flat or low-sloped commercial structure roofing is modified Bitumen, torch down, it becomes a durable, weather-resistant roof covering that is sold in rolls. Heated with a torch, the seams of modified Bitumen are sealed, or you can choose a cold-applied installation method or self-adhering method. The roofing contractor will mechanically attach to the roof deck using cap nails or disc plating to ensure the roofing is protected from uplifts by a strong wind. 

What is modified bitumen made of?

Modified Bitumen is asphalt roofing revolutionized. Modified Bitumen is made from asphalt and an assortment of rubber modifiers and diluents that are connected in a variety of ways. The more common way that contractors install modified Bitumen with a heat application where the seams are melted together by heat to create a seal.

Modified Bitumen is made with multiple layers and yet is still judged as a single ply because of the base sheet or underlayment. Proper drainage and insulation I still needed with this roofing process and will typically have a ten to fifteen-year warranty by the manufacturer. 

What is the difference between built-up roofing and modified Bitumen?

A BUR roofing system offers the following qualities: 

  • Provides multi-layer protection that creates a watertight barrier
  • Relatively inexpensive in a standard specification use
  • Weather-resistant year-round
  • Resistant to heat conduction between a building’s exterior and interior, reducing energy costs
  • ROI from a long lifespan up to 40 years
  • Ideal for most flat or low-slope commercial roofs
  • More layers applied during install, the better the roofing system

A Modified Bitumen roofing system offers the following qualities:

  • Extremely tear-resistant due to the reinforcement layer of fiberglass or polyester
  • Ideal for flat or low-slope commercial roofing that has a high amount of foot traffic
  • Instinctive durability, weather-resistant that minimizes repairs
  • Energy-efficient with a top layer that can be upgraded to cool roof features
  • Can be upgraded to solar reflectance and thermal emission, even absorb heat that is reflected from sunlight, which lowers cooling bills
  • Flexible material that is impact resistant 
  • Contacts and expands with temperature without losing its shape

How long should a modified bitumen roof last?

Modified Bitumen roofing system is one of the industry’s most robust commercial roofing systems. Because it is temperature and weather-resistant, and it is flexible and versatile. No other commercial roofing can have polymer material sheets added to it to increase its durability. A modified bitumen roof that is professionally installed and has regular inspection and maintenance can provide a lifespan of twenty years or longer. 

slightly aged roof made of bitumen

How is modified bitumen roofing installed?

There are two forms of installing modified bitumen roofing: The oldest method is modified bitumen torch down, and the other is a peel-and-stick installation. Because there is an inherent danger of fire, the torch-down method should only be done by an experienced and qualified roofer. The following are essential steps for installing a modified bitumen roof: 

  1. Clear debris and dirt from the roof.
  2. Lay heavy roofing felt over decking, insulation, or old roof, using cap nails to secure the felt along the bottom and top and up the middle.
  3. Install drip edge flashing, using a primer for adhesion. 
  4. Roll out a sheet of modified bitumen roofing material, leaving a few inches of overhang on the sides. 
  5.  Ensure the modified bitumen material is perfectly flat then roll up halfway with care. 
  6. Wear eye protection, heavy gloves, and long sleeves and ignite the propane torch.
  7. Run the propane tip along the crease of the roofing felt and roofing roll. 
  8. When bubbles are formed, using your foot, gently roll the modified bitumen roofing forward.
  9. Place the next modified bitumen roofing sheet so that it overlaps the first one and repeat this process. 

Let’s briefly discuss the differences between modified Bitumen vs tpo. Modified Bitumen has been used in the United States since the mid-70s and is the more common and traditional roofing material for commercial buildings. TPO is a new kid on the block in comparison and has only been in the industry since the 1990s. Both are excellent for temperature changes. TPO roofing is picking up in popularity and is giving Modified Bitumen a run for the money in some areas. Dial 281-300-4363 today for your roofing needs!