What Is A Modified Bitumen Roof System?

roofer installs a bitumen roof

Bitumen Roofs Are Durable Yet Lightweight

If you are wanting a commercial roofing system that is extremely durable and affordable, then consider getting a modified bitumen roof. Made of melted asphalt, this type of roofing system is best for flat commercial roofs as it still provides a strong protection against weather, but is lightweight and won’t add any additional pressure to your roof. In fact, modified bitumen is so strong, that can hold up to 300 pounds. That means that repairmen can walk on your roof to perform duties like commercial HVAC installation without damaging the membrane. If you are needing a modified bitumen roof for your Richardson, TX building, call the roofers at Pillar Roofing & Construction at (972) 798-8901 for installation today.

How To Identify Modified Bitumen

You can identify a modified bitumen roof by their classic gray or black liquid tar or roll system that is then laid out on the roof. The liquid version of a bitumen roof is very messy, while the rubber rolled version installs quickly like that of all other single ply roofs. It should be noted that a bitumen roof is not technically a single ply roof, and is considered a two-ply roof. Basically a combination of a built up roof and a single ply roof, a modified bitumen roof can be melted down to be elastic like single ply roofs, but is made up of the same materials that are used to create built up roofs. Consisting of six layers, a modified bitumen roof is made up of polyester of fiberglass matting that forms the durable and strong membrane. Insulation, base sheets, adhesive, a surface coat to resist UV rays and weathering, and flashing to protect leaks from gaps in the roof.

How Long Should a Modified Bitumen Roof Last?

In order to make your bitumen roof last 20 years, it needs to be properly installed. So how is modified bitumen roofing installed? First off, you have to choose which type of modified bitumen you want, whether that is SBS or APP. SBS (styrene-butadiene-styrene) allows for a more flexible roofing membrane and lets the roof expand and contract more. APP (attactic polypropylene) lets your roof age more slowly and therefore last longer. SBS is the type of modified bitumen material more often chosen because of its synthetic rubber additive that allows it to be more flexible and durable.

A modified bitumen roof can be installed in two ways: conventional or inverted. The conventional way involves using torching, asphalts, or cold adhesives. The inverted way of installing a SBS modified bitumen roof consists of applying two-ply rolls that overlap each other.

Why Modified Bitumen Is So Popular

Modified bitumen roofs are a popular choice for commercial roofs because of their durable yet flexible materials. Being able to have strong properties like tar mixed in with rubber additives to make it flexible and waterproof give it an edge over other competing roofing systems by combining them. Modified bitumen is extremely dangerous and messy to install since it involves fire and melted tar, so professional installation is a must. Because of this, their popularity has decreased some due to the mishandling of unprofessional and untrained roofers. Can modified bitumen roofing be repaired? Yes, they can be repaired, but a more effective way of extending the life of your bitumen roof is by getting a restorative roof coating applied over your damaged roof. This will help your roof last another 20 years. For professional installation of a modified bitumen roof in Richardson, TX, call Pillar Roofing & Construction at (972) 798-8901 today.

Modified Bitumen Vs EPDM

Because modified bitumen is a two-ply membrane, it often gets compared to single-ply membranes like EPDM. While there are some similarities between the two, both have distinct advantages and disadvantages that make them stand out from each other.

Modified Bitumen Roofing Details

bitumen over a pipe on the roof

Bitumen Is Waterproof and Works Like Flashing To Seal The Hard-To-Reach Places of Your Roof

  • The rubber additives make the roof elastic and flexible, allowing it to expand and contract around the temperature and climate
  • Thick thanks to the melted asphalt modifiers that are added in the distillation process that replaces standard roofing plasticizers
  • Durable and weather resistant
  • Protects against UV rays and water damage
  • Lasts 20 years
  • Can get restored with roof coatings which allows the roof to be recyclable and cuts down on roofing landfill waste
  • The factory manufactured SBS rolls are easy to install and control
  • Easy to repair common damages from wear and tear over time
  • Involves melting asphalt with fire to create tar, which is messy and dangerous
  • The smells of the tar are pungent during installation

EPDM Roofing Details

  • Dramatically lowers energy costs thanks to its white and reflective coating which resists UV rays
  • Available in its original black coating or it can be painted over with a white acrylic coating to receive the reflective benefits
  • Can be produced in cost efficient long strips that can be cut up to create rubber shingles for residential roofs
  • Resistant to weather, heat, and fire
  • Resistant to thermal shocks, abrasions, and ozone pollution.
  • Lasts 20 years
  • Can get restored with roof coatings which allows the roof to be recyclable and cuts down on roofing landfill waste