Commercial and Flat Roofing
Modified Bitumen Roofing
Modified bitumen is made of asphalt reinforced with polymer, in rolls that are adhered in layers. It has a tough, granulated surface and handles foot traffic well, which makes it a common choice for low-slope roofs with equipment and walkways.
- Best forLow-slope roofs with foot traffic or equipment
- Typical planBase sheet, cap sheet, flashing, granule surface
- TeamCrews who apply rolled roofing with care
- Pairs well withCoatings and maintenance programs
What you get
What modified bitumen roofing includes
- 1A tough surfaceThe granulated cap sheet stands up to sun, weather and foot traffic.
- 2Layers of protectionTwo or more layers give redundancy against leaks.
- 3Good with equipmentMechanical units, walkways and drains are well supported.
- 4RepairablePatches and seams can be repaired and re-coated.
How it goes
From the first visit to the finished roof
- 1Prepare the deckInsulation and a base sheet are installed.
- 2Apply the capThe cap sheet is adhered with overlapping seams.
- 3Flash the detailsEdges, drains and curbs get matching membrane flashings.
- 4Inspect and coatThe roof is checked and, if specified, finished with a coating.
Good fit when
Is modified bitumen roofing right for you?
- You have a low-slope roof with equipment or foot traffic
- You want a layered system
- Your building is a shop, office or apartment
- You like a durable surface
Questions
About modified bitumen roofing
How is modified bitumen different from TPO or EPDM?
It is a layered, asphalt-based system with a granulated surface, while TPO and EPDM are single-ply sheets. Each has strengths, and we compare them for your building.
Can it be coated?
Yes. A reflective coating can extend its life and cool the roof.
Is it only for commercial buildings?
It is common on commercial roofs, and some homes with low slopes use it too.
Related services
Often paired with this
Flat Roof InstallationNew low-slope and flat roofs with the right insulation, drainage and membrane for the building.See the service 
Roof Coatings and RestorationReflective coatings and repairs that extend the life of a sound flat or metal roof.See the service 
Commercial RoofingRoof replacement, repair and maintenance for offices, shops, churches, warehouses and apartment buildings.See the service Where we work
Find modified bitumen roofing near you
Pick your city to see local conditions and the services people ask for most.
Thinking about modified bitumen roofing?
Call or text, or send the form. Tell us about your roof and we will tell you how we would approach it.