Modified Bitumen Roofing Systems
Durable, Multi-Layer Commercial Roofing Solutions Managed by Superior Roofing Inc.
Modified Bitumen roofing has long been a trusted option for flat and low-slope commercial roofs, offering a hybrid between traditional built-up roofing (BUR) and modern single-ply systems. While still in use today, installation methods and safety considerations have significantly changed how and when Modified Bitumen is installed.
At Superior Roofing Inc., Modified Bitumen is offered as an installation option—though it is now used far less frequently, primarily due to the hazards associated with torch-applied systems. However, we routinely inspect, maintain, and repair existing Modified Bitumen roofs, helping property owners safely extend roof life and plan future replacements.
This page explains what Modified Bitumen roofing is, how it’s installed, its pros and cons compared to other systems, maintenance needs, and typical life-cycle cost, so you can determine whether it’s right for your building and how it’s used today.
What Is Modified Bitumen Roofing?
Modified Bitumen roofing is an asphalt-based, multi-ply commercial roofing system designed for flat and low-slope roofs. It enhances traditional asphalt roofing by adding polymer modifiers that improve flexibility, durability, and temperature resistance.
There are two primary formulations:
- SBS (Styrene-Butadiene-Styrene) – Rubber-modified for flexibility
- APP (Atactic Polypropylene) – Plastic-modified for heat resistance
Modified Bitumen is commonly found on:
- Office buildings
- Medical and institutional facilities
- Retail and mixed-use properties
- Industrial buildings
- Older commercial roofs transitioning from BUR systems
Roof Replacement
A new roof not only enhances your home’s curb appeal but also ensures safety and peace of mind for years to come.
Roof Repair
Whether you are dealing with leaks, weather damage, or just an aging roof, Superior Roofing has you covered!
Storm Damage
For the best storm damage repair and replacement services in Illinois. We make fast and expert work of repairs or replacement of your roof.
Commercial
A reliable roof is crucial for protecting your assets and ensuring business continuity. Our high-quality roofing solutions are tailored to your commercial needs.
Residential
A strong, reliable roof is essential for your family’s safety and comfort. Trust our experienced team to deliver exceptional results that stand the test of time.
Maintenance
Protect your commercial roof investment with a customized preventive maintenance plan designed to extend roof life, prevent costly leaks, and ensure warranty compliance.
How Modified Bitumen Roofing Is Installed
Installation method is one of the most important considerations with Modified Bitumen roofing.
Common Installation Methods
Torch-Applied (Torch-Down)
Membrane sheets are heat-welded using an open flame to melt asphalt backing and bond layers together.
Important Safety Note
Torch-applied roofing is considered high-risk due to fire hazards.
If torch application is used:
- The contractor must be torch-certified
- Strict fire-watch and safety protocols must be followed
Because of these risks, torch-applied Modified Bitumen is far less common today.
Self-Adhered Systems
Sheets include factory-applied adhesive backing, eliminating open flames and significantly improving jobsite safety.
Cold-Applied Systems
Adhesives bond the membrane without heat, offering safer installation for occupied buildings.
Superior Roofing Inc. installs Modified Bitumen systems only when conditions and safety protocols make sense—and always with certified crews.
Pros and Cons of Modified Bitumen Roofing
Advantages of Modified Bitumen Roofing
Multi-Layer Redundancy
Offers more protection than single-ply systems with overlapping plies.
Excellent Puncture Resistance
Well-suited for roofs with foot traffic and mechanical equipment.
Proven Performance History
Modified Bitumen has decades of successful use in commercial roofing.
Versatile Installation Options
Can be adapted using self-adhered or cold-applied methods for safer installs.
Smooth or Granulated Surface Options
Granulated cap sheets provide added UV protection and slip resistance.
Considerations & Limitations
Torch-Applied Hazards
Open-flame installation increases fire risk and insurance scrutiny.
Labor-Intensive
More seams and layers mean longer installation time than single-ply systems.
Weight & Thickness
Heavier than TPO, PVC, or EPDM systems.
Declining Popularity
Modern roofing systems often deliver similar performance with less risk.
EPDM vs Other Commercial Roofing Systems
|
Roofing System |
Key Difference |
| TPO Roofing | Reflective, welded seams, higher heat resistance |
| PVC Roofing | Chemical resistance, higher upfront cost |
| EPDM | Multi-layer durability, more seams |
| BUR Roofing | Long history, heavier and labor-intensive |
| Modified Bitumen | Asphalt-based hybrid with layered protection |
Modified Bitumen is often best suited for specific retrofit scenarios or buildings that already have this system in place.
Maintenance Requirements for Modified Bitumen Roofs
Modified Bitumen roofs are durable but benefit greatly from routine inspections and maintenance.
Recommended maintenance includes:
- Semi-annual professional inspections
- Seam and lap inspections
- Drain and scupper cleaning
- Monitoring granule loss or surface cracking
- Prompt repair of punctures or membrane splits
At Superior Roofing Inc., we regularly maintain existing Modified Bitumen roofs to help owners avoid premature replacement.
Typical Cost & Life-Cycle Spend
Installation Cost (When Installed)
- Approximately $6–$10 per square foot, depending on system type and insulation
Expected Service Life
- 20–25 years, with proper installation and maintenance
Maintenance Costs
- Moderate and predictable
- Lower when addressed proactively
Total Cost of Ownership
Modified Bitumen offers solid value over its lifespan, but modern systems often deliver lower risk and faster installation at similar long-term cost.
Is Modified Bitumen Roofing Right for Your Property?
Modified Bitumen may make sense if:
- Your building already has a Modified Bitumen roof
- You need a durable, multi-ply system
- Safety-approved installation methods are used
- You prefer a proven, asphalt-based solution
It may not be ideal if:
- Open-flame work is restricted
- Fast installation is required
- Lightweight or highly reflective systems are preferred
Superior Roofing Inc.’s Approach to Modified Bitumen Roofing
Our position is clear and transparent:
- We maintain and repair existing Modified Bitumen roofs
- We install Modified Bitumen systems when appropriate and safe
- Torch-applied systems are used only when necessary and with certified crews
- We do not default to hazardous installation methods
We also help property owners:
- Evaluate remaining roof life
- Compare safer modern alternatives
- Plan phased replacements
- Reduce emergency repairs and liability exposure
Final Thoughts: A Practical, Safety-First Roofing Strategy
Modified Bitumen roofing still has a place in commercial roofing—but how it’s installed and maintained matters more than ever.
If your building has a Modified Bitumen roof, Superior Roofing Inc. can help you:
- Keep it watertight
- Manage safety and risk
- Extend service life
- Plan a smart transition to modern systems
The right roof isn’t just durable—it’s installed responsibly and managed wisely.