Modified Bitumen Roofing Systems
Built Tough for Complex Roofs and Heavy Use
Modified Bitumen (Mod-Bit) is one of the most time-tested and flexible roofing systems for flat and low-slope commercial buildings. Reinforced with polymers and applied in multiple layers, it provides excellent durability, weather protection, and ease of maintenance — making it a go-to choice for high-traffic roofs, complex penetrations, or roofs requiring redundancy.
At Independent Roofing, we install both APP and SBS modified bitumen systems using a variety of application methods to match your facility’s needs.
What Is Modified Bitumen?
Modified Bitumen is an asphalt-based membrane system reinforced with synthetic rubber or plastic for added flexibility and strength. It’s often installed in multi-layer configurations, offering redundancy and high durability — especially in demanding environments.
Two Main Types:
- SBS (Styrene-Butadiene-Styrene): Flexible, rubber-modified for cold-weather performance
- APP (Atactic Polypropylene): Rigid, plastic-modified for UV and heat resistance
Mod-Bit vs. Single-Ply Roofing
| Feature | Modified Bitumen | Single-Ply Systems |
|---|---|---|
| Waterproofing Layers | Multi-layer (redundant) | Single membrane |
| Foot Traffic Resistance | Excellent | Moderate to good |
| Flexibility in Install | High (multiple methods) | Moderate |
| Cost | Mid-to-high | Low to mid |
| Repairability | Easy and localized | Requires welding or adhesives |
| Best For | High-abuse or complex roofs | Energy efficiency / fast installs |
Benefits of Mod-Bit Systems
Redundant waterproofing with base, interply, and cap sheet layers
Withstands foot traffic, roof-mounted equipment, and extreme weather
Torch-applied, cold-adhesive, self-adhered, or mechanically fastened
Localized issues can often be fixed without full replacement
Decades of field use in commercial and industrial settings
Ideal Use Cases
Mod-Bit is especially well-suited for:
Commercial buildings with complex penetrations (vents, skylights, drains)
Facilities with frequent rooftop traffic (HVAC maintenance, mechanicals)
Roofs requiring multiple application methods due to site conditions
Buildings in extreme climate zones (very hot or cold)
Application Methods We Offer
Every roof is different. We choose the best method for your structure, safety needs, and project timeline:
- Torch-Applied: Reliable heat-welded seams; ideal for dry, open areas
- Cold Adhesive: Great for sensitive buildings or safety-restricted sites
- Self-Adhered: Faster, low-odor install for active facilities
- Mechanically Fastened: Lightweight option for recover or retrofit projects
We’ll help you weigh each based on slope, surface, weather, and insurance requirements.
Want to Know If Mod-Bit Is Right for Your Building?
We’ll evaluate your current roof or project specs and recommend the best system — even if it isn’t Modified Bitumen.
