Modified bitumen (MB) stands as another remarkable roofing solution, extensively employed in commercial properties spanning from retail centers to multi-family apartment complexes. It serves as an incredibly cost-effective and adaptable roofing system, ideal for low-slope or flat roofs. As one of the earliest ‘modern’ roofing methods, its enduring efficacy has stood the test of time, bolstered by recent technological advancements that have rendered it a durable and secure roofing material suitable for both single and multi-family dwellings.
Modified bitumen comprises asphalt infused with modifiers that impart plastic or rubber-like properties, significantly enhancing its durability. Comprising six fundamental layers, these can be combined in various configurations:
- Insulation: Providing R-value to regulate temperature, keeping heat out during summer and retaining warmth in winter. Additionally, the insulation offers a stable foundation for the other layers.
- Base Sheets: Utilizing modified or unmodified plies beneath the membrane.
- Modified Bitumen Membrane: A reinforced sheet of modified bitumen, employing materials such as polyester, fiberglass, or composite carriers for added strength.
- Adhesive: A bonding agent that affixes all layers together, applicable via hot or cold methods.
- Surfacing: A protective coat safeguarding against UV rays and weathering, offering cooling options for ‘cool roofing.’
- Flashing: Ensuring protection around roof edges and perforations created by vents, HVAC units, etc.
Benefits of Modified Bitumen Roofing:
Resistance: Demonstrating superior fire resistance and exceptional waterproofing properties.
Application Flexibility: Offers diverse application methods including heat welding, cold adhesive, and hot asphalt. Additionally, it provides a wide range of surfacing options, including ‘cool roofing.’
Durability: Possessing high tensile strength, resilience against thermal shock and splitting, and the potential for exceptional resistance to fire, wind, and hail with suitable surfacing or coatings.
Cost-Effectiveness: Among the most economically viable materials per square foot for commercial roofing. Its ease of installation contributes to reduced labor costs.
Low Maintenance: Requires minimal maintenance over an approximate 20-year lifespan. Toward the end of this period, coatings can be applied to further extend its serviceable life.