What is a significant benefit of using a modified bitumen in BUR systems?

Using modified bitumen in Built-Up Roofing (BUR) systems provides improved thermal performance, which is a significant benefit. Modified bitumen incorporates additives, such as APP (Atactic Polypropylene) or SBS (Styrene-Butadiene-Styrene), which enhance the material's flexibility, resilience, and resistance to temperature fluctuations. This makes modified bitumen particularly effective in environments with extreme weather conditions, as it can withstand higher temperatures without softening and lower temperatures without becoming brittle.

The improved thermal performance also contributes to energy efficiency by reflecting more sunlight and reducing heat absorption, which can lead to lower cooling costs for buildings. This benefit is critical in commercial applications where roofing durability and efficiency are paramount.

The other options do not accurately represent the benefits provided by modified bitumen. For instance, while installation time can vary depending on the specifics of the project, modified bitumen does not fundamentally reduce installation time compared to traditional BUR systems. Similarly, while maintenance needs may differ based on the system and environmental factors, modified bitumen does not inherently require less maintenance; it generally offers longevity and durability instead. Lastly, the claim that modified bitumen increases flammability is inaccurate, as the technology aims to improve fire resistance rather than compromise it.