NASCLA Accredited Practice Exam

The weight range of roofing base sheets used in built-up roofing (BUR) systems typically falls between 45 to 80 pounds per square. This weight range is important because it ensures the sheets are robust enough to provide durability and support for the multiple layers that characterize BUR systems.

Base sheets serve several functions, including acting as a foundation layer for the built-up roofing and contributing to the overall water resistance and stability of the roofing system. The weight of 45 to 80 pounds per square indicates that the materials are substantial enough to withstand environmental factors such as wind, rain, and temperature fluctuations while maintaining structural integrity.

Heavier weight options, such as those above this range, might be used for specialized applications but generally fall outside standard specifications for BUR systems. Therefore, understanding the standard weight helps contractors select appropriate materials for their roofing projects to ensure both compliance with industry standards and optimal performance of the roofing system.