What is the minimum slope allowed for double-coverage roll roofing?

The correct option for the minimum slope allowed for double-coverage roll roofing is indeed 1 inch per foot. This specification is important because it ensures proper water drainage from the roofing surface, which helps to prevent pooling and potential leaks. Double-coverage roll roofing systems are designed with an overlap that creates two layers of protection against the elements. A slope of at least 1 inch per foot is essential to maintain effective drainage, ensuring that water flows off the roof rather than accumulating, which can lead to deterioration of the roofing material and structural damage over time.

Higher slopes, such as 2 inches per foot or more, although technically permissible and advantageous in terms of drainage, are not the minimum requirement for safe and effective installation of double-coverage roll roofing. Thus, the minimum requirement is a balance between functionality and practicality, making 1 inch per foot the most suitable and standard guideline for this type of roofing system.