What does "positive roof drainage" refer to?

"Positive roof drainage" refers to the ability of a roof to effectively drain water away, ensuring that water does not pool on the surface and that it flows towards designated drainage points, such as gutters or downspouts. This is crucial for the longevity of the roof, as standing water can lead to leaks, material degradation, and structural issues. A well-drained roof helps prevent water-related damage and extends the life of roofing materials.

The other options do not accurately capture the essence of positive drainage. For instance, a slope of 3:12 may contribute to drainage, but it isn't a complete definition since drainage depends on the effective removal of water, not just the angle of the roof. Redirecting water to the eave is part of the drainage process, but it does not encompass the overall system's efficacy in preventing water accumulation. A roof designed to hold standing water negates the concept altogether, as holding water can lead to problems rather than addressing drainage needs.