What is the primary benefit of adding valley flashing to a roof?

The primary benefit of adding valley flashing to a roof is weather protection. Valley flashing is crucial in directing water away from the roof valleys, where two slopes meet, thus preventing water accumulation and potential leaks. By channeling water to the gutters, valley flashing helps to guard against water damage, which can lead to mold growth, structural issues, and decay of roofing materials over time. This added layer of protection is essential for maintaining the integrity and longevity of the roofing system.

While cost reduction, aesthetic appeal, and ventilation improvement may be factors in roof design or maintenance, they do not encompass the primary function of valley flashing. The principal goal is to ensure that the roof can effectively handle rain and runoff, which directly ties into the overall protection of the building from the elements.