Where should vent flashing be installed on an asphalt shingle roof?

Vent flashing should be installed between shingles on an asphalt shingle roof to effectively prevent water intrusion while allowing for ventilation. This location is crucial because it enables the vent to be properly integrated into the roof system, promoting airflow and reducing moisture buildup in the attic space.

When vent flashing is installed between the shingles, it protects the roof's integrity by ensuring that water sheds away from the vent rather than being directed into the structure. This placement also allows the flashing to be adequately secured and sealed to both the shingles and the vent pipe, creating a watertight seal that significantly reduces the risk of leaks.

Other locations for vent flashing, such as under shingles or along the eaves, do not provide the same level of protection and effectiveness. Vent flashing properly positioned between shingles ensures that both roof coverage and ventilation are optimized.