How can the presence of step flashing on an asphalt shingle roof typically be verified?

The presence of step flashing on an asphalt shingle roof can be verified by lifting the shingles adjacent to the chimney or wall. Step flashing is installed between the roof and vertical structures like chimneys or walls to create a watertight seal. By gently lifting the shingles in this area, an inspector can visually confirm whether step flashing is present and properly installed.

Inspectors typically look for step flashing because its absence can lead to leaks, making it a critical component of roof waterproofing. If the flashing is in place, it should be visible beneath the shingles. This method allows for a direct assessment of the roof’s flashing details, which is essential for ensuring the roof's integrity.

Other options do not provide a reliable means to verify the presence of step flashing. For instance, counter flashing is a different type of flashing that works in conjunction with step flashing but doesn't indicate its presence. Knowing the age of the shingles or the number of layers does not provide specific information about their installation or the flashing condition.