What should inspectors look for in the bonding of asphalt shingles?

When inspecting the bonding of asphalt shingles, shading effects are a crucial factor to observe. Shading variations can indicate issues with the installation or material quality, which affects the roof's performance. Inconsistent shading may imply that the shingles were produced in different batches or that there was a problem during the installation process leading to uneven exposure to light or wear. This can not only impact the aesthetic appeal of the roof but can also be an indicator of inconsistent thermal performance, which can lead to premature aging or failure of the shingles.

In contrast, while evidence of weathering, signs of improper alignment, and curling edges are important observations during an investigation, they are not specifically indicators of bonding quality. Weathering generally suggests the shingle's age and durability rather than the initial bond quality. Improper alignment may reflect installation errors, but it doesn't directly relate to the bonding strength between shingles. Curling edges typically indicate a roofing issue due to factors like temperature changes or moisture but do not specifically assess how well the shingles are bonded together upon installation. Recognizing shading effects helps inspectors understand the overall performance and maximizing the lifespan of asphalt shingles.