Organic shingles tend to _____ along the plane where the outer layer of asphalt bonds to the inner core of less viscous asphalt.

The phenomenon referred to in organic shingles is known as delamination. This term describes the process where the layers of materials separate from one another, particularly at the interface between the layers. In the case of organic shingles, there's a transition layer where the outer layer of asphalt bonds to the less viscous inner core. Over time, due to various factors such as exposure to weather conditions, temperature fluctuations, or improper installation, this bond can weaken. As a result, the shingles can start to peel apart or delaminate along this plane.

Understanding delamination is crucial for home inspectors, as it can indicate wear and potential failure in roofing materials. Identifying this issue during an inspection can help in assessing the overall condition of the roof and informing homeowners about needed repairs or replacements. In contrast, the other options like attach, expand, or compress do not accurately describe the behavior occurring at the bonding layer when the integrity of the shingles is compromised.