What is the outcome when hailstones strike rain-cooled, hard asphalt?

When hailstones strike rain-cooled, hard asphalt, the outcome is the loosening of granules from the surface. This phenomenon occurs because the impact of hail, which can be significant, causes the asphalt's granules to become dislodged. The hail's force can disrupt the bond between the granules and the asphalt matrix, especially when the asphalt has been cooled by rain, making it more brittle.

This loosening is critical for maintaining the integrity of the roofing material. Granules serve multiple functions, such as protecting the underlying asphalt from UV rays, providing water shedding capabilities, and enhancing aesthetic appeal. If granules are loosened, it can lead to increased exposure of the asphalt to damaging elements, reducing the efficacy of the roofing system.

While the other outcomes might seem plausible, they do not accurately describe the immediate interaction between hailstones and rain-cooled asphalt. For instance, embedding granules refers to a process where granules are pressed into the asphalt, which is not typically a reaction to hail impacts. Simplifying asphalt is not a relevant concern in this context, as it does not pertain to physical damage from hail. Additionally, though hail impacts may affect the lifespan of the roof in the long run, the immediate effect of