What is the term used to describe when aluminum flakes migrate to the surface of a roof coating?

The term used to describe the phenomenon where aluminum flakes migrate to the surface of a roof coating is known as "leafing." This occurs when the aluminum particles, which are sometimes used in coatings for their reflective properties, rise to the top layer of the coating. The process leads to a visible metallic appearance on the surface. This is typically done intentionally during the formulation of the coating to enhance its ability to reflect sunlight and reduce heat absorption in buildings.

In contrast, terms like flaking, leaching, and peeling represent different issues or processes. Flaking refers to pieces of the coating breaking off, which can indicate adhesion problems or deterioration. Leaching refers to the process where soluble materials are washed away from a surface, which isn't relevant in this context. Peeling involves a failure of the coating to adhere properly to the substrate, causing it to lift away from the surface. Understanding these distinctions is important when diagnosing issues with roof coatings and their performance.