What type of damage does alligatoring refer to in coating systems?

Alligatoring refers specifically to the cracking pattern that develops in a hard coating when it is applied over a softer substrate. This phenomenon resembles the skin of an alligator, hence the term "alligatoring." It typically occurs due to the incompatibility between the flexibility and expansion properties of the two layers; when the softer substrate moves or expands, the harder coating cannot accommodate this movement, leading to the formation of cracks in an interconnected pattern.

Over time, as stress builds up, this leads to visible cracks that can compromise the integrity and appearance of the coating system. Understanding this mechanism is crucial for inspectors, as identifying alligatoring can help in diagnosing application issues, assessing the condition of a coating system, and recommending appropriate repair or maintenance actions.