Degradation at the surface or within the bulk of a paint film occurs by solar ultraviolet irradiation, heat, moisture or pollution. Damage accumulates through its lifetime until the coating no longer maintains its appearance or protective properties. Results from modeling the deterioration by Monte Carlo or other statistical approaches can be used with simple, well-established models of macroscopic properties to elucidate the kinetics of degradation and thus the service lifetime. Predictions for gloss, fracture toughness, contact angle etc. are consistent both in trend and time scale with the behavior observed by many workers. Repeated application of individual erosion events leads to a Gaussian distribution of surface features so that asymptotic approximations can be found for macroscopic properties using these same simple models.