Why is the elastomeric roof coating dirty?
Over a long period of time, it is not unusual that some dirt can accumulate on the surface of a coating. However, significant dirt early in the life of a coating is not desirable. When the surface of a roof coating is very dirty (hopefully after many years of service), the dirt can be removed by power washing with a mild soap and water cleaning solution, followed by a power wash with just water. This can be done as part of a maintenance program to keep a coating looking fresh; or, if the coating has been in service for many years, it could be time to apply another fresh coating of high-quality elastomeric roof coating.
