Why spring is the right time to clean off winter grime, salt residue, and exterior buildup. Winter is hard on commercial buildings. Salt from sidewalks gets tracked against entryways. Freezing rain pushes dirt and road grime into brick and concrete. Mildew and algae start forming in shaded corners as temperatures swing. By the time the weather breaks, most commercial properties in the Philadelphia suburbs are wearing a full season of buildup, and it shows. Spring is the right