These two pictures show the Acadia Parish Courthouse in Crowley, La. before pressure washing by Exterior Cleaning Services Inc. and three and a half years later (this week). It looks just as good today as it did the day after it was pressure washed.
There are two reasons it still looks so great over three years later despite being shaded by several huge live oaks, which of course is a prime environment for mold, mildew, and algae growth on buildings. Firstly, it was thoroughly cleaned with great care and skill by Exterior Cleaning Services. Secondly, ECS partnered with the Acadia Parish Police Jury to apply an annual preventive treatment which has has been extremely effective at preventing mold, mildew, and algae from reestablishing themselves and making the building looking dirty and neglected as it did before cleaning project.