When Rhodes Hall was built in 1904 for one of Atlanta’s richest families, the rough-cut, granite-block mansion was the epitome of the New South’s opulence and was a center for Atlanta’s society. However, mortar was falling out of the joints and mold, mildew, and decades of air pollution had blacked the once shiny, silvery-gray stone by the time the Georgia Trust for Historic Preservation acquired the property for its headquarters in the 1980s.

In 1999, Metro Waterproofing, Scottdale, Ga., undertook the job of cleaning and repointing the historic exterior. A light-duty restoration cleaner was selected despite the extreme condition of the façade.