DETERIORATION MECHANISMS IN SANDSTONE
Sandstone has been a popular building material in the United States, where it was widely used in the east for 19th century brownstone houses. On the west coast, many buildings were clad with local sandstone, especially following the 1906 San Francisco earthquake and fire. A great belt of sandstone and shale is found in California north of San Francisco. One particular type of local sandstone, “Colusa Sandstone” was used to clad such prominent San Francisco structures as the Westin St. Francis Hotel, the James Flood Building, the Ferry Building, and the Kohl Building. Today, approximately eighty years later, the sandstone cladding on these buildings is showing signs of severe deterioration.