Washington’s Capitol building is getting a much-needed cleaning. The $3.4 million project started last month and entails masonry preservation, as well. The masonry preservation work includes cleaning of the plaza area, as well as the large dome that has blackened over the years due to lichen that grows on the sandstone. The last time the dome was cleaned was in 2012, when no cleaning agents were used, which officials say may have led to a faster reappearance of lichen.
This time the cleaning combines the use of low water pressure and gentle cleaning agents. SHKS Architects of Seattle completed design work for the project in August and Pioneer Masonry of Seattle is doing the cleaning and restoration work.
Source: The Washington Times