Smithsonian Institution Building “The Castle”

Smithsonian Institution Building “The Castle”

Location Washington, DC

Category Cultural

Water Infiltration Investigation, Thermal Moisture Survey, 3rd Party Building Envelope Inspection Services

Designated as a National Historic Landmark, the Smithsonian Institution was established in 1846. The Smithsonian Institution Building, more commonly known as “The Castle,” was designed by James Renwick, Jr. in a Romanesque revival style and constructed from1847 to 1855. The exterior of the facade is composed of red sandstone, which was quarried in Montgomery County, Maryland. Until 1881, The Castle housed the Smithsonian Institution’s operations, including research, administration, lecture and exhibit halls, libraries, laboratories, storage, and living quarters for the Secretary of the Smithsonian. Today, The Castle houses administrative offices and the main Smithsonian Visitor Center.

Hoffmann Architects addressed building envelope issues with The Castle’s flag tower and stone masonry facade:

Flag Tower: The area in and around the third floor of the flag tower was known to have moisture infiltration; however, the causes and remedies were unknown. Hoffmann Architects conducted a water infiltration investigation, which included a thermal moisture survey of the interior of the flag tower. It was determined that the primary source of water to the interior was through defects in the exterior building envelope. Deteriorated mortar joints and stone along the entire height of the flag tower has resulted in multiple areas with peeled paint, window deterioration, and mold growth. In addition, water freezing inside of the pipes resulted in burst pipes, causing damage to the interior spaces. Hoffmann Architects provided a report detailing the firm’s observation of existing conditions and repair recommendations to address the excessive amount of water infiltrating the wall and floor assemblies.

Stone Masonry Facade: Since The Castle is designated as a National Historic Landmark, special attention to the quality of the workmanship and materials selected for installation was required to satisfactorily preserve and restore the historic elements and finishes. Hoffmann Architects conducted an assessment of the existing mortar, displaced stones, sealant joints, the stone surface, roof scuppers, and downspouts. During the repair phase, Hoffmann Architects made regular site visits, attended meetings, prepared detailed field observation reports, and verified that the repair work was performed in compliance with the construction documents and the Secretary of the Interior’s Standards for the Treatment of Historic Properties.