Hotel Monaco Historic Cornice Repair

Located near the Verizon Center in DC's Penn Quarter neighborhood, Hotel Monaco resides in the former US General Post Office building, a National Historic Landmark.  Built in two phases between 1839 and 1866, the original building was designed by Robert Mills, the same architect who later designed the Washington Monument. Clad in an all-marble facade, the Neoclassical and Palladian-style building was adapted into a hotel in 2002. 

On July 15, 2010, a long section of the decorative marble lower cornice, located on the building's exterior facade, suddenly fell. SK&A's Repair & Restoration Division performed an initial investigation, concluding that the failure was caused by water infiltration through cracked and open mortar joints in the parapet capstone and cornice that expanded during multiple freezing-and-thawing cycles. SK&A also identified additional nearby elements of the cornice in need of repair.

To aid in the selection of replacement marble and repair design decisions, samples of marble and mortar were collected and transferred to a specialized historic testing agency. In addition, petrographic analysis of the existing mortar was performed to determine the type, composition, quantity, and mixture ratio of the binder and aggregates. Upon completion of historic research, the source of the original marble was located in the nearby Beaver Dam quarry in Cockeysville, MD—providing an ideal match of materials as well as a savings in cost and time.

SK&A consequently managed the overall design and execution of the historic repairs. Crews in the field meticulously removed the unstable portions of cornice. In addition to the replacement of the failed pieces, further repairs were completed, including: repointing, Dutchman repairs, face patching epoxy crack injection, pinning and stabilizing of loose and/or exfoliating facade elements and general cleaning of the marble facade with the repair area.

In 2012, the completed project was awarded the National Award of Excellence in the Historic Category by the International Concrete Repair Institute.