Story

The Smithsonian Institution’s Hirshhorn Museum and Sculpture Garden (HMSC) is a leading voice for contemporary art and culture that provides a national platform for the art and artists of our time. Designed by architect Gordon Bunshaft, the museum’s striking cylindrical form is its most remarkable and distinctive feature, allowing a flowing visitor experience, as one can move through the museum without encountering corners or abrupt changes in direction. After 50 years of operation, the effects of weather, age, and initial design and construction deficiencies began to show wear and tear on this architectural gem. A phased multi-year investigation to assess the conditions of the building exposed several issues with the precast panels on the exterior façade, including compromised lateral attachments; absent insulation and barriers for vapor, air, and water resistance; and poor energy performance. These issues resulted in condensation and water infiltration, causing deterioration to interior wall and floor assemblies, and finishes. Additionally, the roof assembly was at the end of its useful life cycle, raising concerns about water infiltration in the collections storage space below. In 2020, Grunley was selected to perform the $23.2 million project to repair the museum’s façade. During the project, which remained occupied and operational, Grunley improved the energy performance and waterproofing of the museum’s exterior wall and roof assemblies; removed all panels from the existing building; installed new insulation and waterproofing; fabricated and installed new exterior precast concrete wall panels to match the existing panels; replaced the balcony curtainwall; and demolished and replaced the roof. The project required full replacement of the existing precast panels with new precast panels. Sequencing involved removal of existing precast panels; substrate preparation inclusive of concrete repairs to ensure an acceptable substrate for the fluid-applied waterproofing; application of waterproofing and insulation; and installation of the new panels. The project site had very restrictive access and loading restrictions. To ensure appropriate access for the entirety of the façade, a full system scaffold, including a winch system, was erected. Unexpected blistering of the newly installed roofing membrane was discovered after 25% of the new roof replacement had been completed. Once this was discovered, Grunley worked collaboratively with the design team to conduct a months-long investigation and mockups. Ultimately, it was determined that a vapor mitigation coating was needed prior to the roofing membrane installation. The client’s primary goals were to address public and collection safety, energy conservation, and structural deterioration due to water infiltration and condensation. By successfully completing the roof replacement, the museum’s collections storage is no longer at risk of water infiltration. With the new panels and associated waterproofing and insulation, the building energy performance is better regulated which conserves energy and provides for a better user experience. Lastly, the structural integrity of the building is better protected due to minimized condensation and water infiltration. Grunley met the goals of the client to improve building performance and kept the building open to the public.