Iron Fence Assessment—United States White House—Private

In 2009-2010, we performed a comprehensive conditions assessment of an historic perimeter fence at the United States White House in Washington, DC. Portions of the fence date to the early part of the 19th century, with later additions throughout the 20th century. In addition to wanting to better understand the condition of their fence and the repairs required, the client requested we develop a way to easily distinguish original fence elements from later additions.

To that end, we performed a comprehensive on-site survey and produced written and photographic documentation of the fence, including an illustrated glossary of conditions and materials. Recommendations for rehabilitation were developed to be sensitive to the historic materials, including compatible repairs, recasting lost elements, and providing a long-lasting coating. We also performed extensive non-destructive testing using a portable XRF (x-ray fluorescence) device to identify alloy makeup. Through this investigation, we were able to identify the metallurgical hallmarks that differentiated different phases of construction, which successfully allowed users to categorize historic versus modern fence components with relative ease.