Independence Hall National Historic Park, Philadelphia, Pennsylvania

Rehabilitation of Merchant’s Exchange Building – National Park Service

Project Summary

The $3.2 million project involved the rehabilitation of the exterior of the Merchant’s Exchange Building. The majority of the Merchants’ Exchange Building is constructed with Pennsylvania blue marble, a naturally soft and porous marble. The column capitals on the east and west elevations are carved from Carrara marble. Both types of marble had significantly deteriorated over time due to many factors, including the composition of the marble, weathering, temperature changes, and pollutants both in the air and from vehicle exhaust in the building’s urban location. This led to: cracking and flaking; differential erosion; contour scaling and exfoliation; dimensional loss; open and deteriorated joints; deformation and displacement; and efflorescence and staining.


Construction Management, Inspection