Restoring a stone treasure
The renovation and restoration of a former pachyderm exhibit delivers a new home for children’s zoo at the Philadelphia Zoo
However, in recent years, partly due to advancements in animal management guidelines, the zoo made the difficult decision of relocating the pachyderms to larger exhibits, within the zoo and elsewhere, so that the animals could enjoy more enriching and diverse experiences. When the Pachyderm House’s exterior yards and large indoor areas became available, it was selected as the home for the new children’s zoo and education center. Although the design process began in 2006, construction did not begin until late 2011, and the zoo opened to the public last summer.
The project is an adaptive reuse of the building and site. Because it originally housed large pachyderms and was renovated as an education center, the entire building envelope had to be upgraded. The team had an envelope consultant survey the exterior to establish the scope of the work. The primary issue with the stonework in the space was mortar degradation. There were also areas where the Wissahickon schist stone had flaked off. In these cases, the stone was removed and replaced.
“A fundamental goal of the adaptive reuse is restoration of the building exterior,” said David Ade, Principal at SMP Architects. “The existing Vermont slate roof and Wissahickon schist facades were found to be in relatively good condition and were replaced with the same, where necessary. New copper gutters and downspouts were installed throughout all roof areas as was copper flashing, as needed. Mortar analysis determined that the masonry facade had been treated with shell pointing at some time, likely during the first half of the building’s life. Because the shell pointing was in acceptable condition on a majority of the facade surfaces, it was determined that it would remain and be repaired, where necessary.”
The original stone came from a local quarry and the replacement stone was pulled from the client’s onsite stockpile of (Wissahickon mica schist). “Because there is a mix of sizes and colors within the stonework, it was not difficult to match,” said Ade. “The mortar was more challenging and required a series of mock-ups before an acceptable color mix was established.” In addition to replacing damaged stone, existing pieces needed to be cleaned. The construction team used Sure KleanLight Duty Restoration Cleaner by Prosoco for masonry cleaning of iron leached rust and atmospheric staining. Enviro KleanReVive, also by Prosoco, was used for removing biological deposits.
Reaction to the finished project has been very positive. KidZooU has been recognized with a Preservation Achievement Award by the Preservation Alliance for Greater Philadelphia.
Hamilton Family Children’s Zoo and Faris Family Education Center
Owner: The Zoological Society of Philadelphia, Philadelphia, PA
Architect: SMP Architects, Philadelphia, PA
Existing Masonry Assessment: CVM Engineers, King of Prussia, PA
Landscape Architect: Viridian Landscape Studio, Philadelphia, PA
Construction Manager: W.S. Cumby, Springfield, PA
Stone Mason: Mara Restoration, Glenside, PA
Restoration Products: Prosoco, Lawrence, KS