Trinity Cathedral Graveyard, Pittsburgh

Several people – mainly graduate students – from the Architectural Conservation Laboratory at the University of Pennsylvania in Philadelphia are completing a third stint restoring and treating the gravestones in the cemetery adjacent to the cathedral.
Teresa Duff, the site supervisor for the project, explains that the people from the university first worked on the stones 17 years ago.
“The next conservation campaign was in 2001, and the treatments from 1990 were reexamined and reevaluated,” she explains. “This third – and final – campaign allows us to look at all the markers and treat them all.”
The cemetery, once a large urban burial ground that has diminished in size over the years as bodies were moved to make way for downtown buildings, predates the cathedral. It hasn’t been in active use for more than 130 years, Duff says.
“The earliest marker dates back to approximately 1787,” she says. “Most of the markers are from the 1800s, and the last burials were about 1870. Some of the markers have been replaced by families since then.”
Duff adds that there are approximately 150 markers at the site. She and her crew have been responsible for noting the location of each one, then excavating it and evaluating its condition.
“Once we do a condition assessment, we determine what treatment the stone needs,” she says. “Sometimes, if it’s in good condition, it just needs a cleaning. We get the surface soil off it, and if there’s some soiling from atmospheric conditions, we’ll use an acidic cleaner on the stone.”
For stones in worse condition, more serious measures are taken.
“If a stone is in pieces, we’ll use epoxy to re-adhere the pieces together, or we’ll use drilling and pinning,” Duff says. “There we’ll drill holes and use a polymer with a fiberglass or stainless-steel pin. We also do injection epoxy for areas that are starting to delaminate, and we grout larger cracks.
“It’s done on a case-by-case basis, which makes it interesting and challenging, and it also helps keep history alive.”
All the work has been done on-site, and because of the other work being done on the property, after each stone is treated it’s stored in a custom-made crate awaiting the completion of the landscaping portion of the project.
“There’s going to be quite a bit of re-grading,” says Duff. “It will vary from 6”-12” by location, but the landscaping looks like it will be gorgeous and much more organic in its walking paths and development. Once that’s done, we’ll put the stones back in their proper locations.”
Duff says the restoration project at Trinity Cathedral isn’t out of the ordinary for the Architectural Conservation Lab, which combines art and architectural history along with archeology, and operates under the direction of Frank G. Matero.
The lab has an on-going contract with the National Park Service to do work at Mesa Verde National Park in Colorado, and later this fall it will begin restoring the terrazzo floors of the New York State Pavilion built for the 1964 New York World’s Fair.

This article first appeared in the October 2007 print edition of Stone Business. ©2007 Western Business Media