PRITCHARD TOMB CONSERVATION PROJECT
SUMMARY OF WORK
Initial preparation for the project involved engaging the services of Andrew Todd, stone conservator in Vancouver, to prepare an overview report about sandstone degradation and how it should be treated.
As-found drawings using a CAD system were made in April 1995 and a photographic record of the tomb was started.
Based on Andrew Todd's recommendations we searched for a stone conservator who could provide the on-site advice we needed throughout the project. On the recommendation of professional conservators at the Royal British Columbia Museum we contacted Patricia Leavengood, stone conservator, of Seattle. She visited the Pritchard Tomb in June 1995 and she submitted her report in the summer of 1995. Her major recommendation was to treat the sandstone with a German product based on silicic ethyl esters. Prior to treatment a chemical analysis of the sandstone had to be conducted.
Under Patricia Leavengood's supervision, core samples of the sandstone were drilled out and sent to the conservation laboratories of ProSoCo in Kansas City. Some sandstone responds well to the treatment, while some does not. The sandstone of the Pritchard Tomb, being extremely soft and based on its chemical composition, proved to be ideal for treatment with the stone strengthener known as OH. Before the recommendation to use OH was accepted, a second opinion from well-known Canadian conservator, Martin Weaver, was solicited. He supported Patricia Leavengood's advice. A copy of the OH product data sheet is enclosed with this report.
Conditions for application of the chemical required a long stretch of dry, warm weather. The resulting delay in making the application stems mainly from waiting for the ideal conditions.
In order to help ensure dry conditions the Old Cemeteries Society requested the City of Victoria to stop watering the grass around the Pritchard Tomb.
In the meantime, based on Ms. Leavengood's recommendations, the tomb was prepared for treatment by the removal of creeping plants that had grown around its base and halfway up its sides. The limbs of trees overhanging the tomb were also removed. These plants dropped sap onto the tomb and retained moisture around it, thus accelerating deterioration. Removal of the plants and limbs was done by City of Victoria parks crews.
While the plants were being removed the City of Victoria suggested that the tomb would be enhanced if unused electrical light standards be removed from around the perimeter of the tomb. The Old Cemeteries Society agreed to this work which has greatly enhanced the aesthetics of the tomb. Following removal of the light standards, the City of Victoria also re-set some of the sandstone curbing around the tomb.
It was planned to apply the consolidant during the summer of 1996, but wet conditions at the time we had arranged to do the application forced us to delay the work until the summer of 1997.
Meanwhile, during the fall of 1996 a violent windstorm felled two massive elm trees in the Old Burying Ground. While the Pritchard Tomb was not endangered by them, the Old Cemeteries Society took advantage of the situation to study an underground burial vault uncovered by the roots of one of the trees. An archaeologist was hired to make the investigation and to submit a report. This helped us to better understand how the Pritchard Tomb was built because it has an underground vault beneath it, too.
In preparation for the application of the chemical consolidant the monument had to be physically scaled top to bottom to remove all lose stone fragments. This had to be done carefully and slowly by hand. Scaffolding was erected around the tomb during August 1997 and the work was completed in about two weeks. Then a thorough washing with a non-ionic soap completed this phase. Several weeks had to be left so the stone could dry out.
Once it was scaled and washed and dried the tomb had to be patched. This involved using a mortar-like compound similar in composition to the sandstone. It was applied over a period of several weeks by Innovative Structural Preservation Ltd. of Victoria. The purpose was to fill cracks where moisture could enter the sandstone and to build up the roofline in order to encourage rain water to run off. The patching was needed for conservation, not cosmetic reasons. Consideration was given to pinning fragments of sandstone that had previously broken off back onto the monument, but it was decided the sandstone was too deteriorated to withstand this procedure. The fragments have been safely stored.
Once the patching had dried the tomb was ready to have the chemical applied. However, the end of September and much of October 1997 were wet. During the last possible window of opportunity on October 20, 1997 the chemical was applied. This was also done by Innovative Structural Preservation Ltd. and involved three successive cycles of low pressure sprayings of the tomb. The first two cycles included three separate applications; the third cycle included one application only. All non-sandstone surfaces of the tomb were masked so that the spray did not come in contact with them.
During the early part of the project, work was coordinated by Norm Truswell. In 1996 he was not available to continue so Kathleen Trayner of Alizarin Consulting was asked to assume project management responsibilities. Ongoing liaison with the City of Victoria, ordering the chemical, scheduling of work and photography were done by her. Administrative details such as insurance and recruitment and training of workers to help with the scaling and washing was done by Melissa Bruce, a Summer Job Creation Program employee of the Old Cemeteries Society during the summer of 1997.
Initial observation of the Pritchard Tomb after treatment shows that delamination and crumbling of the sandstone has ceased or slowed down. Some water repellency has been observed. Monitoring of the results will be ongoing.
The Pritchard Tomb is believed by the Old Cemeteries Society to be the most significant nineteenth century monument in British Columbia. Now it should be able to withstand the elements for many years longer and to continue serving as the focal point in Victoria's Old Burying Ground.
The Old Cemeteries Society wishes to thank the many agencies and individuals that assisted with funding and making possible the Pritchard Tomb Restoration Project. The experience gained by the Society during this four-year project has prepared it to move on to other monument restorations in the Old Burying Ground.
PRITCHARD TOMB CONSERVATION