Pittock Mansion, an iconic historic structure located in the west hills of Portland, Oregon, was constructed in 1914 and is owned by the City of Portland – Portland Parks & Recreation. Since 1999, PRC has been working with PP&R with evaluation, budgeting, and design of various exterior components, including the roof, the exterior stone, and the four exterior terraces on the building. After finally obtaining funding (including a generous sum via private donations), a much-needed restoration of the terraces was implemented.
PRC was retained as the design lead for the project, and included on their team Peter Meijer Architect as the historic consultant, and TM Rippey Consulting Engineers for all structural work. The project design included removal and re-use of many of the terrace’s sandstone balustrade components, including salvage of a small quantity of balusters for historic significance. Existing sandstone components - including base blocks, top rails, and balusters - which were too deteriorated to be re-used were discarded and new sandstone components were created and installed. A variety of shop-applied and in-place repairs were performed on the sandstone to improve appearance and performance.
The project included removal of all construction materials over all terraces down to existing cast-in-place concrete structures so that waterproofing systems could be replaced. New systems were designed to improve drainage and moisture control, improve membrane performance and longevity, and incorporated stainless steel and copper flashings into a hot rubberized asphalt waterproofing membrane. Once all membrane and flashings were in place, sandstone components were installed with improved structural anchorage, and the terraces were covered with a new thick-set quarry tile assembly.
Services provided by the Team included Construction Administration assistance and QA/QC inspections during the course of construction, with all materials and details thoroughly documented. The project was completed just ahead of the Pittock Mansion’s Centennial year, celebrating 100 storied years of existence.