St. Vibiana's was the seat of the Los Angeles Diocese since its original construction in the 1880's. Originally an all-brick facade, it was remodeled in the 1920's to incorporate a more Baroque-inspired front entry. It was also severely affected by the Northridge quake, among others, over the course of the years.
Saving the veneer of the second oldest public structure in Los Angeles called for removal and reinstallation of large portions of the limestone veneer, as well as repairs to brick and interior marble.
The original brickwork had been coated with cement stucco in the 1920's remodel, and this skin had failed in multiple locations where stress cracks penetrated the unreinforced masonry walls.
This damage could be observed easily, and the local plant life didn't hesitate to take advantage of the prevailing tendency to deferred maintenance.
The limestone facade at the main entry had suffered quite a bit over the years, with seismic damage from movement, as well as the accumulation of carbon and soiling in the harsh urban environment.
There were numerous locations where limestone blocks had shifted or been loosened due to seismic activity.
The limestone and brick on the facade walls was pushed out by seismic activity at several locations, requiring the complete removal and reinstallation of these masonry elements.
Several examples of previous 'maintenance' required removal to complete the process of getting back to a good starting point on the facade. This attempt at pigeon control eventually succeeded only in providing a good catch-point for feathers and droppings.
This image shows the loose limestone and brick veneer being removed piece by piece until sound unshifted material is reached. Note the cast-in-place concrete support wall and rebar anchors from the 1920's remodel.
Each limestone unit was labeled prior to removal to ensure its proper placement in the exact same location.
Both removal and installation of the limestone veneer units required the use of special rigging and hoisting equipment to protect both the integrity of the stones and the safety of the craftspeople.
Re-installation was then executed using a carefully controlled program of placement, allowing the blocks to be re-aligned in their original configuration.
As each stone was set in place, clamps were used to temporarily secure the unit while mortar back-fill and stainless steel anchors were installed to provide permanent support.
The large blocks on the cornice were especially challenging, given the weight of the blocks (avg. 800-1000 lbs. each) and the location at the highest point on the limestone portion of the facade.
Using multiple lifting hoists, the stones were each lifted out of place to prepare the setting bed for the re-installation of each stone in its proper orientation.
To provide some measure of stabilization in the event of future seismic activity, over 3,000 stainless steel spiral pins were inserted, two per block, in the limestone ashlar veneer, tying each stone back to the supporting wall with a mechanical anchor. In addition, over 2,000 linear feet of grout joints were re-pointed using matching mortar.
In some areas of the main entry, the Sierra White granite had deteriorated and lost original material.
Matching granite was purchased to fabricate and install new inserts where required.
Cleaning of the limestone was carefully executed to remove the worst of the surface soiling and carbon deposits, but emphasis was also placed on not 'over cleaning' the limestone. The 'gentlest means possible' was the watchword for this phase of the work.
The interior Sanctuary space is now the site of social and entertainment functions at regular and frequent intervals.
The restoration of St. Vibiana's was the beginning of a new life for this venerable Los Angeles landmark.