San Bernardino County Courthouse
San Bernardino, San Bernardino, California
Selective Removal, Restoration, and Reinstallation of Decorative Plaster, Painted Canvas, Porcelain Ceramic Tile, and Natural Stone
The courthouse had accumulated damage during previous quake activity over the years, and it became necessary to implement the seismic upgrade and restoration of the interior and exterior surfaces while the building was still in use and courts were in session. While decorative plaster and painted canvas ceilings were one of the more interesting aspects of this project, there were numerous other media addressed as well, including marble, cast stone, cement stucco, glazed brick, porcelain tile, and concrete.
Wikipedia Reference: http://en.wikipedia.org/wiki/San_Bernardino,_California
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Finished in 1926 in a Classic Revival style, the courthouse has served as the judicial center of the county, but needed some intervention if this was to continue. |
The exterior is a combination of cast stone and cement stucco, and had endured the types of decay common for these materials after more than 80 years |
As with so many buildings of this type and age, damage to the exterior decorative components could be easily traced to the oxidation of interior steel reinforcement bars. |
These areas of damage were usually located in places where water could collect and then be absorbed into the porous cast stone body. |
Expansion of the iron due to oxidation (iron jacking) then caused the cast stone to spall and fall from the building facade. |
Careful survey and documentation ensured that all these areas of deterioration could be identified and repaired with specialty repair mortars formulated to match the cleaned original surface in color, texture, and surface. |
Several cleaning mockups were executed to determine the most effective and least agressive means and methods. |
The original cast stone brackets at the soffit had begun to fall from the building in earlier years due to the same iron jacking problem, and were removed en masse. Approximately 50% of the original brackets were saved for later reinstallation, with the remaining units repoduced in matching cast stone. |
Care was taken to prepare and patch each area of previous steel decay prior to reinstallation of the corbels. |
Several areas of precast ogee trim were also reproduced and installed to complete exterior repairs. |
Interior work involved marble and ceramic tile surfaces on both walls and floors. |
Ceramic wall tiles had lost their glazed surface or had prior damage and penetrations in several areas. Here the tiles to be replaced have been treated with the first important step in selective removal form such a delicate surface. Here, cuts were made with diamond saws to allow the designated tiles to be carefully chipped out without damaging the adjacent undamaged material. |
Once the damaged tiles are completely removed, the substrate can be cleaned and prepared for installation of new matching tile. |
In some areas complete walls had to be removed to facilitate the installation of new concrete structural upgrades. Here the new tiles are being installed over previously place shotcrete. |
Here a similar bathroom with the completed ceramic tile installation. |
For many of the interior marble walls the normal procedure would have been to remove the marble panels prior to the installation of new shotcrete or steel seismic upgrades. This project involved a novel and efficient alternative method which called for the removal of the backup plaster wall, bracing of the marble panels from the decorative side, and installation of the new shotcrete to the back side of the marble veneer, after the installation of stainless steel saddle anchors in the back of the stone panels. |
From a preservation perspective, this fulfilled one of the primary mandates of disturbing significant historic fabric as little as possible. |
For repairs of porcelain tile flooring, we were able to carefully and selectively remove portions of original flooring slated to be removed or covered.. The tiles could then be cleaned and prepared for individual installation as needed in the hallway floors slated to remain. |
This guaranteed that newly installed patches where structural grout was injected would be a perfect match. |
One of the most challenging aspects of the project was the creation of new methods to install seismic upgrades without destroying the original plaster and canvas decorative ceilings. |
There were also some locations in the courtrooms where falling original plaster vent covers required the temporary placement of supports until the restoration could be fully executed. |
In areas requiring replacement of original triim, molds were taken of adjacent sound material, and new matching trim manufactured and installed. over new mesh and plaster support. |
Frequently we were installing both previously removed original plaster trim as well as newly manufactured units, as always trying to salvage and re-use as much historic fabric as possible. |
Final detailing could then be executed at seams and borders. |
Here an entire beam cover has been fabricated and installed and is now ready for final decorative painting. |
Final painting and cleaning of the adjacent painted canvas panels will complete the restoration of this area. |
Several ceiling panels also needed to be selectively removed so that structural work could take place in the inner ceiling areas. Decorative canvas panels were encapsulated on the painted side of the canvas with water-based adhesives and tissue paper to stabilize the historic painted surface before peeling back the canvas panels. |
We devised a system in which large diameter foam rollers were suspended from a metal frame adjacent to the ceiling work area. The stabilized canvas could then be carefully peeled away from the plaster substrate and rolled over the foam support. After peeling enough canvas for structural access, the whole support unit was wrapped in plastic to protect the painted canvas from dust. |
Once internal structural work was completed, the missing plaster was replaced by first re-establishing the ceiling support and mesh prior to new plaster installation. |
The ceiling panels had a wonderful variety of patterns and colors |
The design required close attention to the fine details of the pattern. |
All painted decorative surfaces were cleaned of dirt and soiling using the safest possible method to avoid damaging original pigments. |
This image shows a previously removed and rolled canvas panel after reinstallation and prior to final application of the clear protective sealer. |
Reinstallation of the canvas panels usually began with the preparation of the plaster surface before unrolling the canvas. |
Slow and careful pressure by a team of installers was required to guarantee wrinkle-free finished surfaces. |
Larger canvas panels called for greater numbers of team members |
The process could be characterized as the reinstallation of historic wallpaper but on a horizontal surface. |
As canvas was unrolled and pressed into place, the protective tissue paper and plastic sheet was removed and disposed. |
Final placement and detailing of the canvas could then be completed. |
After cleaning and touchup inpainting, the entire panel received a clear protective coating. |
The courthouse is visibly the same, but the internal changes will make sure that the next century of use is less risky to the occupants. |