810 Spring St.
Los Angeles, LA, California
Cleaning, Replication and Repair of an Existing Terra Cotta Facade
This classic brick and terra cotta facade was in serious need of cleaning and repairs due to deferred maintenance and rusting of the internal steel anchors.
Click on images below to view at larger size.
Earthquake damage began the long process of decay and failure of the decorative terra cotta trim at the lower floors, and when moisture was able to seep in through the cracks left from multiple seismic events, it caused the expansion of internal steel anchors and severe damage to the historic veneer of the building. |
As with so many contemporaneous structures of this period, the dawn of the new millenium was accompanied by extenuated decay and damage due to environmental and seismic issues. |
The usual list of material shortcomings were in evidence here. Internal mild steel reinforcing components had conspired to produce serious and widespread damage over much of the decorative horizontal water course at the 2nd floor. |
Damage was allowed to progress to the stage where entire terra cotta units were falling off the facade. |
Our first task in the workplan was to stabilize the rest of the 300-foot long horizontal water course using stainless steel 'staples' and epoxy adhesive to mechanically restrain the terra cotta pieces as a unit. |
Once the pins were installed and cured and all other repairs completed, the entire top of the water course was properly waterproofed. Contemporary sealant technology allows us to anticipate a 20-30 year lifespan from this repair, and renewing it in the future will be much less labor- and resource-intensive. |
Once stabilization was complete we could turn our attention to the careful dismantling and removal of approximately 30% of the terra cotta components in the water course, due to the usual ironjacking phenomenon described in the projects above. In this case you can easily track the horizontal axis of the internal steel reinforcing bar. |
This piece of internal rebar began life with a diameter of approximately 1/2". Oxidation and weathering have reduced it to the size of a small diameter wire. |
Selective demolition and disassembly involved the use of high speed diamond tooling and cutting machines. |
While every effort was made to preserve as much original terra cotta fabric as possible, it was not infrequent that the original material was too extensively damaged to be safely re-used. In these cases moulds taken from the original building were made and then used to produce GFRC units matching in profile and size. |
Here an entire corner is being replaced in the new GFRC material, which is then coated with epoxy-based paint to match the original cleaned glaze appearance. |
Typical patterns of stress relief at the window openings led to frequent failure of the decorative terra cotta at the voussiours. |
Here the repair solution used a stainless steel mesh support for a mortar repair formed by hand. |
Once the partial repair using mortar is cured, it can then be coated similar to the GFRC units described previously. |
This repair method allowed us to restore the original profile while removing the least amount of original material. |
Interior entry terra cotta utilized unit replacement with new GFRC, using moulds taken from the adjacent original surfaces. |
The same area fully restored. |
Interior Lobby work included cleaning and resurfacing the marble walls and floors, and the replication of missing marble trim at the arches, as well as the installation of new onyx reception desk components. |
For this entry on Spring St., we were fortunate to have the opposite terra cotta entry to the lobby still on the facade of the building, confirming our source information for the mould work. |
The fully restored entry on Spring St. |