Concrete Repair for AMDA (Vine Tower)

Hollywood, Los Angeles,
California, USA

The former Vine Tower Building is now the West Coast headquarters of the American Musical and Dramatic Academy. It was constructed in the 20s, using materials and techniques common for this period. We restored and preserved the board formed cast-in-place concrete veneer using specialty repair mortars.

Wikipedia Reference:

http://en.wikipedia.org/wiki/American_Musical_and_Dramatic_Academy

Eliminating the falling debris from the decayed concrete veneer of this 1920s Hollywood office tower called for the removal of large quantities of failed concrete prior to patching and repairs.
The building had undergone several changes over the years, including some creative paint schemes, but the basic original Deco look and appearance was essentially unaltered.
As with many older concrete structures built around this period, the internal steel reinforcing bars were placed too close to the finish surface in the forming process. Iron decay caused internal pressure and the signs were evident on a widespread basis.
A screwdriver and a little hand pressure were usually all that was necessary to dislodge the potentially dangerous spalled masonry.
To begin the pre-project survey, we used a combination of fixed- and suspended-stage scaffolding access, and mapped the exterior surface of the building facade.
Careful documentation and record keeping are essential in projects of this nature, in order to gain some degreee of control over the most unpredictable aspects of this type of project.
Once these areas were positively identified, we began the methodical removal of all locations of failed concrete, using diamond-tipped saw blades to produce a clean edge to the repair area.
Some of the elevations on the building, such as the east and south, had more damage, due to the orientation of the facade to weathering patterns in SoCal.
Some areas had a suprisingly high ratio of failed- to sound concrete. In all cases, the exposed steel re-bar was coated to resist corrosion prior to the application of patching mortars.
The decorative components of the veneer allowed our craftspeople to utilize their sculptural skills in reproducing lost detail.
These bas-relief figures were damaged by the same symptoms that afflicted the flat wall surfaces
A new coat of paint also helped to accentuate the detail and expression in the modeling of the figures.
The cleaning plan assumed that a no-chemical coating removal technique would be the best way to remove the old paint on the surface, since the hard concrete could resist the force of pressurized water much more effectively and safely than a deteriorated cast stone or limestone.
This parapet freestanding figure provides a glimpse of the restoration process when old surface coatings are present. Here, the old coating is clearly weathered and failing.
Here the old coating has been removed with pressurized water, and repairs can now be made, as needed.
It’s still important to make the historic concrete and pre-cast as weather-resistant as possible, and painting the cleaned surfaces was a cost-effective and efficient method of achieving that end.
Our hope is that this current cycle of building preservation will serve the owners for a long time and ensure the presence of this historic facade for years to come.