Rescuing City College's Historic Shepard Hall with Brush-On® 40
Built in 1907, Shepard Hall has been the long-standing symbol of City College of
New York overlooking Harlem in Manhattan’s northwest end. Architect George Browne
Post's neo-gothic design was very bold, but ultimately doomed to structural decay. Rather
than creating stone veneer over a reinforced structure, most of the elaborate glazed
terra-cotta façades were built as load bearing. The terra-cotta was simply too weak to
resist decades of exposure to the elements. Eventually the façades began to crack and
crumble, allowing rainwater to further damage the structure. By 1988 the entire building
was in serious danger of collapse. It was then that the Dormitory Authority of the State
of New York stepped in to save the landmark.
MJM Studios was contracted as part of the $4 million restoration of Shepard Hall.
Their expertise in restoration work employing glass fiber reinforced concrete (GFRC) made
them uniquely qualified to take on such a massive project. Smooth-On users MJM used
Brush-On urethane rubber to make molds of the massive stained glass arches that adorn the
main hall, among many other elements. Brush-On® 40 picked up perfect detail
from the arches and could be used multiple times to cast duplicate GFRC elements. The cast
façades were then separately bolted to steel channels, allowing for natural thermal
movement and easy replacement of individual units in the future, if necessary.
The arches of the main hall had been structurally compromised from a century of exposure to the elements.
Shepard Hall: Built in 1907, the load-bearing terra-cotta façades were in danger of collapse.
One of the surviving arches is prepared for the mold making process.
Brush-On® 40 urethane rubber is applied by mold makers at MJM Studios.
4 layers of Brush-On® 40 are added to an ultimate mold thickness of 3/8'' (1cm).
Once the rubber fully cures, spray concrete and chopped fiber is used to create a support shell for the rubber mold.
The support shell is built up to an appropriate thickness.
Once the concrete has fully cured, the mold can be seated in the support shell.
The cast façades were separately bolted to steel channels, allowing for natural thermal movement and easy replacement of individual units in the future, if necessary.
A replacement GFRC arch is installed.
When all arches and other damaged elements had been replaced, the once crumbling Shepard Hall was restored to its former grandeur.
A room with a view: The restored stained glass as seen from inside Shepard Hall will inspire City College students for many years to come.