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Process photo showing stained stone Courtesy of MTFA Design + Preservation
at left and a cleaned area at right.

Photo © Prakash Patel Close-up view of the restored façade Photo © Prakash Patel
At each step, they experimented with techniques, cleaning solutions, elevations. “It was a thrill to see it work when we finally got the
and the sequence in which to use them, searching for the most treatment and sequence right,” she said.
effective way to bring the marble back to its original glory. In addition to the façade cleaning, the conservation team
As a first step, the building was power washed at very low carefully assessed the integrity of the façade, looking for any
pressure. Next, atomized water was misted over the marble for cracking or corroding of underlying steel reinforcements. They
three hours, gently opening the pores of the stone in preparation were able to pinpoint just the corroded steel and stabilize the
for deeper cleaning. “My first goal was not to flood the basement structure without dismantling entire facades. To ensure that
where the archives were stored,” said Edwards, “so we really future generations of conservators will not have to repeat the
limited the amount of water we put on the building.” work, the copper flashing along the building parapet was
A very delicate microabrasion of finely ground glass was replaced with an angled marble ledge to shed water away from
used on portions of the façade. Then came the application of the marble facades.
a customized poultice: a paste of clay powder and ammonia A renovation adding a 12,000-square-foot public pavilion
containing a special agent that binds tightly to the offending under the library’s front lawn is now underway. The project
copper ions to lift the stains from the marble. “Standard involves extensive excavation and foundation work and
poultices didn’t work,” said Edwards. “We had to experiment on Edwards said she checks in regularly with the construction
how to pre-treat the marble, how to apply the poultice, how long team to make sure her building stays clean.
to leave it on.” The conservators perfected their techniques on
the rear of the building before moving on to the more prominent

BASTIONS OF CULTURE 15