NYC 9/11 Public Portal Document
Friday 15 of Mar 2002, Mayor Office ->718 595 4544 Page 25 of 29
A cleaning system appropriate for a specific masonry material may not be appropriate for
adjacent masonry mortar joints. The removal of paint/stain on mortar joints should be avoided if
possible.
Reducing the strength of the removal agent and/or the pressure applied for removing the
paint/stain can minimize "clean spots" left on masonry.
Masonry surfaces should be tested with non-staining ph strips after removals are completed in
order to ensure that the substrate has been adequately neutralized. Neutralizing a surface
involves removing all chemical and/or cleaning agents from the fabric. A substrate that has not
been neutralized can lead to subsequent damage of the historic fabric.
Applied Paint (Signage) Signific^t Interior Historic Fabric: If paint (signage) is applied
tu,,
to significant interior fabric (e.g. murals, mosaics, decorative metals) an experienced
architectural and/or art conservator should be consulted regarding any treatment or removal. It is
possible to successfully remove applied overpaint from even the most decorative or fragile
substrates.
Health, Safety, and Environmental Issues:
It is the responsibility of the Applicant to obtain all local, federal and state permits prior to the
commencement of work and adhere to all local, state and federal laws with respect to the
application and disposal of potential hazardous waste materials.
Sources:
AIC Ethics and Standards Committee. "AIC Code of Ethics and Guidelines for Practice."
Revised August, 1994.
Grimmer, Anne E. "Dangers of Abrasive Cleaning to Historic Buildings." Preservation Brief
Number 6. Washington, DC: National Park Service, 1979.
New York Landmarks Conservancy. Historic Building Facades: The Manual for Maintenance
and Rehabilitation. New York: John Wiley & Sons, Inc., 1997.
Weaver, Martin E. "Removing Graffiti from Historic Masonry." Preservation Brief Number
38. Washington, DC: National Park Service, 1995.
Note: National Park Service Preservation Briefs, including those referenced in these
performance standards, are available on the Internet; keyword Preservation Briefs.
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NYC-WTC 000093812
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