Programmatic agreement for building cleaning following disaster, March 2002

NYC 9/11 Public Portal Document

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) to Significant Interior Historic Fabric: If paint (signage) is applied 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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