Fax forwarding DEP briefing materials for Mayor's meeting, March 2002

NYC 9/11 Public Portal Document Y’’

Friday 15 of Mar 2002, Mayor Office ->718 595 4544 Page 22 of 29

r • + Requirements ami Performance Standards Remo^ ing .Applied Paint (Signage) from Masonry

I. Requirements

(General: .AJl work related to historic buildings shall comply with the ‘Sea-etan' of [he Interior'.': Standards far the Treatment of Historic Properties. Treatment approaches will be in the ■‘gentlest means possible." and all methods should be material and building specific. Remo\'al of .Applied Paint (signage) from masonry should be done a.s soon as possible. Programs for the removal of applied paint from historic building’labric shall be developed on a case-by-case basis with regard to each building and all associated building materials. Harsh treatments and inappropriate cleaning methods, including abrasive cleaning and certain chemical applications. can permanently damage significant historic building fabric and character-defining features. Traditional abrasive applications such a.s '‘sand-blasting" and high-pressure water cleaning shall not de used.

II. Perfoinianee Standards

Qualified Contractor(s)/ConsuJtant(s): .A qualified professional such as a historic preservation or a building conseiwation expert shall be consulted to develop) an appropriate removal program for each building. .A qualified contractor or building conservator, e.xperienced in the removal of applied paint (signage) and cleaning of historic buildings shall be used to perform work.

Testing: Prior to the remox al of applied paint, identify the paint type and the substrate to which the paint i.s applied. Identification of the paint type and substrate material (e.g. stone, cast stone. brick, terra cotta) combined with professional interpretation of test results will aid in the determination of tlie most appropriate removal method. .Alter a cleaning program i,s selected, the method shall be tested and evaluated by a qualified professional prior to application, bach building and building material shall be assessed and tested prior to developing and implementing cleaning programs. It is expected that several methods of removal will be tested before an appropriate removal method is found.

WTC Site Specific Considerations:

Masonry surfaces shall be free of dust prior to implementing a remo'. al program. It is possible, based upon composition of the particulates generated by the disaster, that the dust and'or debri.? on the facade may chemically react with applications and masonry substrate during the cleaning pr(.'cess. creating deposil.s that will cause problems to the building overtime. Dust and debris deposited on buildings should be tested and. if determined necessary, properly removed prior to the application of water or liquid cleaning agents, (see Performance Standards for Cleaning Masonry E.Kteriors).

T!ie Applicant should ensure that potential disaster related damages to the building which may include, but are not limited to, openings in building facades, dust on building materials, cracks, open mortar joints, and weakened or damaged materials are identified by a qualified professional prior to cleaning the facade. Precautions should be taken prior

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