140P2021R0055-0005_Att05-RevSpec-040140_52_StoneMasonryCleaning_210712_0005.pdf

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STONE MASONRY CLEANING

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SECTION 04 01 40.52 – STONE MASONRY CLEANING

PART 1 – GENERAL

1.1 GENERAL REQUIREMENTS

A. Work of this Section, as shown or specified, shall be in accordance with the requirements of the Contract Documents.

1.2 DESCRIPTION

A. Work of this Section includes all labor, materials, equipment, and services necessary to complete the work of masonry cleaning as shown on the Drawings, as specified herein, and as may be required by conditions and authorities having jurisdiction, including, but not limited to, the following:

1. Cleaning general soiling and heavy soiling from masonry to be consolidated using detergent cleaners and pressurized water rinsing.

2. Cleaning biological growth from masonry using biocide and water rinsing.

3. Removing iron stains from masonry using chemical removers and water rinsing.

4. Removing copper stains from masonry using chemical removers and water rinsing.

5. Protecting window openings, door openings, and other openings in building exterior from water entry before beginning masonry cleaning.

B. Related Work Specified Elsewhere

1. Stone Masonry Restoration – Section 04 01 40.91

2. Stone Consolidation – Section 04 01 40.93

1.3 QUALITY ASSURANCE

A. Masonry Cleaning Specialist: Award stone masonry cleaning work to a firm regularly engaged in cleaning masonry on historic buildings that can demonstrate to Government’s satisfaction that, within previous ten years, the firm has successfully completed at least five projects similar in scope and type to work required on this Project involving buildings designated as Landmarks by local governmental authorities, buildings listed in the National Register of Historic Places, or buildings listed in a State Register of Historic Places under the direction of preservation authorities.

1. Foreman: Stone masonry cleaning shall be directly supervised by a full-time foreman with experience equal to or greater than that required of Masonry Cleaning Specialist. Foreman shall read and speak English fluently. Foreman shall be on site daily for duration of work of this Section. Same foreman shall remain on Project throughout work unless Owner deems foreman’s performance unacceptable.

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2. Mechanics: Stone masonry cleaning shall be carried out by a steady crew of skilled mechanics who are thoroughly experienced with materials and methods specified and have a minimum of three years’ experience cleaning masonry on historic buildings similar to the work required by this Section. In acceptance or rejection of work of this Section, no allowance will be made for workers’ inattention or lack of skill.

B. Laws, Codes, and Regulations: Work of this Section shall comply with applicable federal, state, and local laws, codes, and regulations.

C. Alternate Stone Masonry Cleaning Methods: If Contractor proposes use of cleaning procedures and products other than those specified and Contracting Officer gives preliminary approval following required submittals, Contractor shall perform tests and create mock-ups demonstrating ability of proposed products and procedures to produce specified cleaning results and for comparison with specified mock-ups at no additional cost. No alternate method shall be permitted until Contracting Officer has approved it.

D. Daily Log: Contractor shall keep onsite and available for inspection a daily log describing stone masonry cleaning operations. Log shall record temperature at beginning and ending of work, weather conditions, whether masonry was wet or dry prior to beginning work, personnel on site, areas cleaned and procedures used, areas inspected and accepted, and other relevant information.

E. Access for Observation and Approvals: Provide Restoration Consultant access on a continuing basis to locations on which mock-ups are being carried out, on which work is ongoing, and where work has been completed to allow for observation and approvals. Provide pipe scaffolding and manpower to move and reconfigure scaffolding and planking, personnel lift and manpower to operate lift, or other means of access complying with applicable laws and regulations regarding safety and acceptable to Contracting Officer. Provide manpower and equipment to facilitate observation and approvals.

1. Extent of Access: Provide Contracting Officer with hands-on access to each and every area of masonry surface that has been cleaned. No approval of stone masonry cleaning will be given before Contracting Officer is provided hands-on access to all surfaces that have been cleaned. Provide access for reinspection of areas where stone masonry cleaning work was not approved on first or subsequent inspections until Contracting Officer approves work.

2. Relocation of Means of Access: If Contractor moves scaffolding, lift, or other means of access before providing Contracting Officer with hands-on access to each and every surface of masonry that has been cleaned and to each and every masonry surface that has been cleaned after previous cleaning work was rejected, Contractor shall reinstall means of access to provide for close-up inspection by Contracting Officer at no additional cost to Owner.

F. Building Elevations Showing Masonry Cleaning Progress: On large-scale mounted elevations of the building indicate daily the following: areas currently being cleaned, areas previously cleaned but not yet accepted by Contracting Officer, and areas cleaned and accepted by Contracting Officer. Indicate required information using visual means acceptable to Contracting Officer.

G. Onsite Instruments: Maintain accurate instruments for measuring conditions at Project site to allow assessment of conditions during stone masonry cleaning work.

1. Temperature Measurement: Measure temperature before beginning and during progress of work of this Section as required to ensure compliance with specified conditions for stone masonry cleaning.

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2. pH Measurement: Measure pH of masonry surfaces following chemical cleaning to ensure that each surface has been properly neutralized.

H. Prohibited Materials and Methods: The following methods are strictly prohibited and shall not under any circumstances be used for work of this Contract: sandblasting, steam (except as specifically indicated herein and approved by Contracting Officer), and use of nonproprietary acids, alkalis, and other products not manufactured specifically for stone masonry cleaning.

I. Knowledge of Site and Project Conditions: Before submitting bid, Bidders shall make themselves thoroughly familiar with the Drawings and Specifications, with the scope of this Project, and with conditions at the Project site relating to requirements of this Section and limitations under which the work will be performed and shall determine or verify dimensions and quantities. Submission of a bid shall be considered conclusive evidence that Contractor is thoroughly familiar with Project requirements and site conditions and limitations.

1.4 SUBMITTALS

A. General: Submit the following in compliance with the requirements of the Contract Documents.

Revise and resubmit each item as required to obtain Contracting Officer’s approval.

B. Qualification Data: Qualification data for firm and personnel specified in “Quality Assurance” Article that demonstrates that both firm and personnel have capabilities and experience complying with requirements specified. For firm and foreman, provide a list of at least five completed projects similar in size, scope, and character to the work required on this Project. For each project list project name, address, architect, conservator, supervising preservation agency, scope of contractor’s work, and other relevant information. Submit this information with the bid.

C. Work Description: Prior to any stone masonry cleaning work on site, submit detailed description of proposed materials and procedures for each substrate and condition requiring stone masonry cleaning. Submit new written descriptive information. Photocopies of Contract Documents, excerpts from Contract Documents, and/or duplication of text in Contract Documents will not be accepted for Work Description. Do not begin work on site until work description has been approved in writing. Description for each condition shall include, but not be limited to:

1. Cleaning: Materials, methods, tools, and equipment for each type of stone masonry cleaning specified herein.

2. Protection: Description, including drawings, of proposed materials and methods of protection for preventing harm, damage, or deterioration caused by work of this Section to all persons (whether involved in the Work or not); building elements, materials, and finishes; surrounding plants, landscape, and site; and the environment (including air and water).

3. Alternate Cleaning Methods and Materials (If Any): Contractor proposed alternate methods and materials (if any) to those specified for any phase of stone masonry cleaning. Provide evidence of successful use on comparable projects and demonstrate effectiveness for use on this Project.

D. Product Data: Submit manufacturer’s published technical data for each product to be used in work of this Section including material description, chemical composition (ingredients and proportions), physical properties, recommendations for application and use, test reports and certificates verifying that product complies with specified requirements, and Safety Data Sheets

(SDS).

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E. Schedule of Stone Masonry Cleaning: Prior to commencing stone masonry cleaning operations, submit a complete detailed schedule for testing and mock-ups and for completion of stone masonry cleaning.

1. Provide schedule in visual form and in 8-1/2 by 11 inch format or foldout therefrom.

2. After stone masonry cleaning operations commence, submit updated schedule on a weekly basis.

F. Waste Disposal Program: Prior to commencing stone masonry cleaning operations, submit a written description of proposed materials and methods for collection, treatment, and disposal of wastes resulting from stone masonry cleaning operations.

G. Daily Log: Submit copy of daily log to Contracting Officer each week.

H. Testing and Mock-Ups: Prepare test panels and mock-ups as described in Articles “Testing” and “Mock-Ups,” below.

1.5 TESTING

A. General: Before beginning mock-ups or general stone masonry cleaning work, test cleaning and coating removal methods on sample areas to determine most effective product and procedure for cleaning each substrate and for removing each type of coating from each substrate. Do not proceed with mock-ups or general stone masonry cleaning work until Contracting Officer has approved results of testing in writing.

1. Perform tests in locations directed by Contracting Officer.

2. Notify Contracting Officer 48 hours prior to start of testing.

3. Contracting Officer will monitor testing. No testing done in absence of Contracting Officer will be accepted.

4. Use crew that will perform the work and follow requirements of this Section.

5. Materials, dilutions, dwell times, and procedures are subject to modification by Contracting Officer during testing process. Contracting Officer will choose products and procedures to be used for cleaning masonry and for removing soiling and coatings based on results of test panels. Modifications of sequence, chemical dilution, substitute reagents, and equivalent procedures shall be executed at no additional cost.

a. Do not apply products to masonry surfaces without verifying dilution with Contracting Officer.

6. After test panels are complete, allow seven days for thorough drying and appearance of possible adverse effects prior to final evaluation.

7. Perform additional testing as necessary to determine proper chemicals and procedures, including dilutions and dwell times, to Contracting Officer’s satisfaction.

B. Provide the Following Test Panels

1. Cleaning General Soiling and Heavy Soiling from Masonry to be Consolidated Using

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Detergent Cleaners and Pressurized Water Rinsing: Prepare at least one 2-sq.-ft. test panel for each product specified for testing. Prepare additional test panels using different products, application procedures, dwell times, and removal procedures as directed.

2. Removing Biological Growth from Masonry Using Biocide and Water Rinsing: Prepare at least one 1-sq.-ft. test panel on each type of masonry from which biological growth is to be removed using each biocide specified for testing. Provide additional test panels using different products, application methods, dwell times, and removal methods as directed.

3. Removing Iron Stains from Masonry Using Chemical Removers and Water Rinsing:

Prepare at least one 1-sq.-ft. test panel on each type of masonry from which iron stains are to be removed using each chemical remover specified for testing. Provide additional test panels using different products, application methods, dwell times, and removal methods as directed.

4. Removing Copper Stains from Masonry Using Chemical Removers and Water Rinsing:

Prepare at least one 1-sq.-ft. test panel on each type of masonry from which copper stains are to be removed using each chemical remover specified for testing. Provide additional test panels using different products, application methods, dwell times, and removal methods as directed.

1.6 MOCK-UPS

A. General: Following completion of testing and before beginning general stone masonry cleaning work, prepare mock-ups to provide standards for work of this Section. Do not proceed with stone masonry cleaning until Contracting Officer has approved mock-ups.

1. Locate mock-ups as directed by Contracting Officer.

2. Notify Contracting Officer 48 hours prior to start of each mock-up.

3. Contracting Officer will monitor mock-ups. Mock-ups not performed in presence of Contracting Officer will be rejected.

4. Use crew that will perform the work and follow requirements of this Section.

5. Repeat mock-ups as necessary to obtain Contracting Officer’s approval.

6. Allow mock-ups to dry for one week to allow natural color to return and problems to appear. Notify Contracting Officer when mock-ups are ready for inspection.

7. Protect approved mock-ups to ensure that they are without damage, deterioration, or alteration at time of Substantial Completion.

8. Approved mock-ups in undamaged condition at time of Substantial Completion may be incorporated into the Work.

9. Approved mock-ups will represent minimum standards for stone masonry cleaning.

Subsequent stone masonry cleaning work that does not meet standards of approved mock-ups will be rejected.

B. Prepare the Following Mock-Ups

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1. Cleaning General and Heavy Soiling from Marble Masonry: One panel, 6 sq. ft.

2. Removing Iron Stains from Masonry: One panel, 2 sq. ft. or size of iron stain, whichever is less, on each type of masonry from which iron stains are to be removed.

3. Removing Copper Stains from Masonry: One panel, 2 sq. ft. or size of copper stain, whichever is less, on each type of masonry from which copper stains are to be removed.

4. Cleaning Biological Growth from Masonry: One panel 9 sq. ft. or size of biological growth, whichever is less, on each type of masonry from which biological growth is to be removed.

5. Sealing Window Openings To Prevent Water Entry: One entire window.

1.7 DELIVERY, STORAGE, AND HANDLING

A. Deliver products to site in manufacturer’s original containers with labels identifying manufacturer, product, ingredients, instructions for use, and safety precautions. Products shall not be delivered until MSDS sheets for products are available on site.

B. Deliver, store, and handle products and materials to prevent damage, deterioration, degradation, and intrusion of foreign material.

C. Discard and remove from site deteriorated materials, contaminated materials, and products that have exceeded their expiration dates. Replace with fresh materials.

1.8 PROJECT CONDITIONS

A. Safety: Protect persons, whether involved with work of this Section or not, from harm caused by work of this Section.

1. Erect temporary protective covers at doorways to building that must remain in operation during course of stone masonry cleaning work when work is ongoing around or above doorways.

2. Provide protection to prevent persons, except properly protected masonry cleaning personnel, from coming in contact with masonry cleaning materials and waste from masonry cleaning process.

3. Provide workers personal protective equipment and take other measures to ensure that workers are not harmed as a result of work of this Section.

B. Protection of Building: Protect building elements and finishes from damage and from deterioration caused by stone masonry cleaning work. Repair damage to materials and to finishes resulting from work of this Section to Contracting Officer’s satisfaction at no additional cost to Owner.

1. Adjacent Materials: Protect adjacent materials, including but not limited to masonry, metals, glass, paint, and sealants, from masonry cleaning solutions and abrasives that might adversely affect such materials.

2. Spread of Masonry Cleaning Solutions: Do not clean masonry during winds of sufficient force to spread masonry cleaning solutions to unprotected surfaces. Cease masonry-cleaning operations when winds may carry chemicals, rinse water, or run-off from chemical

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3. Window and Door Openings and Other Penetrations in Building Skin: Prevent masonry cleaning solutions and waste products from entering behind masonry surface at penetrations in skin. Provide reversible temporary seals that will prevent water and chemicals from entering openings and that will not damage or deteriorate substrate. Remove temporary seals following stone masonry cleaning. Restore substrates to condition before installation of temporary seals.

a. Infiltration: If Contractor notices that water or chemicals are penetrating building skin or if Contractor is told that water or chemicals are penetrating building skin, Contractor shall cease cleaning operations immediately. Cleaning operations shall not proceed until cause of infiltration has been eliminated.

4. Monitoring for Water Entry: When water, detergents, or chemicals are being applied to the exterior masonry, Contractor shall designate one trained person to examine interior spaces and surfaces for evidence of water infiltration. If water infiltration is detected, masonry cleaning operations shall cease immediately. Masonry cleaning operations shall not proceed until cause of infiltration has been eliminated.

C. Protection of Surroundings: Protect adjacent buildings, site, landscape features, public rights of way, motor vehicles, and other surrounding elements from damage and from deterioration resulting from stone masonry cleaning work.

1. Collect and dispose of runoff and residue from stone masonry cleaning operations by legal means and in manner that prevents soil erosion, undermining of paving and foundations, damage to sidewalks, water penetration into building interiors, and harm to buildings, landscape elements, and natural bodies of water and water table.

D. Surfaces To Receive Work: The Drawings are two-dimensional representations of three-dimensional objects and do not show all surfaces of building components on which work is to be performed, including surfaces concealed from view behind objects shown; surfaces of projections, reveals, returns, and other elements perpendicular to or at an oblique angle to surfaces shown; concealed surfaces of profiled members and of ornament; and surfaces of profiled members and of ornament not drawn in detail. Perform work on surfaces of projections, reveals, returns, profiled members, and ornaments associated with surfaces indicated to receive work and on surfaces of building components concealed behind building components shown. It is the specific intent of the Contract Documents to include work on all surfaces within Project area, whether or not shown on the Drawings, except as specifically indicated otherwise.

1. Sequence: Clean masonry before beginning masonry restoration as specified in Section 04 01 40.91 – “Stone Masonry Restoration,” except as specifically indicated otherwise.

a. Preconsolidation: Preconsolidate masonry indicated to be consolidated before cleaning as specified in Section 04 01 40.93 – “Stone Consolidation.”

2. Staging: Schedule and stage stone masonry cleaning so that no runoff from cleaning operations comes in contact with previously cleaned masonry elements.

F. Preconstruction Meeting: Convene a preconstruction meeting to discuss stone masonry cleaning and its effect on adjacent elements, materials, and finishes. Attendees shall include Owner’s Representatives, Architect, Contracting Officer, Construction Manager, firm(s) that will perform stone masonry cleaning, and other entities that might be affected by stone masonry cleaning

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1.9 ENVIRONMENTAL REQUIREMENTS

A. Use of Water: Do not perform stone masonry cleaning work that will wet masonry materials or cause them to be wet when ambient temperature is below 40 deg F or when temperature of air or masonry is expected to drop below 40 deg F within 72 hours as predicted for Philadelphia by the National Weather Service. Do not begin work when any part of wall or any materials are frozen or subject to freezing.

1.10 COLLECTION AND DISPOSAL OF WASTE PRODUCTS

A. General: Collect, contain, test, and dispose of solid and liquid wastes in accordance with applicable federal, state, and local laws and regulations.

B. Collection: Provide gutters and troughs to collect runoff from stone masonry cleaning operations for pretreatment prior to disposal. Do not allow waste materials from stone masonry cleaning operations to flow or drop onto adjacent roofs; setbacks; sidewalks; trees, shrubs, plants, grass, and other plantings; soil; or structures. Direct waste materials to collection vessels for treatment.

C. Neutralizing: Neutralize stone masonry cleaning waste products to a pH of between 5.0 and 9.5.

Propose specific methods and materials for neutralization in Waste Disposal Program submission.

D. Disposal: Dispose of stone masonry cleaning run-off by legal means that prevent erosion, undermining, damage to plant material, and water penetration into building.

1. Install protection and waste collection systems before beginning stone masonry cleaning work.

2. Test drains and other water removal systems to ensure that they are functioning properly before cleaning operations begin. Notify Contracting Officer at once if drains or systems are stopped or blocked. Do not begin work of this Section until drains are in good working order.

3. Filter stone masonry cleaning runoff to prevent suspended solids such as masonry residue from entering drains and drain lines. Contractor at his own expense shall clean out drains and drain lines that become blocked or filled with sand or other solids as a result of work performed under this Section.

4. Dispose of waste products at regular intervals. Do not allow waste products to accumulate on site.

1.11 POSSIBLE HARMFUL EFFECTS OF BIRD MATTER

A. During work of this Section, bird droppings and other bird related matter may be encountered.

This matter may contain substances, including agents of diseases such as Histoplasmosis and Cryptococcosis, that are harmful, and occasionally fatal, to humans.

B. Prevent people other than properly protected workers from coming in contact with such matter.

C. Prevent workers without appropriate protection from touching, ingesting, inhaling, or contacting in any other way bird droppings and other bird related matter.

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D. Handle and dispose of bird related matter in complete compliance with applicable federal, state, and local laws and regulations and in a manner that does not threaten health and welfare of public and workers.

1.12 LEAD-CONTAINING PAINT (LCP)

A. General: Perform work that disturbs lead-containing paint (LCP), handle material that involves lead-containing paint, and transport and dispose of lead-containing paint and residue in compliance with applicable federal, state, and local laws and regulations for identification, removal, labeling, handling, containerization, transportation, and disposal of lead-containing material including, but not limited to, those referenced herein.

B. U.S. Department of Labor OSHA Regulations: Including but not limited to: Title 29, Code of Federal Regulations (CFR) Section 1926.62: “Lead Exposure in Construction” and Title 29, CFR Section 1910.1200: “Hazard Communication Standard.”

C. U.S. Environmental Protection Agency (USEPA) Regulations: Including but not limited to: Title 40 CFR Part 262: “Standards Applicable to Generators of Hazardous Waste” and Part 263:

“Standards Applicable to Transporters of Hazardous Waste.”

D. U.S. Department of Transportation (USDOT) Regulations: Including but not limited to: 49 CFR Parts 172, 173, 174, 175, 177, 178, 179, and 180.

PART 2 – PRODUCTS

2.1 MANUFACTURERS AND SUPPLIERS

A. General: Provide products by the following manufacturers or approved equals.

B. Chemique, Inc., 315 North Washington Avenue, Moorestown, NJ 08057 (800-225-4161).

C. Dumond Chemicals, Inc., 1501 Broadway, New York, NY 10036 (212-869-6350).

D. Limeworks.us, 3145 State Road, Telford, PA 18969 (215-536-6706).

E. ProSoCo, Inc., 3741 Greenway Circle, Lawrence, KS 66046 (800-255-4255).

F. Shore Chemical Company, 2917 Spruce Way, Pittsburgh, PA 15201 (800-860-4978).

2.2 CLEANING MATERIALS

A. General: Provide the following products for use in testing for cleaning substrates and conditions indicated. Test using dilutions as specified by Contracting Officer. Provide products selected during testing for use in mock-ups and for use in cleaning building and at dilutions as selected and approved by Contracting Officer in each case at no additional cost to Owner.

B. Cleaners for Testing for Removing General Soiling and Heavy Soiling from Marble Masonry.

Test each of the following or approved equal:

1. Enviro Klean 2010 All Surface Cleaner, manufactured by ProSoCo, Inc.

2. Sure Klean Light Duty Restoration Cleaner, manufactured by ProSoCo, Inc.

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3. Ion 417 Architectural Cleaner/Restorer, manufactured by Chemique, Inc.

4. C-13 Limestone Cleaner/Restorer, manufactured by Chemique, Inc.

5. Light Duty Cleaner, available from Cathedral Stone Products.

C. Cleaners for Testing for Removing Biological Growth from Masonry. Test each of the following or approved equal:

1. Enviro Klean ReVive, as manufactured by ProSoCo., Inc.

2. Enviro Klean ReKlaim Cleaner with ReKlaim Activator, as manufactured by ProSoCo., Inc.

a. Neutralizer: Sure Klean Limestone and Masonry Afterwash, as manufactured by ProSoCo., Inc.

3. D/2 Biological Solution, available from Limeworks.us

4. Chemique C13, as manufactured by Chemique, Inc.

D. Removers for Testing for Removing Iron Stains from Masonry Substrates: Test each of the following, or approved equal:

1. Artisan Light Duty Rust Remover, as manufactured by Chemique, Inc.

2. Artisan Light Duty Rust Remover, as manufactured by Chemique, Inc., mixed with attapulgite clay, available from Superior Materials, Inc., to form a poultice.

3. Safe n’ Easy Rust Remover, available from Dumond Chemicals, Inc.

E. Removers for Testing for Removing Copper Stains from Masonry Substrates: Test each of the following or approved equal:

1. Sure Klean T-515 Copper Stain Remover Parts A & B (clay powder and chemical additive), manufactured by ProSoCo, Inc.

2. ShoreBest 2380 Copper Stain Remover, manufactured by Shore Chemical Company.

3. Site Mixed Poultice of Ammonium Chloride and attapulgite clay, available from Superior Materials, Inc.

F. Water for Chemical Cleaning, Pressure Rinsing, and Other Work of this Section: Clean, potable, free of oils, acids, alkalis, salts, organic matter, soluble and insoluble iron, and other substances detrimental to surfaces being cleaned and non-staining.

1. Source: Subject to requirements specified, water may be obtained from city water supply.

2. Distribution: Pump water to locations where work of this Section is being performed at pressure and flow rate required for optimum cleaning using each process.

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2.3 MISCELLANEOUS MATERIALS

A. Sealant: Manufacturer’s standard one part acrylic latex sealant. Use exclusively for temporary sealing of cracks and joints around penetrations during stone masonry cleaning work.

1. Do not use sealant containing silicone or other elastomeric product.

B. Backer Rod: Closed cell expanded polyethylene rod, sized 25 percent greater than joint to be sealed.

C. Protection Materials: Provide materials recommended by cleaner manufacturers for products to be used that will protect from damage caused by chemicals without causing damage to materials to be protected.

1. Glass and Metal Protection: “Strippable Acid Stop” manufactured by ProSoCo, Inc., or approved equal.

2. Plastic Sheeting: Polyethylene sheeting shall be a minimum of 6 mils thick.

2.4 EQUIPMENT FOR WATER AND CHEMICAL CLEANING

A. General: Provide equipment and accessories necessary to distribute water at pressures and flow rates necessary for stone masonry cleaning.

B. Pressure Pumps: Pressure pumps capable of producing water flow at a rate of 6 gallons per minute at a pressure of 300 psi at nozzle on end of hose. Pumps, or a combination of pumps plus pressure reducing valves, shall have capability of providing water at a steady pressure and flow rate at all pressures from 100 psi to 300 psi. Pumps shall have working pressure gauges. Pumps found to be without working pressure gauges shall be removed from site, and work shall cease until pumps have been replaced with pumps having working pressure gauges. Pumps shall have no ferrous elements in contact with liquid stream.

C. Particulate Filter: Provide a 5-micron particulate filter in line with water supply. All water used for stone masonry cleaning shall be filtered.

1. Replace particulate filter as required to provide filtered water with no particles greater than 5 microns at pressure and flow rate specified.

D. In-line Pressure Gauges: Each water line used for pressure rinsing shall have a working pressure gauge within 15 feet of nozzle used for rinsing.

E. Spray Nozzles for Pressure Rinsing: Nozzles shall be of nonferrous metal and shall have a minimum 15-degree fan tip.

F. Brushes: Natural fiber bristle or synthetic fiber bristle only. No metal bristle brushes are permitted.

G. pH Indicator

1. Electronic pH Indicator Pen: Suitable for use intended and approved by Contracting Officer.

2. pH Strips or Paper: Non-staining litmus paper with appropriate range approved by

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Contracting Officer. Furnish pH strips on site during entire period when work of this Section is being performed.

2.5 MIXING CHEMICAL CLEANING SOLUTIONS

A. General: Dilute chemical cleaning materials as determined following results obtained through test panels. Manufacturer’s recommended dilutions may be modified to reflect results of test panels and approved mock-ups.

1. Supply all dilutions of chemical cleaners at no additional cost.

B. Create test panels using a minimum of two dilutions for each product where dilution is recommended by manufacturer or requested by Contracting Officer.

PART 3 – EXECUTION

3.1 GENERAL STONE MASONRY CLEANING REQUIREMENTS

A. General: These requirements apply to all work of this Section.

B. Areas To Be Cleaned: Locations of materials to be cleaned are designated on Drawings.

C. Stone Masonry Cleaning Progress: Clean masonry systematically in full-height, top-to-bottom sections of areas to be cleaned.

1. Stone Masonry Cleaning with Water: Begin stone masonry cleaning using water at top of section to be cleaned and proceed to bottom of section before moving to adjacent section.

D. Timing: Control timing of stone masonry cleaning operations (including dwell times of cleaners and misting times) to ensure that specified times are maintained. Do not allow chemicals to remain on surfaces longer than dwell times determined during testing and confirmed during mock-ups. Do not allow surfaces to be water misted longer than times determined by testing and confirmed during mock-ups.

E. Water Pressure and Flow Rate: Limit water pressure and flow rates to maximum pressures specified herein and to lower pressures as required to avoid damaging masonry, metals, sealants, and other materials and finishes.

1. Pressure: 300 psi or less as required to avoid damage to materials being cleaned.

2. Flow Rate: 6 gallons per minute.

3. Distance from Masonry Surface: Hold nozzle at a uniform distance from masonry surface as determined by testing and confirmed by mock-up to provide optimum cleaning without damaging masonry surface but at least 12 inches from stone surface.

4. Adjustments: If any building material is damaged or deteriorated by water rinsing, immediately cease work. Do not begin pressure rinsing again until water pressure and flow rate have been adjusted to avoid damage to building materials.

F. Uniform Cleaning: Clean masonry to achieve uniform results so that flat surfaces, edges, corners, crevices, profiles, and recessed areas are uniformly clean.

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G. Alteration: Stone masonry cleaning procedures, including cleaning chemical, chemical dilution, and dwell time may be altered by Contracting Officer based on site conditions.

H. Completion of Stone Masonry Cleaning: Cleaned masonry shall match approved mock-ups.

Areas are subject to additional cleaning as directed by Contracting Officer in order to match mock-ups. Work of stone masonry cleaning on each surface shall not be considered complete until Contracting Officer has inspected surface and so notified Contractor in writing.

3.2 TESTING

A. General: Perform testing under direction of Contracting Officer following requirements of Article “Testing,” above, to determine most appropriate products and procedures for cleaning each substrate before preparing mock-ups or beginning general stone masonry cleaning work.

3.3 MOCK-UPS

A. General: Provide mock-ups under direction of Contracting Officer following requirements of “Mock-Ups” Article, above, to confirm products and procedures selected during testing and to provide standards for evaluation of the stone masonry cleaning work.

3.4 CLEANING SOILING FROM MASONRY USING CHEMICAL REMOVER AND

PRESSURIZED WATER RINSING

A. General: Clean masonry free of soiling using cleaning chemical selected during testing followed by pressurized water rinsing. Cleaned masonry shall match approved mock-up to Contracting Officer’s satisfaction.

B. Cleaner Application and Removal: Apply and remove cleaner following method of application and dwell times determined during testing and confirmed during mock-ups. Scrub surface gently with fiber bristle brushes. Rinse surface thoroughly using water at a maximum pressure of 300 psi and flow rate of 6 gpm.

C. Additional Cleaning: Repeat above procedure as necessary to achieve uniformly clean masonry to provide surface matching standard of approved mock-up.

3.5 REMOVING IRON STAINS FROM MASONRY USING CHEMICAL STAIN REMOVERS

AND WATER RINSING

A. General: Remove iron stains from masonry using chemical stain remover and form of stain remover (liquid, gel, and/or poultice) selected during testing and confirmed during mock-up to achieve masonry surface free of iron stains matching approved mock-up to Contracting Officer’s satisfaction.

B. Remover Application and Removal: Apply remover following method of application and dwell time determined during testing and confirmed during mock-ups. Remove chemical following manufacturer’s directions. Rinse surface thoroughly using water at a pressure of 300 psi and flow rate of 6 gpm, overlapping passes slightly.

C. Additional Removal: Repeat above procedure as necessary to achieve uniformly clean masonry free of iron stains with surface matching standard of approved mock-up.

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3.6 REMOVING COPPER STAINS FROM MASONRY USING CHEMICAL STAIN REMOVERS

AND WATER RINSING

A. General: Remove copper stains from masonry using chemical stain remover and form of stain remover (liquid, gel, and/or poultice) selected during testing and confirmed during mock-up to achieve masonry surface free of copper stains matching approved mock-up to Contracting Officer’s satisfaction.

B. Remover Application and Removal: Apply remover following method of application and dwell time determined during testing and confirmed during mock-ups. Remove chemical following manufacturer’s directions. Rinse surface thoroughly using water at a pressure of 300 psi and flow rate of 6 gpm, overlapping passes slightly.

C. Additional Removal: Repeat above procedure as necessary to achieve uniformly clean masonry free of copper stains with surface matching standard of approved mock-up.

3.7 CLEANING BIOLOGICAL GROWTH FROM MASONRY USING BIOCIDE AND WATER

RINSING

A. General: Clean masonry free of biological growth using biocide selected during testing followed by pressurized water rinsing. Cleaned masonry shall match approved mock-up to Contracting Officer’s satisfaction.

B. Biocide Application and Removal: Apply biocide following method of application and dwell time determined during testing and confirmed during mock-ups. Scrub surface with fiber-bristle brushes. Rinse surface thoroughly using water at a maximum pressure of 300 psi and flow rate of 6 gpm.

1. Apply neutralizer if required and rinse surface thoroughly using water at a maximum pressure of 300 psi and flow rate of 6 gpm. Test surface with pH strips and repeat rinsing until masonry surface pH is between 6 and 8.

C. Additional Cleaning: Repeat above procedure as necessary to achieve uniformly clean masonry free of biological growth to provide surface matching standard of approved mock-up.

3.8 CLEANING PREVIOUS COATINGS FROM MASONRY USING LOW-PRESSURE, MICRO

ABRASIVE CLEANING SYSTEM

A. General: Clean masonry free of general soiling using micro abrasive cleaning system to match approved mock-up.

B. Cleaning: Carefully clean masonry surface using minimum pressure to achieve desired cleaning without damage to stone. Hold nozzle a consistent distance from masonry surface as determined during testing. Overlap passes slightly to ensure surfaces are thoroughly cleaned.

C. Rinsing: Rinse surfaces thoroughly using water at a pressure of 300 psi and flow rate of 6 gpm, overlapping passes slightly.

D. Additional Cleaning: Repeat above procedure as necessary to achieve uniformly clean masonry to provide surface matching standard of approved mock-up.

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3.9 ADJUSTMENT AND PROTECTION

A. Reclean surfaces that do not have a uniform clean appearance matching approved mock-ups to achieve uniformly clean surfaces matching approved mock-ups.

B. Protect cleaned surfaces from dirt and soiling from other than normal atmospheric pollution until Project completion. Reclean surfaces that become soiled to Contracting Officer’s satisfaction at no additional cost to Owner.

END OF SECTION 04 01 40.52