Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
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We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
PART 1—GENERAL
1.01 SUMMARY
- This procedure includes guidance on cleaning Academy Black Granite.
- See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
- Safety Precautions
- Historic Structures Precautions
- Submittals
- Quality Assurance
- Delivery, Storage and Handling
- Project/Site Conditions
- Sequencing and Scheduling
- General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).
1.02 DEFINITIONS
- Pressure Readings: Described herein, shall be measured at the nozzle of the spray apparatus, not at the masonry surfaces as follows:
- Low pressure wash shall measure between 100 psi and 400 psi.
- Medium pressure wash shall measure between 400 psi and 800 psi.
- High pressure wash shall measure between 800 psi and 1200 psi.
- Construction Engineer: As referred to hereinafter, means that person or persons representing the Government or acting for the Government’s Contracting Officer.
1.03 QUALITY ASSURANCE
- Cleaning operations shall be carried out by a firm with a minimum of five years specialized experience in the cleaning of historic architectural masonry.
- The Contractor shall submit to the Architect written record of projects for which the Contractor has performed masonry cleaning of materials the same as those on this building.
- The Contractor shall arrange with the Construction Engineer for a site test of protective methods and cleaning materials and methods which he proposes to use to prove that chemical damage to glass, polished black granite, or air conditioning units, painted surfaces, trees, shrubbery, and grass will not occur.
- Regulatory Requirements: Comply with municipal and Federal regulation governing the cleaning, chemical waste disposal, scaffolding and protection to adjacent properties.
- Field Samples:
- The Contractor shall clean 20 square feet (approximate) sample panels on each type of masonry. Locations of sample panels to be cleaned will be selected by the Construction Engineer.
- Prior to cleaning sample panels, the Contractor shall submit to the Construction Engineer his written description of cleaning methods, working pressures, materials and equipment proposed for use in cleaning each type of masonry. Visual samples of any chemicals shall be submitted along with letters of certification from manufacturer that chemical concentrations do not exceed those specified above.
- Adjust the cleaning concentrations, working pressures and methodologies during test panel cleaning, as directed by the Construction Engineer.
- Sample panels shall be cleaned by the Contractor using methods, materials, and working pressures previously submitted and approved. Samples of cleaning shall be performed in the presence of the Construction Engineer. The working pressures during sample panel cleaning must be used up to the previously submitted and approved capacities to determine the best working pressure.
- The Contractor shall obtain the Construction Engineers written approval of cleaning methods, working pressures, materials, equipment used and sample panels before proceeding with building cleaning operations. For this written approval purpose, the Contractor shall allow a minimum of seven calendar days after completion of sample cleaning to permit the Construction Engineer to study the sample panels for negative reactions. Approved sample panels shall be marked and left unaltered. Approved samples will be used as the standard for similar work throughout the project.
1.04 DELIVERY, STORAGE AND HANDLING
- Packing and Shipping: Deliver materials to the site in the manufacturer’s original and unopened containers and packaging, bearing labels as to the type of material, brand name and manufacturer’s name. Delivered materials shall be identical to tested materials.
- Storage and Protection: Store materials off the ground in a dry, clean location. Remove materials which are damaged or otherwise not suitable for use from the job site.
1.05 PROJECT/SITE CONDITIONS
- Environmental Requirements: No cleaning shall be executed when air or masonry surface temperature is below 45 degrees F, unless adequate approved means are provided for maintaining a 45 degree F temperature of the air and materials for 48 hours subsequent to cleaning.
1.06 SEQUENCING AND SCHEDULING
- Perform general cleaning of masonry before the repair and pointing of the masonry, unless mortar joints are in poor condition. Serious deterioration could foster excessive moisture infiltration into the masonry. Perform final wash down of the masonry no less than 30 days after masonry repair and pointing is completed.
- Perform cleaning and washing of the exterior masonry only during hours of natural daylight.
PART 2—PRODUCTS
2.01 MANUFACTURERS
- The Procter & Gamble Co.
2.02 MATERIALS
- Soap for Black Granite: Mild detergent with no abrasives and water soluble, such as “Tide” (Proctor and Gamble), or approved equal.
- Warm Water: Potable, non-staining and free of oil, acids, alkalis, and organic matter; heated to approximately 180 degree F.
2.02 EQUIPMENT
- Garden hose.
- Brushes: Fiber bristle brushes
PART 3—EXECUTION
3.01 EXAMINATION
- Tests/Inspection: Inspect site conditions and drainage to determine that cleaning operations can be conducted without endangering or causing interference with other materials or work at the site and to determine that drainage is adequate to safely carry away all waste material produced during the cleaning operations.
3.02 PREPARATION
- Protection:
- All necessary precautions shall be taken to protect all parts of the building not being cleaned from damage during the cleaning process. The Contractor shall use masking tape where applicable to seal edges of coverings during masonry cleaning operations, and remove such coverings when masonry cleaning operations are completed on that section of the building.
- All work shall proceed in an orderly fashion; working from top to bottom of each scaffold width and from one end of the elevation to the other.
- Take all necessary precautions and protective measures to protect surrounding materials on the site and surfaces of the building not being cleaned, from coming in contact with the cleaning materials and run-off.
- Take necessary precautions to protect workmen and pedestrians from cleaning chemicals, overspray and run-off.
- Provide protection to prohibit chemicals or run-off from coming in contact with or being applied onto or metallic surfaces. Build dams to divert flowing water to drains in compliance with municipal codes. Contain or dilute used cleaning materials prior to disposal in accordance with code.
- The Contractor shall test all drains which he plans to use to assure that those drains are functioning properly before beginning masonry cleaning operations in each area. The Contractor shall immediately report the location of drains which are stopped up or blocked to the Construction Engineer.
- During cleaning operations, the Contractor shall prevent solids, such as masonry cleaning residue, from the drains and drain lines. Drains shall be serviced daily. The Contractor will be held responsible for cleaning out drains and drain lines which become blocked or filled as a result of work performed under this contract.
3.03 ERECTION, INSTALLATION, APPLICATION
- Pre-wet the granite with a low pressure (100-400 psi) warm water.
- Apply soap diluted in water 1:32 by volume using a soft fiber brush and allow to stand 3-5 minutes.
- Scrub surface and rinse granite with low pressure clean water to remove all soap and soil from granite.
U.S. General Services Administration