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.
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.
- This procedure includes guidance on stripping built-upcoatings from marble surfaces. These may include floor coatings splashed onto adjacent marble surfaces.
- 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
- 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 SYSTEM DESCRIPTION
- Performance Requirements: The objectives for marble cleaning are to remove dirt, grime and coatings from the surfaces without damaging the underlying material and to give all the marble a clean uniform appearance without blotches.
- Sample panels for cleaning and patching shall be prepared for approval and shall establish a standard for all marble work. The locations and types of control samples are to be indicated on a plan, with a photograph of each control sample to be submitted to the Contracting Officer's representative. No work shall commence until written approval for the control samples has been obtained from the Contracting Officer's representative.
- The Contractor shall clean sample panels 2'-0" by 2'-0" in area, on each color and type of marble,for approval by the Contracting Officer's representative. Locations of sample panels to be selected by the Contracting Officer's representative.
1.04 QUALITY ASSURANCE
- Regulatory Requirements:
- Comply with municipal and Federal regulations governing all work included in this section and including, but not limited to, cleaning, waste disposal and protection to adjacent properties.
- Contractor: The work shall be performed by a firm possessing a minimum of five (5) years of specialized experience in the restoration and clearing of historic architectural marble, similar to that which is required in this project. The Contractor shall submit to the Contracting Officer's representative references of previous work, justifying the firm's experience. The Contacting Officer's representative reserves the right to approve or disapprove the use of the Contractor contingent upon their experience.
- NOTE: The quality of the work is highly dependent on the competence of the Contractor because it is not possible to anticipate every variation encountered in the surfaces, job conditions and methods used.
- ProSoCo, Inc.755 Minnesota AvenueP.O. Box 1578 Kansas City, KS 66117800/255-4255 or 913/281-2700
- Eastern Marble Supply Company
- Water: Potable, non-staining and free of oils, acids,alkalis and organic matter.
- Polishing Compound - An acid-free abrasive compound containing no caustic or harsh fillers or ingredients with natural resins added, manufactured specifically for polishing interior marble surfaces, such as "RS2B" (Eastern Marble Supply Company), or approved equal.
- Cleaning Agents -(General Cleaning): A poultice incorporating surfactants and biodegradable detergents in dry form for the removal of general staining.Commercially available. The poultice is mixed with water and an additive containing special deter gents and wetting agents, such as "Sure Klean Marble Poultice", "Sure Klean Marble Poultice Additive" (ProSoCo, Inc.), or approved equal.
- Cleaning Agents -(Built-Up Coatings): a non-acidic gel-like application for removal of built-up stains using thixotropic alkali materials with a pH value between 7 and 10, such as "Sure Klean Liquid Marble Cleaner", "Sure Klean T-942 Limestone Cleaner" (ProSoCo Inc.), or approved equal.
- Stainless steel trowel
- Wood scrapers
- Stiff bristle brushes (non-ferrous bristle)
- Take all necessary precautions and measures to protect all surrounding materials from damage that might be incurred during the marble restoration work. Any damage caused by the Contractor to other materials is unacceptable and shall be repaired or replaced by the Contractor to the satisfaction of the Contracting Officer's representative, at not cost to the Government.
- Improper use of chemicals may constitute a health hazard. Refer to manufacturer's Material Safety Data Sheets for hazard data, special protection,for use and precautions to be taken in handling and storage. Comply with manufacturer's recommendations for proper use of chemicals.
3.02 ERECTION, INSTALLATION, APPLICATION
- Cleaning Existing Built-Up Coating from Marble:
- Strip built-up splashed floor coatings from the lower part of marble veneer walls by applying thixotropic alkali materials to the stone ("Sure Klean Liquid Marble Clean er", and low pressure cold water rinsing (less than 100 psi). Brush apply the materials undiluted and let dwell for 20 to 60 minutes depending on field test trials. Do not allow cleaners to dry. The Contractor should clean one whole panel at a time, so as to maintain a uniform result on each panel and prevent cleaning overlap.
- Before rinsing, scrub for 5 to 10 minutes with bristle brushes to loosen tenacious coatings. Do not use metal brushes. Repeat application for stubborn build up. Do not allow cleaners to come in contact with the adjacent materials.
- General Cleaning of Marble: Remove soiling and stains from marble veneer using a poultice incorporating surfaces and detergents.
- Prepare the poultice by mixing the additive with the dry poultice (fuller's earth) to the consistency of thick cream and apply a AC" thick layer to the pre-wet masonry using a stainless steel trowel or a non-ferrous implement.
- Cover the poultice with a membrane and allow to dry for 8 to 24 hours depending on field test trials.
- Scrape poultice from the masonry with a non-metallic implement and scrub with water and a fiber bristle brush.
- Rinse with low pressure water to remove all traces of the poulticing materials. The removal of crusted splashed coatings should precede general poultice cleaning in order to achieve a uniform result.