U.S. General Services Administration
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 removing built- up coatings from interior marble surfaces, followed by general surface cleaning. These coatings may include built-up splashed floor coatings and general soiling and staining.
- Any use of cleaning products on historic materials should be based on results of test area in an inconspicuous location working with the technical assistance of the product manufacturers to ensure compatibility with substrate and to avoid damage. Adjust concentrations and dwell times according to each material and condition.
- 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).
PART 2 - PRODUCTS
2.01 MANUFACTURERS
- Diedrich Technologies, Inc.
www.diedrichtechnologies.com - ProSoCo, Inc.
www.prosoco.com
2.02 MATERIALS
- For General Staining: Use a poultice incorporating= surfactants and detergents for the removal of general staining, such as “Sure Klean Marble Poultice” (ProSoCo, Inc.), or “General Purpose Poultice” (Diedrich), or approved equal.
- For removal of Built-up Stains: Use thixotropic alkali materials, such as “Sure Klean 942 Limestone & Marble Cleaner” (ProSoCo, Inc.), or “910PM Polished Marble” (Diedrich), or approved equal.
- Liquid Strippable Masking Agent: Manufacturer’s standard liquid, film forming, strippable masking material for protecting glass, metal and polished stone surfaces from damaging effect of acidic and alkaline masonry cleaners, such as “Sure Klean Strippable Masking” (ProSoCo, Inc.), or approved equal.
- Plastic for covering poultice
- Water: Potable, non-staining and free of oils, acids, alkalis and organic matter.
2.03 EQUIPMENT
- Brushes: Natural or synthetic fiber bristle only. The use of wire brushes or steel wool is not permitted.
- Wood spatula
PART 3 - EXECUTION
3.01 PREPARATION
- Protection: Protect all adjacent surfaces using liquid strippable masking agent.
- Surface Preparation: Work to proceed from top of wall downwards. Work shall not be considered complete until the Contracting Officer or designated representative has so notified the contractor in writing.
3.02 ERECTION, INSTALLATION, APPLICATION
- Remove Built-Up Coatings:
- Apply undiluted marble cleaner to the marble surface using a soft bristle synthetic brush (natural fibered brushes are not suitable).
- Dwell time shall be approximately 20 to 60 minutes in accordance with approved test procedures, but do not allow the stripper to dry out. Before rinsing, scrub for five to ten minutes to loosen stubborn coatings.
- Sponge rinse the surface thoroughly using fresh, clear water. Change the rinse water frequently.
- Remove waste water as work progresses by wet vacuum or other appropriate means. Do not allow water to pond on the floor.
- General Cleaning:
- Prepare the cleaning poultice by mixing the liquid additive with the dry poultice (Fuller’s earth) to a thick cream consistency. Mix thoroughly so that the poultice has a smooth even consistency.
- Clean dirt or dust from the surface being treated prior to application of poultice.
- Prewet marble and apply a 1/4” thick layer of poultice to the stained surface using a stainless steel trowel or other non-ferrous implement.
- Cover the poultice with a plastic membrane and allow to dry 8 to 24 hours, depending on test samples.
- Scrape the poultice from the masonry with a non-metallic implement and scrub with water and a non-metallic fiber bristle brush.
- Rinse all traces of chemical residue with low pressure cold water (300 psi) using spray nozzles with 15 to 20 wide nozzle tips. Nozzles shall be held perpendicular to the surface at a working distance of 1.5 to 2.5 feet. All pressure pumps shall be equipped with working pressure gauges.
- Capture all runoff water and dispose of it properly. Do not allow the runoff to collect on unprotected surfaces.