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.
PREFACE: The cleaning or removal of stains from tile may involve the use of liquids, detergents or solvents which may run off on adjacent material, discolor the tile or drive the stains deeper into porous tile. Use the products and techniques described here only for the combinations of dirt/stain and tile specified.
- This procedure includes guidance on removing grease stains from ceramic tile.
- See "General Project Guidelines" 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).
- The Procter & Gamble Co.
NOTE: Chemical products are sometimes sold under a common name. This usually means that the substance is not as pure as the same chemical sold under its chemical name. The grade of purity of common name substances, however, is usually adequate when available, as they tend to be less expensive. Common names are indicated below by an asterisk (*).
- Sodium Carbonate (Na2CO3):
- A sodium salt of carbonic acid used especially in making soaps and chemicals, in water softening, in cleaning and bleaching and in photography; A hygroscopic crystalline anhydrous strongly alkaline salt.
- Other chemical or common names include Carbonate of soda*; Sal soda*; Soda*; Soda ash*; Washing soda*.
- Potential Hazards: CAUSTIC TO FLESH
- Available from chemical supply house, grocery store or supermarket, hardware store, paint store or water and sanitation supply distributor.
- Sodium Hydroxide (NaOH): (as alternative)
- A white brittle solid that is a strong caustic base used especially in making soap, rayon, and paper.
- Other chemical or common names include Caustic soda*; Hydrate of soda*; Hydrated oxide of sodium*; Lye*; Mineral alkali*; Soda lye*; Sodic Sodium hydrate*.
- Potential Hazards: CAUSTIC TO FLESH AND FLAMMABLE (WHEN IN CONTACT WITH ORGANIC SOLVENTS).
- Available from chemical supply house, drugstore or pharmaceutical supply distributor, hardware store, or paint store.
- Neutral pH Detergent such as "Orvus" (Procter and Gamble), or approved equal, using dilution as determined by tests on material to be cleaned.
- Clean, potable water
- Clean natural fiber rags
- Garden hose and pneumatic spray nozzle
- Stiff bristle brushes (no iron wire)
- Wood scrapers, knife blades and spatulas
- Examine the ceramic tile surface carefully to determine the type and cause of staining before proceeding with any cleaning operation.
3.02 ERECTION, INSTALLATION, APPLICATION
- Mix 10% sodium carbonate in water (use 5% sodium hydroxide or caustic soda if required).
- Wash the surface with the solution using a stiff bristle brush; Allow the mixture to remain on the surface for approximately 1 hour.
- Rinse thoroughly with clean, clear water and allow to dry.
- Repeat the process as required to achieve the desired level of cleanliness.