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.
PREFACE: The cleaning or removal of stains from tile involves 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.
PART 1–GENERAL
1.01 SUMMARY
- This procedure includes guidance on the routine cleaning and removal of miscellaneous stains from ceramic tile including mildew, blood, ink and beverages. This procedure may be used on both glazed or unglazed tiles.
- 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 before doing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).
PART 2–PRODUCTS
2.01 MATERIALS
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 for stain removal work, and these products should be purchased when available, as they may be less expensive. Common names are shown below by an asterisk (*).
- All-purpose cleaner such as “Mr. Clean,” “Top Job,” “Fantastik,” “Lestoil,” or equivalent.
- Commercial cleaner such as “Tilex,” or equivalent.
- White vinegar
- Non-abrasive household scouring agent such as “Ajax Liquid,” “Liquid Comet,” or “Bon Ami,” or equivalent.
- Undiluted neutral soap such as “Ivory”, “Joy” or equivalent.
- Household bleach:
CAUTION: Do not mix ammonia with chlorine bleaches, a poisonous gas will result! Do not use bleach on bird droppings.- Other chemical or common names include Sodium Hypochlorite; Bleaching solution*; Laundry bleach*; Solution of chlorinated soda*.
- Potential Hazards: Caustic to Flesh
- Available from chemical supply house, grocery store or supermarket, hardware store or janitorial supply distributor.
- Trisodium Phosphate: NOTE: this chemical is banned in some states such as california. Regulatory information and alternate or equivalent chemicals may be requested from the Environmental Protection Agency (EPA regional office and/or the state office of environmental quality.)
- Strong base-type powdered cleaning material sold under brand names.
- Other chemical or common names include Sodium
- Orthophosphate; Tribasic sodium phosphate;
- Trisodium orthophosphate; TSP*; and Phosphate of soda*.
- Potential Hazards: CORROSIVE TO FLESH.Available from chemical supply house, grocery store or supermarket or hardware store.
- Laundry detergent
- Clean, potable water
2.02 EQUIPMENT
- Clean natural fiber rags, or sponges
- Nylon scouring pad
- Stiff bristle brushes (no iron wire)
PART 3–EXECUTION
3.01 EXAMINATION
- Examine the ceramic tile surface carefully to detect the type and cause of staining before proceeding with any cleaning operation.
3.02 ERECTION, INSTALLATION, APPLICATION
- For Periodic Cleaning:
- Wipe tiles with a damp sponge and all-purpose cleaner.
-OR- - Spray on “Tilex” following manufacturers’ instructions.
OR- - Wipe tiles with a 50/50 solution of white vinegar in water.
- Wipe tiles with a damp sponge and all-purpose cleaner.
- For More Persistent Dirt Build-up:
- Scrub the surface with a nonabrasive household scouring agent.
-OR- - Scrub the surface with an all-purpose cleaner and a nylon scouring pad
- Scrub the surface with a nonabrasive household scouring agent.
- For Neglected Tile Surfaces:
- Coat tile with an undiluted neutral soap.
- Allow to dry and stand for several hours.
- Mix additional soap with warm water and wipe over the tile surface.
- Sprinkle the surface with scouring powder and scrub with a stiff bristle brush.
- Thoroughly rinse the surface with clean, clear water and a sponge.
- Dry with a clean, soft cloth or towel.
- For Mildew or Other Miscellaneous Stains:
- Mix 1 qt. household bleach, 3 qts. water, 3 oz. TSP and 1 oz. detergent.
- Scrub mixture into the surface using a stiff bristle brush or nylon scrubbing pad.
- Follow by scrubbing with a scouring powder.
- Rinse thoroughly with clean, clear water and dry with a clean, soft cloth or towel.