Removing Beverage Stains from Concrete

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 concrete may involve the use of liquids, detergents or solvents that may run off on adjacent material, discolor the concrete or drive the stains deeper into porous concrete. Use the products and techniques described here only for the combinations of dirt/stain and concrete specified.

PART 1---GENERAL

1.01 SUMMARY

  1. This procedure includes guidance on removing beverage stains (such as tea, coffee, soft drinks, beer, wine and liquor) from concrete by scrubbing or by using chemical solvents in the form of a poultice.

  2. Safety Precautions:

    1. Do not save unused portions of stain-removal materials.

    2. Do not store any chemicals in unmarked containers.

    3. Excellent ventilation must be provided wherever any solvent is used. Use respirators with solvent

    4. No use of organic solvents indoors shall be permitted without substantial air movement. Use only spark-proof fans near operations involving flammable liquids.

    5. Provide adequate clothing and protective gear where the chemicals are indicated to be dangerous.

    6. Have available antidote and accident treatment chemicals where noted.

  3. Read "General Project Guidelines" along with this specification. 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 guidelines cover the following sections:

    1. Safety Precautions

    2. Historic Structures Precautions

    3. Submittals

    4. Quality Assurance

    5. Delivery, Storage and Handling

    6. Project/Site Conditions

    7. Sequencing and Scheduling

    8. General Protection (Surface and Surrounding)

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 tend to be less expensive. Common names are indicated below by an asterisk (*).

  1. Materials for Washing:

    1. Commercial Bleach containing 5% Sodium hypochlorite.

    1. -OR-
    1. Javelle Water, Made by User:

      1. See "Making Javelle Water" for guidance on preparation and availability of ingredients.

      2. Javelle water consists of Calcium Hypochlorite (CaCl2O2) and Sodium Carbonate (Na2CO3)

      3. Potential Hazards of Calcium Hypochlorite: CAUSTIC TO FLESH; FLAMMABLE (WHEN IN CONTACT WITH ORGANIC SOLVENTS), TOXIC FROM CONTACT, INHALATION AND INGESTION.

      4. Potential Hazards of Sodium Carbonate: CAUSTIC TO FLESH.

  2. Materials for Poulticing:

    1. Glycerol (C3H8O3):

      1. A sweet syrupy hygroscopic trihydroxy alcohol usually obtained by the saponification of fats and used especially as a solvent and plasticizer.

      2. Other chemical or common names include Glycerine; Glyceryl hydroxide; Glycyl alcohol; 1,2,3-propanetriol; Propenyl alcohol.

      3. Potential Hazards: FLAMMABLE.

      4. Available from chemical supply house, drug store or hardware store.

    2. Isopropyl Alcohol (C3H8O):

      1. A volatile flammable alcohol used especially as a solvent and rubbing alcohol.

      2. Other chemical or common names include Dimethyl carbinol; Isopropanol; 2-propanol.

      3. Available from chemical supply house, dry cleaning supply distributor, drug store, hardware store, paint store or printer's supply distributor.

    3. Cotton wadding

    4. Mineral water

    5. Clean dry towels for blotting the area after treatment

  3. Clean, potable water

  4. Accessible source of water, soap and towels for washing and rinsing in case of emergencies associated with the use of chemicals

2.02 EQUIPMENT

  1. Poulticing Equipment:

    1. Glass or ceramic container for mixing the solution

    2. Wooden utensil for stirring the ingredients

  2. Wood or plastic spatula

  3. Stiff bristle brushes (non-metallic)

PART 3---EXECUTION

3.01 PREPARATION

  1. For safety, provide adequate wash solutions (i.e. water, soap and towels) before starting the job.

  2. Whenever acid is used, the surface of the concrete should be thoroughly rinsed with water as soon as its action has been adequate. Otherwise, the acid will continue etching the concrete even though the stain is gone.

3.02 ERECTION, INSTALLATION, APPLICATION

NOTE: DO NOT TRY MORE THAN ONE TREATMENT ON A GIVEN AREA UNLESS THE CHEMICALS USED FROM PRIOR TREATMENT HAVE BEEN WASHED AWAY.

  1. Wash the Stain:

    1. Using a stiff bristle brush, scrub the surface with hot soapy water and rinse.

    2. If staining remains, scrub with a bleach containing sodium hypochlorite OR with Javelle water.

      1. Before use, dilute 1 part of the commercial solution of laundry bleach (5% sodium hypochlorite) or 1 part of Javelle water with 6 parts of water.

      2. NOTE: DO NOT MIX BLEACH SOLUTION WITH JAVELLE WATER.

    3. Thoroughly rinse the surface with clean water and allow to dry.

    -OR-

  2. Poultice the Stain (for additional guidance on poulticing, see "Removing Unknown Stains from Marble Using a Poultice"):

    1. Mix 1 part glycerol in 4 parts water.

    2. For a faster acting solution, mix 1 part glycerol, 2 parts isopropyl alcohol and 4 parts water.

    3. Soak bandage of cotton wadding in the mixture.

    4. Apply the bandage to the stained surface and allow to dry.

    5. Using a wooden spatula, remove the dried bandage from the surface.

    6. Thoroughly rinse the surface with clean water and allow to dry.

    7. Repeat the process as necessary to achieve the desired level of cleanliness.