Spot Cleaning Stains on Wood Floors

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

  1. This specification provides guidance on removing dark spots, white marks, grease and oil stains, mold or mildew, and wax or chewing gum from wooden floors.

  2. 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. Steel wool pads (Fine Grade 000).

  2. Mineral Spirits:

    1. A petroleum distillate that is used especially as a paint or varnish thinner.

    2. Other chemical or common names include Benzine* (not Benzene); Naphtha*; Petroleum spirits*; Solvent naphtha*.

    3. Potential Hazards: TOXIC AND FLAMMABLE.

    4. Safety Precautions:

      1. AVOID REPEATED OR PROLONGED SKIN CONTACT.

      2. ALWAYS wear rubber gloves when handling mineral spirits.

      3. If any chemical is splashed onto the skin, wash immediately with soap and water.

    5. Available from construction specialties distributor, hardware store, paint store, or printer's supply distributor.

  3. Sealer.

  4. Solvent-based floor wax.

  5. Household Vinegar:

    1. Potential Hazards: CORROSIVE TO CONCRETE, STEEL, WOOD AND GLASS.

    2. Available from grocery store or supermarket.

    3. Vinegar contains about 4% acetic acid and may be suitable for some purposes requiring acetic acid.

  6. Household bleach:

    1. Other chemical or common names include bleaching solution*, laundry bleach*, sodium hypochlorite (NaOCl) and solution of chlorinated soda*.

    2. Potential Hazards: CAUSTIC TO FLESH.

    3. Available from chemical supplier, grocery store or supermarket, hardware store or janitorial supply distributor.

  7. Oxalic acid, aka (COOH)2 or C2H2O4:

    1. A poisonous strong acid that occurs in various plants as oxalates and is used especially as a bleaching or cleaning agent and in making dyes.

    2. Other chemical or common names include dibasic acid, ethanedioic acid, acid of sugar*.

    3. Potential Hazards: TOXIC; CORROSIVE TO CONCRETE, STEEL, WOOD AND GLASS.

    4. Available from chemical supplier, dry cleaning supply distributor, drugstore or pharmaceutical supply distributor, hardware store, or photographic supply distributor (not camera shop). (Often sold under a manufacturer's brand name; the chemical name may appear on the label.)

  8. Paper towels and clean, soft cotton cloths.

  9. Plastic bags.

  10. Ice cubes.

  11. Clean, potable water.

2.02 EQUIPMENT

  1. Industrial-sized floor buffer.

  2. Plastic spatula.

PART 3---EXECUTION

3.01 PREPARATION

  1. Protection:

    1. Carefully read manufacturer s instructions for any chemical to be used for cleaning. Follow recommendations for safety and handling as well as application.

    2. Be sure to provide adequate ventilation when using solvents.

  2. Surface Preparation: ALWAYS test selected method of cleaning on a small area before beginning the actual job.

3.02 ERECTION, INSTALLATION, APPLICATION

NOTE: USE CAUTION WHEN USING SCOURING POWDER AS IT CAN PERMANENTLY SCRATCH WOOD FLOORS. DO NOT USE WATER-BASED CLEANING SOLUTIONS OR CLEANERS THAT REQUIRE RINSING WITH WATER. USE A SOLVENT OR SOLVENT-BASED CLEANING WAX.

  1. For Dark Spots:

    1. Rub area with steel wool and mineral spirits.

    2. Then, wet a rag with household vinegar and apply to the stain. Allow to sit on dark spot for a few minutes.

    3. Repeat this process if it seems to lighten the stain.

    4. If the spot does not lighten, mix a 50/50 solution of household bleach and water and apply to the stain.

    5. If the spot still does not lighten, then apply oxalic acid to the center of the spot. Avoid getting bleach on the surrounding wood. Several applications may be necessary.

    6. When the spot has disappeared, neutralize the bleach with vinegar and allow to dry. Sand, stain and refinish to match the original color.

  2. For White Water Marks:

    1. White marks are usually a stain in the finish, not in the wood.

    2. Rub the mark with very fine steel wool and apply paste wax.

  3. For Grease and Oil Stains:

    1. Blot stain with clean towels.

    2. Saturate stain with dry cleaning fluid. Check appearance every few minutes.

  4. For Mold or Mildew:

    1. Wipe area with rag soaked in household bleach.

    2. Provide adequate ventilation in future to eliminate damp, stagnant air conditions that can result in the growth of mold and mildew.

  5. For Wax or Chewing Gum:

    1. Put ice cubes in a plastic bag and place on top of the wax or chewing gum. Allow it to sit for a few minutes.

    2. When the material has hardened, scrape it away with a plastic spatula and recoat the floor with floor polish.

3.03 ADJUSTING/CLEANING

Upon completion of stain removal, rinse the area thoroughly, and allow to dry. Repair any areas where finish has been removed.