Standard Testing Sequence for Removing Unknown Stains from Concrete

Procedure code:
371003G
Source:
Historic Concrete: Investigation & Repair - Pre-Conference Training Course, APT Annual Meeting, 1989.
Division:
Concrete
Section:
Concrete Cleaning
Last Modified:
07/11/2016

STANDARD TESTING SEQUENCE FOR REMOVING UNKNOWN STAINS FROM CONCRETE

PART 1---GENERAL

1.01 SUMMARY

A. These guidelines outline a testing sequence of trial and error techniques that may be used to determine the most effective method of removing unknown stains from concrete.

B. It is important to identify the cause of staining and the nature of the stain as part of selecting the proper removal techniques.

C. For removal of a specific stain type, see the appropriate procedure(s) as listed below:

  1. Aluminum Stains: See 03710-04-S.

  2. Asphalt Stains: See 03710-05-S.

  3. Beverage Stains: See 03710-06-S.

  4. Blood Stains: See 03710-07-S.

  5. Bronze and Copper Stains: See 03710-44-S.

  6. Candy and Confectionery Stains: See 03710-08-S.

  7. Caulking Compound Stains: See 03710-09-S.

  8. Chewing Gum: See 03710-10-S.

  9. Coal Tar Stains: See 03710-12-S.

  10. Creosote Stains: See 03710-13-S.

  11. Curing Compound Stains: See 03710-14-S.

  12. Surface Dirt: See 03710-15-S.

  13. Efflorescence: See 03710-16-S.

  14. Epoxy Coatings and Epoxy Adhesives: See 03710-17-S.

  15. Finishing and Curing Discolorations: See 03710-18-S.

  16. Fire, Smoke, Soot, Pitch and Wood Tar Stains: See 03710-19-S.

  17. Graffiti (paint-based): See 03710-21-S.

  18. Grease Stains: See 03710-01-S.

  19. Gypsum Plaster Stains: See 03710-22-S.

  20. Ink Stains: See 03710-24-S.

  21. Iodine Stains: See 03710-25-S.

  22. Iron Rust Stains: See 03710-26-S.

  23. Mildew Stains: See 03710-28-S.

  24. Moss Stains: See 03710-29-S.

  25. Linseed, Soybean and Tung Oil Stains: See 03710-30-S.

  26. Lubricating and Petroleum Oil Stains: See 03710-31-S.

  27. Old Resilient Flooring Adhesives: See 03710-03-S.

  28. Paint, Shellac and Varnishes: See 03710-32-S.

  29. Perspiration Stains: See 03710-33-S.

  30. Plywood or Joint Sealant Stains: See 03710-34-S.

  31. Tobacco Stains: See 03710-37-S.

  32. Urine Stains: See 03710-38-S.

  33. Wood Stains: See 03710-42-S.

PART 2---PRODUCTS

2.01 MATERIALS

A. See individual procedures for specific solvents, bleaches and acids that may be used in stain removal.

B. Clean, potable water

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

2.02 EQUIPMENT

A. Nylon bristle brushes (metallic brushes should not be used)

PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

A. If the type of stain cannot be identified, conduct tests in an inconspicuous area.

B. If a particular stain type is suspected, begin by using simple cleaning techniques as outlined in item C. below. If this fails, then proceed to item D. and use solvents or bleaches judiciously selected for removal of those materials believed to be causing the discoloration.

C. Always start with the mildest method of cleaning and proceed to stronger methods. Use small test patches until a satisfactory surface is restored. Use materials in the following sequence:

  1. Water with soft brushes

  2. Water with mild soap

  3. Water with stronger soap

  4. Water with stronger soap plus ammonia

  5. Water with stronger soap plus vinegar. Note: Only after trying these methods in this sequence should one proceed to stronger chemical cleaners as outlined below.

D. If the nature of the stain is completely unknown, begin testing various agents on inconspicuous areas of stained concrete in the following sequence until an effective method is determined.

  1. Organic Solvents

  2. Oxidizing bleaches, like those based on peroxides or hypochlorites. Avoid using any colored oxidizing agent like potassium permanganate which might impart additional color to the stain.

  3. Reducing bleaches, some of which are used in an acidic medium

  4. Acids and other acidic materials

 

END OF SECTION

Last Reviewed 2016-07-11