Historic Preservation - Technical Procedures
Removing Creosote Stains From Concrete
Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989
Removing Creosote Stains From Concrete
REMOVING CREOSOTE STAINS FROM CONCRETE
THE CLEANING OR REMOVAL OF STAINS FROM CONCRETE MAY INVOLVE THE
USE OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH 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.
A. This procedure includes guidance on removing creosote
staining from concrete using a poultice containing
B. Safety Precautions:
1. DO NOT save unused portions of stain-removal
2. DO NOT store any chemicals in unmarked containers.
3. EXCELLENT VENTILATION MUST BE PROVIDED WHEREVER ANY
SOLVENT IS USED. USE RESPIRATORS WITH SOLVENT
NOTE: SOME OF THE SOLVENTS LISTED ARE KNOWN
CARCINOGENS AND MAY BE BANNED IN SOME STATES.
4. No use of organic solvents indoors should be
allowed without substantial air movement. Use only
spark-proof fans near operations involving
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.
C. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. 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).
D. For additional information on poulticing, see 04455-02-R.
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 (*).
A. Benzene (C6H6):
1. A colorless, volatile, flammable, toxic, liquid,
aromatic hydrocarbon used in organic synthesis, as
a solvent and as a motor fuel.
2. Other chemical or common names include Benzol;
Benzole; Phene; Phenyl hydride; Coal naphtha*;
3. Potential Hazards: FLAMMABLE.
4. Available from automotive supply distributor,
chemical supply house, dry cleaning supply
distributor, hardware store or paint store.
5. Benzene and benzine should not be confused.
Benzene is a distinct chemical compound obtained
from coal tar. Benzine is a mixture of aromatic
hydrocarbons of similar boiling points derived from
B. Filler material such as hydrated lime, talc or whiting
C. Mineral water
D. Clean dry towels for blotting the area after treatment
E. Scouring powder
F. Clean, potable water
A. Glass or ceramic container for mixing the solution
B. Wooden utensil for stirring the ingredients
C. Wood or plastic spatula
D. Stiff bristle brushes (non-metallic)
1. Provide adequate wash solutions (i.e. water, soap
and towels) before starting the job.
2. Whenever acid is used, the surface should be
thoroughly rinsed with water as soon as its action
has been adequate. Otherwise it 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
A. Mix a poultice by selecting the quantity of hydrated
lime, powdered talc or whiting needed to cover the
affected area. Add Benzene and mix to form a thick
B. Thoroughly wet the concrete surface to be treated with
clean, clear water.
C. Apply the poultice mixture to the stained area using a
wood or plastic spatula and allow to dry. Be sure to
spread the poultice well beyond the stained area. The
liquid portion of the paste will migrates into the
concrete where it will dissolve some of the staining
material. Then the liquid will gradually move back
beyond the concrete surface and into the poultice, where
it will evaporate, leaving the dissolved staining
material in the poultice.
D. When the poultice has dried, brush or scrape it off with
a wooden scraper.
E. Using a stiff bristle brush, scrub the surface with
scouring powder and clean water to remove any residual
F. Thoroughly rinse the area with clean, clear water and
allow to dry.
G. Repeat the process as necessary to sufficiently remove
END OF SECTION