Historic Preservation - Technical Procedures
- Removing Chewing Gum From Concrete
- Procedure code:
- Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989
- Concrete Cleaning
- Last Modified:
- Removing Chewing Gum From Concrete
- Last Modified:
REMOVING CHEWING GUM 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 chewing gum
and its residual staining left on concrete using freezing
agents and chemical solvents.
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
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 (*).
Aerosol Freezing Agents
B. Use one of the following solvents in a poultice (see
Section 3.02 below for related procedures):
1. Other chemical or common names include Methylated
2. Potential hazards: TOXIC AND FLAMMABLE.
3. Available from hardware store, paint store or
printer's supply distributor.
4. Denatured alcohol, which carries no liquor tax,
should be a satisfactory substitute for ethyl
alcohol for stain removing purposes.
1. A colorless volatile heavy toxic liquid with an
ether odor used especially as a solvent or as a
2. Other chemical or common names include Methylene
3. Potential Hazards: CARCINOGEN; TOXIC: INHALATION, CONTACT AND INGESTION; IF IT DECOMPOSES FLAMABLE.
4. Available from chemical supply house, dry cleaning
supply distributor, drugstore or pharmaceutical
supply distributor, or paint store.
C. Filler material such as whiting, diatomaceous earth or
D. Mineral water
E. Clean dry towels for blotting the area after treatment
F. Clean, potable water
G. Accessible source of water, soap and towels for washing
and rinsing in case of emergencies associated with the
use of chemicals
A. For Poulticing:
1. Glass or ceramic container for mixing the solution
2. Wooden utensil for stirring the ingredients
B. Wood or plastic spatula
C. 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. Use a manufactured freezing agent or ice to make the gum
brittle and easier to remove.
B. Scrape off as much gum as possible using a wood or
C. To remove any residual staining, apply a poultice made
with denatured alcohol or chloroform (see Section 2.01 above).
1. Mix whiting material from Section 2.01 with
denatured alcohol to create a thick paste. Select
the amount of whiting or filler material to make a
poultice of the required size. Add denatured
alcohol to obtain the proper paste-like
2. Thoroughly wet the concrete surface to be treated
with clean, clear water.
3. Apply the 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.
4. When the poultice has dried, brush or scrape it off
with a wooden scraper.
5. Wash the surface thoroughly with hot water
containing sodium orthophosphate.
6. Thoroughly rinse the area with clean, clear water
and allow to dry.
7. Repeat the process as necessary to sufficiently
remove the stain.
D. If treatment with denatured alcohol does not sufficiently
remove the stain, try poulticing with chloroform, carbon
disulfide or carbon tetrachloride (follow procedures for
Section 3.02 C.1-7. above).
END OF SECTION