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Historic Preservation - Technical Procedures
Removing Smoke Stains From Brick Masonry
Tech Notes On Brick Construction - 20
Brick Unit Masonry
Removing Smoke Stains From Brick Masonry
REMOVING SMOKE STAINS FROM BRICK MAS= ONRY
THE CLEANING OR REMOVAL OF STAINS FROM MASONRY MAY INVOLVE THE
USE OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH MAY RUN OFF ON
ADJACENT MATERIAL, DISCOLOR THE MASONRY OR DRIVE THE STAINS DEEPER
INTO POROUS MASONRY. USE THE PRODUCTS AND TECHNIQUES DESCRIBED
HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND MASONRY SPECIFIED.
A. This procedure includes guidance on removing smoke stains
from brick masonry.
B. 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 Precaution= s
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).=0CPART 2---= PRODUCTS
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 adequa= te
for stain removal work, and these products should be purchas= ed
when available, as they tend to be less expensive. Com= mon
names are indicated below by an asterisk (*).
A. Scouring powder containing bleach
Alkali detergent or commercial emulsifyi= ng agent.
B. Trichloroethylene (highly refined solvent):
CAUTION: TRICHLOROETHYLENE IS HIGHLY TOXIC AND MAY REACT
WITH STRONG ALKALIS SUCH AS FRESH CONCRE= TE TO FORM
1. Other chemical or common names include Ethinyl
2. Potential Hazards: TOXIC= .
3. Available from automotive supply distributor,
chemical supply house (both commercial and
scientific), dry cleaning supply distributor, paint
store, photographic supply distributor (not camera
shop), or printer's supply distributor.
C. Filler material such as diatomaceous earth or powdered
D. 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 brush
E. Masking tape
3.01 ERECTION, INSTALLATION, APPLICATION
NOTE: WHEN CLEANING, AVOID OVERCLEANING. AIM FOR ACHIEVING
85% CLEAN. MOST DAMAGE OCCURS WHEN ATTEMPTING TO CLEAN THE
NOTE: TEST CLEAN A SMALL AREA BEFORE ATTEMPTING TO CLEAN
A. Scrub the affected area with a stiff bristle brush and
scouring powder containing bleach.
Brush or spray apply an alkali detergent or commercial
B. For small stubborn stains, apply a poultice of
trichloroethylene and inert filler mater= ial.
1. Thoroughly rinse the area to be treated with
2. Mix the liquid solution to be used in a glass or
3. Thoroughly moisten the stained surface with this
liquid. Be sure to dampen well beyond the stain.
4. Mix the remaining liquid with the white absorbent
material to form a paste the consistency of oatmeal
or cake icing. (App= roximately one pound of paste
is needed for every square foot of surface area to
5. Using a wooden or plastic spatula, apply the paste
to the stained surface in layers no more than 1/4
inch thick. The poultice should extend well beyond
the stain to prevent forcing the stain into
previously clean masonry.=
6. Check the coating for air pockets or voids.
7. Cover the poultice with plastic sheeting and seal
with masking tape.
8. Let set for 48 hours (unless otherwise specified).
9. After set period, dampen the poultice with mineral
10. Remove the poultice with a wooden or plastic
spatula to avoid scratchi= ng the surface.
11. Thoroughly rinse the cleaned area with mineral
water, blot with clean towels and allow the surface
12. Repeat the process as necessary to remove any
remaining residue until a desired level of
cleanliness is achieved.<= br>
END OF SECTION