Removing Dirt From Brick Masonry
- Procedure code:
- Tech Notes On Brick Construction - 20
- Brick Unit Masonry
- Last Modified:
REMOVING DIRT FROM BRICK MASONRY
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 THE POROUS MASONRY. USE THE PRODUCTS AND TECHNIQUES
DESCRIBED HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND MASONRY
A. This procedure includes guidance on cleaning brick
masonry to remove accumulations of surface dirt.
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 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).
A. Diedrich Chemicals Restoration Technologies, Inc.
7373 S. 6th Street
Oak Creek, Wisconsin 53154
414/764-0058 or 800/323-3565
B. ProSoCo Inc.
755 Minnesota Avenue
P.O. Box 1578
Kansas City, KS 66117
C. Red Devil, Inc.
2400 Vauxhall Road
Union, NJ 07083
201/688-6900 or 800/423-3845
A. For Light Dirt:
1. Trisodium Phosphate:
NOTE: THIS CHEMICAL IS BANNED IN SOME STATES SUCH
AS CALIFORNIA. REGULATORY INFORMATION AS WELL AS
ALTERNATIVE OR EQUIVALENT CHEMICALS MAY BE
REQUESTED FROM THE ENVIRONMENTAL PROTECTION AGENCY
(EPA) REGIONAL OFFICE AND/OR THE STATE OFFICE OF
a. Strong base-type powdered cleaning material
sold under brand names.
b. Other chemical or common names include Sodium
Orthophosphate; Tribasic sodium phosphate;
Trisodium orthophosphate; TSP*; Phosphate of
soda*; (also sold under brand names such as
c. Potential Hazards: CORROSIVE TO FLESH.
d. Available from chemical supply house, grocery
store or supermarket or hardware store.
2. Laundry detergent
B. For Heavy Dirt:
1. Muriatic acid (generally available in 18 degree and
20 degree Baume solutions):
CAUTION: DO NOT USE MURIATIC ACID ON LIGHT COLORED
BRICK AS THEY ARE MORE SUSCEPTIBLE TO "ACID BURN"
THAN DARKER BRICKS.
a. A strong corrosive irritating acid.
b. Other chemical or common names include
Chlorhydric acid; Hydrochloric Acid (30-35%):
Hydrogen chloride; Marine acid*; Spirit of
salt*; Spirit of sea salt*.
c. Potential Hazards: TOXIC, CORROSIVE TO FLESH;
CORROSIVE TO CONCRETE, STEEL, WOOD OR GLASS,
d. Available from chemical supply house,
drugstore or pharmaceutical supply
distributor, or hardware store.
Commercial Cleaning Compound such as "Sure Klean
Restoration Cleaner" (ProSoCo, Inc.), or approved equal.
C. For Rough-textured Brick:
1. Oxalic acid (COOH)2 or (H2C2O4):
a. A poisonous strong acid that occurs in various
plants as oxalates and is used especially as a
bleaching or cleaning agent and in making
b. Other chemical or common names include
c. Potential Hazards: TOXIC; CORROSIVE TO
CONCRETE, STEEL, WOOD OR GLASS.
d. Available from chemical supply house, 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.)
D. White vinegar or commercial neutralizer such as "Sure
Klean Masonry Restorer" (ProSoCo, Inc.), 101 Masonry
Restorer/Cleaner (Diedrich Chemicals), or approved equal.
E. Clean, potable water
A. Non-metallic container
B. Stiff bristle brush
C. Wooden or other non-metallic scraper
3.01 ERECTION, INSTALLATION, APPLICATION
NOTE: WHEN CLEANING, AVOID OVERCLEANING. AIM FOR ACHIEVING
85% CLEAN. MOST DAMAGE OCCURS WHEN ATTEMPTING TO CLEAN THE
NOTE: BEGIN CLEANING BY USING THE GENTLEST METHOD POSSIBLE.
TEST CLEAN A SMALL AREA BEFORE ATTEMPTING TO CLEAN LARGE
A. Mix solution or cleaner:
1. For light dirt: Mix 1/2 cup (0.14 L) trisodium
phosphate and 1/2 cup (0.14 L) laundry detergent in
1 gallon (3.79 L) clean, clear water.
2. For heavy dirt: Mix 9 parts clean water with 1
part muriatic acid in a non-metallic container.
POUR ACID INTO WATER NOT THE REVERSE.
CAUTION: DO NOT ALLOW METAL TOOLS TO COME IN
CONTACT WITH THE ACID. DO NOT MIX THE ACID
SOLUTION STRONGER THAN RECOMMENDED AS A STRONGER
CONCENTRATION MAY STAIN THE MASONRY SURFACE.
Try using a commercial cleaning compound suitable
for use on brick (follow manufacturer's recommended
dilution and application instructions).
3. For rough-textured brick: Mix 1 lb (0.45 kg)
oxalic acid crystals with 1 gallon (3.79 L) of
B. Apply the solution to the brick and scrub the surface
using a stiff bristle brush. Allow the solution to
remain on the brick for 5 to 10 minutes or as recommended
by manufacturer (if proprietary product is used).
C. Use a wooden scraper to remove heavy crusts as necessary.
DO NOT USE METAL SCRAPERS OR CHISELS AS METAL MARKS LEFT
ON THE BRICK WILL OXIDIZE AND CAUSE STAINING.
D. Thoroughly rinse the surface with clean, clear water and
allow to dry.
E. Repeat the process as necessary to achieve the desired
level of cleanliness.
F. If acid or commercial cleaner is used, neutralize the
surface using white vinegar or a proprietary chemical
neutralizer. A neutral pH (7 pH) should be achieved.
1. Allow neutralizer to stand on wall about three
minutes before rinsing. DO NOT LET IT DRY!
2. Thoroughly rinse the surface with clean, clear
3. Test the pH with litmus paper or phenolphthalein:
a. Dissolve a 2" piece of phenolphthalein in
b. Brush the solution onto the surface. If it
turns a shade from pink to magenta there is
still chemical residue.
4. Continue to neutralize the surface and test until
there is no color change in the phenolphthalein
solution or the litmus paper registers neutral.
END OF SECTION