General Cleaning Of Granite
- Procedure code:
- Hsr - Interior Building, Washington, Dc, 1988
- Last Modified:
GENERAL CLEANING OF GRANITE
A. This procedure includes guidance on the removal of
surface dirt and environmental pollution from exterior
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).
C. For precautions relating to pressure washing, see 04510-04-S.
A. Diedrich Technologies, Inc.
B. ProSoCo, Inc.
A. Commercial masonry cleaner with a maximum 4% acid
concentration, surfactants and wetting agents such as
"Sure Klean Restoration Cleaner" - undiluted (ProSoCo,
Inc.), or "Diedrich 101G Granite, Terracotta and Brick
Cleaner" - diluted 1:4 to achieve a maximum 4% acid
concentration (Diedrich Technologies, Inc.), or approved
B. Clean, potable water
A. Pressure water rinsing equipment (measuring between 100
and 400 psi for low-pressure; between 400 and 800 psi for
B. Fan-type spray tips (15 degree fan spray)
C. Stiff bristle brushes (non-metallic)
D. Plastic spatula
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
NOTE: DO NOT TREAT THE SURFACE WITH ACID CLEANER MORE THAN
A. Saturate the granite with clean, warm water sprayed at a
low pressure (between 100 and 400 psi). Remove bird
excrement and debris from granite prior to the
application of acidic granite cleaner (see 04510-02-R for
B. Spray-apply cleaner evenly to the stained surface at 125
psi. or as recommended by manufacturer, or brush-apply
cleaner using a soft fiber bristled brush.
C. Allow cleaner to stand on the surface for 3-5 minutes or
as recommended by manufacturer.
D. Thoroughly rinse the surface with clean, clear water at
medium pressure (between 400 and 800 psi). Nozzle should
be held between 18 and 30 inches from the surface. Stone
should be left clean without streaking or staining.
END OF SECTION