Removing Exfoliated Granite
- Procedure code:
- National Capitol Region Specifications
- Last Modified:
REMOVING EXFOLIATED GRANITE
A. This procedure includes guidance on removing exfoliation
from granite surfaces.
NOTE: THE INTENT OF THIS PROCEDURE IS NOT TO REFINISH OR
BRIGHTEN THE GRANITE; RATHER, IT IS TO REMOVE LOOSE
MATERIAL THAT OTHERWISE WOULD RETAIN DIRT AND MOISTURE.
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).
1.03 QUALITY ASSURANCE
1. Contractor performing the work shall have a minimum
of 5 years experience in masonry restoration work
of the type described for this project.
2. If requested by the Owner, furnish a statement of
the experience and qualifications of the firm and
of the key personnel who will work on this project.
Include the names and addresses of successful
projects completed, and for each, the name and
address of the owner and the architect.
B. Reference Standards:
1. Secretary of the Interior's "Standards for
2. Preservation Brief No. 1, "The Cleaning and
Waterproofing of Historic Masonry Buildings".
C. Test Panels: Each alternative method for each type of
A. Clean, potable water
B. Weathered or dry-grit blasted flat block of granite or
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 (25 degree fan spray)
C. Stiff fiber-bristle brushes
3.01 ERECTION, INSTALLATION, APPLICATION
A. General rinsing of granite surface: Maximum 800 PSI, 5-
10 GPM, 25 fan angle, not less than 6" from surface, at
an angle of 45 to 90 from wall surface. Take special
care to protect all adjacent materials not intended for
abrasive treatment, such as polished granite, wood or
NOTE: IF WATER SOAKING AND PRESSURE RINSE SATISFACTORILY
REMOVE FRIABLE SURFACE MATERIAL LOOSENED BY SALT
CRYSTALLIZATION, THE FOLLOWING PROCEDURE MAY NOT BE
B. Removal of exfoliated granite material: If required to
remove all loose material, rub granite surface with a
weathered or dry-grit blasted flat block of granite or
END OF SECTION