General Cleaning Of Exterior Polished And Honed Granite

Procedure code:
National Capitol Region Specifications
Last Modified:



1.01     SUMMARY

        A.   This procedure includes guidance on cleaning exterior
             polished and honed granite.

        B.   Safety Precautions:
             1.   The work specified herein requires knowledge of
                  older materials and methods and a high degree of
                  skill to execute properly.  This work should be
                  performed only by an experienced, pre-qualified
                  contractor.  It is not recommended that building
                  maintenance personnel perform this work.
             2.   This outline specification contains recommended
                  materials which may be toxic.  The manufacturer s
                  literature on application techniques, appropriate
                  protection for workers and disposal procedures for
                  materials should be complied with in conjunction
                  with all regulatory requirements referenced in this
        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

             3.   Submittals

             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.   Product Data:
             1.   Submit manufacturer's technical data for each
                  product indicated including recommendations for
                  their application and use to the Contracting
                  Officer or the designated representative.  Include
                  test reports and certifications substantiating that
                  products comply with requirements.
             2.   Prior to commencing the cleaning operations, submit
                  to the Contracting Officer or the designated
                  representative a written description of the
                  materials, methods, and equipment proposed for
                  cleaning each type of masonry included in the work
                  of this section including, but not limited to:
                  cleaning products and chemical components, method
                  of application, dilution of application,
                  temperature of application, length of time of
                  surface contact, method of rinsing surface
                  (temperature, pressure, and duration), repetition
                  of procedures, etc.
             3.   Protection Program:  Prior to commencing the
                  cleaning operations, the Contractor shall submit to
                  the Contracting Officer or the designated
                  representative for approval, a written description
                  of proposed materials and methods of protection for
                  preventing damage to adjacent materials, vehicular
                  and pedestrian traffic, and the building interior
                  during the cleaning of stone.

        B.   Samples:
             1.   Prior to the start of masonry cleaning, prepare for
                  approval a sample panel, approximately 3 x 3 feet in
                  area, on each type of masonry included in the work
                  where directed by the Contracting Officer or the
                  designated representative.
             2.   Adjust the chemical concentrations, working
                  pressures and methodologies during test panel
                  cleaning, as directed by the Contracting Officer s
             3.   Clean sample panels using methods, materials, and
                  working pressures previously submitted and
                  approved. Perform sample panel cleaning in the
                  presence of the Contracting Officer or the
                  designated representative.
             4.   Where chemical cleaners and poultices are tested,
                  perform testing in the presence of the
                  manufacturer's representative.
             5.   Obtain written approval from the Contracting
                  Officer or the designated representative of
                  cleaning methods, working pressures, materials,
                  equipment used and sample panels before proceeding
                  with building cleaning operations. Allow a minimum
                  of seven calendar days after completion of sample
                  cleaning to permit study of sample panels for
                  negative reactions.  Retain approved panels in
                  unaltered condition, suitably designated during
                  construction as a standard for judging completed


        A.   Qualifications:
             1.   The objective of stone cleaning is to remove
                  soiling, stains and crusts from the granite without
                  damaging underlying material and to give all stone
                  a clean, uniform appearance without blotches,
                  streaks, or other irregularities.  Use the gentlest
                  means to meet the cleaning objective.
             2.   Cleaning Standard:  Prepare sample panels for
                  approval which shall establish a standard for
                  general stone and brick cleaning.  Cleaning shall
                  not commence until written approval is obtained for
                  sample panels and submittals from the Contracting
                  Officer or the designated representative.

        B.   Regulatory Requirements:  Comply with municipal and
             Federal regulations governing the cleaning, chemical
             waste disposal, scaffolding protection to adjacent
             properties and workers.


        A.   Environmental Requirements:
             1.   No cleaning shall be executed when air or masonry
                  surface temperature is below 45 degrees F, unless adequate,
                  approved means are provided for maintaining a 45 degrees F,
                  temperature of the air and materials during, and
                  for 48 hours subsequent to, cleaning.
             2.   Perform cleaning and rinsing of the exterior
                  masonry only during daylight hours.



        A.  ProSoCo, Inc.

        B.  Chemique, Inc.

        C.  Diedrich Technologies, Inc.
2.02     MATERIALS

        A.   Detergent:  Commercially available surface active liquid
             cleansing agent specifically formulated for cleaning
             masonry, such as "Ion 417" (Chemique Inc.), or
             approved equal.
        B.   Liquid Strippable Masking Agent:  Manufacturer's standard
             liquid, film forming, strippable masking material for
             protecting glass, metal and polished stone surfaces from
             damaging effect of acidic and alkaline masonry cleaners,
             such as "Sure Klean Strippable Masking" (ProSoCo, Inc.), "Diedrich
             Acid Guard" (Diedrich Technologies, Inc.), or approved

        C.   Water:  Potable, non-staining and free of oils, acids,
             alkalis and organic matter .

2.03     EQUIPMENT

        A.   Brushes:  Natural fiber bristle only.  The use of wire
             brushes or steel wool is not permitted.

        B.   Garden hose with fan tip nozzles



        A.   Protection:

             1.   Take all necessary precautions and measures to
                  protect surrounding materials on the site, surfaces
                  of the building not being cleaned, adjacent
                  buildings, pedestrians and vehicles from coming in
                  contact with cleaning chemicals, over spray, or
                  runoff.  Products used for masonry cleaning may be
                  harmful to painted, polished, glazed, or metallic
                  surfaces.  Any damage to materials caused by the
                  cleaning operations is unacceptable and shall be
                  repaired or replaced by the Contractor to the
                  satisfaction of the Contracting Officer or the
                  designated representative at no cost to the
             2.   Provide protection from water damage to building,
                  structure, or building contents as required.
             3.   Protect trees and plants around the building from
                  contamination or damage. The Contractor shall be
                  responsible for replacing with new stock, any
                  trees, shrubbery or grass damaged by the cleaning
             4.   Test all drains and other water removal systems to
                  assure that drains and systems are functioning
                  properly prior to performing any cleaning
                  operations.  Notify Contracting Officer or the
                  designated representative immediately of any and
                  all drains or systems that are found to be stopped
                  or blocked.  Contractor shall repair drains if so
                  directed by the Contracting Officer or the
                  designated representative.  Do not begin work of
                  this Section until the drains are in working order.
             5.   Provide a method to prevent solids such as stone or
                  mortar residue from entering the drains or drain
                  lines. Contractor shall be responsible for cleaning
                  out drains and drain lines that become blocked or
                  filled by sand or other solids because of work
                  performed under this Contract.


        A.   Dilute detergent with 3 parts water to 1 part
             concentrate, or use appropriate dilution as determined by
             field testing.
        B.   Brush apply to granite, scrub for 10 minutes with stiff
             bristle brushes.
        C.   Rinse the treated area thoroughly using pressurized cold
             water, not exceeding 300 psi, sprayed through nozzles
             fitted with 15 to 20" wide tips.  Nozzles shall be held
             perpendicular to the surface at a working distance of 1.4
             to 2.0 feet. All pressure pumps shall be equipped with
             working pressure gauges.              
        D.   Rinse from the bottom of the treated area to the top
             flushing each section of the surface with a concentrated
             stream of water.  To avoid streaking on vertical walls,
             take care to keep the wall below wet and rinsed free of
             cleaner and residues.
        E.   The surfaces below the sections of brick to be cleaned
             shall be protected from run-off.
        F.   Repeat procedures if necessary to remove heavier build-up
             of soiling.

                         END OF SECTION

Last Reviewed 2014-12-23