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Historic Preservation - Technical Procedures

Spectitle:

Removal Of Ferrous Staining From Brick, Granite, Concrete And Limestone

Procedure code:

0420008R

Source:

National Capitol Region Specifications - Cohen Building

Division:

Masonry

Section:

Unit Masonry

Last Modified:

02/24/2012

Details:

Removal Of Ferrous Staining From Brick, Granite, Concrete And Limestone



REMOVAL OF FERROUS STAINING FROM BRICK, CONCRETE AND LIMESTONE


PART 1--- GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on removing ferrous
         staining from exterior brick, concrete and limestone
         surfaces.

         1.   Remove soiling, stains and crusts from the
              limestone and 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.   If the exterior masonry has been previously
              subjected to inappropriately harsh and uneven
              cleaning, it is expected that the cleaning will
              reveal the original colors and textures of the
              brick, but that it will not completely correct the
              differential effects of the previous cleaning.
              Clean brick to remove soiling, stains and crusts to
              the extent feasible without further damaging the
              brick.

    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

         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).  


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Diedrich Chemicals Restoration Technologies, Inc.
         300A East Oak Street
         Oak Creek, WI  53154
         414/764-0058 or 800/323-3565

    B.   ProSoCo, Inc.
         755 Minnesota Avenue
         P.O. Box 1578
         Kansas City, KS  66117
         800/255-4255 or 913/281-2700

2.02 MATERIALS

    A.   Ferrous-Based Stain Remover: Commercially available
         liquid stain removing compound made up of blended organic
         acids in combination with special chelating and wetting
         agents specifically formulated for treatment and removal
         of metallic oxides from masonry, such as "Sure Klean
         Ferrous Stain Remover" (ProSoCo, 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 Acid Stop" (ProSoCo, Inc.), "Diedrich
         Acid Guard" (Diedrich Chemicals), or approved equal.

    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.


PART 3---EXECUTION

3.01 PREPARATION

    A.   Protection:  Protect the surfaces below the sections of
         masonry to be cleaned of ferrous stains from run-off
         using liquid strippable masking agent.

    B.   Surface Preparation:

         1.   Commence ferrous stain removal immediately after
              general cleaning of masonry (see 03710-15-R, 04211-
              04-R, and 04460-03-R for guidance on the general
              cleaning of concrete, brick and limestone
              respectively).

         2.   Proceed from the top of the wall downward. Work
              shall not be considered complete until the
              Contracting Officer's representative has so
              notified the Contractor in writing.

         3.   Filter the water with a 5 micron particulate filter
              placed in line with the water supply. Replace the
              filter as needed during the work.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Prewet wall with clean, clear water immediately before
         applying ferrous-based stain remover.

    B.   Apply ferrous-based stain remover with natural fiber
         bristle brush. Allow to dwell on the surface for three to
         five minutes.

    C.   Rinse all traces of chemical and residue with pressurized
         cold water. Repeat procedure if necessary. Rinse water
         pressure shall not exceed 300 psi, and shall be sprayed
         through nozzles fitted with 15 to 20  wide nozzle tips.
         Nozzles shall be held perpendicular to the surface at a
         working distance of 1.5 to 2.5 feet. All pressure pumps
         shall be equipped with working pressure gauges.

    D.   Repeat procedure if necessary to remove all traces of
         ferrous stain.

                         END OF SECTION