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Historic Preservation - Technical Procedures

Spectitle:
Treating Dusting Of Concrete Floors

Procedure code:
0371002R

Source:
Hspg Prepared For Nps - Sero

Division:
Concrete

Section:
Concrete Cleaning

Last Modified:
02/24/2012

Details:
Treating Dusting Of Concrete Floors



TREATING DUSTING OF CONCRETE FLOORS


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on how treating dusting
         of concrete floors.  Dusting is a problem evident as a
         powdered material that develops at the surface of
         hardened concrete.

    B.   The treatment described in this procedure includes
         mopping with a fluosilicate and water mixture.

         1.   Fluosilicate makes the concrete surface harder and
              more impermeable.

         2.   This treatment also improves the concrete surface
              for the application of oil base paints and
              varnishes.

    C.   Safety Precautions:

         1.   DO NOT save unused portions of stain-removal
              materials.

         2.   DO NOT store any chemicals in unmarked containers.

         3.   EXCELLENT VENTILATION MUST BE PROVIDED WHEREVER ANY
              SOLVENT IS USED.  USE RESPIRATORS WITH SOLVENT
              FILTERS.

         4.   No use of organic solvents indoors should be
              allowed without substantial air movement.  Use only
              spark-proof fans near operations involving
              flammable liquids.

         5.   Provide adequate clothing and protective gear where
              the chemicals are indicated to be dangerous.

         6.   Have available antidote and accident treatment
              chemicals where noted.

    D.   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 MATERIALS

    NOTE:  Chemical products are sometimes sold under a common
    name.  This usually means that the substance is not as pure as
    the same chemical sold under its chemical name.  The grade of
    purity of common name substances, however, is usually adequate
    for stain removal work, and these products should be purchased
    when available, as they tend to be less expensive.  Common
    names are indicated below by an asterisk (*).

    A.   Fluosilicate:

         1.   Magnesium Fluosilicate:

              a.   Other chemical or common names include
                   Magnesium silicofluoride.

              b.   Potential Hazards:  TOXIC.

              c.   Available from construction specialties
                   distributor (often sold under manufacturer's
                   brand name; the chemical name may appear on
                   the label).

         2.   Zinc Fluosilicate:

              a.   Other chemical or common names include Zinc
                   silicofluoride.

              b.   Available from construction services
                   distributor (often sold under a manufacturer's
                   brand name; the chemical name may appear on
                   the label).

    B.   Clean, potable water

2.02 EQUIPMENT

    A.   Garden hose and pneumatic spray nozzle

    B.   Stiff bristle brushes (non-metallic)

    C.   Mopping Tools:

         1.   Wet mop

         2.   Mop bucket

         3.   Wringer

         4.   Sponge mop and squeegee


PART 3---EXECUTION

3.01 PREPARATION

    A.   Protection:  Provide adequate wash solutions (i.e. water,
         soap and towels) before starting the job.

3.02 ERECTION, INSTALLATION, APPLICATION

    NOTE:  DO NOT TRY MORE THAN ONE TREATMENT ON A GIVEN AREA
    UNLESS THE CHEMICALS USED FROM PRIOR TREATMENT HAVE BEEN
    WASHED AWAY.

    A.   Make sure the floor is clean before you begin.

    B.   Mix 1 pound of fluosilicate (a mixture of 20% zinc
         fluosilicate and 80% magnesium fluosilicate) with 1
         gallon of water.

    C.   Mop the mixture generously on the concrete surface and
         allow to dry.

    D.   If additional coats are necessary, mix 2 pounds of
         fluosilicate (20/80 as in 3.02 B. above) in 1 gallon of
         water and apply as in 3.02 C. above.  Two or three coats
         may be necessary.

    E.   When the last coat has dried, thoroughly rinse the
         surface with clean, clear water and scrub with a stiff
         bristle brush to remove any crystals that have formed.

                         END OF SECTION