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Historic Preservation - Technical Procedures

Spectitle:

Removing Bird Repellent Gels From Masonry

Procedure code:

0451001R

Source:

The Preservation Notebook Series - Gsa/Pbs

Division:

Masonry

Section:

Masonry Cleaning

Last Modified:

02/24/2012

Details:

Removing Bird Repellent Gels From Masonry



REMOVING BIRD REPELLENT GELS FROM MASONRY


THE CLEANING OR REMOVAL OF STAINS FROM MASONRY MAY INVOLVE THE
USE OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH MAY RUN OFF ON
ADJACENT MATERIAL, DISCOLOR THE MASONRY OR DRIVE THE STAINS DEEPER
INTO THE POROUS MASONRY.  USE THE PRODUCTS AND TECHNIQUES
DESCRIBED HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND MASONRY
SPECIFIED.


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on removing bird
         repellent gels from masonry and removing any residual
         stains left behind.

    B.   One method of bird control involves the use of a toxic
         irritant gel, applied like caulk to horizontal surfaces
         where birds roost.  One result is the presence of a
         gummy, oily residue which can attract dirt, stain masonry
         and soil occupants who come in contact with it.

    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).

1.02 SUBMITTALS

    A.   Product Data:

         1.   Protection Program:  Prior to the execution of
              cleaning samples, submit to the RHPO a written
              description of the methods and materials for
              protection of all surrounding materials not to be
              cleaned.

         2.   Waste Water Collection and Removal:  Prior to
              execution of cleaning samples, submit to the RHPO a
              written description of methods of waste water and
              chemical collection and removal.

         3.   Submit to the RHPO in triplicate a written
              description of the methods, materials, and
              equipment proposed for use in cleaning each type of
              masonry specified.  Submit actual samples of each
              cleaning product to be used, along with
              manufacturer certifications that chemical
              ingredients conform to those specified for each
              cleaning procedure.

    B.   Samples:

         1.   Clean a representative sample of approximately 10
              square feet of stone surface at locations selected
              by the RHPO, for each type of stone to be cleaned
              and each different procedure to be performed,
              including scraping to remove gel bulk.  The samples
              accepted by the RHPO will be marked and left
              undisturbed to serve as standards for the entire
              job.

         2.   Sample cleaning procedures must be executed in the
              presence of the RHPO and must demonstrate the
              Contractor's ability to perform each specified
              cleaning procedure without harming masonry.  Damage
              to masonry as a result of cleaning operations may
              result in the technician's dismissal from the
              project.

         3.   Adjust cleaning materials and methodologies during
              test panel cleaning as directed by the RHPO.

         4.   Allow a minimum of seven calendar days after
              completing cleaning samples to permit the RHPO to
              study the sample panels for negative reactions.

         5.   Do not proceed with cleaning until cleaning samples
              have been approved in writing by the RHPO.

         6.   Approved samples shall be marked and left unaltered
              for the duration of the project.  Approved samples
              shall be used as the standard for similar work
              throughout the project.

    C.   Quality Control Submittals:  

         1.   Submit written program for each phase of
              restoration process including protection of
              surrounding materials on building during
              operations.  Describe in detail materials, methods
              and equipment to be used for each phase of
              restoration work.

         2.   If alternative methods and materials to those
              indicated are proposed for any phase of restoration
              work, provide written description, including
              evidence of successful use on other, comparable
              projects, and program of testing to demonstrate
              effectiveness for use on this project.

1.03 QUALITY ASSURANCE

    A.   Qualifications:

         1.   General Objective:  The objectives of stone
              cleaning are to remove bird repellent gel without
              damaging underlying material and to give the stone
              a clean uniform appearance.  Protection of the
              stone from damage is the highest priority.  Overly
              aggressive cleaning that damages or discolors the
              surface of the stone will not be accepted.

         2.   Contractor Qualifications:  This work must be done
              by a firm specializing in the cleaning of historic
              masonry.  Refer to the Competency of Bidder Clause,
              Sections 00120 and 00900 for submission
              requirements.

         3.   In the event that the Contractor wishes to modify
              any cleaning method specified, he must submit his
              proposal in writing to the RHPO for consideration.
              The RHPO may ask for test samples before approval.
              Approval or rejection of the Contractor's request
              will be at the RHPO's discretion.  Any such changes
              shall be at no additional cost to the Government.

    B.   Regulatory Requirements:  Comply with municipal and
         Federal regulations governing cleaning, chemical waste
         disposal and scaffolding.


PART 2---PRODUCTS

2.01 MANUFACTURERS

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

2.02 MATERIALS

    A.   Cleaning Products:

         1.   Repellent Gel Remover:  Solvent based, methylene
              chloride paint stripper formulated for removal of
              paint, tar, and adhesives from stone, such as Sure
              Klean 509 Paint Stripper (ProSoCo, Inc.), or
              approved equal.

         2.   Oily Stain Remover:  Solvent mixture of methylene
              chloride, ketone, methyl alcohol, and aromatic
              hydrocarbon, formulated for the removal of oily
              stains from stone, such as Sure Klean T1012
              (ProSoCo, Inc.), or approved equal.

         3.   Poultice:  Blend the following to form a paste:

              a.   Sure Klean T1012 (ProSoCo, Inc.), or approved
                   equal.

              b.   Poultice clay containing soda ash (sodium
                   carbonate), talc (magnesium silicate hydrate),
                   and fullers earth (magnesium aluminum
                   silicate) (ProSoCo, Inc.), or approved equal.

    B.   Clean, potable water

2.02 EQUIPMENT

    A.   Tools:

         1.   Gel Scraper (use for removal of gel residue only):
              Sharp steel blade, held at a shallow angle against
              surface to avoid damage to stone

         2.   Poultice Scraper:  Non-metallic spatula

         3.   Brushes:  Fiber bristle brushes (non-metallic)


PART 3---EXECUTION

3.01 PREPARATION

    A.   Protection:  Following approval of proposed protection
         scheme as outlined in 1.02, install protection as
         follows:

         1.   Take all precautions necessary 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, overspray, or runoff.

         2.   Use polyethylene film, masking tape, and whatever
              means necessary to protect plantings, automobiles,
              building occupants, and building surfaces not being
              cleaned.  Remove such coverings when masonry
              cleaning operations have been completed at that
              area of the building.

         3.   Repair or replace with new stock, at no cost to the
              Government, to the RHPO's satisfaction, any
              materials or plantings damaged by scaffolding,
              laborers, cleaning materials, or cleaning
              operations.

         4.   Prior to full scale cleaning, perform, in the
              presence of the RHPO, a site test of the protective
              methods to prove that chemical damage to stone,
              glass, interior finishes, and other surfaces not
              being cleaned will not occur.

         5.   Test all drains and other water removal systems to
              assure that they are functioning properly prior to
              initiating cleaning operations.  Notify the RHPO
              immediately of all blockages.  Repair drains if so
              directed by the RHPO.  Do not begin cleaning until
              drains are in working order.

         6.   Provide a method to prevent solids such as stone or
              mortar residue from entering drains or drain lines.
              Clean out drains or drain lines that become blocked
              because of work performed under this Contract.

         7.   Follow manufacturer instructions regarding the safe
              storage and use of all products and equipment.
              Remove all solvents, soiled rags, applicators, and
              other flammable materials daily and dispose off-
              site according to Federal and municipal
              regulations.

    B.   Surface Preparation:

         1.   Examine masonry to be cleaned prior to installing
              protection and executing sample panels.  Notify
              RHPO immediately of any masonry damage observed.
              Use caution in installing protection and
              undertaking cleaning in damaged areas.  Clean and
              rinse by gentlest means possible and follow RHPO's
              recommended precautions to avoid further damage to
              deteriorated masonry.

         2.   Following approval of submitted materials and
              written description of methods as stipulated under
              1.02 A, execute sample panels as directed in 1.02
              B.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Removal of Bird Repellent Gel:

         1.   Remove bulk of gel by carefully scraping masonry
              surface with a steel blade.  Hold blade at a
              shallow angle to avoid scratching or abrading stone
              surface.  Scratching or otherwise damaging masonry
              will result in the cleaning technician's dismissal
              from the project.

         2.   Apply and remove solvent paint stripper, as
              directed by manufacturer, as many times as
              necessary to remove surface coatings remaining
              after scraping bulk of repellent gel.

    B.   Removal of Repellent Gel Stains:

         1.   Apply Oily Stain Remover to dry stone in areas
              where gel stains remain after removal of repellent
              gel.

         2.   Trowel apply poultice-solvent mixture immediately
              after application of Oily Stain Remover.  Apply
              poultice to a minimum thickness of 1/4 inch.

         3.   Cover the poultice with plastic film to keep it
              from drying out for a minimum of 24 hours.  Press
              film to poultice and tape or otherwise seal the
              edges to exclude air.

         4.   Remove plastic cover and allow the poultice to dry
              thoroughly.

         5.   Remove poultice by scraping with a nonmetallic
              spatula.  Wash the surface thoroughly with clean,
              clear water.

         6.   Repeat steps 1 through 5 as necessary to obtain
              results matching approved samples.

                         END OF SECTION