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Historic Preservation - Technical Procedures

Spectitle:

Replacing Joint Sealants Between Architectural Bronze Window Frames And Exterior Stone Masonry

Procedure code:

0790001R

Source:

National Capitol Region Specifications - State Department

Division:

Thermal And Moisture Protection

Section:

Joint Sealers

Last Modified:

02/24/2012

Details:

Replacing Joint Sealants Between Architectural Bronze Window Frames And Exterior Stone Masonry



REPLACING JOINT SEALANTS BETWEEN ARCHITECTURAL BRONZE WINDOW FRAMES
AND EXTERIOR STONE MASONRY


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on replacing damaged or
         deteriorated joint sealants between heads, jambs, and
         sills of architectural bronze window frames and exterior
         stone masonry.

    B.   Architectural Bronze is an alloy of copper, commonly
         composed of approximately 57% copper (Cu), 40% zinc (Zn)
         and 3% lead (Pb); it is actually a "leaded brass".

    C.   For general information on the characteristics, uses and
         problems associated with bronze (including architectural
         bronze, see 05010-03-R.

    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).

1.02 REFERENCES

    A.   American Society for Testing and Materials (ASTM), 100
         Barr Drive, West Conshohocken, PA 19428, (610) 832-9585
         or FAX (610) 832-9555.

1.03 SYSTEM DESCRIPTION

    A.   System Performances: Provide joint sealers that have been
         produced and installed to establish and maintain
         watertight and airtight continuous seals.

1.04 SUBMITTALS

    A.   Product date from manufacturers for each joint sealer
         product required, including instructions for joint
         preparation and joint sealer application.

    B.   Samples of Initial Selection Purposes: Submit three (3)
         samples of the following items:

         1.   Caulking compound; after Contracting Officer's
              Representative selection from manufacturer's color
              chart, submit three (3) tubes.

         2.   Pre-molded filler; submit three (3) segments, 12"
              minimum length.

    C.   Certificates from manufacturers of joint sealers
         attesting that their products comply with specification
         requirements and are suitable for the use indicated.

    D.   Qualification data complying with requirements specified
         in Quality Assurance article. Include list of completed
         projects with project name, names of Architects and
         Owners, addresses and telephone numbers.

    E.   Sample Mock-Ups for Verification Purposes: Prior to
         installation of joint sealers, apply elastomeric sealants
         to each type of joint (3' minimum length) for further
         verification of colors selected from sample submittals
         and to represent completed work for qualities of
         appearance, materials, and application. Locate mock-ups
         as directed by Contracting Officer.

1.05 QUALITY ASSURANCE

    A.   Installer Qualifications: Engage an installer who has
         successfully completed within the last 5 years at least
         3 joint sealer applications similar in type and size to
         that of this project.

    B.   Single Source Responsibility for Joint Sealer Materials:
         Obtain joint sealer materials from a single manufacturer
         for each different product required.

    C.   Preconstruction Compatibility and Adhesion Testing: Use
         test methods standard with manufacturer to determine if
         priming and other specific joint preparation techniques
         are required to obtain rapid, optimum adhesion of joint
         sealers to joint substrates. Perform tests under normal
         environmental conditions that will exist during actual
         installation.

1.06 DELIVERY, STORAGE AND HANDLING

    A.   Packing and Shipping:  Deliver materials to project site
         in original unopened containers or bundles with labels
         informing about manufacturer, product name and
         designation, color, expiration period for use, pot life,
         curing time and mixing instructions for multi component
         materials.

    B.   Storage and Protection:  Store and handle materials to
         prevent their deterioration or damage due to moisture,
         temperature changes, contaminants, or other causes.
   
1.06 PROJECT/SITE CONDITIONS

    A.   Environmental Requirements:  Do not proceed with
         installation of joint sealers when ambient and substrate
         temperature conditions are outside the limits permitted
         by joint sealer manufacturer or below 40 F or when joint
         substrates are wet due to rain, frost, condensation, or
         other causes.

1.07 WARRANTY

    A.   All work under this section shall be guaranteed for not
         less than five (5) years from the date of final
         acceptance by the Government against leaks and weather
         penetration.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Dow Corning Corporation
         1225 Northmeadow Parkway, Ste. 104
         Roswell, GA  30076
         404/751-7979

         P.O. Box 994
         Midland, MI  48686-0994
         517/496-4000

    B.   General Electric Co.
         Waterford, NY 12188
         518/237-3330

    C.   Pecora Corporation
         165 Wambold Road
         Harleysville, PA  19438
         800/522-1285 or 215/723-6051
         -or-
         2601 Oakland Avenue
         Garland, TX  75041
         800/523-6688 or 214/278-8158

    D.   Tremco, Inc.
         3735 Green Rd.
         Beachwood, OH  44122
         800/321-7906

2.02 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.   General:

         1.   Compatibility: Provide joint sealers, joint fillers
              and other related materials that are compatible
              with one another and with joint substrates under
              conditions of service and application, as
              demonstrated by testing and field experience.

         2.   Colors: Provide color of exposed joint sealers
              indicated or, if otherwise indicated, as selected
              by the Contracting Officer from manufacturer's
              standard colors.

    B.   Silicone Sealant: One-part silicone-based, nonsag,
         elastomeric sealant, complying with ASTM C920, Type S,
         Class 25, Grade NS, such as "Dow Corning 790" (Dow
         Corning Corp.), "Silpruf SCS2000 Sealant" (General
         Electric Co.), or approved equal.

    C.   Polyurethane Sealant: One-part polyurethane-based
         sealant; complying with ASTM C920, Type S, Class 25. Use
         self-leveling type for joints of floors and pavements,
         such as "Dynatrol 1" (Pecora Corp.), "Dymonic" (Tremco,
         Inc.), or approved equal.

    D.   Miscellaneous Sealant Materials:

         1.   Joint Primer/Sealer: Provide type recommended by
              sealant manufacturer for joint surfaces to be
              primed or sealed.

         2.   Bond Breaker Tape: Provide plastic tape as
              recommended by sealant manufacturer for sealant-
              contact surfaces where bond must be avoided for
              proper performance of sealant. Provide self-
              adhesive tape where applicable.

         3.    Xylol:

              a.   Any of three toxic, flammable, oily, isomeric,
                   aromatic hydrocarbons that are di-methyl
                   homologues of benzene and are obtained from
                   wood tar, coal tar, or petroleum distillates;
                   Also a mixture of xylenes and ethyl-benzene
                   used chiefly as a solvent.

              b.   Other chemical or common names include Xylene
                   (C8H10); P-xylene; 1,4-dimethyl benzene.

              c.   Potential Hazards:  TOXIC AND FLAMMABLE.

              d.   Available from chemical supply house, hardware
                   store, paint store or printer's supply
                   distributor.

              -OR-

              Naphtha:

              a.   A petroleum distillate that is used especially
                   as a paint or varnish thinner.

              b.   Other chemical or common names include Benzine*(not Benzene); Mineral spirits; Petroleum
                   spirits*; Solvent naphtha*.

              c.   Potential Hazards:  TOXIC AND FLAMMABLE.



              d.   Safety Precautions:

                   1)   AVOID REPEATED OR PROLONGED SKIN CONTACT.

                   2)   ALWAYS wear rubber gloves when handling
                        mineral spirits.

                   3)   If any chemical is splashed onto the
                        skin, wash immediately with soap and
                        water.

              e.   Available from construction specialties
                   distributor, hardware store, paint store, or
                   printer's supply distributor.

         4.   Clean, potable water.

         5.   Clean, soft cloths.

2.03 EQUIPMENT

    A.   Caulking gun

    B.   Wire brushes (non-ferrous bristles)

    C.   Tooling stick or knife


PART 3---EXECUTION

3.01 PREPARATION

    A.   Surface Preparation:

         1.   All openings, joints, or channels to be sealed
              shall be thoroughly clean, dry and free from dust,
              oil, grease, loose mortar or any other foreign
              matter.

         2.   Masonry surfaces forming sides of joints shall be
              wire-brushed with non-ferrous brush, then air-blown
              clear.

         3.   Prime or seal joint surfaces where recommended by
              sealant manufacturer. Confine primer/sealer to
              areas of sealant bond only.

         4.   Set joint fillers without twists, and to allow for
              bond breakers, backer rods and sealants. Do not
              leave gaps between ends of joint filler units.

         5.   Install sealant backer rod for sealants, except
              where recommended to be omitted by sealant
              manufacturer.

         6.   Install bond breaker tape where required by
              manufacturer's recommendations to ensure that
              sealants will perform as intended.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Caulking shall be gun-applied through a nozzle opening of
         such a diameter so that the full bead of sealant is
         gunned into the joint, filling the joint completely
         without gaps or air pockets. A superficial or skin bead
         will not be acceptable.

    B.   All beads shall be tooled immediately after application
         to ensure firm, full contact with the inner faces of the
         joints. Excess material shall be struck off with a
         tooling stick or knife, dipped in solvent to avoid
         tearing or stripping of the bead.

    C.   The finished bead shall be flush with the surface, or as
         otherwise indicated by the Contracting Officer's
         Representative.

    D.   Provide two weep holes at window lintels, 1'-0" in from
         each jamb.

    E.   Install sealants to depths as recommended by sealant
         manufacturer to provide uniform shapes which allow
         optimum sealant movement capability.

    F.   Do not allow sealants to spill onto adjoining work.
         Adjacent surfaces which have been soiled by sealing
         operations shall be cleaned immediately and left in a
         clean and neat condition.

3.03 ADJUSTING/CLEANING

    A.   Excess compound shall be cleaned off non-porous surfaces
         while uncured, using a solvent such as commercial xylol
         or naptha. On porous surfaces, the excess sealant should
         be allowed to cure and be removed by non-abrasive
         mechanical means approved by the Contracting Officer's
         Representative.

    B.   Remove all rubbish, cartons and debris resulting from
         caulking operations daily during the performance of the
         work.

                         END OF SECTION