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Historic Preservation - Technical Procedures

Spectitle:

Patching Metal Gutters

Procedure code:

0763103R

Source:

Hspg Prepared For Nps - Sero

Division:

Thermal And Moisture Protection

Section:

Gutters & Downspouts

Last Modified:

02/24/2012

Details:

Patching Metal Gutters



PATCHING METAL GUTTERS


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on patching metal
         gutters using a soldered metal patch, a caulked metal
         patch or a fabric patch.

    B.   Gutters with soldered joints are usually under continual
         stress due to expansion and contraction following changes
         in temperature.  An overloaded gutter can also cause
         holes, popped seams, and deteriorated straps.

    C.   Safety Precautions:

         1.   Wear rubber-soled shoes that have non-slip or grid
              type tread (preferably sneakers with a high top for
              good ankle support).  Avoid wearing loose clothing.

         2.   Wear a safety belt or harness secured to a chimney
              or other substantial element.  Leave only enough
              slack to perform the work comfortably in one area,
              and adjust the slack as the work proceeds on other
              sections of the roof.

         3.   Be sure the roof is clear of debris and water.

         4.   Do not work on wet or snow-covered roofs.  Work on
              cleated walkboards.

         5.   Steep roofs:  On roof slopes greater than 4 inches
              rise per foot, special consideration must be given
              to both footing and materials handling.

              a.   Chicken ladders or cleats secured at the top
                   for adequate footing.

              b.   Approved safety lines should be secured with
                   manila rope.

              c.   Carry a limited amount of materials so that
                   balance and footing are not impaired.

              d.   Scaffolding, ladders and working platforms as
                   required to execute this work.

    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 MANUFACTURERS

    A.   Sheetmetal and Gutters:  (for metal patch)

         1.   Albert J. Wagner & Son
              3762 N. Clark Street
              Chicago, IL  60613
              312/935-1414

         2.   Conklin Metal Industries
              P.O. Box 1858
              Atlanta, GA  30301
              404/688-4510

         3.   Davenport, Peters
              129 South Street
              Boston, MA  02111
              617/542-1811

         4.   J.C. Lauber Co.
              504 E. LaSalle Ave.
              South Bend, IN  46617
              219/234-4174

    B.   Sealants:

         1.   Revere Products (division of Pioneers)
              P.O. Box 35311
              Cleveland, OH  44131-0311
              216/573-7100
              "Miracle Seal"

         2.   Magic American Chemical Corp.
              23700 Mercantile Rd.
              Cleveland, OH  44122
              216/464-2353
              "Patch Magic"

         3.   Evode, Inc.
              Somerdale, NJ
              "Flashbond"

         4.   Geocel, Ltd.
              53280 Marina Dr.
              Elkhart, IN  46514
              219/264-0645

    C.   Silicone Caulk:

         1.   Dow Corning Corporation
              1225 Northmeadow Parkway, Ste. 104
              Roswell, GA  30076
              800/662-0661 ext. 40

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.   Solder

    B.   Rosin soldering flux

    C.   Gutter sealant such as "Miracle Seal" (Revere Chemical
         Corp.), "Patch Magic" (Magic American Chemical Corp.),
         "Flashband" (Evode, Inc.), "Geocel Water Seal 100"
         (Geocel, Ltd.), or approved equal.

    D.   Silicone caulk

    E.   Metal primer such as Rust-Oleum, or approved equal

    F.   Flashing cement or roofing compound for embedding fabric
         patch

    G.   Burlap, roofing membrane or building paper

    H.   Appropriate metal for patching material

    I.   Mineral spirits:

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

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

         3.   Potential Hazards:  TOXIC AND FLAMMABLE.

         4.   Safety Precautions:

              a.   AVOID REPEATED OR PROLONGED SKIN CONTACT.

              b.   ALWAYS wear rubber gloves when handling
                   mineral spirits.

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

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

    J.   Muriatic acid:

         1.   A strong corrosive irritating acid.  Generally
              available in 18 degree and 20 degree Baume
              solutions.

         2.   Other chemical or common names include Chlorhydric
              acid; Hydrochloric Acid (30-35%); Hydrogen
              chloride; Marine acid*; Spirit of salt*; Spirit of
              sea salt*.

         3.   Potential Hazards:  TOXIC, CORROSIVE TO FLESH;
              CORROSIVE TO CONCRETE, STEEL, WOOD OR GLASS,
              FLAMMABLE.

         4.   Available from chemical supply house, drugstore or
              pharmaceutical supply distributor, or hardware
              store.

2.03 EQUIPMENT

    A.   Safety belt or harness

    B.   Ladders and scaffolding

    C.   Chicken ladder, safety belt or harness

    D.   Soldering copper, soldering iron

    E.   Straight snips for cutting straight or slightly curved
         lines in sheet metal 24 gauge or lighter

    F.   Handy tongs for bending the edges of the solder

    G.   Wire brush or steel wool

    H.   Clean, soft cloths

    I.   Heavy gloves and protective gear


PART 3---EXECUTION

3.01 EXAMINATION

    A.   Inspect for:

         1.   Metal corrosion factors:  In varying degrees each
              type of sheet metal is likely to deteriorate from
              chemical action resulting in pitting or streaking.
              The cause may be airborne pollutants, acid
              rainwater, acids from lichen or moss, or alkalis
              found in mortar.

         2.   Maintenance problems:  Corrosion around nails.
              Roof cement on gutters may hide leaks that have not
              been corrected.

         3.   Inspect for gutters that are split or cracked with
              loose, broken, out of place, hangers, corners or
              slopes, or pulling of fasteners, broken joints or
              seams; excessive staining or punctures of gutter
              fabric.

         4.   Inspect for signs of deteriorated mortar joints
              and/or paint that is peeling, cracking,
              alligatoring, chipping, or chalking on surfaces
              behind gutters and downspouts.
   
         5.   Inspect for cracks, splits, punctures, and dirt
              stains on downspouts as well.

    B.   Inspect the underside of the roof cornices.  Water stains
         may be evidence of ice dams.

    C.   Check gutters as a part of the annual roof inspection
         (preferably in late autumn).  Repair defects immediately
         because gutters are a critical part of the roof fabric.
         Small gutter leaks may force water into concealed cornice
         and roof areas leading to major defects.  It is
         recommended that a professional survey be carried out
         every five years.

    D.   Inspect soldered gutters annually, and resolder any
         broken joints.  

         NOTE:  SOLDERING USUALLY REQUIRES A FAIRLY HIGH LEVEL OF
         EXPERIENCE.

    E.   Inspect all parts of the drainage system, including
         downspouts, flashing, conductor heads, leaders, roof
         drains, and scuppers.  Be sure to include these in the
         work list when maintenance or repair are being made to
         the gutters.

    F.   See also 07631-01-S "General Inspection and Maintenance
         of Gutters and Downspouts".

3.02 PREPARATION

    A.   Protection:

         1.   At the end of each work day, provide building
              protection for any exterior gutter element removed
              for repair or replacement, if water penetration is
              possible.

         2.   Landscape work adjacent to or within the ground
              work areas for gutter maintenance shall be
              protected.  Provide plank barriers to protect tree
              trunks.  Tie-up spreading shrubs, and cover as
              necessary, allowing the plants to breathe.  Remove
              the covering and ties at the end of each work day.
              Set scaffold ladder and legs away from plants.
              Pruning requests shall be directed to the Regional
              Architect.

         3.   Keep trees trimmed to prevent branches from
              scuffing or moving downspouts.

         4.   Set ladders on an incline whereby the bottom of the
              ladder is approximately 25% of the height from the
              base of the building.  Do not rest ladders on
              gutters.

    B.   Surface Preparation:

         1.   Flush silty residue to the downspout.  Remove
              strainers.

         2.   When moss, lichen, or fungus is present, wipe or
              scrape off growth.  Saturate biological areas with
              a disinfectant solution.

3.03 ERECTION, INSTALLATION, APPLICATION

    A.   Repairing With a Soldered Metal Patch:  

         NOTE:  USE A METAL PATCH MADE FROM THE SAME METAL AS THE
         GUTTER.  IF DISSIMILAR METALS ARE USED, GALVANIC
         CORROSION IS LIKELY TO OCCUR.

         1.   Remove all deteriorated and corroded metal using a
              wire brush or steel wool.

         2.   Cut patching material so that it overlaps sound
              metal by 2 inches on all sides of the damaged area.

         3.   To allow for the normal expansion and contraction
              of the material, solder patch on the "uphill" side
              of the patch only.

         4.   With chemical paint stripper, remove any paint from
              the metal surrounding the patch.  If there's any
              roofing tar, remove it by scraping, followed by
              scrubbing with mineral spirits.  

              CAUTION:  THIS SOLVENT IS VERY FLAMMABLE.

         5.   Clean the gutter and the metal patch piece by
              scouring with a wire brush or steel wool.

         6.   For guidance on soldering, see 05010-07-R
              "Procedures for Soldering Metal".

    -OR-

    B.   Repairing With a Caulked Metal Patch:  

         1.   Clean the gutter thoroughly by scouring with a wire
              brush or steel wool.

         2.   Cut a metal patch of appropriate size made from the
              same metal as the gutter.

         3.   Apply a liberal amount of silicone caulk over the
              area to be patched.

         4.   Bed the metal patch firmly in the caulk, paying
              special attention to the seal at both ends of the
              patch.

         NOTE:  ALTHOUGH SILICONE CAULK SHOULD HAVE A USEFUL LIFE
         OF 10 OR MORE YEARS, THIS KIND OF PATCH REQUIRES CAREFUL
         MONITORING THROUGH ANNUAL MAINTENANCE CHECKUPS.

    -OR-

    C.   Repairing With a Fabric Patch:

         1.   Clean the gutter thoroughly by scouring with a wire
              brush or steel wool.

         2.   Apply metal primer such as Rust-Oleum, or approved
              equal, to protect the metal from acids contained in
              black roofing compound or flashing cement (used in
              securing the fabric patch).

         3.   Apply a coating of flashing cement or roofing
              compound.

         4.   Imbed a fabric material such as burlap, roofing
              membrane or building paper in the cement.

         5.   Cover patch with another coat of flashing cement.

         CAUTION:  AVOID COATING THE ENTIRE METAL GUTTER WITH A
         COATING SUCH AS ROOFING CEMENT.  IF ANY WATER DOES GET
         UNDER SUCH A COATING, IT WILL BE HELD IN CONTACT WITH THE
         METAL INDEFINITELY.

    D.   Commercial products such as "Miracle Seal" or "Patch
         Magic," may also be used.  Follow manufacturer's
         instructions.  

                             END OF SECTION