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Historic Preservation - Technical Procedures
Patching Metal Gutters
Hspg Prepared For Nps - Sero
Thermal And Moisture Protection
Gutters & Downspouts
Patching Metal Gutters
PATCHING METAL GUTTERS
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
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
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
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).
A. Sheetmetal and Gutters: (for metal patch)
1. Albert J. Wagner & Son
3762 N. Clark Street
Chicago, IL 60613
2. Conklin Metal Industries
P.O. Box 1858
Atlanta, GA 30301
3. Davenport, Peters
129 South Street
Boston, MA 02111
4. J.C. Lauber Co.
504 E. LaSalle Ave.
South Bend, IN 46617
1. Revere Products (division of Pioneers)
P.O. Box 35311
Cleveland, OH 44131-0311
2. Magic American Chemical Corp.
23700 Mercantile Rd.
Cleveland, OH 44122
3. Evode, Inc.
4. Geocel, Ltd.
53280 Marina Dr.
Elkhart, IN 46514
C. Silicone Caulk:
1. Dow Corning Corporation
1225 Northmeadow Parkway, Ste. 104
Roswell, GA 30076
800/662-0661 ext. 40
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 (*).
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
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*;
3. Potential Hazards: TOXIC AND FLAMMABLE.
4. Safety Precautions:
a. AVOID REPEATED OR PROLONGED SKIN CONTACT.
b. ALWAYS wear rubber gloves when handling
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
2. Other chemical or common names include Chlorhydric
acid; Hydrochloric Acid (30-35%); Hydrogen
chloride; Marine acid*; Spirit of salt*; Spirit of
3. Potential Hazards: TOXIC, CORROSIVE TO FLESH;
CORROSIVE TO CONCRETE, STEEL, WOOD OR GLASS,
4. Available from chemical supply house, drugstore or
pharmaceutical supply distributor, or hardware
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
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
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
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
NOTE: SOLDERING USUALLY REQUIRES A FAIRLY HIGH LEVEL OF
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
F. See also 07631-01-S "General Inspection and Maintenance
of Gutters and Downspouts".
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
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
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
B. Surface Preparation:
1. Flush silty residue to the downspout. Remove
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".
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
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.
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
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
D. Commercial products such as "Miracle Seal" or "Patch
Magic," may also be used. Follow manufacturer's
END OF SECTION