Historic Preservation - Technical Procedures
- Repairing A Metal Shingle Roof
- Procedure code:
- Hspg Prepared For Nps - Sero
- Thermal And Moisture Protection
- Metal Shingles
- Last Modified:
- Repairing A Metal Shingle Roof
- Last Modified:
REPAIRING A METAL SHINGLE ROOF
A. This procedure includes guidance on making minor repairs
to a metal shingle roof.
B. Safety Precautions:
1. Wear rubber-soled shoes that have non-slip tread
(preferably sneakers with a high top for good ankle
support). Avoid wearing loose clothing.
2. Wear a safety-belt or harness and secure it to the
chimney or other substantial object. Leave only
enough slack so that work can be performed
comfortably in one area, and adjust that slack as
you work 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 slopes where the roof is steeper
than 4 inches rise per foot, special consideration
must be given to footing and handling of materials.
a. Secure chicken ladders or cleats at the top
for adequate footing.
b. Hand and secure approved safety lines with
ropes of sufficient strength.
c. Carry a limited number of materials so that
balance and footing are not impaired.
d. Establish regulations for any foot traffic.
Many roofing materials should not be walked
on. When working on lead roofing, a self-
supporting ladder might be hung from the roof
ridge. Such items should be specifically
designed and kept in a storage area adjacent
to the roof access. Plank ceiling joists
under roof hatch.
B. 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).
1.02 PROJECT/SITE CONDITIONS
A. Environmental Requirements:
1. Wet weather: Do not repair roofing in misty, rainy
weather. Do not apply paint, putty or epoxy to
damp surfaces or in misty or rainy weather. Do not
remove exterior elements of structures when rain is
in the forecast or in progress.
2. Hot weather: Maximum application temperatures:
Paint--85 degrees F, Putty--80 degrees F, and Epoxy--80 degrees F. Work in
shade when temperature is above 75 degrees F. Work around
the structure in the shade away from the sun.
3. Cold weather: Minimum application temperatures:
Paint -- 50 degrees F, Putty--50 degrees F, and Epoxy--55 degrees F.
A. Rinse dirt with water annually.
B. Keep the roof clear of debris, and trim all overhanging
branches that might cause mechanical damage.
C. Inspect for and eliminate ant hills and/or bird droppings
which can corrode sheet metals.
D. Inspect the secureness of cleats and fasteners and the
condition of the sheet metal after particularly heavy
A. Berridge Manufacturing Company
B. Gerard Roofing Technologies
C. W.F. Norman Corp.
D. Zappone Manufacturing
E. Other sources: see Traditional Building Magazine,www.traditional-building.com;
and other building trades publications and websites.
A. Metal shingles to match existing
B. Sheet metal (for patch) compatible with metal shingles
C. Rivets or nails compatible with sheetmetal type
D. Solder, flux
E. Silicone sealer
F. Flashing cement
A. Chicken ladder, safety belt or harness
B. Protective gloves and gear
C. Straight snips for cutting straight or slightly curved
lines in sheet metal 24 gauge or lighter
D. Soldering copper, soldering iron
E. Handy tongs for bending the edges of the solder
F. Wire brush or steel wool
1. At the end of each work day, provide building
protection for any exterior roofing element removed
for repair or replacement.
2. Remove only a quantity of roofing which may be
replaced on that same day. At the end of the day,
use 15 pound roofing felt or polyethylene sheeting
to drape over missing roofing and insert under roof
unit laps or temporarily secure areas of existing
roofing and roof as required to make roof
watertight and windproof.
3. Keep areas trimmed to prevent branches from
scuffing roofing surfaces.
3.02 ERECTION, INSTALLATION, APPLICATION
A. For Small Rusted Areas:
1. Remove rust using a wire brush.
2. Apply an iron oxide primer.
3. Apply a finish coat of paint to match existing.
NOTE: METAL SHINGLES OF GALVANIZED OR TERNE-COATED STEEL
WILL LAST MANY YEARS IF KEPT PAINTED.
B. For Damaged Metal Shingles: Solder a patch.
NOTE: A SINGLE METAL SHINGLE IS ALMOST IMPOSSIBLE TO
REPLACE BECAUSE OF THE WAY THEY INTERLOCK. THEREFORE,
PATCHING IS THE BEST REPAIR SOLUTION. FOR INDIVIDUAL
SHINGLE REPLACEMENT, SEE SECTION 3.02 D. BELOW.
1. Thoroughly clean the area to be patched of all rust
and/or roofing cement - clean down to shiny metal.
2. Cut a patch from the same metal, about two inches
larger than the hole.
3. Fold the edges under 1 (one) inch and snip off the
corners. This makes the patch stronger and takes
off easily damaged sharp corners.
4. Place a weight, such as a brick, over the patch to
hold it firmly to the metal. If the patch is on a
vertical surface, clamp or tack-solder it in place.
5. Solder patch in place (see 05010-07-R for guidance
on soldering metal).
C. If a soldered repair is not feasible, try patching the
shingle using a commercial sealing product such as gutter
tape or a tripolymer adhesive with tape backing.
Patch the damaged shingle with sheetmetal and flashing
1. Clean the metal with a wire brush or steel wool.
2. Cut a sheet-metal patch that overlaps the hole at
least 3 inches on all sides.
3. Coat the back of the patch with flashing cement.
4. Press the patch firmly into place--just hard enough
so that the cement doesn't ooze onto the roof.
5. Prime and paint the patch to match the rest of the
NOTE: THESE PATCHES ARE ONLY TEMPORARY.
D. For Individual Shingle Replacement:
1. If it is possible to remove one (or a few)
shingle(s) for replacement, fit replacement or
repaired shingle into place.
2. Secure shingle by toenailing two nails (each nail
1" from shingle edge) through shingle at exposure
line. If possible, nail so that nail heads will be
covered by butt of the shingle in the above course.
3. Cover nail head with a dab of clear silicone
END OF SECTION