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Historic Preservation - Technical Procedures

Spectitle:
Repairing A Metal Shingle Roof

Procedure code:
0731301R

Source:
Hspg Prepared For Nps - Sero

Division:
Thermal And Moisture Protection

Section:
Metal Shingles

Last Modified:
02/24/2012

Details:
Repairing A Metal Shingle Roof



REPAIRING A METAL SHINGLE ROOF


PART 1---GENERAL

1.01 SUMMARY

    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 substant= ial 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-cov= ered roofs.  Work on
              cleated walkboards.

         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
                   manila rope.

              c.   Carry a limited number of materials so that
                   balan= ce and footing are not impaired.

              d.   Establish regul= ations for any foot traffic.
                   Many roofing materials should not be walked
                   on.  When working on lead roofing, a self-
                   suppo= rting ladder might be hung from the roof
                   ridge.  Such items should be specifically
                   desig= ned 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 Precaution= s

         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 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=F8F, Putty--80= =F8F, and Epoxy--80=F8F.  Work in
              shade when temperature is above 75=F8F.  Work around
              the structure in the shade away from the sun.

         3.   Cold weather:  Minimum application temperatures:
              Paint -- 50=F8F, Putty--5= 0=F8F, and Epoxy--55=F8F.

1.02 MAINTENANCE

    A.   Rinse dirt with water annually.

    B.   Keep the roof clear of debris, and trim all overha= nging
         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 parti= cularly heavy
         storms.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Berridge Manufacturing Company
         1720 Maury
         Houston, TX  77026
         713/223-4971 or (800) 231-8127

         (Metal shingles sold through nationwide distributors.
         Free brochure).

    B.   Conklin Tin & Plate Co.
         P.O. Box 2662
         Atlanta, GA  30301
         404/688-4510

         (Metal Roofing shingles sold direct.  Complete product
         catalog, $5; roofing information, $3).
    C.   Gerard Roofing Technologies
         955 Columbia St.
         Brea, CA  92622
         714/529-0407

         (Metal roofing tiles produced from 28-ga= uge galvalume
         steel with proprietary acrylic resin that binds stone
         coating to the surface.  Free liter= ature).

    D.   RTS Company
         1805 Newton Avenue
         San Diego, CA  92113
         619/696-0102

         (Metal roofing tiles.  Free literat= ure).

    E.   W.F. Norman Corp.
         P.O. Box 323
         Nevada, MO  64772
         417/667-5552 or 800/641-4038

         (Metal shingles in 1908 patterns sold direct and through
         distributors.  Specify "Norman Roofs" for free literature
         and price sheet).

    F.   Zappone Manufacturing
         N. 2928 Pittsburgh
         Spokane, WA  99207
         509/483-6408

         (Interlocking metal shingle systems, available in copper
         or aluminum.  Free literature).

2.02 MATERIALS

    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

2.03 EQUIPMENT

    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


PART 3---EXECUTION

3.01 PREPARATION

    A.   Protection:

         1.   At the end of each work day, provide building
              protection for any exteri= or 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 requi= red 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 INDEFINITELY IF KEPT PAINTED.  

    B.   For Damaged Metal Shingles:  Solder a patch.<= br>
         NOTE:  A SINGLE METAL SHINGLE IS ALMOST IMPOSSIBLE TO
         REPLACE BECAUSE OF THE WAY THEY INTERLOC= K.  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 =AB 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 produ= ct such as gutter
         tape or a tripolymer adhesive with tape backing.

         -OR-

         Patch the damaged shingle with sheetmetal and flashing
         cement:

         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
              roof.

         NOTE:  THESE PATCHES ARE ONLY TEMPO= RARY.  

    D.   For Individual Shingle Replacement:

         1.   If it is possible to remove one (or a few)
              shingle(s) for replacemen= t, 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
              sealer.

                         END OF SECTION