Historic Preservation - Technical Procedures
- Repairing Damaged Or Missing Ornamental Metal
- Procedure code:
- National Capitol Region Specifications - Old Executive Off
- Ornamental Metalwork
- Last Modified:
- Repairing Damaged Or Missing Ornamental Metal
- Last Modified:
REPAIRING DAMAGED OR MISSING ORNAMENTAL METAL
A. This procedure includes guidance on repairing existing
ornamental metal work by removing, repairing and
reinstalling existing pieces, or if too damaged,
installing new ornamental metal to match.
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).
A. American Society for Testing and Materials (ASTM), 100
Barr Drive, West Conshohocken, PA 19428, (610) 832-9585
or FAX (610) 832-9555.
B. American Welding Society (AWS), P.O. Box 351040, 550 Le
Jeune Road, NW, Miami, FL 33135.
C. National Association of Architectural Metal Manufacturers
(NAAMM), 221 N. LaSalle Street, Chicago, IL 60601.
D. Steel Structures Painting Council (SSPC), 4400 Fifth
Avenue, Pittsburgh, PA 15213.
A. Product Data: Submit manufacturer's fabricator's and
finisher's specifications and installation instructions
for products used in ornamental metal work, including
finishing materials and methods.
B. Submit manufacturer's technical data for each product
indicated including chemical analysis and recommendations
for their application and use. Include test reports and
certifications substantiating that products comply with
C. Shop Drawings: Submit shop drawings for fabrication and
installation or ornamental metal work. Include plans,
elevation and detail sections. Indicate materials,
methods, finishes and types of joinery, fasteners,
anchorages and accessory items; specify finishes. Provide
setting diagrams and templates for anchorages, sleeves
and bolts installed by others. Fabricated parts and
fasteners to be of the same metal as historic to avoid
D. Samples: Submit samples, 6" square, of each metal and
finish required. Prepare samples on metal of same alloy
and thickness to be used for the work. Where normal color
and texture variations are to be expected, include 2 or
more units in each set of samples showing the limits of
such variations. Full-size samples will be prepared and
submitted for the architect's approval for each article.
E. Model: Provide model of castings made as directed until
the model conforms to the Contract drawings or to
subsequent directions until approval of the model is
F. Restoration Program: Submit written program for each
phase of restoration process including protection of
surrounding materials on building and site during
operations. Describe in detail materials, methods and
equipment to be used for each phase of restoration work.
1.04 SYSTEM DESCRIPTION
A. Design Requirements:
1. Design components to allow for expansion and
contraction for a minimum ambient temperature range
of 100 F (37.8 C) without causing buckling,
excessive opening of joint or over stressing of
welds and fasteners.
2. Form ornamental metal work to the required shapes
and sizes, with true curves, lines and angles.
Provide necessary rebates, lugs and brackets for
assembly of units. Use concealed fasteners wherever
3. Comply with AWS for recommended practices in shop
welding. Provide welds behind finished surfaces
without distortion or discoloration of the exposed
side. Clean exposed welded joints of all welding
flux, and dress on all exposed and contact
4. Mill joints to a tight, hairline fit. Cope or miter
corner joints. Form joints exposed to weather to
exclude water penetration.
5. Provide castings that are sound and free of warp or
defects which impair strength and appearance. Mill
joints to a close fit and finish exposed surfaces
to smooth, sharp, well-defined lines and arises.
6. Comply with NAAMM "Metal Finishes Manual" for
finish designations and application
7. Match color, direction, and texture of existing
ornamental metal work for new and replacement
1.05 QUALITY ASSURANCE
A. Mock-ups: Prepare sample panels for each type of
ornamental metal material indicated to be repaired or
1.06 PROJECT/SITE CONDITIONS
A. Protect surrounding surfaces of building from damage
resulting from ornamental metal restoration work.
A. Provide materials which have been selected from their
surface flatness, smoothness and freedom from surface
blemishes where exposed to view in the finished unit.
Exposed-to-view surfaces which exhibit pitting, seam
marks, roller marks, "oil-canning" stains, discolorations
or other imperfections on the finished units will not be
B. Aluminum: Comply with the following standards for the
forms and types of aluminum for the required items of
1. Aluminum Extrusions: Alloy and temper recommended
by aluminum producer of finisher for type of use
and finish indicated, and with not less than the
strength and durability properties specified in
ASTM B221 for 6063-T5.
2. Bars, Rods and Wire: ASTM B211.
3. Castings: ASTM B26 or B108; alloy 214 for natural
anodized finish, and alloy 43 for color anodized or
baked enamel finish.
4. Forgings: ASTM B247, alloy 6061-T6.
C. Stainless Steel: Comply with the following standards for
the forms and types of stainless steel for the required
items of work.
1. Type: AISI Type 302/304.
2. Bar Stock: ASTM A276.
3. Plate: ASTM A167.
4. Castings: ASTM A296, iron-chromium-nickel alloy.
D. Bronze: Comply with the following standards for the forms
and type of bronze for the required items of work. Alloys
listed refer to standards of the Copper Development
1. Temper: Provide bronze materials in standard
commercial tempers and hardness, as required for
fabrication, strength and durability.
2. Extruded Shapes: ASTM B455; Alloy C38500,
3. Plates and Bars: Alloy C28000 Muntz Metal.
4. Rod and Wire: ASTM B134, Alloy C23000.
5. Castings: ASTM B584; match color of other bronze.
E. Miscellaneous Materials:
1. Welding Electrodes and Filler Metal: Type and alloy
of filler metal and electrodes as recommended by
producer of the metal to be welded, and as required
for color match, strength and compatibility in the
2. Fasteners: Furnish of same basic metal and alloy,
matching finished color and texture as the metal
being fastened. Provide Phillips flat-head screws
for exposed fasteners, countersunk for flush
3. Anchors and Inserts: Furnish inserts to be set in
concrete or masonry work, and provide other
anchoring devices as required for the installation
of ornamental metal items. Provide toothed steel or
lead shield expansion bolt devices for drilled-in-
place anchors. Provide galvanized or cadmium-coated
anchors and inserts for exterior installations.
a. Provide units with exposed surfaces matching
the texture and finish of the metal item
4. Bituminous Paint: SSPC-Paint 12 (cold-applied
5. Protective Lacquer: Clear non-yellowing for
protection of the finished metal surface.
A. Protection: Protect mechanical finish on exposed
surfaces from damage by application of strippable
temporary protective covering prior to shipment.
B. Surface Preparation: Coat concealed surface which will
be in contact with concrete, masonry, wood, or dissimilar
metals, in exterior work and work to be built into
exterior and below grade walls and decks, with a heavy
coat of bituminous paint. Do not extend coating onto
3.02 ERECTION, INSTALLATION, APPLICATION
A. Coordinate and furnish anchorages and setting drawings,
diagrams, templates, instructions and directions for the
installation of items having integral anchors which are
to be embedded in concrete or masonry construction.
Coordinate delivery of such items to the project site.
B. Provide anchorage devices and fasteners where necessary
for securing ornamental metal items to in-place
construction; including, threaded fasteners for concrete
and masonry inserts, toggle bolts, through-bolts, lag
bolts, wood screws and other connectors as required.
C. Perform all cutting, drilling and fitting required for
the installation of the ornamental metal items. Set the
work accurately in location, alignment and elevation,
plumb, level and true, measured from established lines
D. Form tight joints with exposed connections accurately
fitted with uniform reveals and specs for sealants and
joint fillers. Where cutting, welding and grinding are
required for proper shop fitting and jointing of the
work, restore finishes to eliminate any evidence of such
E. Do not cut or abrade finishes which cannot be completely
restored in the field. Return items with such finishes to
the shop for required alterations, followed by complete
refinishing or provide new units at Contractor's option.
F. For guidance on cleaning ornamental metal, see 05700-02-
END OF SECTION