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UniSpec II - Store Planning 022213
SECTION 07620 - SHEET METAL FLASHING AND TRIM
PART 1 - GENERAL
1.1 SUMMARY
A. Section Includes:
1. Fascia and roof edge trim.
2. Counterflashing over base flashing.
3. Metal parapet cap.
4. Door hoods.
5. Refrigeration line hood.
6. Curb covers.
B. Related Sections:
1. Section 04200 – Unit Masonry Assemblies: Metal reglets for masonry.
2. Section 06100 - Rough Carpentry: Wood blocking and nailers.
3. Section 07530 - Elastomeric Membrane Roofing: Roof penetration flashing and seals.
4. Section 07711 - Gutters and Downspouts.
5. Section 07900 - Joint Sealers.
6. Section 09900 - Paints and Coatings.
1.2 REFERENCES
A. The publications listed below form a part of this specification to the extent referenced. Publications are referenced
within the text by the basic designation only.
B. American Architectural Manufacturers Association (AAMA):
1. AAMA 621 - Voluntary Specifications for High Performance Organic Coatings on Coil Coated Architec-
tural Hot Dipped Galvanized (HDG) and Zinc-Aluminum Coated Steel Substrates.
C. ASTM International (ASTM):
1. ASTM A 653 - Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Gal-
vannealed) by the Hot-Dip Process.
2. ASTM A 755/A - Steel Sheet, Metallic Coated by the Hot-Dip Process and Prepainted by the Coil-Coating
Process for Exterior Exposed Building Products.
3. ASTM A 792/A - Steel Sheet, 55% Aluminum-Zinc Alloy-Coated by the Hot-Dip Process
4. ASTM B 749 –Lead and Lead Alloy Strip, Sheet, and Plate Products
5. ASTM D 226 - Specification for Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing.
6. ASTM D 523 - Standard Test Method for Specular Gloss
7. ASTM D 4586 - Specification for Asphalt Roof Cement, Asbestos Free.
D. National Roofing Contractors Association (NRCA):
1. NRCA - Low Slope Roofing Manual.
E. Sheet Metal and Air Conditioning Contractors National Association (SMACNA):
1. SMACNA - Architectural Sheet Metal Manual, Fifth Edition, 1993.
F. Steel Structures Painting Council (SSPC):
1. SSPC-Paint 12 - Cold-Applied Asphalt Mastic (Extra Thick Film).
2. SSPC-Paint 20 Type II - Zinc Rich Primers - Organic.
1.3 QUALITY ASSURANCE
A. Perform work in accordance with SMACNA "Architectural Sheet Metal Manual" and NRCA "Low Slope Roofing
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Manual" standard details and requirements.
B. Supplier Certification: Provide certification from galvanized sheet steel supplier stating that materials conform to
ATSM A 653, G90 hot-dipped galvanized steel.
1.4 DELIVERY, STORAGE AND HANDLING
A. Stack preformed material to prevent twisting, bending, or abrasion, and to provide ventilation.
B. Prevent contact with materials during storage that may cause discoloration, staining, or damage.
PART 2 - PRODUCTS
2.1 SHEET MATERIALS
A. Galvanized Steel: ASTM A 653 Commercial Quality and Lock-Forming Quality, G90 coating designation hot-dip
galvanized, mill phosphatized for painting where exposed to view from ground level. Sheet metal gages shall be
as shown or as follows where not shown:
1. Flashing and Counter Flashing: 24 gage.
2. Fascia and Edge Trim: 24 gage.
3. Door Hood: 18 gage.
4. Wall-Mounted Refrigeration Line Hood: 18 gage.
5. Curb-Mounted Refrigeration Line Hood: 22 gage.
6. Curb Cover: 20 gage.
2.2 ACCESSORIES
A. Fasteners: Galvanized steel finish exposed fasteners to match flashing metal. Furnish exposed fasteners with soft
EPDM washers as manufactured by the following:
1. Kwik-Pro Screws, by Hilti.
2. Trugrip GT, by ITW Buildex.
B. Sealant: Specified in Section 07900.
C. Sealing Mastic: Single component gun grade butyl or polyurethane sealant as recommended by roofing manufac-
turer.
D. Bituminous Coating: SSPC - Paint 12, solvent-type bituminous mastic, nominally free of sulfur, compounded for
15 mil dry film thickness per coat.
E. Draw Band: Stainless steel.
F. Underlayment:
1. Asphalt Saturated Felt: ASTM D 266; No. 30 pound asphalt saturated organic roofing felt, nonperforated.
G. Zinc-Rich Primer: SSPC-Paint 20 Type II.
2.3 FABRICATION
A. Form sections true to shape, accurate in size, square, and free from distortion or defects.
B. Fabricate cleats of same material as sheet, interlockable with sheet.
C. Form pieces in longest possible lengths.
D. Hem exposed edges on underside 1/2 inch; miter and seam corners.
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E. Fabricate corners to form one piece with minimum 18 inches long legs; rivet for rigidity.
F. Fabricate vertical faces with bottom edge formed outward 1/4 inch and hemmed to form drip.
G. Fabricate flashings to allow toe to extend 4 inches over roofing. Return and brake edges.
H. Fabricate exposed sheet metal components with provisions for thermal expansion.
I. Continuously weld or solder all joints in curb covers. Touch up damaged galvanizing with zinc rich primer.
2.4 FINISH
A. Paint metal surfaces exposed to view from ground level in accordance with Section 09900, and as indicated on
Drawings, unless otherwise shown to be prefinished.
PART 3 - EXECUTION
3.1 INSPECTION
A. Verify roof openings, curbs, pipes, sleeves, ducts, or vents through roof are solidly set.
B. Verify roofing membrane termination and base flashings are in place, sealed, and secure.
C. Beginning of installation means acceptance of existing conditions.
3.2 PREPARATION
A. Field measure site conditions prior to fabricating work.
B. Install starter and edge strips, and cleats before starting installation.
3.3 INSTALLATION
A. Install sheet metal flashing and trim in accordance with applicable details of SMACNA "Architectural Sheet Metal
Manual" and NRCA "Low Slope Roofing Manual." Anchor units of work securely in place by methods indicated,
providing for thermal expansion of metal units; conceal fasteners where possible, and set units true to line and lev-
el. Install work with laps, joints, and seams that will be permanently watertight and weatherproof.
B. Bed flanges of metal flashings in plastic cement or sealing mastic where required for waterproof performance.
C. Apply bituminous coating on surfaces in contact with dissimilar materials including the following:
1. Dissimilar metals as defined in SMACNA Appendix A-3.
2. Preservative treated wood.
D. Roof Edge Trim:
1. Install sheet metal edge trim in accordance with SMACNA Figure 2-1, profile as indicated on Drawings.
Nail edge trim flange at 3 inches on center, in staggered pattern.
2. Thermal Expansion Joints: Install roof edge trim in 10 foot lengths with a 1/4 inch gap joint with a 6 inch
cover plate in accordance with SMACNA Figure 2-5A. Set the cover plate in sealant, nail through opening
in edge trim, and loose lock to the drip edge.
3. Corner Joints: Notch and lap. Set laps in sealant and rivet for rigidity. Space rivets at 1 inch on center.
E. Parapet Cap Flashing – Option A:
1. Install sheet metal fascia with cleat in accordance with SMACNA Figure 2-6, profiles and as indicated on
Drawings.
a. Set cleat in full bed of sealant, overlaying and concealing continuous parapet waterproofing mem-
brane.
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b. Secure cleat to nailer at 6 inches on center.
c. Secure fascia to wood nailer with fasteners at 3” o.c. staggered per basic flange nailing pattern.
2. Thermal Expansion Joints: Install parapet fascia in min 10 foot lengths with 4 inch lap joint in accordance
with SMACNA Figure 2-5B. Set lap in sealant.
F. Parapet Cap Flashing – Option B:
1. Install sheet metal coping with continuous cleat in accordance with SMACNA requirements, profiles as
indicated.
a. Set cleat in full bed of sealant, overlaying and concealing continuous parapet waterproofing mem-
brane.
b. Secure cleat at 6 inches on center to nailer.
2. Install coping in accordance with SMACNA Figure 3-1 over shaped fiber board; secure roof side edge us-
ing washered screws in staggered pattern through slotted or oversized holes located at maximum 12" on-
center.
3. Provide coping in minimum 10 to maximum 25 foot lengths.
4. Provide thermal expansion joints using joints in accordance with SMACNA Figure 3-3, Covered Plate
Seam. Set lap in beds of sealant.
G. Curb-Mounted Refrigeration Line Hood: Install galvanized sheet metal hood with gasketed fasteners at 8 inches
on center and as indicated on Drawings. Seal all joints in hood and pipe penetrations to provide weatherproof en-
closure.
H. Reglet and Counterflashing System:
1. Surfaced Mounted Reglet:
a. Set reglet parallel to roof line in full bed of sealant. Provide minimum 2 inch end lap at continuous
elevations.
b. Secure to wall with neoprene/stainless steel washers and drive pins at maximum 16 inches on cen-
ter.
c. Provide a continuous, full bead of sealant at top edge of reglet between flashing and wall. Sealant
bead shall be of sufficient width to provide a 45 degree angle with vertical surface.
2. Masonry Joint Reglet: Specified in Section 04200.
3. Counterflashing: Provide counterflashing of the type indicated or required to match reglet system. Insert
counterflashings into reglets to form tight fit. Counterflashing shall be installed in such a manner as to pro-
vide for continuous contact at base flashing with sufficient pressure at point of contact to prevent disloca-
tion. Lap inside corners. Notch and hook-seam outside corners. Set laps and seams in sealant.
a. Provide minimum 2 inch end lap at continuous elevations.
b. Change in elevation of 4 inches, provide 8 inch end lap.
c. Change in elevation of 8 inches, provide 12 inch end lap.
I. Curb Covers:
1. Install felt underalyment over plywood, and secure in place with galvanized roofing nails.
2. Install metal cover over felt underlayment, and anchor to wood nailer on curb through vertical flange of
cover using gasketed fasteners spaced 12” o.c. maximum.
END OF SECTION