NOTE This standard covers the materials, performance, fabrication, and installation of preformed and field-formed metal roof panel systems, including the panels, concealed or exposed attachment, underlayment, sealants, and integral closures. The panel system types within scope are mechanically seamed standing seam, snap-lock standing seam, batten-seam, and exposed-fastener through-fastened profiles. Both structural systems spanning open framing or purlins and architectural systems over a continuous solid deck are within scope. (1.1)

NOTE Panel-integrated flashing, eave, rake, ridge, valley, and penetration trim are within scope. This standard does not cover the following, which are coordinated with this section but specified elsewhere: (1.4)

NOTE The following standards are referenced in this section; the edition adopted by the authority having jurisdiction governs where a conflict exists. (2.1)

NOTE Action Submittals (3.1)

NOTE Informational Submittals (3.2)

NOTE Closeout Submittals (3.3)

NOTE Qualifications (4.1)

NOTE Field roll-forming, where used, shall be performed by an operator trained and certified by the roll-forming machine manufacturer. (4.1.3)

NOTE Mockups (4.2)

NOTE A mockup demonstrates the seam appearance, finish color, flashing integration, and oil-canning characteristics before full production proceeds. (4.2.1)

NOTE Oil-Canning (4.3)

NOTE Oil-canning is a visible waviness in the flat areas of light-gauge metal panels caused by internal stresses, thermal movement, and forming, and is an inherent characteristic of formed metal, not a defect. (4.3.1)

NOTE Striations, ribs, or a stiffening rib in the flat pan should be specified where a reduced appearance of oil-canning is desired. (4.3.3)

NOTE Wind Uplift (5.1)

NOTE Wind uplift is the dominant structural demand on a metal roof; the panel-and-clip assembly must resist the net uplift pressure at field, perimeter, and corner zones determined from the site design wind speed. (5.1.1)

NOTE Water Penetration (5.2)

NOTE Standing seam systems resist water by seam height and geometry; the required test method depends on whether the governing concern is static head (ponding, snow melt) or wind-driven rain. (5.2.1)

NOTE Fire Classification (5.3)

NOTE Bare metal panels are non-combustible and typically achieve a Class A material rating, but the assembly classification depends on the deck, underlayment, and any insulation below the panel. (5.3.1)

NOTE Where a UL-listed assembly is specified, the assembly shall carry a UL 790 listing for the required class; a UL 790 listing satisfies ASTM E108 but the reverse is not true. (5.3.3)

NOTE Thermal Movement (5.4)

NOTE A long metal panel run expands and contracts significantly with temperature; the clip and seam must accommodate that movement or the panel will buckle and the clip slots will tear. (5.4.1)

NOTE The base metal and coating shall be selected for the corrosivity of the service environment, including coastal salt exposure, industrial pollutants, and agricultural ammonia. (6.1)

NOTE Aluminum or coated aluminum panels should be specified in marine and coastal environments within roughly one mile of salt water where bare and galvanized steel corrode rapidly. (6.2)

NOTE Bare Galvalume panels shall not be used in environments with standing water, animal confinement, or continuous condensation, where the aluminum-zinc coating degrades. (6.4)

NOTE Seam Type (7.1)

NOTE The seam type governs minimum slope, water-tightness, and installation method, and is the single most consequential selection in a metal roof specification. (7.1.1)

NOTE Structural vs. Architectural Substrate (7.2)

NOTE A structural panel spans between purlins or open framing and carries its own uplift rating tied to span and purlin spacing; an architectural panel requires a continuous solid deck below it. Substituting one substrate for the other voids the tested rating and is a frequent source of field conflict. (7.2.1)

NOTE Minimum Slope (7.3)

NOTE Each seam type has a minimum slope below which wind-driven water and static head overwhelm the seam; specifying a panel below its rated slope is a leak source. (7.3.1)

NOTE Panel Coverage Width (7.4)

NOTE Narrower panels reduce oil-canning on wide flat pans but increase the number of seams and the installed cost. (7.4.1)

NOTE Base Metal (8.1)

NOTE The base metal sets the corrosion resistance, structural capacity, and cost of the panel; the choice is driven by environment, span, and budget. (8.1.1)

NOTE Gauge and Thickness (8.2)

NOTE Heavier gauge increases structural span capability and reduces oil-canning; lighter gauge reduces cost and is appropriate for short architectural runs over solid deck. (8.2.1)

NOTE Finish System (8.3)

NOTE The exterior coating governs color retention, chalk and fade resistance, and warranty length; the PVDF 70% fluoropolymer coating is the architectural standard. (8.3.1)

NOTE Color and Cool-Roof Compliance (8.4)

NOTE Not all colors are available in a finish that meets cool-roof solar reflectance thresholds; dark colors usually do not qualify. The color and any reflectance requirement must be reconciled before the palette is locked. (8.4.1)

NOTE Clips and Attachment (9.1)

NOTE Clips transfer uplift from the panel to the structure and, on long runs, allow the panel to move; clip material and design must suit both the panel metal and the thermal movement demand. (9.1.1)

NOTE Fasteners (9.2)

NOTE Concealed clip fasteners and exposed panel fasteners both must resist pull-out under uplift and corrosion over the service life; exposed fasteners additionally seal the penetration. (9.2.1)

NOTE Sealants and Butyl Tape (9.3)

NOTE Standing seam joints and low-slope conditions rely on a continuous sealant bead inside the seam; the sealant must be compatible with both the coating and the base metal or it can react, lose adhesion, or void the finish warranty. (9.3.1)

NOTE Closures and Trim (9.4)

NOTE Closures seal the corrugation profile at terminations against wind-driven rain, insects, and birds; trim integrates the panel field with adjacent surfaces. (9.4.1)

NOTE Flashing and trim detailing should follow the SMACNA Architectural Sheet Metal Manual where a project-specific detail is not provided. (9.4.5)

NOTE Isolation of Dissimilar Metals (9.5)

NOTE Aluminum, copper, and zinc each corrode galvanically when in direct contact with, or in runoff from, a more noble or more active metal; an isolation layer breaks that circuit. (9.5.1)

NOTE Underlayment under a metal panel sees far higher surface temperatures than under most other roof coverings; standard felt or synthetic underlayment can off-gas and bond to the panel underside, so a high-temperature self-adhered product is required. (10.1)

NOTE Standard organic felt underlayment shall not be used directly beneath metal roof panels. (10.4)

NOTE General (11.1)

NOTE Installation should follow the applicable details of the NRCA Roofing Manual for metal panel roof systems where a project detail is not provided. (11.1.3)

NOTE Substrate Preparation (11.2)

NOTE Panel Installation (11.3)

NOTE Field-cutting of panels shall be performed with tools that do not damage the coating; abrasive saws that throw hot metal filings onto the finish shall not be used. (11.3.4)

NOTE Penetrations and Terminations (11.4)

NOTE Protection (11.5)

NOTE Panels and accessories shall be stored off the ground, on a slope, and covered with a breathable cover to prevent water entrapment and white-rust staining of bare or Galvalume surfaces. (12.2)

NOTE Panels stored on site shall be kept dry, as trapped moisture between nested panels causes water staining and coating damage. (12.4)

NOTE Three distinct warranties apply to a metal roof: the finish (fade and chalk), the weathertightness of the installation, and the overall system; each has a different obligor and duration. (13.1)

NOTE Spare panels and matching touch-up coating allow future repair with the original profile and color, which can become unavailable after a finish line is discontinued. (14.1)