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Metal Roof Panels

Written and maintained by SynC.

Rev5
IssuedOct 12, 2026
LicenseCC BY 4.0
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1 Scope

1.1 Systems Covered

NOTE This standard governs the formed metal panels that form the watershedding plane of a roof, together with the clips, fasteners, sealants, closures, underlayment, panel-integrated trim, penetration flashings, curbs, and snow retention that make those panels a weathertight roof. (1.1.1)
NOTE Four panel families are treated as selectable alternatives: mechanically seamed standing-seam panels whose vertical legs are folded together in the field, snap-lock standing-seam panels whose legs engage by hand pressure, batten-seam panels whose upturned legs are covered by a separate cap, and through-fastened lapped panels secured by exposed gasketed screws through the panel face. (1.1.2)
NOTE Each family is available either as a structural panel that spans between purlins or open framing and carries wind and gravity load on its own section, or as an architectural panel that requires a continuous solid deck beneath it. The family and the substrate condition are independent decisions, and this standard records them separately. (1.1.3)
NOTE A metal roof is a kinetic assembly. A panel run of ordinary length changes length by a measurable fraction of an inch between a winter night and a summer afternoon, and every clip, seam, trim piece, curb, and penetration is detailed either to let that movement happen or to resist it at one deliberate point. The most consequential idea in this standard is that nothing restrains a floating panel except its designated fixed point; a curb screwed through the pan, an over-driven trim fastener, or a rigid pipe boot concentrates the movement at the nearest free point and tears the seam or the clip there. (1.1.4)
1.1.5 The panel system shall be furnished as a complete system from a single panel manufacturer, including panels, clips, fasteners, seam sealant, closures, and panel-integrated trim.
1.1.6 Every component of the installed system shall be a component of the tested assembly relied on for uplift resistance, water penetration resistance, and fire classification.
1.1.7 Substitution of any component of a tested assembly shall be resubmitted with evidence that the substituted assembly retains the required uplift resistance, water penetration resistance, and fire classification, and the Contractor shall not proceed with the substituted assembly until the Engineer of Record has accepted that evidence in writing.

1.2 Work Governed by Companion Standards

NOTE The following work is outside this standard and is governed elsewhere: (1.2.1)
  • Vertical and soffit metal wall cladding, including matching wall panels, which is governed by Metal Wall PanelsMetal Wall PanelsResolves to the current adopted revision.sync/metal-wall-panels
  • Sheet membrane roofing, governed by Membrane RoofingMembrane RoofingResolves to the current adopted revision.sync/membrane-roofing, and fluid-applied roofing, governed by Fluid Applied RoofingFluid-Applied Roofing and CoatingsResolves to the current adopted revision.sync/fluid-applied-roofing
  • Asphalt shingle roofing and the underlayment beneath shingles, governed by Asphalt Shingle RoofingAsphalt Shingle RoofingResolves to the current adopted revision.sync/asphalt-shingle-roofing
  • Shop-formed and field-formed architectural sheet metal furnished as a separate scope, including copings, counterflashings, and reglets, governed by Sheet Metal Flashing And TrimSheet Metal Flashing and TrimResolves to the current adopted revision.sync/sheet-metal-flashing-and-trim, and manufactured low-slope roof edge systems, governed by Roof Specialties And CopingsRoof Specialties and CopingsResolves to the current adopted revision.sync/roof-specialties-and-copings
  • Eave-hung gutters, leader heads, and downspouts furnished as a separate scope, governed by Gutters And DownspoutsGutters and DownspoutsResolves to the current adopted revision.sync/gutters-and-downspouts
  • Roof thermal insulation, vapor retarders, and the air barrier plane of the roof, governed by Building Thermal InsulationBuilding Thermal InsulationResolves to the current adopted revision.sync/building-thermal-insulation and Air BarriersAir BarriersResolves to the current adopted revision.sync/air-barriers
  • The roof deck and its attachment, governed by Steel DeckSteel DeckResolves to the current adopted revision.sync/steel-deck and Wood SheathingWood Structural Panel SheathingResolves to the current adopted revision.sync/wood-sheathing
  • The purlins, joists, and trusses that carry the panels, governed by Cold Formed Metal FramingCold-Formed Metal FramingResolves to the current adopted revision.sync/cold-formed-metal-framing, Steel JoistsSteel JoistsResolves to the current adopted revision.sync/steel-joists, and Wood Roof TrussesPre-Engineered Wood Roof TrussesResolves to the current adopted revision.sync/wood-roof-trusses
  • Roof panels, trim, and closures furnished and erected as part of a pre-engineered metal building package, governed by Metal Building SystemsMetal Building SystemsResolves to the current adopted revision.sync/metal-building-systems
  • The roof hatch, smoke vent, and skylight units themselves, governed by Roof Hatches And Smoke VentsRoof Hatches and Smoke VentsResolves to the current adopted revision.sync/roof-hatches-and-smoke-vents and SkylightsSkylights and Unit SkylightsResolves to the current adopted revision.sync/skylights; the curb framing, panel penetration treatment, and cricket that receive those units on a metal panel roof are governed here
  • Roof drains, overflow drains, and interior storm piping, governed by Roof DrainageRoof DrainageResolves to the current adopted revision.sync/roof-drainage
  • Photovoltaic racking, fall-protection anchorage, and lightning protection conductors clamped to the seams, governed by Photovoltaic SystemsPhotovoltaic SystemsResolves to the current adopted revision.sync/photovoltaic-systems, Fall Protection AnchorageRoof and Facade Fall Protection AnchorageResolves to the current adopted revision.sync/fall-protection-anchorage, and Lightning ProtectionLightning Protection SystemsResolves to the current adopted revision.sync/lightning-protection; the seam capacity those clamps rely on is confirmed here
  • Perimeter and movement-joint sealants at the building wall, governed by Joint SealantsJoint SealantsResolves to the current adopted revision.sync/joint-sealants
NOTE Eave gutters, ridge and hip caps, rake and eave trim, valley metal, and transition flashings that the panel manufacturer furnishes as part of the panel system are governed here, because they share the panel's metal, finish, movement provisions, and warranty. The same pieces furnished as a separate scope are governed by Sheet Metal Flashing And TrimSheet Metal Flashing and TrimResolves to the current adopted revision.sync/sheet-metal-flashing-and-trim and Gutters And DownspoutsGutters and DownspoutsResolves to the current adopted revision.sync/gutters-and-downspouts, and a given piece is specified under one standard, never both. (1.2.2)
NOTE Underlayment beneath metal roof panels on a solid deck is part of the panel assembly and is governed here; Asphalt Shingle RoofingAsphalt Shingle RoofingResolves to the current adopted revision.sync/asphalt-shingle-roofing governs the underlayment beneath shingles, and Membrane RoofingMembrane RoofingResolves to the current adopted revision.sync/membrane-roofing has no underlayment layer. The temperature a metal panel reaches in sun is the reason this assembly's underlayment is specified separately from the shingle underlayment. (1.2.3)

1.3 Code Basis

1.3.1 Metal roof panels shall comply with the roof covering provisions of IBC Chapter 15 as adopted in Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code, including the material, slope, underlayment, and attachment provisions of IBC Section 1507.4 and the wind resistance provisions of IBC Section 1504.
1.3.2 Structural panels that span open framing shall be designed as cold-formed steel or aluminum structural members under the structural provisions of Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code, and the panel manufacturer's published section properties and tested span capacities shall be the basis of that design.
1.3.3 Where this standard, the Contract Documents, the adopted code, the panel manufacturer's published instructions, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

2 Referenced Standards

2.1 Materials, fabrication, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited in the Contract Documents.
2.2 The edition of the building code and energy code that governs is the edition adopted by the Authority Having Jurisdiction, recorded as Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code and Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code.
Standard Title
IBC International Building Code, Chapter 15 — Roof Assemblies and Rooftop Structures
IECC International Energy Conservation Code
ASHRAE 90.1 Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
ASCE 7 Minimum Design Loads and Associated Criteria for Buildings and Other Structures
ASTM A653/A653M Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process
ASTM A792/A792M Steel Sheet, 55% Aluminum-Zinc Alloy-Coated by the Hot-Dip Process
ASTM A755/A755M Steel Sheet, Metallic Coated by the Hot-Dip Process and Prepainted by the Coil-Coating Process for Exterior Exposed Building Products
ASTM A924/A924M General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process
ASTM A240/A240M Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
ASTM B209/B209M Aluminum and Aluminum-Alloy Sheet and Plate
ASTM B370 Copper Sheet and Strip for Building Construction
ASTM B69 Rolled Zinc
ASTM D226/D226M Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing
ASTM D4869/D4869M Asphalt-Saturated Organic Felt Underlayment Used in Steep Slope Roofing
ASTM D1970/D1970M Self-Adhering Polymer Modified Bituminous Sheet Materials Used as Steep Roofing Underlayment for Ice Dam Protection
ASTM D8257/D8257M Mechanically Attached Polymeric Roof Underlayment Used in Steep Slope Roofing
ASTM E108 Fire Tests of Roof Coverings
UL 790 Standard Test Methods for Fire Tests of Roof Coverings
ASTM E1514 Structural Standing Seam Steel Roof Panel Systems
ASTM E1637 Structural Standing Seam Aluminum Roof Panel Systems
ASTM E1592 Structural Performance of Sheet Metal Roof and Siding Systems by Uniform Static Air Pressure Difference
ASTM E1646 Water Penetration of Exterior Metal Roof Panel Systems by Uniform Static Air Pressure Difference
ASTM E1680 Rate of Air Leakage Through Exterior Metal Roof Panel Systems
ASTM E2140 Water Penetration of Metal Roof Panel Systems by Static Water Pressure Head
ASTM E1886 Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials
ASTM E1996 Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes
UL 580 Tests for Uplift Resistance of Roof Assemblies
UL 1897 Uplift Tests for Roof Covering Systems
UL 2218 Impact Resistance of Prepared Roof Covering Materials
FM 4471 Approval Standard for Class 1 Panel Roofs
FM 4474 Evaluating the Simulated Wind Uplift Resistance of Roof Assemblies Using Static Positive and/or Negative Differential Pressures
FM Global Data Sheet 1-31 Panel Roof Systems
AAMA 621 Voluntary Specification for High Performance Organic Coatings on Coil Coated Architectural Hot Dipped Galvanized (HDG) and Zinc-Aluminum Coated Steel Substrates
AAMA 2604 Voluntary Specification, Performance Requirements and Test Procedures for High Performance Organic Coatings on Aluminum Extrusions and Panels
AAMA 2605 Voluntary Specification, Performance Requirements and Test Procedures for Superior Performing Organic Coatings on Aluminum Extrusions and Panels
AAMA 611 Voluntary Specification for Anodized Architectural Aluminum
AAMA 501.2 Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems
ASTM D523 Specular Gloss
ASTM D2244 Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
ASTM D4214 Evaluating the Degree of Chalking of Exterior Paint Films
CRRC-1 Cool Roof Rating Council Product Rating Program Standard
SMACNA Architectural Sheet Metal Manual Architectural Sheet Metal Manual
NRCA Roofing Manual Metal Panel and SPF Roof Systems
MCA Metal Roof Installation Manual Metal Construction Association Metal Roof Installation Manual

3 Submittals

3.1 Action Submittals

NOTE The uplift rating, the water penetration rating, and the fire classification each belong to the assembly as tested, with its clip, clip spacing, substrate, underlayment, and fastener. A panel submitted without its clip and fastener schedule cannot be checked against any of them, which is why this standard requires the package as a whole. (3.1.1)
3.1.2 The Contractor shall submit the following for review and acceptance as one package before materials are ordered or field roll-forming begins:
  • Product data for the panel system identifying the panel family, profile, seam height, coverage width, base metal and its governing material specification, gauge or thickness, metallic coating designation, finish system, and interior-face coating
  • Shop drawings showing panel layout and module, panel lengths, endlap locations where panels are endlapped, the designated fixed point of each panel run, clip type and spacing by roof zone, fastener type and spacing, and every eave, rake, ridge, hip, valley, transition, penetration, curb, and expansion condition
  • Structural calculations for structural panels and for clip attachment, sealed by a professional engineer where the jurisdiction or the Contract Documents require it, demonstrating that the panel, clips, and fasteners resist the design uplift pressures in every roof zone within the tested span and attachment limits
  • The uplift test report, classification, or approval listing relied on, in the configuration matching the project
  • Water penetration and, where required, air leakage test reports for the panel system
  • Fire classification listing for the complete assembly on the specified deck or framing and at the specified slope
  • Underlayment, ice barrier, seam sealant, closure, fastener, and thermal spacer block product data
  • Finish product data and the finish warranty specimen stating the chalk, color change, and film integrity criteria and the warranty period
  • Color and finish samples on the specified base metal in the specified gauge, of sufficient size to evaluate color and gloss in daylight, and a panel sample not less than 12 in long showing the seam, pan treatment, and finish
  • Snow retention product data and the layout calculation, where snow retention is required
  • Curb product data and shop drawings for every curb set on the panels
  • Installer qualification evidence and the field roll-forming operator certification where panels are field-formed
  • The proposed warranty forms and the conditions the manufacturer places on issuing them
Action Submittals Requiredcheckbox
☑ Panel system product data
☑ Shop drawings with layout, fixed points, clip and fastener schedule, and every termination
☑ Sealed structural and attachment calculations
☑ Uplift test report, classification, or approval listing
☐ Water penetration and air leakage test reports
☑ Fire classification listing for the complete assembly
☑ Underlayment, sealant, closure, fastener, and spacer block product data
☑ Finish product data and finish warranty specimen
☑ Color, finish, and panel samples
☐ Snow retention product data and layout calculation
☐ Curb product data and shop drawings
☑ Installer qualification evidence and roll-forming operator certification
☑ Proposed warranty forms and issuance conditions
3.1.3 Product data submitted as a marked catalog page shall have the proposed profile, gauge, coating, finish, and clip clearly identified.

3.2 Informational Submittals

3.2.1 The Contractor shall submit the following for information before the pre-installation conference:
  • The manufacturer's written installation instructions for the specific panel, clip, and seamer in use
  • The proposed sequence of work, including how partially completed roof areas will be made watertight at the end of each work period
  • A schedule of the temporary loads the Contractor intends to place on installed panels, including material staging and equipment
  • The field water test procedure where field water testing is required
  • Safety data sheets for sealants, cleaners, and touch-up coatings
Informational Submittals Requiredcheckbox
☑ Manufacturer installation instructions for the panel, clip, and seamer
☑ Sequence of work and nightly water cut-off method
☑ Schedule of temporary rooftop loads
☐ Field water test procedure
☐ Safety data sheets

3.3 Closeout Submittals

3.3.1 The Contractor shall submit the following before final acceptance and before the manufacturer's warranty is executed:
  • The executed finish warranty and, where required, the executed manufacturer weathertightness warranty
  • The executed Contractor workmanship warranty
  • The manufacturer's final inspection report, where manufacturer field representation is specified, and the Contractor's written resolution of each item on it
  • Field water test reports where field testing was performed
  • Record drawings showing the as-installed panel layout, fixed points, clip type, every penetration and curb, every endlap, and every field repair
  • Touch-up coating in each color in sealed factory containers, with the manufacturer's instructions for its use and its limits
  • Maintenance instructions covering inspection frequency, permitted cleaning methods, debris removal at valleys and gutters, sealant renewal locations, snow retention inspection, and the procedure for authorizing rooftop work after acceptance
Closeout Submittals Requiredcheckbox
☑ Executed finish warranty and manufacturer weathertightness warranty
☑ Executed Contractor workmanship warranty
☐ Manufacturer final inspection report and resolution of each item
☐ Field water test reports
☑ Record drawings of layout, fixed points, penetrations, curbs, endlaps, and repairs
☑ Touch-up coating with instructions and limits
☑ Maintenance instructions

4 Quality Assurance

4.1 Installer Qualifications

NOTE Standing-seam work is unforgiving at exactly the places that are hard to inspect afterward: the seam fold behind a curb, the closure under a ridge cap, and the sealant inside an endlap. Manufacturer authorization programs exist because a weathertightness warranty is underwritten on the installer as much as on the panel, and where the warranty is conditioned on an authorized installer the qualification and the warranty are the same decision seen twice. (4.1.1)
4.1.2 The panel installer shall meet the qualification basis selected in the datasheet.
Installer Qualification Basisradio
● Current panel manufacturer authorization for the specified system
○ Manufacturer-approved installer with documented comparable metal roof projects
○ Documented comparable metal roof projects of the same seam type
4.1.3 Where the manufacturer's weathertightness warranty is conditioned on an authorized installer, that condition shall govern regardless of the qualification basis selected.
4.1.4 The roofing foreman assigned to the project shall have not less than five years of documented field experience installing the seam type specified.
4.1.5 Where the Contractor proposes to replace the qualified foreman during the work, the replacement's qualifications shall be submitted and accepted before the change takes effect.

4.2 Field Roll-Forming Qualification

NOTE A panel rolled on site from coil is the same product as a factory panel only when the machine is the manufacturer's, is set up by a trained operator, and is checked against the profile tolerance as production proceeds. A portable machine that is out of adjustment produces a seam that will not fold or snap correctly along its entire length, and the defect is not visible until the seamer stalls. (4.2.1)
4.2.2 Where panels are field roll-formed, the machine shall be the panel manufacturer's or a machine the panel manufacturer has approved in writing for the specified profile.
4.2.3 The roll-forming operator shall hold a current certification from the machine manufacturer for the machine in use.
4.2.4 The Contractor shall check the first panel rolled each day, and each panel rolled after any machine adjustment, against the manufacturer's published profile tolerances before that panel is installed.
4.2.5 Coil used for field roll-forming shall be the panel manufacturer's coil in the specified base metal, gauge, metallic coating, and finish, and shall be documented by the coil tag and mill certification.

4.3 Pre-Installation Conference

NOTE Most metal roof leaks begin at a trade boundary: a curb set by the mechanical trade through a floating panel, a lightning conductor screwed through the pan, or a gutter hung by another trade that pins the eave. The conference exists to settle, in advance and on paper, who installs each attachment to the roof, in what sequence, and under what rule for panel movement. (4.3.1)
4.3.2 Before panel work begins, the Contractor shall convene a pre-installation conference attended by the Contractor, the roofing foreman, the panel manufacturer's representative where field representation is specified, the Engineer of Record, and each trade whose work penetrates, bears on, or clamps to the roof panels.
4.3.3 The conference shall cover the accepted assembly, the sequence of work, substrate acceptance, underlayment and ice barrier extent, the fixed point of each panel run, clip spacing by roof zone, curb and penetration responsibility by trade, snow retention layout, the weather limits of this standard, warranty conditions, and rooftop load and access control after acceptance.
4.3.4 The Contractor shall record and distribute conference minutes within five business days of the conference.

4.4 Mockups

NOTE A mockup fixes the seaming, the eave and rake closure sequence, and the acceptable appearance of the pan, including oil-canning, as an object the parties can stand on before those choices are repeated across the roof. A standalone mockup can be rebuilt without consequence; an in-place mockup commits the first roof area as the standard and is the economical choice where the roof is small or the profile is one the installer has placed before; no mockup suits a utilitarian through-fastened roof where appearance is not a criterion. (4.4.1)
4.4.2 The mockup requirement shall be as selected in the datasheet.
Mockup Requirementradio
○ Standalone mockup built before production installation
○ In-place mockup, the first area of installed work retained in the finished roof
○ Not required
4.4.3 Where a mockup is required, it shall include not less than three full panels, one eave termination, one rake termination, one ridge or high-side termination, and one penetration, built on the project substrate with the specified underlayment and clips.
4.4.4 The mockup shall be reviewed and accepted by the Engineer of Record and, where manufacturer field representation is specified, by the manufacturer's representative before production installation proceeds.
4.4.5 The accepted mockup shall establish the standard of workmanship and of appearance, including the acceptable degree of oil-canning, for the remainder of the work.
4.4.6 Where the in-place mockup is selected, the mockup area shall be integrated into the completed roof and shall carry the same warranties as the surrounding roof.

4.5 Oil-Canning Acceptance

NOTE Oil-canning is the visible waviness in the flat pan of a formed metal panel caused by residual stress in the coil, by forming, by thermal movement, and by substrate irregularity. It is an inherent characteristic of light-gauge flat metal rather than a defect of fabrication, and no consensus test method measures it, which is why acceptance is fixed against the mockup rather than against a number. Wider pans, lighter gauge, high-gloss dark finishes, and a substrate that is out of plane all make it more visible. (4.5.1)
4.5.2 Oil-canning shall not be cause for rejection where the installed panels conform to the appearance of the accepted mockup and to the manufacturer's published flatness tolerances.
4.5.3 Where the parties disagree whether installed panels conform to the accepted mockup, the Engineer of Record shall make the initial determination.
4.5.4 Where no mockup is required, the manufacturer's published flatness tolerances shall govern.

4.6 Manufacturer Field Representation

NOTE Manufacturer site visits are how a weathertightness warranty is underwritten; the same visits catch a wrong clip, a missed sealant bead, or a pinned panel while the correction is still a panel rather than a roof area. (4.6.1)
4.6.2 Manufacturer field representation shall be as indicated in the datasheet.
Manufacturer Field Representationcheckbox
☑ Attendance at the pre-installation conference
☐ Site visit at the start of panel installation
☐ Interim site visits during panel installation
☑ Final inspection before warranty issuance
☑ Written report for each site visit
4.6.3 Reports from each manufacturer site visit shall be included in the closeout submittal.
4.6.4 The Contractor shall provide safe access and shall schedule the work so that each specified manufacturer visit occurs at the installation milestone it is intended to observe.

5 Environmental and Service Conditions

5.1 Corrosion Exposure

NOTE The base metal, metallic coating, finish, and fasteners each have a service life that depends on the atmosphere: salt aerosol within a few miles of a coast, acid deposition in an industrial atmosphere, and the ammonia of animal confinement each attack a different part of the assembly. Aluminum-zinc coated steel outlasts galvanized steel in most atmospheres but is attacked by alkaline runoff and by continuous wetting; aluminum is unaffected by salt aerosol but is attacked by alkali and by contact with copper; galvanized steel tolerates animal-confinement ammonia better than aluminum-zinc coated steel does. Galvanic compatibility is a hard constraint in every exposure. (5.1.1)
5.1.2 The base metal, metallic coating, finish, and fasteners shall be selected for the corrosion exposure category of the site as selected in the datasheet.
Corrosion Exposure Categoryradio
○ Inland, normal atmospheric
○ Industrial or urban atmosphere
○ Coastal or marine
○ Agricultural, animal confinement, or chemical exposure
5.1.3 Where the coastal or marine category applies, fasteners shall be stainless steel, and the base metal, metallic coating, and finish shall be of grades the panel manufacturer publishes as warrantable for that exposure.
5.1.4 Where the agricultural, animal confinement, or chemical exposure category applies, the base metal and metallic coating shall be of a type the panel manufacturer publishes as warrantable for that exposure, and the finish warranty shall state that the exposure is covered.
5.1.5 Aluminum-zinc alloy-coated steel shall not be installed where it will be continuously wetted by alkaline runoff from mortar, fresh concrete, or treated wood, and shall not be installed in direct contact with wet treated wood.
5.1.6 Runoff from copper, including runoff carried by a copper gutter or flashing, shall not discharge onto aluminum, aluminum-zinc alloy-coated steel, or galvanized steel surfaces.

5.2 Thermal Movement Design

NOTE Steel changes length by roughly 0.0000065 in per inch per °F and aluminum by roughly twice that, so a 100 ft steel panel moves about three quarters of an inch over a 100 °F surface temperature swing and an aluminum panel about an inch and a half. The surface temperature range is wider than the air temperature range, because a panel in sun runs well above ambient and a panel radiating to a clear night sky runs below it, and a dark finish widens the range further. Floating clips, slotted trim fasteners, and movement-tolerant penetration flashings are sized to this range. (5.2.1)
5.2.2 The panel system shall accommodate thermal movement over the design panel surface temperature range without buckling, seam separation, clip disengagement, fastener fatigue, sealant failure, or audible movement at the fixed point.
5.2.3 The design panel surface temperature range shall be derived from Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum, Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum, and the solar absorptance of the selected finish color, and shall be stated on the shop drawings.
Design Panel Surface Temperature Rangerange
Not less than
°F
100250
Derived — Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum, Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum, and the solar absorptance of the selected finish color (by default)
5.2.4 Each panel run shall be fixed to the structure at one point only and shall be free to move at every other clip, trim connection, and penetration.
5.2.5 Trim, closures, and flashings attached to the panels shall be attached with slotted holes, sliding cleats, or clips that permit the panel's design movement, and shall not be face-fastened through the pan at more than one line of fasteners per panel run.

5.3 Weather Limits During Installation

NOTE Seam sealant and self-adhering underlayment both have a minimum application temperature below which they do not wet out, and a seamer run on a frosted seam folds ice into the joint. Wind is the other limit: a panel is a sail until it is seamed, and a loose panel in a gust is a hazard to the crew and to the roof below. (5.3.1)
5.3.2 Self-adhering underlayment and seam sealant shall not be applied below the minimum application temperature the product manufacturer publishes, nor onto a surface carrying frost, ice, dew, or standing water.
5.3.3 Panels shall not be set or seamed during precipitation, nor when the substrate or the seam carries frost, ice, or standing water.
5.3.4 Panels shall not be set when the wind speed at the roof exceeds the limit the panel manufacturer publishes for handling the specified panel length, and every panel set during a work period shall be seamed or otherwise secured against uplift before the crew leaves the roof.
5.3.5 The Contractor shall provide temporary water cut-offs at the end of each work period so that no underlayment edge, open seam, or unflashed penetration is left open to precipitation.

6 Wind Uplift Design Basis

6.1 Design Uplift Pressures

NOTE Uplift on a roof is not uniform. Flow separation at the eave and rake and vortex formation at the corners produce suctions several times the field value over a small fraction of the roof area, which is why clip spacing is specified by zone rather than by one number. The pressures are a structural output, following from the building's risk category, mean roof height, exposure, enclosure classification, and the basic wind speed for the site; this standard records them so that the tested assembly can be checked against them. (6.1.1)
6.1.2 The design uplift pressures for the field, perimeter, and corner zones of the roof shall be established by the Engineer of Record in accordance with ASCE 7 and Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code, and shall be as indicated in the datasheet.
Design Uplift Pressure, Field Zonerange
Not less than
psf
0300
Per drawings — the roof wind pressure zone diagram on the structural drawings (deferred by default)
6.1.3 The design uplift pressure for the perimeter zone shall be as indicated in the datasheet.
Design Uplift Pressure, Perimeter Zonerange
Not less than
psf
0400
Per drawings — the roof wind pressure zone diagram on the structural drawings (deferred by default)
6.1.4 The design uplift pressure for the corner zone shall be as indicated in the datasheet.
Design Uplift Pressure, Corner Zonerange
Not less than
psf
0500
Per drawings — the roof wind pressure zone diagram on the structural drawings (deferred by default)
6.1.5 The extent of the perimeter and corner zones shall be as indicated on the roof wind pressure zone diagram on the structural drawings.
6.1.6 Where the Owner's property insurer imposes uplift criteria that exceed the code-derived design pressures, the insurer's criteria shall govern and shall be reflected in the pressures recorded in the datasheet.

6.2 Uplift Rating Method

NOTE The four rating methods answer the same question in different currencies, and the choice follows from who will review the roof and how the panel spans: (6.2.1)
  • ASTM E1592 is a chamber test of the panel, clip, and support system that produces a load and deflection record and an ultimate capacity for a tested span; the capacity, reduced by the safety factor the adopted code requires, is compared zone by zone against the ASCE 7 design pressures, so it supports span-specific engineering and is the method most structural standing-seam systems hold; it is also the method the model code names for metal panels over open framing
  • UL 580 is a pass or fail classification of one fixed assembly under static and oscillating pressure, reported as a class number; it is simple to specify and to verify, but the class is not a design pressure, and the classification holds only for the deck, clip, and spacing tested
  • UL 1897 is a static uplift test of the roof covering system that reports the pressure reached, and it is used where the assembly must demonstrate a pressure beyond the highest UL 580 class or where an existing deck is part of the test
  • FM 4471 is an approval that combines uplift resistance evaluated under FM 4474 with hail, foot traffic, and fire criteria, reported as a Class 1 uplift rating; it is the method a property insured by FM Global will be reviewed against, and the approval also fixes the clip spacing by zone through FM Global Data Sheet 1-31
6.2.2 The basis on which the panel system's uplift resistance is established shall be as selected in the datasheet.
Uplift Rating Methodradio
○ ASTM E1592 structural test with capacity reduced by the code safety factor
○ UL 580 assembly classification
○ UL 1897 uplift test report
○ FM 4471 Class 1 panel roof approval
6.2.3 The rated, classified, or approved uplift resistance of the panel system shall equal or exceed the design uplift pressure for each roof zone.
6.2.4 The rating relied on shall have been established with the clip, clip spacing, fastener, substrate or purlin spacing, seam type, and panel width that will be installed, and a rating established on a different configuration shall not be extended to the project by interpolation unless the panel manufacturer's engineer certifies the extension in writing.
6.2.5 Where the rating method is ASTM E1592, the safety factor applied to the tested capacity shall be the factor Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code and ASCE 7 require for the panel and clip, and the calculation applying it shall be included in the action submittal.
6.2.6 Where a property is insured by FM Global, the panel system shall carry an FM 4471 approval at or above the uplift rating FM Global Data Sheet 1-31 requires for the roof, in addition to any other rating method selected.

6.3 Zone Attachment and Edge Securement

6.3.1 Clip spacing in each roof zone shall be as required by the rating relied on for that zone's design pressure, and shall be shown on the shop drawings by zone.
6.3.2 Clip spacing in the perimeter and corner zones shall be reduced relative to the field zone by the amount the governing rating requires.
6.3.3 The Contractor shall not increase clip spacing, omit clips, or substitute a clip or fastener of a different type, size, or length from that in the governing rating.
6.3.4 Eave, rake, and ridge trim and the panel terminations beneath them shall be attached as detailed in the tested assembly or, where the tested assembly does not address the termination, as detailed by the panel manufacturer's engineer for the perimeter or corner zone pressure at that edge.
6.3.5 The Contractor shall verify the installed clip pattern in each zone against the shop drawings before the pattern is concealed by the next panel.

7 Water Penetration, Air Leakage, and Fire Classification

7.1 Water Penetration Resistance

NOTE A seam leaks in two ways. Static head is water standing against the seam, as it does in a drift, at an ice dam, or on a very low slope where the seam sits in a film of moving water; it is tested by ASTM E2140, which floods the panel to a depth above the seam. Wind-driven rain is water pushed through the seam by pressure difference; it is tested by ASTM E1646, which sprays the panel under a static pressure difference. A low-slope standing-seam roof needs both; a steep roof that drains freely is governed by the second. (7.1.1)
7.1.2 The water penetration test basis for the panel system shall be as selected in the datasheet.
Water Penetration Test Basisradio
○ ASTM E2140 static water head and ASTM E1646 static air pressure difference
○ ASTM E1646 static air pressure difference
○ ASTM E2140 static water head
7.1.3 The panel system shall show no uncontrolled water penetration when tested by the selected basis at the pressure difference or head the panel manufacturer publishes for the specified seam and slope.
7.1.4 Where the test pressure is not stated in the Contract Documents, the ASTM E1646 test pressure difference shall be not less than 20 percent of the design uplift pressure for the field zone and not less than 6.24 psf.
7.1.5 Where the roof slope is less than 1 in 12, the panel system shall carry an ASTM E2140 static head rating at a head not less than the seam height.

7.2 Air Leakage

NOTE A structural standing-seam roof over purlins with blanket insulation below it is often the air barrier plane of the roof, and a roof that is the air barrier is held to the whole-building air leakage requirement of the energy code. Where a separate air barrier exists below the panels, the panel air leakage is a comfort and condensation question rather than a code one, and testing is seldom required. (7.2.1)
7.2.2 Whether the panel system shall be tested for air leakage shall be as selected in the datasheet.
Air Leakage Test (ASTM E1680)radio
○ Required
○ Not required
7.2.3 Where air leakage testing is required, the panel system shall limit air leakage to not more than the rate the manufacturer publishes for the specified seam when tested per ASTM E1680 at a static pressure difference of 1.57 psf, and the rate shall be reported in the action submittal.
7.2.4 Where the panel system is the air barrier plane of the roof, its connection to the wall air barrier at eaves, rakes, and parapets shall be continuous and shall be coordinated with Air BarriersAir BarriersResolves to the current adopted revision.sync/air-barriers.

7.3 Roof Covering Fire Classification

NOTE Metal panels do not burn, but a roof covering classification describes the assembly under external fire exposure, including the deck and underlayment beneath the metal. IBC Section 1505 treats metal sheets on a noncombustible deck or on noncombustible framing without a deck as Class A without a test, so a steel-purlin or steel-deck roof is Class A by the code's own terms; the same panels over a wood deck with an underlayment earn their classification only as a tested assembly, and the listing must cover the underlayment actually used. (7.3.1)
7.3.2 The roof covering fire classification required for the building shall be established from IBC Section 1505 and Table 1505.1 for the construction type and occupancy, and shall be as indicated in the datasheet.
Roof Covering Fire Classificationradio
● Class A
○ Class B
○ Class C
○ No fire classification required by the adopted code for this building
7.3.3 Where the panels are installed over a combustible deck, the classification shall be demonstrated by a current listing under ASTM E108 or UL 790 for the complete assembly, including the underlayment, on the specified deck type and at the specified slope.
7.3.4 Where the panels are installed on a noncombustible deck, or on noncombustible framing without a deck, the Class A classification IBC Section 1505 assigns to metal sheet roof coverings on those substrates shall be documented in the action submittal by citing that provision.
7.3.5 The listing relied on shall cover the slope of the roof area to which it is applied.

8 Panel System Configuration

8.1 Substrate and Span Condition

NOTE A structural panel spans between purlins or open framing on its own section and carries its uplift rating as a function of span; an architectural panel is rated only over a continuous solid deck and depends on the deck for support between clips. The two are different products with different gauges, seam heights, and ratings, and setting one on the other's substrate voids the rating. (8.1.1)
8.1.2 The substrate condition on which the panels are installed shall be as selected in the datasheet.
Panel Substrate Conditionradio
○ Structural panel spanning open purlins or framing
○ Architectural panel over a continuous solid deck
8.1.3 Structural steel panels shall be rated under ASTM E1514, and structural aluminum panels under ASTM E1637, for the purlin spacing indicated on the roof framing plan.
8.1.4 Architectural panels shall be installed only over a continuous solid deck that is itself attached to resist the design uplift pressures, with the underlayment this standard requires between the deck and the panels.
8.1.5 The deck type and its attachment are governed by Steel DeckSteel DeckResolves to the current adopted revision.sync/steel-deck and Wood SheathingWood Structural Panel SheathingResolves to the current adopted revision.sync/wood-sheathing; this standard governs what the panel system requires of the deck surface it is set on.

8.2 Seam and Attachment Type

NOTE The seam type sets the minimum slope, the water penetration resistance, the installation method, and the warranty the manufacturer will offer: (8.2.1)
  • A mechanically seamed standing seam is folded closed in the field by a powered seamer, with sealant inside the fold; it is the only seam rated down to the shallowest slopes, it carries the highest uplift and static head ratings, and it is the seam on which long-term manufacturer weathertightness warranties are written; it costs the seamer pass and is the slowest to install
  • A snap-lock standing seam engages by hand pressure without a seamer and is faster and cheaper to install, with an unsealed seam that depends on slope to drain; manufacturers rate it for steeper slopes than a mechanical seam, and it is the common architectural choice over a solid deck
  • A batten seam closes the joint with a separate cap snapped or seamed over the upturned legs, giving a wider rib and a traditional appearance; it is an architectural system over a solid deck and shares the slope limits of a snap-lock seam
  • A through-fastened lapped panel is secured by exposed gasketed screws through the panel face into the support; it is the lowest-cost system and is fast to install, but every fastener is a penetration whose gasket ages in the sun and whose hole elongates with thermal movement, so it is rated only for steeper slopes and carries no weathertightness warranty beyond the material warranty
8.2.2 The panel seam and attachment type shall be as selected in the datasheet.
Panel Seam and Attachment Typeradio
○ Mechanically seamed standing seam
○ Snap-lock standing seam
○ Batten seam with separate cap
○ Through-fastened lapped panel
8.2.3 Mechanically seamed panels shall be seamed with the panel manufacturer's seamer, to the full fold the rating relied on was tested with, within the time after panel placement the manufacturer publishes.
8.2.4 Snap-lock and batten-seam panels shall be fully engaged along the entire seam length so that no part of the seam is open.
8.2.5 Through-fastened panels shall be attached with gasketed fasteners driven perpendicular to the panel through the rib or the flat as the rating relied on was tested, seated so that the gasket is compressed without being extruded, and at the spacing the rating requires for each roof zone.

8.3 Mechanical Seam Fold

NOTE A single-lock fold turns the seam legs 90 degrees and leaves a vertical fin; a double-lock fold turns them 180 degrees into a flat hook and traps the sealant more completely. The double lock resists static head and uplift better and is the fold the shallowest slope ratings are written on; the single lock is faster to run and leaves a seam that can be opened for a future repair. (8.3.1)
8.3.2 Where a mechanically seamed standing seam is selected, the seam fold shall be as selected in the datasheet.
Mechanical Seam Foldradio
○ Single lock, 90 degree fold
○ Double lock, 180 degree fold
○ Not applicable, seam is not mechanically seamed
8.3.3 The seam fold shall be the fold with which the uplift and water penetration ratings relied on were tested.

8.4 Seam Height and Panel Width

NOTE Seam height is the depth of water the seam can stand in before it is overtopped, and it is also the lever arm that gives the panel its stiffness and its uplift capacity; the lowest seams belong to architectural panels over a solid deck and the tallest to structural panels on long purlin spans and low slopes. Panel width trades seams against flatness: a wider pan needs fewer seams and installs faster, but it oil-cans more and spans less, and through-fastened panels are formed wider than any standing seam because their ribs stiffen the sheet between fasteners. (8.4.1)
8.4.2 The standing-seam height shall be as indicated in the datasheet.
Seam Heightrange
in
11.51.7522.53
Per drawings — the roof assembly schedule (deferred by default)
8.4.3 The panel coverage width shall be as indicated in the datasheet.
Panel Coverage Widthrange
in
121618202436
Per drawings — the roof assembly schedule (deferred by default)
8.4.4 The seam height and panel width supplied shall be those with which the uplift and water penetration ratings relied on were tested.
8.4.5 Panel coverage width shall be uniform across each roof plane except at the edge panel of each plane, which may be field-cut to fit.

8.5 Pan Flatness Treatment

NOTE A stiffening treatment formed into the pan between the seams shortens the unsupported flat and reduces the visibility of oil-canning: striations are shallow continuous corrugations across the full pan and are the most effective, pencil ribs are one or two narrow raised ribs that break the pan into shorter flats, and a flat pan has no treatment and shows the most waviness but reads as the cleanest surface. The treatment changes the panel's appearance and, on structural panels, its section properties, so it is fixed before the rating is checked. (8.5.1)
8.5.2 The pan flatness treatment shall be as selected in the datasheet.
Pan Flatness Treatmentradio
○ Flat pan
○ Striated pan
○ Pencil ribs
○ Minor ribs or flutes
8.5.3 The pan treatment supplied shall be that with which the uplift rating relied on was tested, or the panel manufacturer's engineer shall certify in writing that the rating applies to the treated pan.

8.6 Roof Slope

NOTE Each seam type has a slope below which the seam sits in moving water and static head governs. IBC Section 1507.4 sets a minimum of one quarter unit vertical in 12 for standing-seam panels, one half in 12 for lapped nonsoldered seams with applied lap sealant, and three in 12 for lapped nonsoldered seams without lap sealant; the manufacturer's rated minimum for a snap-lock or batten seam is commonly steeper than the code floor, and the stricter of the two governs. (8.6.1)
8.6.2 The roof slope of each roof plane shall be as indicated in the datasheet.
Roof Sloperange
in/ft
0.2512
Per drawings — the roof plan (deferred by default)
8.6.3 The installed slope of each roof plane shall equal or exceed both the minimum slope IBC Section 1507.4 sets for the selected seam type and the minimum slope the panel manufacturer publishes for the specified seam type and seam height.
8.6.4 Where the design slope is less than the manufacturer's published minimum for the selected seam type, the Contractor shall report the condition in writing before panels are ordered, and shall not proceed until the Engineer of Record has directed a seam type or slope that satisfies this standard.

8.7 Panel Length and Forming Location

NOTE A standing-seam panel is most reliable as a single piece from eave to ridge, because an endlap is a sealed, back-fastened joint that must also float, and it is the one place in the field of the roof where the seam is interrupted. Factory panels are limited by what can be shipped, which is why long runs are rolled on site from coil; a factory panel is formed under controlled conditions and carries the manufacturer's dimensional inspection, while a field-rolled panel can be any length the roof needs and avoids the endlap entirely. (8.7.1)
8.7.2 The panel forming location shall be as selected in the datasheet.
Panel Forming Locationradio
○ Factory roll-formed
○ Field roll-formed at the site from coil
○ Contractor's option, factory or field
8.7.3 Panels shall be furnished in single continuous lengths from eave to ridge, hip, or transition wherever the panel length can be formed and transported, and endlaps shall be used only where the Contractor documents that a continuous panel cannot be furnished.
8.7.4 Where endlaps are unavoidable, they shall occur over a support, shall be staggered between adjacent panels, shall be detailed with a backup plate, sealant, and fasteners as the panel manufacturer details for the specified seam, and shall be shown on the shop drawings.
8.7.5 Endlaps on through-fastened panels shall be sealed with continuous sealant and shall have the lap length the panel manufacturer publishes for the roof slope.

9 Panel Materials and Finishes

9.1 Base Metal

NOTE The base metal sets corrosion resistance, stiffness, thermal movement, weight, and cost: (9.1.1)
  • Aluminum-zinc alloy-coated steel is the predominant commercial roof panel substrate, giving a long atmospheric service life at the stiffness and cost of steel; its coating is attacked by alkaline runoff and by continuous wetting
  • Galvanized steel is the economical substrate and tolerates animal-confinement and alkaline exposures that attack an aluminum-zinc coating, at a shorter atmospheric life
  • Aluminum is unaffected by salt aerosol, is lighter, and forms cleanly, but it moves twice as much with temperature, dents more easily, and costs more per square
  • Stainless steel, copper, and zinc are specialty substrates where the metal itself is the finish and the service life is measured in generations; copper and zinc weather to a patina and shed runoff that stains or corrodes less noble materials below
9.1.2 The panel base metal shall be as selected in the datasheet and shall conform to the material specification this standard assigns to it.
Panel Base Metalradio
● Aluminum-zinc alloy-coated steel
○ Galvanized steel
○ Aluminum
○ Stainless steel
○ Copper
○ Zinc
9.1.3 Aluminum-zinc alloy-coated steel sheet shall conform to ASTM A792/A792M, and where prepainted shall conform to ASTM A755/A755M.
9.1.4 Galvanized steel sheet shall conform to ASTM A653/A653M with a G90 coating designation minimum, and where prepainted shall conform to ASTM A755/A755M.
9.1.5 Aluminum sheet shall conform to ASTM B209/B209M in an alloy and temper the panel manufacturer publishes for the specified profile.
9.1.6 Stainless steel sheet shall conform to ASTM A240/A240M, Type 304 minimum, and Type 316 where the coastal or marine corrosion exposure category applies.
9.1.7 Copper sheet shall conform to ASTM B370, cold-rolled temper, in the weight indicated in the datasheet.
9.1.8 Zinc sheet shall conform to ASTM B69, architectural rolled zinc, in the thickness indicated in the datasheet.
9.1.9 Zinc panels shall be installed over a substrate or underlayment that ventilates the underside of the panel, as the zinc manufacturer publishes, so that condensate does not stand against the metal.

9.2 Steel Sheet Gauge and Metallic Coating

NOTE Heavier gauge increases span, uplift capacity, and dent resistance and reduces oil-canning, at more weight and cost. Nominal thicknesses are about 0.030 in at 22 gauge, 0.024 in at 24 gauge, 0.018 in at 26 gauge, and 0.014 in at 29 gauge; 24 gauge is the common architectural and structural standing-seam gauge, 22 gauge serves long purlin spans and high design pressures, 26 gauge serves through-fastened panels on close supports, and 29 gauge is an agricultural and light-utility through-fastened gauge. (9.2.1)
9.2.2 The steel panel gauge shall be as selected in the datasheet.
Steel Panel Gaugeselect
22 ga
24 ga
26 ga
29 ga
9.2.3 The gauge supplied shall be the gauge with which the uplift rating relied on was tested, and shall not be lighter than the gauge the structural calculation requires for the design span and pressure.
NOTE The aluminum-zinc coating weight carries the coating's life; AZ50 is the coating weight beneath a paint finish and AZ55 is the heavier weight supplied on bare, unpainted panels, where the coating alone is the weathering surface. (9.2.4)
9.2.5 The aluminum-zinc alloy coating designation shall be as selected in the datasheet.
Aluminum-Zinc Coating Designationradio
○ AZ50
○ AZ55
9.2.6 Bare, unpainted aluminum-zinc alloy-coated panels shall be supplied with a clear acrylic coating applied at the mill, or with the AZ55 designation, as the panel manufacturer's finish warranty for bare panels requires.

9.3 Aluminum, Copper, and Zinc Thickness

NOTE Thickness in the non-ferrous metals sets stiffness and dent resistance exactly as gauge does in steel; aluminum roof panels are commonly formed at 0.032 in and 0.040 in, with 0.050 in and heavier for long spans and prominent flat pans, and the model code sets a floor of 0.024 in for aluminum roof panels. (9.3.1)
9.3.2 The aluminum panel thickness shall be as indicated in the datasheet.
Aluminum Panel Thicknessrange
in
0.0240.0320.040.050.063
Per drawings — the roof assembly schedule (deferred by default)
9.3.3 The copper sheet weight shall be as indicated in the datasheet.
Copper Sheet Weightrange
oz/ft²
162024
Per drawings — the roof assembly schedule (deferred by default)
9.3.4 The zinc sheet thickness shall be as indicated in the datasheet.
Zinc Sheet Thicknessrange
in
0.0270.0320.04
Per drawings — the roof assembly schedule (deferred by default)
9.3.5 The thickness or weight supplied shall be that with which the uplift rating relied on was tested, and shall not be less than the structural calculation requires for the design span and pressure.

9.4 Exterior Finish System

NOTE The finish sets color retention, chalk and fade resistance, and the length of the finish warranty: (9.4.1)
  • A two-coat 70 percent polyvinylidene fluoride (PVDF) fluoropolymer coating is the architectural benchmark for ultraviolet, color, and chalk resistance and carries the longest finish warranties; it is softer than the other coatings and shows handling scratches more readily
  • A three-coat PVDF system adds a clear coat over a metallic or mica base and is the system for metallic colors; it costs more and the metallic flake orients with the coil direction, so panels read differently if the direction is mixed
  • A silicone-modified polyester (SMP) coating is harder and lower in cost than PVDF, with shorter chalk and fade warranties; it is the common finish on through-fastened and agricultural panels and on roofs that are not visible from grade
  • A polyester coating is the lowest-cost finish with the shortest weathering performance and is used where the roof is concealed or temporary
  • Anodizing is an integral conversion coating on aluminum with excellent abrasion resistance and a narrow color range, and batch-to-batch color matching is harder than with a coil coating
  • A bare aluminum-zinc or mill finish weathers to a matte gray and is the lowest-cost durable finish on steel; it carries a coating warranty rather than a color warranty
  • Copper and zinc are left to weather naturally, or are supplied prepatinated or preweathered, and their appearance changes with exposure for years
9.4.2 The exterior finish system shall be as selected in the datasheet.
Exterior Finish Systemselect
Two-coat 70 percent PVDF fluoropolymer
Three-coat PVDF fluoropolymer, metallic or mica
Silicone-modified polyester (SMP)
Polyester
Anodized aluminum
Bare aluminum-zinc or mill finish
Natural weathering or prepatinated copper or zinc
9.4.3 PVDF coatings shall contain not less than 70 percent polyvinylidene fluoride resin by weight in the topcoat, and shall meet AAMA 2605 on aluminum and AAMA 621 on metallic-coated steel.
9.4.4 PVDF coatings shall be applied over a primer to a total dry film thickness of not less than 0.9 mil, and three-coat systems shall add a clear topcoat to the thickness the coating manufacturer publishes.
9.4.5 SMP coatings shall meet AAMA 2604 on aluminum and, on metallic-coated steel, shall carry the coating manufacturer's published chalk and fade performance stated in ASTM D4214 and ASTM D2244 terms.
9.4.6 Anodic coatings shall meet AAMA 611, Architectural Class I.
9.4.7 The interior face of coated steel and aluminum panels shall receive a factory-applied wash coat or backer coat of the thickness the panel manufacturer publishes.
9.4.8 Panels with metallic or mica finishes shall be formed and installed in one coil direction, and the direction shall be marked on each panel.

9.5 Color and Cool Roof Performance

NOTE Where the adopted energy code requires a cool roof, the requirement is written as an aged solar reflectance and thermal emittance, or an aged solar reflectance index, rated under CRRC-1; under the IECC it applies to low-slope roofs directly above conditioned space in the warm climate zones, and some state codes extend a lesser requirement to steep-slope roofs. The aged values are what count, and a dark color seldom meets them, so the color and any cool roof requirement are reconciled before the palette is fixed. (9.5.1)
9.5.2 The finish color shall be as indicated in the datasheet.
Finish Colortext
Enter value...
Per drawings — the finish schedule (deferred by default)
9.5.3 Whether a cool roof is required shall be determined from Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code for the roof slope in Climate ZoneClimate ZoneParameterEach project supplies its own value.climate-zone, and shall be as indicated in the datasheet.
Cool Roof Requirementradio
○ Required by the adopted energy code
○ Required by the Owner or a voluntary program
○ Not required
Derived — Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code and the roof slope in Climate ZoneClimate ZoneParameterEach project supplies its own value.climate-zone (by default)
9.5.4 Where a cool roof is required, the finish shall carry a CRRC-1 product rating whose three-year aged solar reflectance and thermal emittance, or aged solar reflectance index, meet the values the adopted energy code or the Owner's program requires for the roof slope.
9.5.5 Where a cool roof is required, the rated values shall be stated in the action submittal and the finish warranty shall cover the rated finish.

10 Clips, Fasteners, Sealants, and Closures

10.1 Panel Clips

NOTE The clip carries uplift from the seam to the structure and, on a floating system, lets the panel slide through it: (10.1.1)
  • A fixed one-piece clip pins the panel at every clip and is used where runs are short enough that the seam and the trim absorb the movement, or on snap-lock architectural panels over a deck where the manufacturer rates the clip for the run length
  • A sliding one-piece clip has a slotted base or a sliding tab that lets the panel move a limited distance, suited to intermediate run lengths
  • A two-piece floating clip has a base fastened to the structure and a separate tab that engages the seam and travels along the base; it accommodates the longest runs and is the clip on which structural standing-seam uplift ratings and long-term weathertightness warranties are usually written
  • The clip's travel limit is the run length limit, and the manufacturer publishes the maximum run for each clip and metal
10.1.2 The panel clip type shall be as selected in the datasheet.
Panel Clip Typeradio
○ Fixed one-piece clip
○ Sliding one-piece clip
○ Two-piece floating clip
10.1.3 The clip supplied shall be the clip with which the uplift rating relied on was tested.
10.1.4 Where the panel run length exceeds the run length the panel manufacturer publishes for a fixed clip in the specified metal, a sliding or floating clip shall be used.
10.1.5 Floating and sliding clips shall be installed centered in their travel at the panel temperature at installation, so that the design movement is available in both directions.
NOTE The clip material trades corrosion resistance against cost, and a clip that contacts a panel of a different metal is a galvanic couple inside the seam: (10.1.6)
  • Galvanized steel clips are the standard clip on coated steel panels
  • Stainless steel clips are used on aluminum, copper, and zinc panels and in the coastal and corrosive exposure categories
  • Aluminum clips are used on aluminum panels where the manufacturer rates them, and are never used with steel panels or steel fasteners that contact the panel
10.1.7 The clip material shall be as selected in the datasheet.
Panel Clip Materialradio
● Galvanized steel
○ Stainless steel
○ Aluminum
10.1.8 Clips on aluminum, copper, or zinc panels shall be stainless steel or a material the panel manufacturer publishes as galvanically compatible with the panel.
10.1.9 Clips in the coastal or marine corrosion exposure category shall be stainless steel.

10.2 Fasteners

NOTE A concealed clip fastener must resist pull-out under uplift for the life of the roof; an exposed through-fastener must do that and also seal its own hole in sun and movement. The fastener material sets corrosion life, and the exposed head must match the panel finish: (10.2.1)
  • Long-life coated carbon steel fasteners are the economical fastener on coated steel panels in the inland category and carry the coating manufacturer's corrosion warranty
  • Stainless steel fasteners, Type 304 or Type 316, are used with aluminum, copper, and zinc panels and in the coastal and corrosive categories, and Type 316 is the fastener for a marine site
  • Stainless-capped carbon steel exposed fasteners put a stainless head and gasket on a carbon steel shank, giving an exposed head that does not rust-stain at a lower cost than solid stainless
10.2.2 The fastener material shall be as selected in the datasheet.
Fastener Materialradio
○ Long-life coated carbon steel
○ Stainless steel Type 304
○ Stainless steel Type 316
○ Stainless-capped carbon steel
10.2.3 Concealed clip fasteners shall be of the type, diameter, length, and embedment with which the uplift rating relied on was tested, and shall be self-drilling or self-tapping screws sized for the purlin or deck thickness.
10.2.4 Fasteners that contact aluminum, copper, or zinc panels or clips shall be stainless steel, and fasteners in the coastal or marine corrosion exposure category shall be stainless steel.
10.2.5 Exposed fasteners shall have a factory-bonded EPDM or equivalent elastomeric sealing washer, shall be driven perpendicular to the panel, and shall be seated so that the washer is compressed without being extruded.
10.2.6 Exposed fastener heads shall be factory-finished to match the panel color, or shall be stainless steel where the panel is unpainted.
10.2.7 Fasteners into wood supports shall penetrate the support not less than the embedment the uplift rating or the panel manufacturer's published pull-out table requires for the wood species and density.

10.3 Seam Sealant

NOTE The sealant inside a standing seam is what makes the seam watertight below the slope at which geometry alone drains it. A factory-applied hot-melt butyl bead sits in the seam leg from the roll-former and is the most consistent; a field-applied butyl tape is placed by the crew and depends on the crew; a snap-lock or batten seam on a steep slope commonly runs dry, relying on the seam geometry and the slope. (10.3.1)
10.3.2 The seam sealant provision shall be as selected in the datasheet.
Seam Sealant Provisionradio
○ Factory-applied butyl sealant in the seam
○ Field-applied butyl tape in the seam
○ Factory-applied sealant with field-applied tape at endlaps and terminations
○ Dry seam, no sealant
10.3.3 The seam sealant provision supplied shall be that with which the water penetration rating relied on was tested for the specified slope.
10.3.4 Mechanically seamed panels installed at a slope of less than 3 in 12 shall have a continuous sealant bead in the seam.
10.3.5 Seam sealant and butyl tape shall be a non-curing, non-skinning sealant the panel manufacturer publishes as compatible with the panel finish and base metal.
10.3.6 Field-applied sealant at trim, closures, endlaps, and penetrations shall be a non-curing butyl, or a low-modulus sealant the panel manufacturer publishes as compatible with the finish, applied continuously and concealed from direct sunlight wherever the detail permits.

10.4 Closures and Dissimilar Metal Isolation

NOTE Closures fill the panel profile at eaves, ridges, and transitions against wind-driven rain, snow, insects, and birds, and they carry the sealant that makes the termination airtight and watertight. A metal closure is durable and is the closure under a mechanically seamed ridge; a closed-cell foam closure conforms to the profile and is faster, but it is the component of the system with the shortest life in sunlight and is protected by the trim above it. (10.4.1)
10.4.2 Inside and outside closures matching the panel profile shall be provided at every eave, ridge, hip, rake, transition, and curb where the profile is open.
10.4.3 Closures shall be closed-cell foam, formed metal matching the panel metal, or an extruded profile, as the panel manufacturer details for the termination, and shall be set in continuous sealant on both faces.
10.4.4 Foam closures shall be shielded from direct sunlight by the trim or panel above them.
10.4.5 Aluminum, copper, zinc, and stainless steel panels and accessories shall be isolated from dissimilar metals, including steel purlins, deck, and clips, by a non-conductive separator tape, a compatible coating, or stainless steel fasteners and clips, so that no galvanic couple is formed.
10.4.6 Where the parties disagree whether a separator or isolation is required at a dissimilar-metal contact, the Engineer of Record shall make the initial determination.

11 Underlayment and Deck Interface

11.1 Underlayment Beneath Metal Panels

NOTE A metal panel in sun reaches a surface temperature that softens an ordinary asphalt underlayment and bonds it to the panel underside, and a self-adhering sheet that is not rated for the temperature flows and loses its bond at the laps. That is why the underlayment beneath a metal roof is rated by temperature rather than selected by the shingle rules, and why the three families differ: (11.1.1)
  • A self-adhering polymer-modified bitumen sheet, high-temperature rated, seals around every clip fastener that passes through it, is itself a secondary waterproofing layer, and is the underlayment on which most manufacturer weathertightness warranties over a solid deck are written; it is the most expensive and it is a vapor retarder, so the assembly below it must be designed to dry inward
  • A mechanically attached polymeric synthetic sheet is light, tear-resistant, and vapor-open, with a high-temperature grade available, and it is used with a self-adhering ice barrier at the eaves, valleys, and penetrations where sealing around fasteners matters
  • An asphalt-saturated organic felt is the traditional underlayment the model code still permits beneath metal panels, at the lowest cost; it is not rated for high temperature, it wrinkles when wet, and panel manufacturers commonly exclude it from a weathertightness warranty
11.1.2 Underlayment shall be installed over the full area of every solid deck beneath metal roof panels, of a type IBC Section 1507 permits beneath metal roof panels.
11.1.3 The underlayment type shall be as selected in the datasheet.
Underlayment Typeradio
● Self-adhering polymer-modified bitumen sheet
○ Mechanically attached polymeric synthetic sheet
○ Asphalt-saturated organic felt
11.1.4 Self-adhering underlayment shall conform to ASTM D1970/D1970M and shall be rated by its manufacturer for continuous service beneath a metal roof panel.
11.1.5 Mechanically attached synthetic underlayment shall conform to ASTM D8257/D8257M and shall be attached with the cap fasteners, spacing, and laps the underlayment manufacturer publishes for the roof slope and for the high-wind exposure where one applies.
11.1.6 Asphalt-saturated felt underlayment shall conform to ASTM D226/D226M Type II or ASTM D4869/D4869M Type IV.
11.1.7 Underlayment shall be lapped to shed water, shall be continuous over the deck before any panel is installed, and shall be turned up at curbs and walls and lapped over eave and valley metal as the panel manufacturer details.
11.1.8 Where a self-adhering underlayment is installed beneath copper or zinc panels, a slip sheet or a vented underlayment the panel manufacturer publishes as compatible shall separate the panel from the adhesive.
11.1.9 Underlayment left exposed to weather before panels are installed shall not remain exposed longer than the underlayment manufacturer's published exposure limit, and underlayment that has exceeded that limit shall be replaced at the Contractor's cost.

11.2 Ice Barrier

NOTE An ice dam forms where meltwater from the warm upper roof refreezes at the cold eave; the water behind the dam stands against the seam and backs up under the panel. A self-adhering membrane from the eave to a line inside the exterior wall is the code's answer, and the code requires it where the jurisdiction has a history of ice forming at the eaves. (11.2.1)
11.2.2 Whether an ice barrier is required shall be determined from the ice barrier provisions of Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code for the site in Climate ZoneClimate ZoneParameterEach project supplies its own value.climate-zone, and shall be as indicated in the datasheet.
Ice Barrier at Eaves and Valleysradio
○ Required
○ Not required
Derived — the ice barrier provisions of Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code for the site in Climate ZoneClimate ZoneParameterEach project supplies its own value.climate-zone (by default)
11.2.3 Where an ice barrier is required, a self-adhering polymer-modified bitumen sheet conforming to ASTM D1970/D1970M, rated for service beneath a metal panel, shall extend from the lowest edge of every roof surface to a line not less than 24 in inside the interior face of the exterior wall, and not less than 36 in each side of the centerline of every valley.
11.2.4 Where the selected underlayment is itself a self-adhering sheet over the full deck, that sheet satisfies the ice barrier requirement.

11.3 Underlayment Temperature Rating

11.3.1 The underlayment beneath metal panels on a solid deck shall be rated by its manufacturer for a continuous service temperature of not less than the value indicated in the datasheet.
Underlayment Service Temperature Ratingrange
Not less than
°F
200220240260
NOTE The 240 °F rating is the grade the North American market labels as high-temperature underlayment and is the rating most panel manufacturers require beneath a warranted metal roof over a solid deck; the higher rating serves dark finishes in hot climates and the lower serves light finishes and ventilated assemblies. (11.3.2)

11.4 Thermal Spacer Blocks Over Purlins

NOTE Where blanket insulation is draped over purlins beneath a structural panel, the clip compresses the blanket to nothing at every purlin and the purlin becomes a continuous thermal bridge; a rigid foam spacer block between the clip and the purlin keeps the blanket at a working thickness over the purlin and is required by the energy code's metal building roof insulation provisions. The block also changes the clip's height and the fastener's length, so it is part of the tested assembly. (11.4.1)
11.4.2 Where blanket insulation is installed over purlins beneath structural panels, a thermal spacer block of the thickness Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code requires for the roof assembly shall be installed between each clip and the purlin, and the clip fastener length shall be increased accordingly.
11.4.3 The spacer block, clip, and fastener combination shall be that with which the uplift rating relied on was tested, or the panel manufacturer's engineer shall certify in writing that the rating applies with the block installed.
11.4.4 The blanket insulation, its facing, and any liner system beneath the purlins are governed by Building Thermal InsulationBuilding Thermal InsulationResolves to the current adopted revision.sync/building-thermal-insulation; this standard governs the block between the clip and the purlin.

12 Trim, Flashings, Penetrations, and Curbs

12.1 Panel-Integrated Trim

12.1.1 Eave, rake, ridge, hip, and transition trim furnished with the panel system shall be of the same base metal, gauge or thickness, metallic coating, and finish as the panels, except that trim gauge may be heavier where the panel manufacturer details it.
12.1.2 Trim shall be detailed and attached to permit the panel's design movement, with slotted holes or sliding cleats at every connection to a floating panel, and shall be sealed to the panels with closures and continuous sealant as the panel manufacturer details.
12.1.3 Eave trim shall be installed under the underlayment at the eave where a solid deck exists and shall be fastened at the spacing the perimeter zone pressure requires, and panels shall be hooked or hemmed to the eave trim where the panel manufacturer details a hooked eave.
12.1.4 Rake trim shall be attached to the rake panel seam or to a rake angle so that the panel's thermal movement along the rake is not restrained.
12.1.5 Ridge and hip caps shall be installed over profile closures set in continuous sealant, shall be attached to the panel seams or to a ridge angle so that the panels float beneath them, and shall be vented where the roof assembly is designed to vent at the ridge.
12.1.6 Where eave gutters are furnished as part of the panel system, they shall match the panel metal and finish, shall be attached so that the panel's movement at the eave is not restrained, and shall be sized and sloped as Gutters And DownspoutsGutters and DownspoutsResolves to the current adopted revision.sync/gutters-and-downspouts requires.
12.1.7 Trim profiles and locations shall be as indicated on the roof plan and the eave, rake, ridge, and transition details.

12.2 Valleys and Transitions

NOTE A valley collects the runoff of two roof planes into one channel, carries snow and ice longer than the field, and is the one place where panels from two planes end against the same piece of metal; valley metal is therefore heavier, wider, and more deliberately sealed than any other trim. A transition from a steep plane to a shallower one, or from panels to a wall, is the same problem in one direction. (12.2.1)
12.2.2 Valley metal shall be of the same base metal and finish as the panels, of a gauge not lighter than the panels, formed with a center diverter rib and with hemmed edges that receive the panel cleats, and shall extend not less than 12 in beneath the panels on each side of the valley centerline.
12.2.3 Valley metal shall be installed over the ice barrier or self-adhering underlayment, shall be cleated to permit movement, and shall not be face-fastened within the water channel.
12.2.4 Panels terminating at a valley or at a sloped transition shall be hemmed or closed at the cut end, sealed to the valley or transition metal with the closure and sealant the panel manufacturer details, and left free to move along the valley.
12.2.5 Panels terminating against a wall shall be turned up or closed with a wall closure, counterflashed by the sheet metal work of Sheet Metal Flashing And TrimSheet Metal Flashing and TrimResolves to the current adopted revision.sync/sheet-metal-flashing-and-trim or by the wall cladding, and detailed so that the counterflashing does not restrain the panel.

12.3 Pipe and Small Penetrations

NOTE A pipe through a floating panel moves with the panel, not with the pipe, so the flashing between them is a flexible boot rather than a rigid collar; the boot's base is formed to the panel profile and its cone grips the pipe, and the whole penetration is placed in the flat of the pan where the base can seal, never through the seam. Penetrations larger than a boot can seal, and penetrations that cannot be placed in the flat, are curbed. (12.3.1)
12.3.2 Pipes, conduits, and other round penetrations shall be flashed with a flexible EPDM or silicone boot having a formable base, set in sealant on the panel and mechanically fastened to the panel through the base at the spacing the boot manufacturer publishes.
12.3.3 Round penetrations shall be located in the flat of the pan, clear of the seam by the distance the boot base requires, and the location of each shall be as indicated on the roof plan.
12.3.4 A round penetration whose diameter exceeds the largest boot the boot manufacturer rates for the panel profile, or that cannot be placed in the flat of the pan, shall be curbed under this standard.
12.3.5 Boots on mechanically seamed and snap-lock panels shall be silicone or a high-temperature EPDM where the pipe carries hot flue gas or exhaust.

12.4 Curbs for Hatches, Vents, and Skylights

NOTE A curb on a metal panel roof either floats on the panels, seamed to the panel ribs at its sides and carried by the panels so that it moves with them, or is framed to the structure below with the panels terminated at its perimeter so that the panels move past it. A floating curb keeps the panel run continuous and is the curb most panel and curb manufacturers detail for standing seams; a structural curb is used where the unit is heavy, where the opening is wide, or where the unit must not move. Either curb needs a cricket or diverter on its upslope side, because a curb is a dam. (12.4.1)
NOTE Curb framing and panel penetration treatment for roof hatches, smoke vents, skylights, and mechanical units set on standing-seam, batten-seam, or through-fastened panels are governed by this standard; the units themselves are governed by Roof Hatches And Smoke VentsRoof Hatches and Smoke VentsResolves to the current adopted revision.sync/roof-hatches-and-smoke-vents and SkylightsSkylights and Unit SkylightsResolves to the current adopted revision.sync/skylights. (12.4.2)
12.4.3 The curb mounting method for units set on the panels shall be as selected in the datasheet.
Curb Mounting on Panelsradio
○ Floating curb seamed to the panel ribs and carried by the panels
○ Structural curb framed to the structure below with panels terminated at the curb
○ Both, selected unit by unit
12.4.4 Curbs set on the panels shall be of the panel manufacturer's design or of a metal roof curb manufacturer's design the panel manufacturer accepts in writing, of the same base metal and finish as the panels or of aluminum where the panels are aluminum, with integral upslope diverter, downslope and side flanges formed to the panel profile, and a water-shedding top rim.
12.4.5 A floating curb shall be seamed or sealed to the panel ribs on each side, shall not be fastened to the structure through the panels, and shall be sized so that the unit it carries does not exceed the load the panel manufacturer permits on the panels.
12.4.6 A structural curb shall be framed to the purlins or deck below, and the panels shall terminate at its perimeter with closures, sealant, and a counterflashing attached to the curb that permits the panels to move.
12.4.7 Every curb wider than 24 in across the slope shall have a cricket or diverter on its upslope side formed of panel metal and sloped to drain to each side of the curb.
12.4.8 The cricket at a skylight or hatch curb shall be fabricated and installed by the roofing work under this standard, coordinated with the unit supplier so that the curb height above the cricket satisfies the unit's required curb height.
12.4.9 Curb locations shall be as indicated on the roof plan.

12.5 Translucent Panel Inserts

NOTE A translucent panel formed to the metal panel profile and set into the panel run admits daylight without a curb, and it is the daylighting the skylight standard sends here. Fiber-reinforced polyester (FRP) is the traditional and lowest-cost material and yellows and loses light transmission over years of ultraviolet exposure; polycarbonate holds its transmission longer, resists impact, and costs more. Either is a fall-through hazard until it is guarded, and either is a glazed opening in a wind-borne debris region. (12.5.1)
12.5.2 Where translucent panel inserts are indicated, the insert material shall be as selected in the datasheet.
Translucent Panel Insert Materialradio
○ Fiber-reinforced polyester (FRP)
○ Polycarbonate
○ Not applicable, no translucent inserts
12.5.3 Translucent inserts shall match the metal panel profile, shall be of a thickness and reinforcement the insert manufacturer rates for the panel span and the design uplift pressure, and shall be sealed and fastened to the adjacent metal panels as the panel manufacturer details.
12.5.4 Translucent inserts shall be guarded against fall-through by a screen or grate beneath the insert, or shall be rated by the insert manufacturer to resist the fall-through load the applicable occupational safety regulation requires, and the guard shall be installed before the roof is accessed for other work.
12.5.5 Where Wind Borne Debris RegionWind Borne Debris RegionParameterEach project supplies its own value.wind-borne-debris-region places the building in a wind-borne debris region, translucent inserts shall be impact-resistant or impact-protected as Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code requires for glazed openings, tested per ASTM E1886 and ASTM E1996 for the missile level the code assigns to the roof.
12.5.6 Translucent insert locations shall be as indicated on the roof plan.

12.6 Snow Retention

NOTE Snow slides off a smooth metal roof in a sheet, and the sheet takes the gutter, the exhaust vent, and whoever is below it with it. Snow retention holds the snow on the roof so it melts in place, and it loads the roof and the seams it is attached to: (12.6.1)
  • A clamp-to-seam bar or rail system grips the seam of a standing-seam panel without penetration, is engineered as a continuous barrier, and is the system used on floating standing-seam roofs because it moves with the panels; the clamp must be listed for the specific seam profile
  • Clamp-to-seam pad guards are individual guards clamped to the seams in a pattern, less costly than a continuous bar and suited to light snow loads and short slopes
  • A mechanically fastened bar or guard is screwed through the panel to the structure and is the system for through-fastened panels, which have no seam to clamp; on a floating standing-seam panel it pins the panel and is not used
  • The design is a structural calculation from the ground snow load, the slope, the panel run length, and the tested holding capacity of the clamp, and it is laid out in rows from the eave upward
12.6.2 Whether snow retention is required, and its type, shall be as selected in the datasheet.
Snow Retention Systemradio
○ Clamp-to-seam continuous bar or rail
○ Clamp-to-seam individual pad guards
○ Mechanically fastened bar or guard through the panel
○ Not required
12.6.3 Snow retention shall be designed by the snow retention manufacturer for the ground snow load, roof slope, and panel run length indicated on the structural drawings and the roof plan, using the tested holding capacity of the clamp on the specified seam profile, and the layout calculation shall be included in the action submittal.
12.6.4 Clamp-to-seam devices shall be listed by their manufacturer for the specific seam profile and seam height installed, shall grip the seam with set screws that do not penetrate the seam, and shall be installed at the torque the device manufacturer publishes.
12.6.5 Snow retention shall not be mechanically fastened through a floating standing-seam panel.
12.6.6 Snow retention shall be of a metal galvanically compatible with the panel, and clamps on aluminum, copper, or zinc panels shall be of aluminum, stainless steel, or the panel metal.
12.6.7 Snow retention shall be located above eaves over entrances, walkways, gutters, rooftop equipment, lower roofs, and wherever indicated on the roof plan.

12.7 Rooftop Attachments by Others

NOTE Photovoltaic racking, fall-protection anchors, lightning conductors, and signage are attached to a standing-seam roof by seam clamps for the same reason snow retention is: the clamp holds without penetrating and moves with the panel. Each of those systems is specified elsewhere, but the seam and the panel are this standard's, and whether the seam can carry the clamp reaction is confirmed here. (12.7.1)
12.7.2 Attachments to the panels by other trades, including the racking of Photovoltaic SystemsPhotovoltaic SystemsResolves to the current adopted revision.sync/photovoltaic-systems, the anchors of Fall Protection AnchorageRoof and Facade Fall Protection AnchorageResolves to the current adopted revision.sync/fall-protection-anchorage, and the conductors of Lightning ProtectionLightning Protection SystemsResolves to the current adopted revision.sync/lightning-protection, shall be made with clamps listed for the specific seam profile and shall not penetrate the panels, unless the Engineer of Record accepts a curbed or boot-flashed penetration under this standard.
12.7.3 The Contractor shall obtain the panel manufacturer's written confirmation that the seam and panel can carry the clamp reactions of each attached system, and shall include that confirmation in the action submittal.
12.7.4 Attachments by other trades shall be installed only after the panels are seamed and inspected, and any damage to the panels or finish caused by those attachments shall be repaired at the cost of the trade that caused it.

13 Testing

13.1 Laboratory Qualification Tests

NOTE Laboratory qualification proves the system before it is committed to the building, and each test is tied to a configuration: a report on a 24 gauge panel at a 5 ft span with a two-piece clip says nothing about the same profile in 26 gauge at 6 ft on a fixed clip. (13.1.1)
13.1.2 The panel system shall be qualified by laboratory testing of the assembly for the selected test package, in a configuration matching the project.
Laboratory Test Package Requiredcheckbox
☑ Uplift resistance by the selected rating method
☐ Water penetration by static water head, ASTM E2140
☑ Water penetration by static air pressure difference, ASTM E1646
☐ Air leakage, ASTM E1680
☑ Roof covering fire classification, ASTM E108 or UL 790
☐ Hail impact resistance, UL 2218 or FM 4471
13.1.3 Where hail impact resistance is included in the test package, the panel system shall carry the UL 2218 class or the FM 4471 hail rating the Contract Documents or the Owner's insurer requires, and the rating shall be stated in the action submittal.
13.1.4 The Contractor shall submit the test reports, classifications, and approvals for the assembly configuration matching the project as part of the action submittal package.

13.2 Field Water Testing

NOTE Field water testing catches what a laboratory specimen cannot: a missed closure, an unsealed endlap, a boot set over a seam, or a curb flange left open at a corner. A calibrated spray applied to fixed, sealed terminations and penetrations, with an observer below, finds those defects while the panel is still accessible. (13.2.1)
13.2.2 Whether field water testing of the installed panel system is required shall be as selected in the datasheet.
Field Water Testingradio
○ Required
○ Not required
13.2.3 Where required, the field water test shall apply the AAMA 501.2 nozzle method, or the panel manufacturer's published spray test procedure, to a representative sample of eave, rake, ridge, valley, endlap, penetration, and curb conditions selected by the Engineer of Record, with an observer at the underside of the roof.
13.2.4 Field testing shall be performed early enough in the installation sequence that a defect found can be corrected before the condition is repeated across the roof, and before the underside of the roof is concealed by a ceiling or liner.
13.2.5 Any leak found shall be located, repaired, and re-tested until passing, and the cost of repair and re-testing shall be borne by the Contractor.

14 Installation

14.1 Substrate Verification

NOTE The purlin spacing, the deck flatness, and the deck attachment are inherited by the roofing Contractor rather than installed, and they govern clip pull-out, seam alignment, and the oil-canning the panels will telegraph. Proceeding over a substrate accepts it. (14.1.1)
14.1.2 Before underlayment or panels are installed, the Contractor shall verify that purlins or deck are installed at the spacing and within the flatness tolerance the panel manufacturer publishes for the specified panel, that the deck or purlin attachment is complete, and that the substrate is dry, clean, and free of protruding fasteners.
14.1.3 The Contractor shall report every substrate deficiency in writing before covering the affected area, and shall not proceed over a deficient area until the deficiency has been corrected and the area re-inspected.
14.1.4 Where the parties disagree whether a substrate condition is a deficiency, the Engineer of Record shall make the initial determination.

14.2 Panel Layout and Fixed Point

NOTE The fixed point is where the panel is pinned to the structure and from which it grows in both directions, and the choice sets where the movement shows: (14.2.1)
  • Fixing at the eave keeps the eave hem and the gutter relationship constant and sends the movement to the ridge, where a ridge cap over closures absorbs it; it is the common choice where the eave detail is the one that must not open
  • Fixing at the ridge keeps the ridge closure constant and sends the movement to the eave, where the panel end travels along the eave trim; it is used where the ridge is the critical seal or where panels on both sides of the ridge are joined
  • Fixing at a point between them halves the travel at each end and is used on the longest runs, where the clip travel at either end would otherwise be exceeded
14.2.2 The fixed point of each panel run shall be as selected in the datasheet.
Panel Fixed Pointradio
○ Fixed at the eave
○ Fixed at the ridge or high side
○ Fixed at an intermediate point on the run
14.2.3 The fixed point of each panel run shall be shown on the shop drawings, and the fixing shall be made with the fixed clip, the pinned fastener row, or the fixed eave hook the panel manufacturer details for the specified panel.
14.2.4 Panels shall be laid out so that seams are straight, parallel, and in alignment across ridges and hips, with the starting panel set square to the eave and checked for alignment at intervals not exceeding ten panels.
14.2.5 Panels shall be installed with seams and laps away from the prevailing wind where the manufacturer's instructions permit the direction of installation to be chosen.

14.3 Seaming and Clip Installation

14.3.1 Clips shall be installed at the spacing shown on the shop drawings for each roof zone, fastened with the fasteners the uplift rating requires, and seated flat on the purlin, spacer block, or deck without rocking.
14.3.2 Mechanically seamed panels shall be seamed within the time after placement the manufacturer publishes, with the seamer set and checked at the start of each run, and no panel shall be left unseamed at the end of a work period.
14.3.3 Seams shall be inspected for complete engagement along their full length, and any seam found open, skipped, or damaged by the seamer shall be corrected before the next panel is placed.
14.3.4 Panels shall not be walked on in the pan where the manufacturer prohibits it, and foot traffic shall be confined to the locations and the protection the manufacturer publishes.

14.4 Field Cutting, Swarf, and Touch-Up

NOTE Steel swarf from a drill or an abrasive saw lands on the finish as hot filings, embeds, and rusts, leaving a stain pattern that reads as a failed coating; cutting with shears or a nibbler and sweeping the roof each day prevents it. (14.4.1)
14.4.2 Field cuts shall be made with shears, a nibbler, or a cold-cutting saw, and abrasive-wheel saws and torches shall not be used on finished panels or trim.
14.4.3 Drill shavings, cut filings, pop-rivet mandrels, and loose fasteners shall be removed from the panels at the end of each work period.
14.4.4 Cut edges shall be deburred, and cut edges of coated steel exposed to weather shall be hemmed or sealed as the panel manufacturer details.
14.4.5 Minor scratches in the finish shall be touched up with the panel manufacturer's touch-up coating in the matching color, limited to the area and the locations the manufacturer permits for touch-up, because field paint weathers differently from the factory finish.
14.4.6 Panels and trim with dents, creases, cracked finish, or scratches through the metallic coating on surfaces visible in the completed work shall be replaced, and where the parties disagree whether damage is visible or a surface is prominent, the Engineer of Record shall make the initial determination.

14.5 Protection of Installed Work

14.5.1 Installed panels shall be protected from the traffic, dropped tools, staged material, and runoff of other trades until final acceptance, and damage caused by another trade shall be repaired at that trade's cost.
14.5.2 Strippable protective film, where supplied on the finish, shall be removed within the exposure period the finish manufacturer publishes, because film left in sunlight bonds to the finish and mars it on removal.
14.5.3 Materials staged on installed panels shall be placed over supports and shall be distributed so that no concentrated load exceeds the panel manufacturer's published limit or the capacity of the deck and framing at that location.

15 Delivery, Storage, and Handling

15.1 Delivery and Site Storage

NOTE Water trapped between nested panels does not drain and does not evaporate, and within days it stains a bare aluminum-zinc surface white and a painted surface with a wet-storage pattern that is permanent. Storage is therefore elevated, sloped, and ventilated, never sealed under a tarp. (15.1.1)
15.1.2 Panels shall be delivered in the manufacturer's packaging with the profile, gauge, finish, color, and coil or lot number legible on each bundle.
15.1.3 Panel bundles shall be stored off the ground on supports, sloped so that any water drains from between the panels, and covered with a breathable cover that sheds rain while permitting air circulation.
15.1.4 Bundles that have taken on water between panels shall be opened, separated, and dried, and panels showing wet-storage staining shall be replaced at the Contractor's cost.
15.1.5 Panels and trim shall be lifted on edge with spreader bars or by enough workers to prevent buckling, and shall not be dragged across one another.
15.1.6 Coil for field roll-forming shall be stored upright on its skid under cover, protected from moisture, dust, and edge damage, and shall be inspected for coil-set, edge waviness, and finish damage before forming.
15.1.7 Sealants, underlayment, and boots shall be stored within the temperature range their manufacturers publish for storage, and self-adhering underlayment shall be stored on end and out of sunlight.

16 Warranty

16.1 Contractor Workmanship Warranty

NOTE The Contractor's warranty covers the installation itself, including the trim, closures, penetrations, and curbs the manufacturer's finish warranty does not reach and the manufacturer's weathertightness warranty may exclude. (16.1.1)
16.1.2 The Contractor shall provide a written warranty against defects in workmanship and against leaks attributable to the installation, for the term indicated in the datasheet, running from the date of substantial completion.
Contractor Workmanship Warranty Termrange
Not less than
years
110
Default: 2 years
16.1.3 The Contractor warranty shall cover the labor and materials required to correct the defect and to repair damage the defect caused to the roof assembly and to the building interior below it.
16.1.4 Where a warranty repair is performed, the repaired work shall carry a fresh warranty term running from the date of the repair, or the remainder of the original term, whichever is longer.

16.2 Finish Warranty

NOTE The finish warranty is written in three measurable terms: chalking per ASTM D4214, in which a higher number is less chalk; color change per ASTM D2244, in Hunter or CIELAB units, in which a lower number is less fade; and film integrity, meaning no peeling, checking, or cracking. The available term tracks the finish: a two-coat PVDF carries the longest warranties at the tightest chalk and fade limits, SMP a shorter term at looser limits, and polyester the shortest. A warranty written at a looser limit over a longer term is not a better warranty. (16.2.1)
16.2.2 The panel manufacturer shall provide a written finish warranty covering chalking, color change, and film integrity for the term indicated in the datasheet.
Finish Warranty Termrange
Not less than
years
510152025303540
16.2.3 The finish warranty shall warrant that chalking will not exceed the limit indicated in the datasheet, measured per ASTM D4214, over the warranty term.
Chalk Rating Over the Warranty Term (ASTM D4214)range
Not less than
rating
69
Default: 8 rating
16.2.4 The finish warranty shall warrant that color change will not exceed the limit indicated in the datasheet, measured per ASTM D2244, over the warranty term.
Color Change Over the Warranty Term (ASTM D2244)range
Not more than
ΔE
310
Default: 5 ΔE
16.2.5 Where the selected finish is bare aluminum-zinc, mill finish, or natural weathering copper or zinc, the finish warranty shall instead cover the metallic coating or the metal against perforation and against failure of any mill-applied clear coating, for the term indicated.
16.2.6 Where the finish warranty available for the selected finish is shorter than the term indicated, or its chalk and fade limits looser than those indicated, the Contractor shall report the difference with the action submittal, and shall not substitute the shorter or looser warranty without the Owner's written acceptance.

16.3 Manufacturer Weathertightness Warranty

NOTE The manufacturer's weathertightness warranty is written on the complete system, including the trim, closures, sealant, and the penetrations and curbs the manufacturer details, and it is the warranty that makes the seam and the installer the manufacturer's problem rather than the Owner's. The types differ in what they pay for: a standard warranty pays labor and material up to a stated dollar limit, and a no-dollar-limit warranty removes the cap, which is why it is conditioned on an authorized installer, the manufacturer's details at every termination, the specified underlayment and clip, and a manufacturer inspection before issuance. Through-fastened systems and dry snap-lock seams are commonly offered no weathertightness warranty at all. (16.3.1)
16.3.2 The manufacturer's weathertightness warranty type shall be as indicated in the datasheet.
Manufacturer Weathertightness Warranty Typeradio
○ No manufacturer weathertightness warranty beyond the finish and material warranties
○ Manufacturer weathertightness warranty up to a stated dollar limit
○ Manufacturer no-dollar-limit weathertightness warranty
16.3.3 The manufacturer's weathertightness warranty term shall be as indicated in the datasheet.
Manufacturer Weathertightness Warranty Termrange
Not less than
years
51015202530
16.3.4 The Contractor shall confirm with the panel manufacturer, before the action submittal package is submitted, every condition the manufacturer places on issuing the warranty type and term indicated, and shall report in writing any project condition, including the slope, the seam type, the underlayment, and any curb or penetration by another trade, that would prevent its issuance.
16.3.5 The Contractor shall not substitute a warranty of lesser type or shorter term than that indicated in the datasheet without the Owner's written acceptance.
16.3.6 The Contractor shall deliver to the Owner, with the warranty, a written statement of the conditions that void or limit coverage, including the procedure by which the Owner obtains the manufacturer's authorization before any attachment to the roof or rooftop work is performed after acceptance.

17 Spare Parts and Attic Stock

17.1 Attic Stock

NOTE A panel profile, a coil color, and a clip design are each discontinued without notice, and a repair ten years on is made from the original roll or not at all; matching stock is procured with the original work for that reason. (17.1.1)
17.1.2 The Contractor shall deliver to the Owner the attic stock selected in the datasheet, matching the installed profile, gauge, finish, and color.
Attic Stock Furnished to the Ownercheckbox
☑ Full-length panels of each profile and color
☑ Clips of each type installed
☑ Fasteners of each type installed
☐ Closures of each profile
☐ Seam sealant and butyl tape
☐ Pipe boots of each size installed
☐ Snow retention clamps and components
☑ Touch-up coating in each color
17.1.3 The number of full-length spare panels of each profile and color shall be as indicated in the datasheet.
Spare Full-Length Panels per Profile and Colorrange
Not less than
each
020
Default: 2 each
17.1.4 Attic stock shall be from the same coil or production lot as the installed panels where the manufacturer can supply it from that lot, and shall be labeled with the profile, gauge, finish, color, and the coil or lot number.
17.1.5 Attic stock shall be delivered to the location on the site the Owner designates, stored as this standard requires for panels, and receipted by the Owner.

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"Metal Roof Panels," SynC Standards, revision 5. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://synergyinconstruction.com/standards/general/metal-roof-panels. Reference material only; not professional engineering advice and provided without warranty. Verify against governing codes and have a licensed professional review before use.