“Non-penetrating clamp for metal roof” does not identify a safe solar attachment. The clamp grips a particular seam shape and transfers load through the roof panel, concealed clips and supporting structure. A quotation must connect the exact clamp model to the exact roof panel profile, material, thickness and seam construction, then show evidence for the directions of load the proposed array will impose.
This guide focuses on the standing-seam grip and PV attachment layout. The general solar mounting bracket guide addresses material, corrosion and broader load-document checks. The roof-flashing guide addresses water shedding around penetrating mounts. Neither replaces seam-profile identification for a clamp-on attachment.
Identify the actual seam before selecting the clamp
Request the roof manufacturer's panel name and drawing revision, seam height and width, fold or snap-lock geometry, cap construction, roof slope, panel width, metal type or grade, nominal thickness or gauge, coating and condition. Include measured sections or a verified profile template, photographs from more than one angle and the roof maker's permitted attachment locations. Record concealed clip type, clip spacing, panel length and whether the roof relies on thermal sliding.
S-5! says its clamp selection depends on roof type, gauge and material. Its S-5-U product page describes different orientations for vertical and certain horizontal seams; the S-5-S page is aimed at snap-lock and some single-fold profiles. Those examples show why a supplier should name the clamp, insert if any, set-screw side and seam engagement in a drawing rather than quote a “universal standing-seam clamp.” S-5! also identifies roof forms its standing-seam clamps do not fit, including face-fastened trapezoidal ribs and corrugated panels. S-5! clamp overview; S-5-U product and fit information; S-5-S product and fit information.
A supplier photograph of a similar roof is only a screening aid. A small difference in fold, overlap, cap or metal thickness can change grip and load behavior. Ask who verified the roof identity and whether the tested specimen matches the installed panel.
Ask for directional load evidence for the assembly
Provide the designer's required actions and combinations: wind uplift normal to the roof, forces parallel to the seam, gravity and any site-specific maintenance, snow or seismic demands. Ask the supplier for the test or engineering reference for the exact clamp–seam combination in each relevant direction, with specimen panel identity, metal thickness and material, installation torque, test direction, failure mode, ultimate result, applicable allowable value and safety-factor basis. A single unlabeled “load capacity” is not comparable.
S-5! reports that holding strength varies with load direction, seam profile, roof material and clamp model. Its published testing description distinguishes negative load normal to the seam from parallel drag load. It also notes that normal-load performance may be governed by the roof panel's clips or seam beam strength rather than by clamp grip alone. Consequently, a clamp test does not establish that the complete roof-to-structure load path is adequate. S-5! load explanation; S-5! test protocols.
Request separate checks for the PV module frame and its mounting zones, rail or rail-less hardware, clamp-to-rail connection, seam, concealed clips, panel and building structure. The module clamp-zone guide covers the module-side interface. A laboratory clamp pull result must not be reported as a complete installed-array wind rating.
Fix torque, orientation and hardware identity
Obtain the current instruction sheet for the exact clamp and any insert, including set-screw count and position, clamp orientation, seating check, tightening sequence, tool, torque range and inspection method. Identify the separate bolt or rail fastener and its own torque; do not apply a set-screw value to a top bolt.
The S-5! installation sheet for its U/S/E/B/V families specifies different set-screw torque ranges for 22-gauge steel and for other metals or thinner steel, calls for a dial-calibrated torque wrench, and describes how set screws dimple rather than penetrate the seam. The sheet also gives orientation and retightening instructions. These are manufacturer instructions for the named families, not a universal torque schedule for every seam clamp. Request the instruction revision and any exceptions corresponding to the quoted model and test record. S-5! U/S/E/B/V and Mini installation instructions.
For field control, specify a sample fit check, tool calibration or verification, torque record frequency, rejected-seam criteria and the disposition of a removed or relocated clamp. S-5! cautions that performance after removal and reinstallation cannot be assumed for its S-5-U clamp. S-5-U product instructions and FAQ.
Place clamps with the roof's load path and movement in view
Show every planned clamp on a roof plan, including array edges, seam spacing, eaves, ridges, expansion joints, panel ends and concealed clip positions. Identify whether the roof maker permits attachment at clip locations and whether a chosen clamp can restrict thermal movement. Require the designer to state the attachment spacing and load-distribution basis for that roof; a catalog spacing example is not a project layout.
S-5!'s PV spacing guidance explains that loads pass through roof panels and concealed clips to the structure, and recommends using the roof's attachment pattern as a conservative starting point after structural adequacy is established. It explicitly leaves verification of panel, clip and structure strength to the project team. Use the guidance to ask for the actual clip map and structural review, not to certify a roof from a clamp quotation. S-5! PV clamp spacing guidance.
Make quotations comparable
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| RFQ field | Evidence to request | Hold point |
|---|---|---|
| Seam and clamp fit | Roof maker/profile and section, material, thickness/gauge, seam construction, exact clamp and orientation, fit confirmation | “Fits standing seam” without an identified roof panel |
| Directional strength | Relevant normal/uplift and parallel/drag evidence for the matched clamp–seam specimen, plus panel/clip/structure review | One generic load number or an ultimate test value presented as an allowable assembly rating |
| Installation and layout | Current clamp instructions, set-screw and top-fastener torques, hardware BOM, tool check, clamp plan and concealed-clip/thermal-movement review | Torque or spacing copied from a different clamp or roof |
Ask bidders to identify every evidence gap as a deviation. Compare alternate clamps only after both have been assessed on the same seam and design actions. If the offered roof material, gauge, clamp insert or fastener changes, request a revised fit and load-evidence response. For electrical continuity or equipment bonding claims, require separate system evidence under the solar mounting bonding guide.
Send a standing-seam clamp RFQ
Send the roof panel schedule and seam section, metal material and thickness, concealed-clip information, module and rail layout, project design actions, attachment zones, target market, quantities and evidence matrix. Request the exact clamp BOM, fit confirmation, directional results, installation instructions, layout assumptions and written deviations.
Send a standing-seam solar clamp RFQ
Buyer FAQ
Does “non-penetrating” mean any seam clamp will fit my roof?
No. It describes the fastening approach, not a match to your seam geometry, material or thickness. Identify the roof profile and obtain an exact-model fit response.
Can one pull-test value cover uplift and drag?
No. S-5! separates normal-to-seam and parallel-to-seam testing. Request evidence for each relevant direction and the full roof load path.
Is the clamp's installation torque the same as the rail-bolt torque?
Do not assume so. Request the current instruction sheet and separate values for set screws and any top bolt or rail hardware, tied to the tested configuration.
Can clamp spacing be copied from another PV roof?
No. Locate the roof's concealed clips, identify the panel-to-structure load path and have the project designer check the proposed array layout and actions.