US-headquartered metal roof engineering company S-5! has released a white paper challenging the assumption solar attachment points must be directly located over purlins to ensure structural adequacy.
The ‘Solar Mounting Off Purlin on Metal Roof Sheeting’ technical paper investigates the assumption via laboratory testing for Australian building codes and standards and documented field performance.
The paper presents evidence that metal roof sheeting can reliably support solar attachments between purlins when systems are property engineered and installed.
Wind uplift resistance, load distribution and the structural role of roof panels are all examined in the paper, supported by static and cyclic load testing results, full-assembly testing and examples of solar installations that have withstood extreme hurricane conditions.
The paper points to utilising proper load distribution and not just proximity to structural purlins as key to evaluating the complete load path, including roof sheeting, solar fixings, and supporting structure.
“Metal roofs come in two distinct styles, each with a different method of attachment: standing seam (or concealed-fix), and exposed-fastened (exposed-fix). In both roof types, the seams or ribs that run from the eave to the ridge act as structural elements,” the paper says.
The paper’s findings support the integrity of S-5!‘s PVKIT 3.0 rail-less solar mounting system and Facet Mount.
“Clamps or brackets are attached to the seams or ribs with an interface called the PVKIT to secure the PV module frames, eliminating the need for rails. The clamps and brackets can be attached anywhere along the seams or ribs, as well as directly over the purlins,” the paper explains.
The PVKIT 3.0 is available in standard and optional integrated 50 mm riser configurations, providing additional space for wire routing, module-level power electronics and other balance of system components.
The S-5! high-pressure cast aluminium Facet Mount offers 16 fastening locations designed for flexibility and increased load distribution while preserving single-ply membrance roof integrity.
S-5! will be exhibiting at All Energy Australia, October 28-29, in Melbourne at Stand Q101.
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