FM Global Approval

Key Takeaways

• FM Global Approval = insurance-driven equipment listing.
• Common in HVHZ regions, high-fire areas.
• FM 4476 + 4478 for PV roof attachment.
• May be required by commercial insurance carrier.
• Solar racking brands offer FM-listed product lines.

What FM 4476 and FM 4478 Cover

FM Global’s approval standards for roof-mounted PV racking test the mounting system as a whole, not just its individual parts: wind uplift resistance, fire propagation across the roof membrane, and hail impact resistance all get evaluated together. That’s a different bar than a typical UL listing, which is mostly concerned with component-level electrical shock and fire-ignition safety. FM Global’s testing instead asks whether the racking will stay attached in a severe wind event and whether a fire starting on one section of the roof will spread the length of the array. In practice, this is why FM-listed hardware turns up most often in two situations: coastal HVHZ projects, and buildings insured by a carrier that has adopted FM Global’s property-loss-prevention data sheets as a policy condition — a requirement that can apply regardless of geography.

When FM Global Approval Actually Gets Required

FM Global Approval isn’t written into the IBC or IRC the way structural load standards are — no building code section mandates it directly. It becomes a project requirement because the property insurance carrier underwriting the building asks for it, most commonly on large commercial and industrial roofs where a wind-uplift failure or roof fire represents a significant loss exposure for the insurer. That means a design team can’t assume code compliance alone covers it; checking the project’s insurance requirements early, alongside the AHJ’s structural and fire code requirements, is the only reliable way to know whether FM-listed racking needs to be specified before the structural calc package and permit set go out.

Related Reading

Because insurance-driven equipment requirements like FM Global Approval tend to surface late if they’re not checked early, they’re worth confirming during the same intake step where a design team pins down local permitting rules — a step covered in more detail in our guide to submitting a solar permit package to an AHJ. This kind of insurance-versus-code distinction also shows up when comparing large commercial roofs against smaller residential jobs, a contrast our commercial vs. residential solar permit design piece walks through. FM Global’s approval sits alongside, not instead of, component-level electrical certification — the parallel process for inverters and modules is summarized in this overview of the IEC 61730 module safety standard.