Florida is best known for hurricanes and high winds, but hail can also damage commercial and industrial roofing systems. For building owners evaluating a new roof or restoration project, an FM Severe Hail (SH) rating can be an important measure of roof-system durability. But does an FM Severe Hail rating actually matter in Florida? The answer depends on the building, its location, the roofing system, and the level of property protection required.
What Is an FM Severe Hail Rating?
An FM Severe Hail (SH) rating is an FM Approvals classification indicating that a roof assembly has been evaluated for resistance to severe hail impacts. FM Global’s current Data Sheet 1-34, Hail Damage, identifies hail hazard areas and provides recommendations for selecting appropriately rated FM Approved roof assemblies. FM’s hail classifications include Moderate Hail (MH), Severe Hail (SH), and Very Severe Hail (VSH).
The rating applies to the tested roof assembly, not simply one roofing material in isolation. That distinction is important because a roof’s hail performance depends on how the membrane or roof covering, insulation, cover board, deck, fasteners, and other components work together.
FM’s guidance also emphasizes that roof assemblies should be selected and installed according to their approval and manufacturer requirements. RoofNav can be used to identify FM Approved assemblies with the appropriate ratings.
Does Severe Hail Rating Matter in Florida?
Yes—but it is not automatically a Florida Building Code requirement for every roof.
Florida has its own roofing product approval and testing requirements. The Florida Building Code recognizes impact-resistance testing methods that can include FM 4470 and TAS 114, depending on the roof application and jurisdiction. Florida’s High-Velocity Hurricane Zone (HVHZ) requirements also impose specific testing and product-approval requirements for applicable roofing systems.
An FM Severe Hail rating therefore should not be confused with Florida’s wind-uplift requirements or HVHZ approvals. Hail resistance and wind resistance are separate performance characteristics. A roof can have a strong wind rating without necessarily having the hail rating needed for a particular FM hail hazard area.
For commercial properties, the distinction can be especially important when an owner, insurer, risk manager, or facility specification calls for FM Approved construction.
Why Is Hail Resistance Important for Florida Commercial Roofs?
Florida’s severe weather environment creates multiple risks at the same time. A commercial roof may need to withstand high winds, wind-driven rain, intense UV exposure, thermal cycling, and occasional damaging hail.
Hail can puncture or fracture roof membranes, damage seams, weaken insulation, and create openings that eventually result in water intrusion. FM Global specifically recommends correcting deficiencies that reduce hail resistance and replacing severely deteriorated roof assemblies when necessary.
For high-value facilities, the consequences can extend beyond the roof itself. A roof failure can lead to interior water damage, equipment damage, business interruption, and costly repairs.
Is FM Severe Hail Required Everywhere in Florida?
No. The appropriate FM hail rating depends on the FM hail hazard classification for the property’s location and the requirements applicable to the project.
FM’s current guidance recommends FM Approved roof assemblies appropriate for the identified hail hazard. In Severe Hail areas, FM recommends assemblies carrying the required SH-level performance and notes that VSH-rated roofs may be considered for high-value or critical facilities where additional protection is warranted.
Florida’s state product-approval system should also be checked when selecting roofing products. The Florida Building Commission’s product approval database allows users to verify whether products are approved for use in HVHZ, outside HVHZ, and whether impact resistance is identified for the product.
What Should Florida Building Owners Ask Their Roofing Contractor?
Before specifying an FM Severe Hail-rated roof, ask the contractor to verify:
- The property’s applicable FM hail hazard classification.
- The complete FM Approved roof assembly—not just individual components.
- The assembly’s hail rating and wind-uplift rating.
- Florida Product Approval requirements applicable to the project.
- Whether the roof is located inside or outside the HVHZ.
- Whether the existing deck and substrate are compatible with the proposed assembly.
- Whether a higher VSH-rated system makes sense for a high-value or mission-critical facility.
Bottom Line
An FM Severe Hail (SH) rating matters in Florida, particularly for commercial and industrial properties where roof durability, business continuity, insurance requirements, or FM Global recommendations are important. However, SH is not a substitute for Florida Product Approval, HVHZ compliance, or proper wind-uplift design.
The best approach is to evaluate the entire roofing assembly against the property’s Florida code requirements, wind exposure, FM hail hazard, building value, and risk profile. A qualified Florida commercial roofing contractor can help verify the appropriate assembly before installation or restoration begins.
Commercial Roof Inspections
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