If you need to verify whether a commercial roof assembly is FM Approved, the first thing to know is that roofing assemblies are generally searched through FM Approvals’ RoofNav, rather than by manually searching the general FM Approval Guide. FM states that FM Approved roofing products and assemblies are listed in RoofNav, which provides current roofing-specific approval information.
Start With RoofNav
RoofNav is FM Approvals’ online database for FM Approved roofing products and assemblies. It allows contractors, architects, engineers, building owners, and facility managers to search for assemblies based on their construction characteristics, components, manufacturers, and performance requirements.
If you already have an FM assembly number from a previous roof specification, inspection report, or contractor, the quickest approach is to search that number directly. If you do not know the assembly number, use the Assembly Search function and build the search from the characteristics of the roof.
Gather Your Roof Information First
Before searching, collect as much information about the existing roof as possible. Useful information may include:
- Roof deck type and thickness
- Insulation type and thickness
- Vapor retarder or air barrier
- Cover board
- Membrane type
- Membrane manufacturer and product name
- Adhesive or fastening method
- Fastener and plate type
- Roof surfacing
- Existing or proposed components
- Required wind-uplift rating
- Fire and hail classifications
The more accurately you identify the existing roof layers, the easier it becomes to determine whether a matching FM Approved assembly exists.
Use Assembly Search
RoofNav’s current search interface allows users to narrow assembly results by characteristics and ratings. FM’s RoofNav Quick Start Guide specifically recommends starting with assembly characteristics and ratings when you do not know the exact roof-layer configuration.
For example, you may start by identifying whether the roof is a mechanically attached, adhered, or other assembly type, then narrow the results by deck, insulation, membrane, and performance requirements.
Pay particular attention to the wind-uplift rating, such as 1-60, 1-90, or another FM rating appropriate for the project. FM guidance states that the selected FM Approved roof system should have a wind rating at least equal to the rating required for the applicable roof zones.
Verify the Entire Assembly—Not Just Individual Products
One of the most important points is that having FM Approved individual roofing products does not automatically mean the complete roof assembly is FM Approved.
FM’s property loss prevention guidance states that individually approved components that have not been approved for use together do not constitute an FM Approved assembly. Substituting a component from an approved assembly can also affect the assembly’s tested performance.
Therefore, compare the complete RoofNav assembly listing against the actual or proposed roof construction.
Ask for the FM Assembly Number
If you are evaluating a roof installed by another contractor, ask for the specific FM RoofNav assembly number. This gives you a precise reference that can be checked against FM’s database instead of relying on a general statement that the roof is “FM Approved.”
If the existing roof documentation is incomplete, a qualified commercial roofing professional can help identify the roof components and determine whether the documented construction corresponds to an FM Approved assembly.
Why This Matters in Florida
For commercial properties in Florida, verifying the complete roof assembly is particularly important when wind resistance, insurance requirements, building-code compliance, or roof replacement specifications are involved. An FM rating should not be treated as a substitute for all applicable Florida Building Code requirements; the assembly must also be appropriate for the project’s design conditions.
Final Takeaway
To find your roof assembly in the FM Approval Guide, use FM Approvals’ RoofNav, gather the roof’s complete construction information, search by assembly characteristics and ratings, and verify the resulting assembly number and component configuration. Do not assume that individual FM Approved products automatically make an entire roof system FM Approved.
For a commercial roof in Florida, having the assembly documentation reviewed before replacement or restoration can help prevent costly specification, wind-uplift, and compatibility problems.
Related Questions
- What is FM Global and why do some Florida properties require FM-approved roofs?
- Where can I find documentation for certified roof assemblies?
- What does FM Data Sheet 1-29 cover for roof securement?
- What is FM 4470 and what does it cover?
- What is an FM 1-90 or 1-180 wind rating?
- How do FM requirements differ from Florida Building Code requirements?
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