RoofNav is FM Approvals’ online database and specification tool for selecting FM Approved roofing assemblies, products, and related components. It is widely used by architects, engineers, roofing consultants, contractors, and building owners when a commercial roofing project requires an FM Approved system. FM states that FM Approved roofing products and assemblies are listed in RoofNav, making it an important reference when developing or reviewing commercial roof specifications.
For commercial roofing projects, RoofNav is more than a product catalog. It helps design professionals identify complete roof assemblies that have been tested and approved for specific performance requirements, rather than simply selecting individual roofing materials.
What Information Does RoofNav Provide?
RoofNav can be used to identify approved combinations of roofing components, including membranes, insulation, cover boards, fasteners, adhesives, and deck-related components. The database also provides information about the approved assembly’s performance characteristics and limitations.
This distinction is important. Using individual FM Approved products does not automatically create an FM Approved roof assembly. FM guidance specifically states that components must be approved for use together as part of the listed assembly. Substituting a component can also affect the assembly’s approved performance.
Depending on the assembly, RoofNav information can address factors such as wind uplift resistance, fire performance, hail resistance, roof slope, deck type, insulation configuration, and securement requirements.
How Is RoofNav Used During Specification?
RoofNav is typically used during the design and specification process in several steps.
1. Determine the project’s performance requirements.
The design team first establishes the roof’s required wind uplift resistance and other applicable performance criteria. FM’s guidance directs users to the RoofNav Ratings Calculator and applicable FM Property Loss Prevention Data Sheets for determining recommended ratings.
2. Identify an appropriate FM Approved assembly.
The designer searches RoofNav for assemblies that match the proposed roof construction, such as the deck type, membrane system, insulation arrangement, and other project requirements.
3. Verify the assembly rating.
The selected assembly must meet or exceed the required performance for the particular roof area. Roof zones can have different wind requirements, so the system should be checked against the applicable Zone 1, Zone 2, or Zone 3 requirements.
4. Incorporate the approved assembly into the specification.
The specification should identify the approved system accurately, including manufacturers, materials, thicknesses, fastening or adhesive requirements, and other critical installation details. FM’s plan-review guidance emphasizes providing exact manufacturer trade names, material thicknesses, application rates, fastener spacing, and roof-layer information.
5. Verify substitutions during bidding and construction.
If a contractor proposes changing a membrane, insulation, adhesive, fastener, or other component, the replacement should be checked to determine whether the resulting combination remains an FM Approved assembly. Simply replacing one product with another that has its own FM approval does not necessarily preserve the assembly’s approval.
Why Does RoofNav Matter in Florida Commercial Roofing?
RoofNav can be particularly important for commercial buildings where wind resistance and property-loss prevention are major concerns. Florida projects may face significant wind exposure, and the required roof system should be selected based on the building’s actual design conditions rather than using a generic roofing assembly.
RoofNav also helps specification teams create clearer project documents. Instead of saying only “install an FM Approved roof system,” the specification can identify a specific approved assembly and its required components and installation criteria.
Bottom Line
RoofNav is FM Approvals’ primary online resource for identifying and verifying FM Approved roofing assemblies and related products. During commercial roofing specification, it helps designers determine required performance, select an approved roof assembly, document the system accurately, and verify that proposed substitutions do not compromise the assembly’s approval.
For a commercial roofing project, the safest approach is to treat the RoofNav listing as a system-level requirement—not simply a list of individually approved roofing products. That distinction can help prevent specification errors, improper substitutions, and performance problems during construction.
Related Questions
- How do I find my roof assembly listed in the FM Approval Guide?
- What is FM Global and why do some Florida properties require FM-approved roofs?
- What does FM Data Sheet 1-29 cover for roof securement?
- How does an FM-rated roof affect insurance premiums?
- What is an FM 1-90 or 1-180 wind rating?
- Where can I find documentation for certified roof assemblies?
- What is FM 4470 and what does it cover?
- What is the difference between a prescriptive and a performance specification?
New Construction Commercial Roofing
