FM Global Roof Requirements: Design Materials and Compliance Guide

FM Global roof requirements establish performance-based standards for commercial and industrial roofing to reduce property risk and ensure long-term reliability. This guide summarizes key criteria, approved materials, installation practices, testing, and documentation to help building owners, designers, and contractors meet FM Global expectations. Adherence to FM Global standards improves roof performance, reduces insurance loss potential, and often lowers premiums.

Topic	Key Takeaway
Design Criteria	Wind, uplift, and live load calculations based on FM Global data
Materials	FM Approved assemblies and materials required for many occupancies
Installation	Factory warranties, certified contractors, and QA documentation
Maintenance	Regular inspections and repairs per FM 1-35 guidance

What FM Global Roof Requirements Cover

FM Global roof requirements are a set of technical standards and approval criteria that address roof system selection, design, installation, testing, and maintenance. These requirements come from FM Global loss-prevention engineering principles and FM Approvals listings. The standards emphasize durability, watertightness, resistance to wind uplift, and predictable performance under fire and environmental stress.

Key Design Criteria For FM Global Roof Compliance

Designers must integrate several performance factors to meet FM Global roof requirements. Critical elements include structural support, wind uplift resistance, snow and live loads, thermal movement, and roof slope. Wind uplift values are based on regional wind maps, roof geometry, and surrounding terrain.

FM Global provides design tables and calculation methods to determine required fastener spacing, adhesive usage, and attachment patterns. These parameters vary by roof assembly weight, roof height, and edge conditions.

Approved Materials And Assemblies

FM Global maintains a directory of FM Approved products and assemblies for roofing membranes, insulation, adhesives, fasteners, and perimeter systems. Selecting FM Approved materials simplifies compliance, as these products are tested to FM standards for performance. Using non-approved components can require additional testing or engineering justification.

• Membranes: EPDM, TPO, PVC, modified bitumen, and built-up roofing assemblies with FM Approval listings.
• Insulation: Polyiso, extruded polystyrene, and mineral wool per FM criteria for compressive strength and fire performance.
• Fasteners And Adhesives: Rated for shear and pullout capacity per FM calculations.

Wind Uplift And Structural Considerations

FM Global calculates uplift pressures using site-specific parameters and applies safety factors to determine attachment schedules. Edge conditions, such as parapets and overhangs, require special reinforcement. Design must account for concentrated loads and ensure the substrate can accept required fasteners safely.

For large or high-rise roofs, FM Global often requires continuous securement methods or engineered attachment patterns to provide margin against severe wind events. Roof edge securement and transition details are frequent focus areas during inspections.

Roof Drainage, Slope, And Moisture Control

Proper drainage is essential to meet FM Global roof requirements because ponding water accelerates membrane damage and increases load. Designs should avoid low spots and specify minimum slopes or tapered insulation systems. FM recommends slope targets and drainage paths to prevent seasonal ponding and exceedance of design live loads.

Vapor retarders and insulation continuity are important for condensation control. FM Global evaluates roof assembly vapor profiles to prevent trapped moisture and thermal degradation of insulation or decking materials.

Installation Practices And Quality Assurance

FM Global expects installation work to follow manufacturer instructions and established procedures. Qualified contractors, factory-trained installers, and documented QA/QC processes are commonly required. Jobsite photos, heat-weld tests, and fastener pull tests help demonstrate compliance during acceptance.

Common installer requirements include pre-installation mock-ups, adherence to FM Approved details, and supervision by a certified Roofing Contractor or a Construction Manager familiar with FM standards.

Testing, Certification, And Documentation

Project documentation supports FM Global roof requirements and typically includes shop drawings, material submittals, FM Approval certificates, test reports, and maintenance plans. Documentation also records any deviations and engineering sign-offs. Clear records expedite underwriting reviews and post-installation inspections by FM Global engineers.

Testing may involve fastener pullout tests, field seam weld tests, and adhesive bond tests. Where non-standard assemblies are proposed, FM Approvals or independent laboratory testing may be necessary to verify performance.

Maintenance, Inspection, And Long-Term Performance

FM Global places strong emphasis on post-installation maintenance to sustain roof performance. Routine inspections, debris removal, sealant replacement, and timely repairs are components of FM-compliant maintenance programs. FM 1-35 provides guidance on roof maintenance frequency and inspection checklists.

Owners should maintain detailed maintenance logs and timely repair records to demonstrate ongoing compliance and to support favorable insurance evaluations and reduced loss potential.

Common Pitfalls And How To Avoid Them

Several common issues cause failures to meet FM Global roof requirements: using non-FM Approved materials without testing, insufficient fastening, poor edge securement, inadequate drainage design, and lack of proper documentation. Early coordination among designers, specifiers, contractors, and the insurer reduces the risk of noncompliance.

• Pitfall: Substituting lower-cost materials late in construction. Remedy: Require submittal approval and maintain an approved product list.
• Pitfall: Incomplete fastener pull tests. Remedy: Conduct representative tests documented in QA reports.
• Pitfall: Insufficient roof slope. Remedy: Use tapered insulation or rework deck details to achieve proper drainage.

Tips For Designers And Owners To Ensure Compliance

Designers and owners can streamline compliance by incorporating FM Global criteria into specifications from project inception, selecting FM Approved systems, and contracting FM-knowledgeable roofing contractors. Pre-construction meetings with FM Global loss prevention engineers help align expectations and reduce costly redesigns.

Include explicit requirements in contracts for mock-ups, certification of installers, material traceability, and post-installation inspections. Budget for higher-quality materials and QA to avoid greater long-term costs from failures or insurance penalties.

Frequently Referenced FM Global Publications And Resources

Several FM Global documents are frequently consulted when addressing roof requirements, including Approval Guides, Property Loss Prevention Data Sheets, and technical bulletins. These resources provide specific numeric criteria and test methods used to evaluate roof systems. Key references include the FM Global Property Loss Prevention Data Sheets and the FM Approvals RoofNav directory.

• FM Global Data Sheets (e.g., On Roofing Systems, Membranes, and Insulation)
• FM Approvals RoofNav Database for FM Approved products
• FM 1-35: Recommended Maintenance Practices for Roofs

How FM Global Reviews And Inspects Roofs

FM Global conducts pre-construction reviews, site inspections during installation, and post-construction evaluations. Inspections focus on critical details such as edge securement, fastener patterns, seam integrity, and drainage implementation. Nonconformities identified during inspection require corrective action and re-inspection before final acceptance.

For insurance underwriting, FM Global may require proof of compliance and may adjust coverages or premiums based on observed roof condition and maintenance records.

Cost Implications And Return On Investment

Meeting FM Global roof requirements can increase upfront costs due to higher-performance materials, testing, and QA; however, these investments often reduce lifecycle costs through fewer leaks, lower repair frequency, and reduced insurance losses. Owners commonly realize lower total cost of ownership and more favorable insurance terms by following FM standards.

When evaluating bids, consider long-term value rather than initial price. FM-compliant roofs tend to have improved warranty coverage and predictable performance that benefits asset protection strategies.

Next Steps For Project Teams

Project teams should begin by reviewing FM Global data sheets relevant to their roof type and accessing the FM Approvals RoofNav to select approved products. Engage FM Global engineering early for complex or high-risk facilities. Document decisions, schedule required tests, and implement a formal maintenance program before closeout to ensure sustained compliance.

Maintaining clear communication between owners, architects, contractors, and FM Global representatives minimizes project delays and supports durable, high-performing roofing systems that meet FM Global roof requirements.

Additional Resources And Links

For up-to-date product listings, technical criteria, and detailed design tables, consult FM Approvals RoofNav and the FM Global website. Professional organizations such as NRCA and RCI provide supplemental guidance on roofing best practices that complement FM requirements. Using a combination of FM documentation and industry best practices yields reliable, compliant roof systems.

Project teams should always verify the most current FM Global criteria and product approvals, as standards and approvals may be updated periodically.