New standard: FM 4484, retrofit coatings for roof-mounted rigid photovoltaic module systems

In July 2025, FM Approvals published a new examination standard – FM 4484 for retrofit coatings for roof-mounted rigid photovoltaic (PV) module systems.

Retrofit roof coatings involve applying a layer of protective liquid material to the roof surface around and underneath existing PV panels. Fire-resistant coatings can reduce fire spread which potentially reduces damage when an incident occurs.

FM 4484 states the testing and certification requirements for these retrofit coatings designed to mitigate fire spread hazards for rigid roof-mounted PV panel assemblies. FM Approvals’ testing and certification requirements evaluate the suitability, performance, durability, and reliability of the coating. During testing, the retrofit roof coating is applied to the top surface of test roofing system in accordance with the coating manufacturer’s specifications.

To successfully complete testing and receive FM Approval, a sample must meet all requirements of FM 4484, including limiting the flame spread and damage to the underlying roof system to less than 6 in. (152 mm) beyond the end of the last PV panel.

If a rooftop PV system contributes to a roof failure that leads to business interruption, the need for roof replacement or reroofing, or contents damage, the costs will surely be greater than the loss of the PV system. FM Approvals’ commitment to innovation in property loss prevention continues to drive the evolution of industry standards, empowering stakeholders to safeguard critical infrastructure.

If you are a manufacturer of retrofit coatings or other roofing-related products, begin the application process for FM Approvals certification here.

We have developed more than 200 standards in various product categories spanning fire protection equipment, electrical equipment, building materials, and emerging technologies. The FM APPROVED certification mark appears on all FM Approved products and is recognized and respected worldwide, instilling confidence in loss prevention products available in your current targeted markets and the markets you consider opportunities for expansion.

All FM Approved products are listed in the Approval Guide and RoofNav, our publicly available listings of tested and certified loss prevention solutions. The Approval Guide is used by contractors, building owners, regulators, and other stakeholders to reference and identify FM Approved solutions that meet our standards of quality, technical integrity, and performance. RoofNav is used by roofing professionals to access the most up-to-date FM Approved roofing information and installation recommendations.

As a leading third-party testing laboratory for the certification of photovoltaic modules and commercial roofing products, FM Approvals objectively tests and certifies products that meet our globally recognized loss prevention standards encourages the use of FM Approved products to improve and advance property loss prevention practices worldwide.