AllShield Blue Achieves FM 4484 Approval – Fire-Safe Protection for Solar Roofs

AllShield Blue is now FM 4484 Approved — the world’s first coating that makes roofs fire-safe and insurable under PV systems. A breakthrough in solar roof safety.

The world’s first FM 4484 Approved fire-protection coating for photovoltaic (PV) systems on existing roofs — proven to make even combustible roofs insurable.

A new global milestone in solar roof safety

After years of research and testing at Kiwa-BDA, Efectis, SGS-Intron, and in collaboration with FM Research and Approvals, AllShield Blue has officially achieved Approval under the new FM 4484 standard — the most demanding fire-safety test ever developed for existing roofs with solar panels.

This global first confirms AllShield Blue as an FM Approved material that prevents fire spread within existing roof systems and beneath photovoltaic arrays, making commercial and industrial roofs fire-safe and insurable — even when the original roof structure is combustible.

FM 4484 is the new Approval Standard that determines whether an existing roof newly equipped with PV systems can be insured, based on risk analysis by insurance companies.

FM Approvals: defining insurable roof safety

FM Approvals sets the technical standards used by insurers worldwide to assess whether roofs and materials are insurable and provides verified data for the risk assessment of each project.
While FM Approvals itself is not an insurer, its engineers evaluate materials and roof assemblies on behalf of FM. Risk assessors and field engineers rely on RoofNav — FM’s global database of FM Approved materials and assemblies — to decide whether a specific roof build-up can be insured, especially when photovoltaic systems are added.

AllShield Blue successfully passed both standard FM Approved test assemblies, using XPS insulation with non-fire-retardant EPDM and a modified-bitumen roof build-up as “worst-case” PV scenarios designed in consultation with FM engineers.
These tests were created to assess how existing combustible roofs behave when AllShield Blue is applied — enabling FM engineers worldwide to approve solar installations on roofs that were previously uninsurable.

Extract from the Approval Report:

3.3.1 All test samples described in Section 3.3 above, with AllShield Blue installed as a retrofit coating for PV panel assemblies having a roof-mounted rigid photovoltaic module system over an existing roof covering, met the requirements of the FM Approvals Standard listed in Section 1.3 above.
3.3.1.1 At no time during testing did the flame spread to within 6 in. (152 mm) of the end of the last PV panel.
3.3.1.2 At no time during testing was fire damage observed to the underlying roof system within 6 in. (152 mm) of the end of the last PV panel.
3.3.1.2.1 Additionally, no fire damage was observed to the underlying roof system within 6 in. (152 mm) of the two lateral edges of the roof system or retrofit coating (as measured from beyond 12 in. [305 mm] from the ignition source).

The American BUR test – the ultimate fire challenge

One of the toughest fire tests ever performed at FM Approvals was conducted on the traditional American Built-Up Roof (BUR) system — a roof type known for its high fire risk and energy density.
A BUR typically consists of a wooden deck with OSB boards, multiple asphalt and bitumen layers, and a non-fire-retardant surface membrane. Under PV panels, these layers can rapidly heat up, causing asphalt to melt and flow down the roof slope, accelerating flame spread.

In this harsh setup, AllShield Blue stopped the fire before it could enter the roof structure.
No burn-through occurred, no secondary ignition was observed, and heat transfer to the substrate remained minimal — even under 760 °C flame temperature and 5.4 m/s wind speed.
The result: even one of the most flammable roof types became functionally non-combustible, making it insurable when protected by AllShield Blue.

FM 4484 Approved Material – ready for insurable solar roofs

With its Approval under FM 4484, AllShield Blue is now listed as an FM Approved material in RoofNav (roofnav.com).
When combined with other FM Approved components, AllShield Blue enables FM Approved roof assemblies that meet insurance requirements for PV-ready commercial and industrial buildings.
For existing combustible roofs, FM engineers can now rely on FM 4484 test data to confirm that adding AllShield Blue makes the roof functionally non-combustible — and therefore insurable under solar load.

A turning point for global PV safety

With FM 4484 Approval, combined with independent tests at Kiwa-BDA and Efectis, AllShield Blue sets a new global standard for fire-safe, insurable solar roofs — even on existing buildings.
It provides building owners, insurers, and engineers with verified proof that rooftop fire risk can be controlled, even on combustible roofs.
This achievement marks a major step toward safer, more sustainable solar energy integration on commercial buildings worldwide.