AllShield BarrierSheet (Cover board) FM 4470 Approved

AllShield BarrierSheet is now FM 4470 Approved as a mineral cover board for flat industrial roofs. This approval confirms compliance with the global benchmark for fire-safe and insurable roof assemblies, enabling FM Approved Class 1 Roof systems with approved membranes.

Since December 2025, AllShield BarrierSheet is officially FM 4470 Approved as a mineral cover board for flat industrial roofs.

This approval confirms that AllShield BarrierSheet complies with the most widely recognised global standard for fire-safe and insurable roof construction. This approval covers Single-Ply, Polymer-Modified Bitumen, Built-Up Roof (BUR) and Liquid Applied roof assemblies for Class 1 and noncombustible roof deck construction.

For roof owners, asset managers and insurers, this provides clarity. A roof assembly incorporating AllShield BarrierSheet as a cover board can achieve FM Approved Class 1 Roof status and is recognised internationally as fire-safe, low risk and insurable.

Even existing non-FM roofs can be upgraded to the level of an FM 4470 Class 1 Roof by installing AllShield BarrierSheet together with a new FM Approved roof membrane and, where required, additional PIR insulation.

Important: despite FM Approval, each individual roof must always receive a final project-specific assessment by the insurer’s risk engineer to confirm full acceptance.

What is FM 4470?

FM 4470, Approval Standard for Single-Ply, Polymer-Modified Bitumen, Built-Up and Liquid Applied Roof Assemblies, is the global benchmark for insurable flat roof systems.

The standard evaluates the performance of a complete roof assembly, including the cover board, insulation, membrane and roof deck construction. Only assemblies that meet all requirements are eligible for FM Approved Class 1 Roof status.

FM 4470 assesses the following performance criteria

Fire performance
No rapid flame spread.
No burn-through of the roof system.
No falling debris that could ignite lower roof layers.

Roof wind/hail Class 1-SH

AllShield BarrierSheet can be used in FM roof assemblies within the Roof Wind/Hail Class 1-SH category. This means it is suitable for roof systems that must meet higher requirements for wind uplift and hail resistance, alongside the broader performance criteria covered under FM 4470. As part of an FM Approved roof assembly, BarrierSheet supports durable, robust rooftops that help building owners, insurers and risk engineers manage risk on industrial and commercial buildings

Durability
Resistance to UV exposure.
Thermal aging under long-term heat cycles.
Mechanical stresses caused by maintenance and rooftop use.

Only assemblies that successfully pass all required tests are listed in RoofNav as FM Approved Class 1 Roofs.

FM 4470 cover board classification

Within FM 4470 roof assemblies, the cover board plays a critical role in the overall fire performance of the roof system.

As an FM 4470 Approved Cover board, AllShield BarrierSheet forms the non-combustible protective layer above the insulation. In combination with approved membranes, this enables roof assemblies to achieve FM Approved Class 1 Roof status while maintaining a lightweight and efficient build-up.

Why insurers require FM 4470

The roof represents one of the largest potential fire-risk surfaces of an industrial building.

Without an FM classification, even a limited ignition source can escalate into extensive fire damage, business interruption and total loss. An FM 4470 Class 1 Roof is recognised as low risk, widely insurable and often eligible for more favourable insurance conditions. A non-classified roof carries a higher risk profile and is frequently difficult or impossible to insure.

With FM 4470 approval for AllShield BarrierSheet as a cover board, insurers gain immediate and objective clarity. Roof assemblies incorporating this component meet the strictest international requirements for fire safety, durability and risk control.

Allshield barriersheet as FM 4470 Cover board

AllShield BarrierSheet is a non-combustible mineral cover board with a weight of 3.0 kg/m², now officially approved under FM 4470. Within approved roof assemblies, BarrierSheet functions as a recognised Class 1 Roof component and directly contributes to the overall fire performance of the system.

Key benefits include:

FM 4470 approved and listed in RoofNav
Recognised as a Class 1 Roof component within approved membrane assemblies.

Non-combustible and durable cover board
BarrierSheet protects the insulation layer, prevents rapid flame spread and contributes to long-term roof resilience.

Compatible with PIR and lightweight industrial roof structures
Allows upgrading to FM standards without requiring structural reinforcement.

Additional non-FM certifications

In addition to FM 4470, AllShield BarrierSheet complies with established European fire-safety classifications and has been subjected to independent fire testing.

BROOF(t1)
Highest European classification for external fire exposure according to CEN/TS 1187 Test 1.
When referring to the general test methodology, the designation BROOF(Tx) is used.

Kiwa-BDA testing
Successful external fire exposure testing on non-FM substrates.

ZAG Ljubljana testing
Independent fire performance testing of roof assemblies incorporating AllShield BarrierSheet.

These certifications and test results confirm that AllShield BarrierSheet is recognised not only under FM standards, but also within the European regulatory framework and independent fire research.