AllShield BarrierSheet in FM Approved roof-PV assemblies under FM 4478

AllShield BarrierSheet is included in RoofNav assembly 568563-0-0 under FM Approvals Report PR472014, covering FM 4470 and FM 4478. This provides a defined FM Approved route for specified commercial roof-PV configurations.

FM 4478 and roof-mounted PV

FM 4478 is the Examination Standard for Roof-Mounted Rigid Photovoltaic Module Systems. It evaluates roof-mounted rigid PV systems within the FM approval framework and provides a recognised route for assessing the roof and PV configuration together.

AllShield BarrierSheet is included in RoofNav assembly 568563-0-0 under Approval Report PR472014. The listed construction defines the relevant roof components, attachment and PV-system conditions that form part of the approval.

This system-level evidence is particularly important for commercial projects because roof systems and PV systems are often designed by different parties. Starting from a listed roof-PV configuration gives the project team a common technical reference before the final design is committed.

BarrierSheet within the approved system

Within RoofNav assembly 568563-0-0, the 2.5 mm BarrierSheet is added to the top insulation layer and installed loose laid, while the roof cover is mechanically attached in accordance with the listed system requirements.

The FM route complements the product-specific fire evidence available from ZAG. In the tested ZAG roof-PV configurations, BarrierSheet prevented direct flame penetration into deeper structural layers. FM Approval separately provides recognised formal coverage for the listed roof-PV system.

Why this matters to owners and insurers

An insurer assessing rooftop PV is interested not only in individual component properties but in how the complete roof-PV configuration is supported by evidence. FM Approval gives insurers a recognised basis for assessing the roof; acceptance always depends on the complete assembly and the project-specific risk assessment.

For owners, this can reduce uncertainty early in the project. Roof construction, waterproofing, structural capacity, PV layout and fire evidence can be coordinated before procurement rather than reconciled after installation decisions have already been made.

For the exact approved configuration, consult the current RoofNav listing and Approval Report PR472014. If you are developing an FM-based commercial roof-PV project, contact AllShield for assistance matching the proposed build-up to the applicable assembly.