AllShield BarrierSheet - FM Approved lightweight Fire board for roof-PV assemblies
Passive Fire Protection for Flat Roofs with PV
AllShield BarrierSheet is developed for fire-safe PV roof build-ups on new, refurbished and existing flat roofs. AllShield BarrierSheet is a 2.5 mm lightweight, A1 non-combustible cementitious Fire board installed beneath the waterproofing membrane. At approximately 3 kg/m², it adds very little weight and can provide a practical solution where structural capacity is limited or where an existing roof can be retained as part of a refurbishment strategy.
FM 4470 and FM 4478 Approved for specified roof and roof-PV assemblies listed in RoofNav, AllShield BarrierSheet adds a passive protective layer between a fire above the waterproofing membrane and the deeper roof construction. In independent ZAG roof-PV fire tests, it prevented direct flame penetration into the lower structural layers in all tested configurations. Its purpose is to help limit deeper fire involvement and reduce the potential for a local PV fire to develop into a more serious roof and building loss.
Working principle
AllShield BarrierSheet creates a continuous, non-combustible layer directly beneath the waterproofing membrane. If fire develops in the PV system or roofing membrane, AllShield BarrierSheet interrupts the direct flame path towards the insulation and deeper roof construction. In the tested ZAG roof-PV configurations, direct flame penetration through the BarrierSheet into lower structural layers was prevented.
The waterproofing membrane and PV components above AllShield BarrierSheet can still burn and heat can still pass into the layers below. The function of AllShield BarrierSheet is therefore not to make the complete roof non-combustible but to maintain a physical separation layer and help limit escalation into deeper combustible roof layers. This passive protection remains in place without depending on detection, power, software or human intervention.
How AllShield BarrierSheet limits fire escalation
When fire develops above the waterproofing membrane, AllShield BarrierSheet provides a non-combustible physical layer between the fire and the deeper roof construction. In independent ZAG roof-PV fire tests, AllShield BarrierSheet prevented direct flame penetration into lower structural layers in all tested configurations.
The tests also showed that heat can still pass through the sheet and that thermal effects can occur in the layers below. AllShield BarrierSheet should therefore be specified for the function demonstrated by the evidence: interrupting direct flame penetration and limiting the pathway for deeper fire involvement within the tested roof-PV configurations.
Performance depends on the complete assembly, including the waterproofing membrane, insulation, deck, installation method, PV configuration and critical roof details.
Quick & Simple Installation
AllShield BarrierSheet is lightweight and designed for straightforward installation using standard roofing methods and equipment. We recommend mechanical fixing with roofing screws and stress plates. The fixing pattern and number of fasteners should follow the AllShield BarrierSheet installation guide and the project-specific wind-uplift requirements.
The recommended 6-fixing pattern provides a simple and practical installation method for standard applications. Depending on the roof build-up and project conditions, the required fixing pattern may be adjusted in accordance with the installation guide and structural or wind-uplift design.
For FM Approved applications, the applicable RoofNav assembly and FM Approval conditions take precedence. In RoofNav assembly 568563-0-0, the 2.5 mm AllShield BarrierSheet is installed loose laid on the top insulation layer while the roof cover is mechanically attached as part of the listed system.
On existing roofs, AllShield BarrierSheet can be incorporated beneath a new waterproofing membrane without necessarily removing the complete existing roof system. This makes it a practical solution for PV retrofit and roof refurbishment projects.
Certifications and Compliance
AllShield BarrierSheet
AllShield BarrierSheet is supported by third-party fire testing, classification and FM Approval for defined roof assemblies. FM Approval Report PR472014 covers AllShield BarrierSheet under FM 4470 and FM 4478 for the applicable configurations listed in RoofNav.
Efectis Classification Report 2025-Efectis-R000983 assigns BROOF(t1) under EN 13501-5 to a defined roof build-up incorporating AllShield BarrierSheet. The classification applies to that construction and the field of application stated in the classification report.
Independent ZAG and Kiwa-BDA testing provides additional evidence for specific roof-PV configurations and fire exposures. Together, these programmes provide designers, risk engineers and insurers with documented evidence for assessment of the relevant roof assembly. FM Approval provides insurers with a recognised basis for assessment while final acceptance always depends on the complete project configuration and the requirements of the approving party.
BarrierSheet FM 4478 Approved
→ BarrierSheet is FM Approved under FM 4478 for the applicable roof-PV assemblies listed in FM RoofNav. Refer to RoofNav and Approval Report PR472014 for the approved configurations.
FM Approvals report PR472014 · 11 December 2025 · RoofNav assembly 568563-0-0
BarrierSheet FM 4470 Approved
→ BarrierSheet is FM Approved under FM 4470 for the applicable roof assemblies listed in FM RoofNav. Refer to RoofNav and Approval Report PR472014 for the approved configurations.
FM Approvals report PR472014 · 11 December 2025 · RoofNav assembly 568563-0-0
AllShield BarrierSheet roof build-up classified BROOF(t1)
→ AllShield BarrierSheet used as a Fire board beneath a new waterproofing membrane.
→ Tested by Efectis according to CEN/TS 1187:2012, Test 1, resulting in BROOF(t1) classification under EN 13501-5.
Efectis report 2025-Efectis-R000983 · Test date 3 July 2025
Product information AllShield BarrierSheet
AllShield BarrierSheet combines low added weight with a non-combustible cementitious construction for use beneath commercial roofing membranes. At approximately 3 kg/m² and 2.5 mm thickness, it provides a practical option where fire protection must be integrated without unnecessarily consuming structural reserve or increasing roof build-up height.
AllShield BarrierSheet is manufactured in 1.00 × 2.00 m sheets for efficient installation on commercial and industrial roofs. The product specifications below describe the standard AllShield BarrierSheet as supplied.
| Product type | Cementitious Fire board |
| Chemical base | Inorganic mineral blend |
| Sheet dimensions | 1.00 × 2.00 m |
| Thickness | 2.5 ± 0.2 mm |
| Weight | Approx. 3.0 kg/m² ± 10% |
| Top surface finish | Woven top layer |
| Underside finish | Non-textured facing |
| Colour | Light grey underside, off-white natural mineral core and off-white top surface |
| Pallet quantity | 100 sheets |
| Area per pallet | 200 m² |
| Packaging | Palletised and wrapped in weather-resistant film |
| Storage conditions | Store indoors in the original unopened packaging. If temporary outdoor storage is unavoidable, elevate pallets and fully protect them with waterproof sheeting. Do not install wet or damaged sheets. |
Technical information AllShield BarrierSheet
AllShield BarrierSheet performance is documented through a combination of third-party classification and approval evidence and manufacturer-declared technical data. The table below identifies the relevant basis for each property.
Fire classifications and approvals should be read together with their applicable reports and fields of application. Physical product data describe AllShield BarrierSheet itself and support project-specific roof and structural design.
| Property | Value | Method |
| Reaction to fire | Class A1 / non-combustible | EN 13501-1 classification |
| Thermal conductivity | 0.3–0.5 W/m·K | Manufacturer-declared |
| Water absorption after 24 h | < 10% | Manufacturer-declared |
| Compressive strength | 10–15 MPa | Manufacturer-declared |
| Flexural strength | Not declared | Manufacturer-declared |
| Water vapour permeability | μ = 20–30 | Manufacturer-declared |
| Operating temperature | -30 °C to +90 °C | Manufacturer-declared |
Projects AllShield BarrierSheet
Protecting what matters. Insurability starts with evidence. Our projects with AllShield BarrierSheet show how passive fire protection, low added roof load and documented system performance can be integrated into real commercial roof-PV projects
Downloads
Frequently asked questions (FAQ)
Which AllShield solution is standard for PV roofs?
For new roofs, roof refurbishment and most existing roofs, AllShield BarrierSheet is our standard solution. It is a lightweight, non-combustible mineral Fire board installed beneath a new waterproofing membrane. It adds only around 3 kg/m² and is far less dependent on weather conditions during installation than a liquid-applied system.
AllShield Blue remains available as a specialty solution for selected existing roof applications where retaining the current waterproofing provides a clear project-specific advantage.
Is AllShield BarrierSheet FM Approved?
Yes. AllShield BarrierSheet is FM 4470 and FM 4478 Approved for roof assemblies with and without rooftop PV systems. The FM documentation describes BarrierSheet as a coverboard used within the complete roof assembly.
What is the AllShield BarrierSheet Fire board?
AllShield BarrierSheet is a 2.5 mm ultra-light, A1 non-combustible roof protection board weighing approximately 3 kg/m². Installed beneath a new waterproofing membrane, it protects the underlying roof layers against fire penetration. Products with this function are also known as a cover board, roof board, fire barrier board, roof protection board or membrane underlayment.
What is a Fire board?
A Fire board is a protective layer installed between the roof insulation or existing roof build-up and the waterproofing membrane. It protects the underlying layers and can improve the fire performance, robustness and durability of the complete roof assembly. It is also known as a roof board, fire barrier board, roof protection board or membrane underlayment.
Which roof systems are compatible with the BarrierSheet Fire board?
BarrierSheet can be used in roof assemblies with common insulation materials such as PIR, EPS and mineral wool and with waterproofing systems including PVC, TPO and bituminous membranes. As a lightweight fire barrier board, BarrierSheet becomes part of the complete roof assembly. The exact build-up must meet the applicable technical, fire and insurer requirements.
Is the BarrierSheet Fire board designed for roofs with solar panels?
Yes. BarrierSheet is designed for flat roofs with PV systems. This non-combustible fire barrier board and roof protection board protects the underlying roof layers against direct flame penetration and helps limit fire escalation within the roof assembly.
How is the BarrierSheet Fire board installed?
BarrierSheet is installed beneath a new waterproofing membrane on new or existing roofs. The ultra-light 2.5 mm boards are easy to handle and install. As a membrane underlayment, the exact installation and fixing method depend on the complete roof assembly, waterproofing system and calculated wind load.
Does AllShield BarrierSheet Fire board add significant weight?
No. BarrierSheet weighs only approximately 3 kg/m² and is just 2.5 mm thick. Its very low additional roof load makes this lightweight roof board particularly suitable for existing commercial and industrial roofs where structural capacity is limited.
Is AllShield BarrierSheet Fire board waterproof?
No. BarrierSheet is a non-combustible fire barrier board and roof protection board, not a waterproofing membrane. It is installed beneath a new waterproof roof membrane where it remains protected as part of the complete roof assembly.
Where has the BarrierSheet Fire board been tested and Approved?
AllShield BarrierSheet has been independently tested by FM Approvals, Kiwa-BDA, Efectis and ZAG in roof fire and roof-and-PV fire tests. It is FM 4470 and FM 4478 Approved, has an A1 non-combustible classification and has been tested in BROOF(t1) roof assemblies.
What is AllShield?
AllShield develops mineral-based coatings and barriers for fire safety, acid resistance and structural durability — with no plastics, no PFAS and a low CO₂ footprint.
Are AllShield products really non-combustible?
Yes. AllShield Blue and BarrierSheets are A1 certified.
Are your products compatible with common materials?
Yes. Proven on over 80% of standard materials including steel, EPS, PIR, PUR, bitumen, PVC, TPO, EPDM (for BarrierSheet), wood and concrete.
What types of buildings use AllShield?
Industrial, commercial and critical infrastructure buildings, especially those with flat roofs, PV systems, chemical zones or aging membranes.
Are your products sustainable?
Yes. AllShield products are VOC-free, REACH-compliant and developed to reduce the environmental impact of the built environment.
Can AllShield BarrierSheet and AllShield Blue be used with PV systems?
Yes. AllShield BarrierSheet is our standard solution for PV roof assemblies and is FM 4478 Approved for applicable roof assemblies. AllShield Blue is FM 4484 Approved and remains available as a specialty solution for selected existing roof applications.
Do they extend the lifespan of roofs?
Yes. AllShield Blue coating offers UV, mechanical and chemical resistance; BarrierSheet protects membranes and insulation as a cover board below a new roofing membrane.
Are they waterproof?
AllShield BarrierSheet is not a waterproofing layer and must always be covered by a waterproof roof membrane. AllShield Blue forms a seamless protective coating but is not intended to replace the primary roof waterproofing system or to repair an existing leaking roof.
Can AllShield BarrierSheet and AllShield Blue be used for roof refurbishment?
Yes. AllShield BarrierSheet is our standard solution for roof refurbishment and PV retrofits and is installed beneath a new waterproofing membrane. AllShield Blue can be applied directly to suitable existing waterproofing membranes in selected projects where retaining the existing membrane provides a clear practical advantage.
What about insurers?
AllShield Blue is FM 4482 and FM 4484 Approved. AllShield BarrierSheet is FM 4470 and FM 4478 Approved. Acceptance by an insurer always depends on the complete roof and PV assembly and the project-specific risk assessment.
