La résistance au feu des panneaux sandwich en PU expliquée

Shandong Fuqiang Technical & Application Team | Corporate Technical / Product Application Team | Published September 26, 2026

PU sandwich panel fire resistance cannot be judged from the polyurethane core alone. Buyers must separate reaction to fire from a timed fire-resistance rating, then verify the complete panel assembly, joints, supports and installation covered by the relevant test or assessment.

Reaction to fire and fire resistance answer different questions

Reaction to fire describes how a material or product behaves when exposed to fire under a defined classification method. Fire resistance describes how an assembly maintains specified functions for a stated period under a defined test. A reaction-to-fire class must not be converted into minutes of fire resistance.

Question	Evidence to request
How does the product contribute to fire?	Classification report for the exact core, facings and construction.
Can the wall or roof separate fire for a stated period?	Assembly test or assessment covering supports, joints, orientation and exposure.
Will the proposed project be accepted?	Local code, designer and authority requirements matched to the project.

What changes the performance of a PU panel?

A PU insulated panel normally combines coated steel facings with a rigid polyurethane foam core. The result depends on core formulation, density, facing thickness, adhesive or bonding process, joint geometry, fasteners, penetrations and the way the panel is supported. The same nominal thickness can therefore have different documented performance when the construction changes.

Fuqiang publishes a hidden-fastener PU three-wave roof panel with 1,000 mm effective coverage, core thickness options from 50 to 150 mm, steel facings around 0.4–0.8 mm and thermal conductivity of no more than 0.023 W/(m·K). Its product page references GB 8624 Grade B1. That reference should be checked against the applicable report; it is not a timed fire-resistance claim.

PU versus rock wool: make the comparison at assembly level

Rock wool is a mineral-fibre core often considered where fire and acoustic requirements are significant. PU can provide strong thermal insulation at a relatively compact thickness. Neither description alone proves the performance of a finished roof or wall. Compare the actual core, facings, joints, fasteners, thickness, orientation and support arrangement.

Decision point	PU panel	Rock wool panel
Thermal design	Review the declared conductivity and complete U-value calculation.	Review the declared conductivity and complete U-value calculation.
Fire documentation	Request evidence for the exact foam formulation and assembly.	Request evidence for the exact mineral-fibre construction and assembly.
Conception des joints	Check foam continuity, facings and seal details.	Check core edge protection, facings and joint compression.

Procurement checks for contractors

1. State the required jurisdiction, building use, fire criteria and exposure direction.
2. Match the report to the quoted panel, including core, facings, thickness and joint.
3. Confirm whether the evidence covers wall, roof, ceiling or partition use.
4. Review openings, penetrations, fasteners, supports and interfaces.
5. Freeze the accepted configuration in the drawings and purchase order.

Ask for report numbers, issuing laboratory, classification scope and any permitted variations. A product brochure that only names a grade is insufficient for a project approval package.

Questions fréquentes

Does a PU core automatically give a sandwich panel a fire-resistance rating?

No. The core is only one part of the construction. Verify the complete tested or assessed panel assembly, including facings, joints, supports and installation.

Is GB 8624 Grade B1 the same as a fire-resistance period?

No. A burning-behaviour classification must not be rewritten as a duration in minutes. Request the applicable evidence for the project requirement.

Can a wall-panel report be used for a roof?

Do not assume it can. Roof and wall assemblies have different loading, orientation, joints and exposure conditions. The report must cover the proposed use.

What should a buyer send when requesting a PU panel quotation?

Send drawings, application, dimensions, quantities, target thermal performance, fire criteria, facing and coating requirements, destination and schedule. The supplier can then confirm the appropriate configuration and documents.

Fuqiang supplies insulated wall and roof panels on a project quotation basis. Final fire compliance should be confirmed by the responsible designer and authority using the documentation for the exact configuration.

For related product information, review the Gamme de panneaux sandwich en PU before sending a project enquiry.

FAQ

Does a PU core automatically give a sandwich panel a fire-resistance rating?

No. The core is only one part of the construction. Verify the complete tested or assessed panel assembly, including facings, joints, supports and installation.

Is GB 8624 Grade B1 the same as a fire-resistance period?

No. A burning-behaviour classification must not be rewritten as a duration in minutes. Request the applicable evidence for the project requirement.

Can a wall-panel report be used for a roof?

Do not assume it can. Roof and wall assemblies have different loading, orientation, joints and exposure conditions. The report must cover the proposed use.

What should a buyer send when requesting a PU panel quotation?

Send drawings, application, dimensions, quantities, target thermal performance, fire criteria, facing and coating requirements, destination and schedule. The supplier can then confirm the appropriate configuration and documents.