Composite Panel Selection Guide for Cleanrooms | Gilcrest

How to Choose Composite Panels for Cleanrooms and Controlled Environments

Choosing the right composite panels is one of the most consequential specification decisions in any cleanroom or controlled environment project. Get it right at the outset and you establish the foundation for a facility that is compliant, easy to validate, and built to perform for years. Get it wrong and you face costly redesigns, non-conforming junctions, and contamination risks that only become visible once construction is complete. At Gilcrest Manufacturing, the guidance is consistent: start with your regulatory requirements, understand what each core material actually does, and specify a complete, documented system rather than individual components in isolation.

For architects working to FM and ISO standards, and for QA and validation teams preparing for GMP audits, the core question is the same: which panel construction is right for this environment? The answer depends on a combination of factors: the classification of the space, the thermal and acoustic demands of the building envelope, the hygiene requirements of the internal surfaces, and whether the facility will need to accommodate multiple ISO grades or evolve over time. This guide works through each of those factors in turn, covering cleanroom construction materials, core types, panel thickness, and what to look for in a composite panel supplier.

Key Takeaways

• Composite panels are not interchangeable: core material, thickness, and system compatibility all directly affect cleanroom compliance and long-term performance.
• PIR cores are suited to thermally driven applications such as building envelopes and cold rooms; aluminium honeycomb cores are the preferred choice for hygiene-critical, non-shedding GMP walls.
• FM approval provides independently verified evidence of fire performance and construction integrity, and is frequently required by insurers and clients on pharmaceutical, semiconductor, and aerospace projects.
• Multi-use facilities require careful zoning at specification stage to ensure panels, profiles, and junctions remain compatible across different ISO grades and operational areas.
• Specifying a complete system, including panels, profiles, doors, vision panels, and ancillaries, from a single composite panel supplier reduces coordination risk and simplifies the validation process.

Understanding Composite Panel Construction

A composite panel, in its simplest form, is a sandwich: two rigid outer skins bonded to a core material that sits between them. The skins are typically steel or aluminium, and they provide the surface finish, structural contribution, and cleanability of the panel. The core is where the real performance differentiation happens. It determines the panel’s thermal resistance, acoustic properties, fire behaviour, and, critically for cleanroom applications, its particle-shedding characteristics.

Understanding what separates a high-performance cleanroom panel system from a standard specification begins with understanding the core. There are three core types relevant to cleanroom and controlled environment projects:

• PIR (polyisocyanurate): A closed-cell rigid foam with high thermal resistance. PIR is the dominant choice for insulated building envelopes, cold stores, and temperature-controlled environments where thermal performance is the primary driver.
• Aluminium honeycomb: A non-shedding, dimensionally stable core constructed from a hexagonal aluminium cell matrix. It contains no loose fibres or particulates, which makes it the standard core material for hygiene-critical cleanroom wall panels in pharmaceutical, semiconductor, and life sciences environments.
• Mineral fibre: A dense, sound-absorbing core used in acoustic applications such as plant rooms, compressor enclosures, and industrial noise control. Mineral fibre panels are not typically specified for ISO-classified cleanroom interiors due to their fibre content.

Knowing which core suits which application is the starting point for any specification. The structural and hygiene advantages aluminium honeycomb holds over traditional materials make it the default choice wherever contamination control is a primary requirement, but PIR and mineral fibre each serve important roles in the broader built environment.

The cleanroom wall material you specify will also determine how the panel performs at junctions. Aluminium honeycomb panels, when specified as part of a fully flush system, eliminate the recesses and shadow gaps that accumulate contamination in conventionally built environments. This is not a cosmetic consideration: it is a compliance requirement under GMP guidelines, and it directly affects a facility’s ability to achieve and maintain audit readiness.

PIR vs. Aluminium Honeycomb: Which Core Do You Need?

This is the question that most frequently arises at specification stage, and the answer is determined by the function of the space rather than by preference or cost alone.

When PIR is the right choice:

PIR cores are the appropriate specification for applications where thermal performance is the primary requirement. This includes insulated building envelopes, cold rooms, blast-freeze facilities, controlled-temperature storage, and any structure where heat loss or condensation control is the governing design criterion. PIR panels deliver high R-values relative to panel thickness, which makes them efficient where thermal bridging and energy performance are key concerns.

When aluminium honeycomb is the right choice:

For ISO-classified cleanrooms, GMP pharmaceutical suites, semiconductor fabrication facilities, and hygiene-critical food production environments, aluminium honeycomb is the standard specification. The reason is straightforward: PIR foam, like all cellular foam materials, can shed microscopic particles over time, particularly at cut edges, mechanical fixings, and areas subject to vibration or repeated cleaning cycles. In a cleanroom operating to ISO Class 5 or stricter, that is not an acceptable risk.

Aluminium honeycomb cores contain no loose fibres, no particulating foam cells, and no materials that degrade under the cleaning agents used in pharmaceutical and life sciences environments. The core is inert, dimensionally stable, and does not compress or creep under normal loading. For GMP-regulated environments, FM-approved aluminium honeycomb cleanroom wall panels provide the combination of non-shedding performance, fire-rated construction, and documented compliance evidence that architects and validation teams require.

When architects and validation specialists ask how to choose the right composite panel for a cleanroom, the answer consistently points to aluminium honeycomb for hygiene-critical interiors: it is the only core type that combines non-shedding performance, dimensional stability, and compatibility with the aggressive cleaning regimes required in regulated environments. The core selection locks in the compliance baseline for the entire project, and it is the one decision that cannot be corrected after installation without full panel replacement.

The critical distinction is this: both PIR and aluminium honeycomb can produce panels that look identical from the outside. The performance difference is entirely in the core, and it only becomes apparent under the conditions that matter most, including cleaning, inspection, and audit. Specifying the wrong core for a regulated environment is not a recoverable error once construction is complete.

Specifying Composite Panels for Multi-Use Cleanroom Facilities

Multi-use facilities present the most complex specification scenario in cleanroom construction. A facility that accommodates both a Grade B pharmaceutical suite and a Grade D corridor, or that combines a cleanroom production area with adjacent controlled storage, cannot be specified as a single homogeneous environment. Each zone has its own ISO classification, its own cleaning protocol, and its own compliance requirements, and the panel system must accommodate all of them coherently.

Zoning and ISO grade compatibility

The first consideration is zoning: identifying which areas require which ISO classification and ensuring that the panel system, including the profiles and junctions at zone boundaries, maintains the integrity of each classification. Junctions between zones are a common source of compliance failures. If the profiles connecting panels of different specifications are not part of a compatible, tested system, the junction detail may not meet the surface finish requirements of either zone. Specifying a complete FM-approved cleanroom panel system from a single source ensures that every component, from the panel face to the base channel to the corner profile, has been designed to work together and can be validated as a cohesive assembly.

Future-proofing through modular design

Multi-use facilities also tend to evolve. Production requirements change, regulatory classifications are updated, and facilities that were designed for one purpose are frequently repurposed or extended. A modular panel system that supports reconfiguration without requiring structural alteration is a significant operational advantage. Aluminium honeycomb panels, by virtue of their dimensional stability and the precision with which they are manufactured, are well suited to modular installation approaches that allow sections to be removed, relocated, or replaced without compromising the surrounding structure.

Validation and audit readiness

For QA and validation teams, the documentation associated with a multi-use facility is as important as the physical installation. Every material in a GMP-regulated environment must be documented, traceable, and supported by test data. Specifying all panels, profiles, doors, and ancillaries from a single composite panel supplier means the documentation pack covers the entire system under a single set of certifications and test reports, rather than requiring the validation team to collate evidence from multiple sources. This is a practical advantage that significantly reduces the administrative burden of qualification and audit preparation. Gilcrest provides full documentation support as part of its standard supply process, which directly supports IQ/OQ activities and ongoing audit readiness.

For projects that fall outside the standard cleanroom envelope, including spray booths, industrial partitions, and OEM equipment enclosures, bespoke composite panel solutions for multi-use applications offer the flexibility to specify PIR, paper honeycomb, or other core constructions where thermal performance or structural adaptability takes precedence over contamination control.

FM Approval and Why It Matters for Cleanroom Wall Panels

FM approval is an independent certification issued by FM Global, one of the world’s leading commercial and industrial property insurers. For composite panel systems, FM approval validates fire performance, construction integrity, and the behaviour of the panel under fire conditions to a rigorous, internationally recognised standard.

What FM approval certifies

FM-approved cleanroom wall panels have been tested and verified to meet FM’s standards for fire resistance, flame spread, and smoke development. The certification process involves independent testing of the complete panel assembly, including skins, core, and adhesive, under controlled fire conditions. It is not a self-declared compliance claim: it is independently audited and documented.

Why it is specified on regulated projects

On pharmaceutical, semiconductor, aerospace, and high-end food production projects, FM approval is frequently a contractual requirement rather than a preference. Insurers may require it as a condition of cover. Clients in regulated industries may specify it to satisfy internal risk management policies. Main contractors may require it to comply with their own supply chain standards. In each case, the ability to provide FM approval documentation at specification stage removes a potential compliance barrier and demonstrates that the panel system has been independently validated to a global standard.

FM-approved vs. non-certified alternatives

The difference between an FM-approved system and a non-certified panel is not always visible in the product itself. Both may use similar materials and construction methods. The distinction lies in the evidence: FM-approved panels come with independently verified test data that can be presented to insurers, auditors, and clients without qualification. Non-certified panels require the specifier or end-user to make their own assessment of fire performance based on manufacturer data alone, which introduces risk at audit and may not satisfy contractual requirements. Gilcrest’s Puracore system carries FM approval across its wall panel range, and full certification documentation is available on request.

Choosing the Right Composite Panel Supplier

The panel itself is only part of the decision. The supplier’s capability, documentation standards, and after-sales support are equally important factors, particularly on regulated projects where the consequences of a supply failure extend well beyond the panels themselves.

When evaluating a composite panel supplier for a cleanroom project, consider the following:

• Certifications and test data: Does the supplier hold FM approval? Can they provide independently verified test reports for fire performance, surface finish, and core material? Documentation should be available at specification stage, not requested after an order is placed.
• Complete system capability: A supplier that provides only panels creates coordination risk. The profiles, base channels, preformed corners, doors, vision panels, and ancillaries that complete a cleanroom installation should all be available from the same source, designed and tested as a compatible system. Specifying cleanroom components from multiple suppliers increases the risk of junction mismatches and complicates the validation documentation.
• Sector experience: Project references in pharmaceutical, life sciences, semiconductor, automotive, and aerospace sectors provide evidence that the supplier understands the compliance requirements of regulated environments. Gilcrest’s Puracore system has been specified and installed in facilities operated by global organisations including Pfizer, GSK, and Rolls-Royce.
• Documentation packs: For GMP-regulated environments, the supplier’s ability to provide material data sheets, test certificates, traceability records, and installation guidance in a format suitable for IQ/OQ documentation is a practical requirement, not an optional extra.
• After-sales support: Cleanroom facilities are long-term assets. A supplier that provides technical support after installation, including guidance on cleaning protocols, repair procedures, and system modifications, reduces the operational burden on facilities and QA teams over the life of the installation.
• Supply chain reliability and lead times: Global supply chains introduce lead time variability that can affect construction programmes. A supplier with an efficient, well-managed logistics operation and a track record of on-time delivery reduces programme risk, particularly on projects with fixed commissioning dates.

Ready to Specify with Confidence

Specifying composite panels for a cleanroom or controlled environment is a decision that shapes the compliance, performance, and operational life of the facility. The core material, panel thickness, system compatibility, and supplier capability all feed into an outcome that will be tested not once, but repeatedly, across every audit, every cleaning cycle, and every operational change the facility undergoes.

Gilcrest Manufacturing works directly with architects, main contractors, installers, and QA teams at specification stage to ensure the right panels are identified for each environment, with the documentation to support it. Panels represent a critical element of a larger project, and getting the specification right from the outset protects every stakeholder in the chain, from the architect who signs off the design to the validation team preparing for their first GMP inspection.

Whether you are specifying cleanroom wall panels for a GMP-regulated pharmaceutical suite, selecting a PIR core solution for an industrial enclosure, or navigating a multi-use application that does not fit neatly into a standard product range, talk to us about your project and our team will help you identify the right panel construction from the outset.

FAQs About Choosing Composite Panels

How do I choose the right composite panel for a cleanroom?

Start with your ISO classification, then pick the core: PIR for thermal envelopes and cold rooms, aluminium honeycomb for non-shedding, GMP-compliant walls. Gilcrest recommends confirming panel type, finish, junction detailing, and FM approval with your supplier at specification stage, before drawings are finalised.

 

What is the difference between PIR and aluminium honeycomb composite panels?

PIR cores give strong thermal insulation for cold rooms and insulated envelopes, while aluminium honeycomb cores are fully non-shedding and dimensionally stable, the standard for hygiene-critical cleanroom walls. Gilcrest’s Puracore range uses aluminium honeycomb throughout.

Are composite panels suitable for multi-use cleanroom facilities?

Yes, provided you specify a modular, fully flush system that handles varied ISO grades across zones and uses compatible profiles from one supplier. Gilcrest advises a zoning review at specification stage, since zone junctions are the main contamination risk.

What cleanroom construction materials are required for GMP compliance?

EU GMP Annex 1 requires smooth, impervious, non-shedding surfaces: typically aluminium honeycomb panels with fully flush junctions and coved floor and ceiling transitions, all documented and traceable. Specifying compliant materials upfront, rather than retrofitting later, is the most reliable route to certification.

What does FM-approved mean for cleanroom wall panels?

FM approval is an independent FM Global certification confirming the full panel assembly (skins, core, adhesive) has been fire-tested for flame spread, smoke, and structural integrity, often a contractual requirement on pharma, semiconductor, and aerospace projects. Gilcrest’s Puracore system is FM approved, with documentation available on request.

 

What thickness of composite panel do I need for a cleanroom wall?

Thickness depends on span, floor-to-ceiling height, and system compatibility: 50mm suits longer spans and heavier loads, 40mm suits shorter spans or tight spaces. Gilcrest recommends confirming thickness at specification stage so it matches the profiles and corner details.

 

Can composite panels be used for both the building envelope and internal cleanroom walls?

They can, but requirements differ: envelopes need weatherproofing and thermal performance (favouring PIR), while internal walls prioritise hygiene and non-shedding cores (favouring aluminium honeycomb). Sourcing both from one supplier streamlines coordination, but confirms each range is specified and certified for its own use.

How do I evaluate a composite panel supplier for a cleanroom project?

Check for relevant certifications (FM approval is a strong indicator), a complete single-source system covering panels, doors, vision panels, and ancillaries, and project references in your sector. Request documentation early, confirm after-sales support for validation and audits, and assess lead-time reliability against your commissioning milestones.