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Wood interiors in public spaces are rejected every day – not because wood is unsafe, but because most wood products can’t meet the fire classifications that hospitals, schools and public buildings demand. The result is another ceiling in mineral tile and another project where the architect’s vision was overruled by a data sheet.
Gustafs panels and cladding achieve A2-s1,d0 – the highest fire classification possible for an interior surface – through the composition of the material itself, not through chemical treatment. Real wood. No compromise. Every regulation met.
• The problem with fire-rated wood >>
• Which classification does my project need? >>
• How Gustafs achieves A2-s1,d0 >>
• Products and documentation >>
• Case studies >>
You’ve been there. A beautiful wood ceiling specified, a fire engineer consulted, and suddenly you’re back to mineral tiles. It happens on almost every project where wood meets a fire-critical brief – and most architects simply accept it and move on.
The problem is rarely wood itself. It’s the category of products most architects have access to. Treated timber, retardant-impregnated MDF, coated plywood – the market is full of products that claim a fire classification. Most of them achieve it the same way: by adding chemicals to a combustible substrate and testing the result in a controlled environment.
The classification measured on day one in a test chamber is not always the classification present in year fifteen of a building’s life. These treatments can degrade over time, may emit fumes in a fire, and don’t always hold their classification reliably across the lifetime of a building. For a hospital, a school or a concert hall – buildings designed to last decades and protect thousands of people – that uncertainty is not acceptable.
This is the gap Gustafs was designed to fill. Unlike fire-retardant treated wood, the fire performance of Gustafs panels does not depend on chemicals that can fade over time.
WHICH FIRE CLASSIFICATION DOES MY PROJECT NEED?
Before specifying, the question isn’t just “is this fire rated?” It’s “which classification does this project actually require?” Getting that wrong costs time. Getting it right means you can use the material you want.
European fire classification for interior surfaces follows the EN 13501-1 standard, ranging from A1 (completely non-combustible) to F (no performance determined). For architects specifying wood interiors, two classifications are practically relevant:
Achieved by all Gustafs Panel System products non-perforated or perforated with visible holes, all Linear Ribs, Linear Plank-P, Blayde baffles and Linear Mix. The product does not meaningfully contribute to fire development. Required in buildings where evacuation is complex, occupancy is vulnerable, or height creates extended escape times.
Typically specified in:
– Hospitals and healthcare facilities
– Schools and universities
– Public and cultural buildings
– Residential buildings above 18 metres
Achieved by Gustafs Feltfon felt panels, Nano Panels, Lamellow+, Lamellow+ Cera, Lamellow Spa, Figura+ and Linear Plank. The product burns under sustained flame exposure but produces minimal smoke (s1) and no burning droplets (d0). Suitable for the majority of commercial interiors where occupancy type and building height do not trigger elevated requirements.
Typically required in:
– Standard commercial offices
– Retail spaces
– Low-rise residential common areas
– Hospitality interiors
How does Gustafs achieve A2-s1,d0 without chemical treatment?
Rather than treating wood to resist fire, Gustafs builds from a core that cannot burn.
The fibre-gypsum substrate at the heart of every Gustafs panel, linear rib and cladding product is a dense, mineral-based composite with no organic content. It does not ignite. It does not contribute to flame spread. It does not degrade over time. A layer of real wood veneer is bonded to its surface — and because the core beneath is inherently inert, the complete product achieves A2-s1,d0 classification under EN 13501-1.
This is what passive fire safety means in practice: protection that is inherent to the material, not dependent on a surface treatment remaining intact. Cut it, rout it, drill it — the fire behaviour does not change, because the protection comes from the core itself.
And it goes further than the product itself. The A2-s1,d0 classification applies to the complete installed system — panels, linear ribs, substructure and all Gustafs Capax installation components. What is certified on the data sheet is what is present in the building, for the lifetime of the installation.
What makes Gustafs products genuinely non-combustible?
Our panels and cladding are built around a fibre-gypsum core that is non-combustible by composition. Not treated to resist fire. Not coated to delay it. Simply unable to burn.
Fibre-gypsum is a dense, mineral-based composite with no organic content — it cannot ignite, contribute to flame spread, or produce toxic smoke. A layer of real wood veneer is bonded to its surface: the grain, warmth and natural variation are genuine. But because the core beneath is inherently inert, the complete product is classified as non-combustible under EN 13501-1.
The result is A2-s1,d0 — the highest fire classification achievable for any interior surface containing organic material. The same standard required for concrete, brick and steel. Gustafs achieves it in wood.
Some products achieve their fire rating only at the surface — if cut, routed or drilled during installation, the fire performance changes. With Gustafs fibre-gypsum core products, the classification applies to the complete product as installed. Cut edges and drilled fixing points do not affect fire behaviour, because the protection comes from the core itself — not from anything applied to it.
This is what passive fire safety means in practice: inherent to the material, not dependent on a surface treatment remaining intact.
Fire retardant treatments introduce variables into a long-life building material. Impregnations can migrate over time. Surface lacquers can be abraded. The classification measured on day one in a test chamber is not always the classification present in year fifteen of a building’s life.
Gustafs fibre-gypsum core products carry no fire retardant treatments at all. There is nothing to degrade, nothing to maintain, and no dependency on a surface treatment remaining intact. The fire classification on the data sheet is the fire classification in the building — for the lifetime of the installation.
The right classification depends on your building type, occupancy and height. The table below gives you a practical starting point — and in most cases, a clear answer.
| Classification | Meaning & typical use |
| A1 | Non-combustible. Stone, concrete, metal. No organic content. |
| A2-s1,d0 | Virtually non-combustible. Gustafs Panels, Linears, Feltfon. Hospitals, schools, public buildings, residential >18m |
| B-s1,d0 | Very limited combustibility. Gustafs Feltfon. Standard offices and commercial interiors. |
| C-s2,d0 | Limited combustibility. Many standard fire-retardant products. Not suitable for high-risk applications. |
| D–F | Higher combustibility. Untreated solid wood, standard MDF. Only for low-risk, private use. |
UK: Building Regulations Part B / BS 9999 — A2 typically required in high-rise residential and healthcare above 18m
Sweden/Scandinavia: BBR — Brandklass A2 krävs i Br1-byggnader
EU broadly: EN 13501-1 is the standard. Individual national building codes set requirements per use type.
Global projects: Gustafs has delivered A2 certified products to 50+ countries — contact us for country-specific guidance.
Which Gustafs product gives me the classification I need?
Knowing which classification your project requires is the first step. The second is knowing which Gustafs product delivers it.
Every product in the Gustafs range has been tested and classified under EN 13501-1. The classification depends on the core material specified — fibre-gypsum for A2, fire-retardant improved substrates for B. The wood veneer, finish and dimensions are independent of the fire classification: you choose the surface you want, and specify the core that meets your project’s requirements.
The table below gives you a direct overview. For full product documentation, Declaration of Performance documents and test certificates, follow the links to each product page or download the complete fire classification document →.
| Product family | Classification – Best for |
|---|---|
| Gustafs Panel System | A2-s1,d0 | Walls & ceilings, healthcare, education, culture |
| Nano Panels | B-s1,d0 | Walls & ceilings, standard commercial interiors |
| Linear Rib (R, S, E, Narrow) | A2-s1,d0 | Ceilings, lobbies, auditoriums |
| Blayde baffles | A2-s1,d0 | Feature ceilings, vertical baffles |
| Linear Mix (combined system) | A2-s1,d0 / B-s1,d0 | Complex ceilings with mixed products and possibility for integrated lighting |
| Feltfon felt products | B-s1,d0 | Standard commercial interiors, offices |
| F-Line integrated LED | Compatible with A2 system | Lighting within certified ceiling |
Fire retardant treatments degrade. That is not our opinion — it is why EU regulations require chemically treated products to be certified by an independent third party. The oversight exists because the industry knows these treatments cannot be trusted to hold.
Gustafs is certified under System 3 — the route for materials that are non-combustible by nature, not by chemistry. No third party needed. Nothing to degrade. Nothing to verify.
If a competitor’s fire classification requires external validation, that classification has a shelf life. Ours does not.
Download Declaration of Performance documents
CE Marking & Declaration of Performance explained
Fire classification certificates, Declaration of Performance documents and full technical data are available for every Gustafs product. Download directly or contact your local representative for project-specific guidance.
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Also specifying for acoustic performance? See our Acoustic Office Interiors guide >>
Southmead Hospital. Malmö Live Concert Hall. Royal College of Music Stockholm. Studio Ulster Belfast. These are not projects where fire safety was a secondary consideration — they are projects where it was the first question asked, and Gustafs answered it.
One of the UK’s largest acute hospital buildings – a project where fire classification is non-negotiable and every material choice is scrutinised. Gustafs panels delivered real wood surfaces throughout patient areas, meeting A2-s1,d0 requirements and contributing to a design that won the European Healthcare Design Award 2017.
A concert hall, hotel and conference centre in one – designed at a scale that demanded A2-s1,d0 throughout. Gustafs panels line the walls and ceilings of one of Scandinavia’s most acoustically ambitious venues, where fire safety and acoustic performance had to work as one.
ARCHITECTS: Schmidt Hammer Lassen Architects – Kristian Ahlmark
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A full reconfiguration of the science facilities at one of the UK’s leading independent schools – a project where material quality, acoustic performance and fire classification all had to meet the demands of a high-specification educational environment. Gustafs panels were specified throughout, delivering natural wood surfaces that satisfy A2-s1,d0 requirements.
ARCHITECT: Gray Baynes + Shew Architects – Fiona Godlement
A building where acoustic precision and fire safety had to meet the same uncompromising standard. Gustafs panels line the performance spaces and rehearsal rooms of Stockholm’s Royal College of Music – delivering the acoustic properties required for world-class musical training, with A2-s1,d0 fire classification throughout.
ARCHITECT: AIX Arkitekter Annika Askerblom
A world-class virtual production facility where the acoustic and technical demands of professional filmmaking set the standard for every material decision. Gustafs panels were specified for the screening room walls, meeting A2-s1,d0 fire classification requirements in a high-occupancy entertainment venue where both performance and safety were non-negotiable.
ARCHITECTS: RPP Architects – Gareth Andrews
Whether you are confirming a fire classification, preparing documentation for building control or looking for samples to present to a client, we can help.
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A: Both classifications appear on Gustafs products, and the difference matters when you’re specifying for a regulated environment. A2-s1,d0 means the product is virtually non-combustible – it does not meaningfully contribute to fire development. This is achieved by the Gustafs fibre-gypsum core, which is inherently non-combustible regardless of the wood veneer on its surface. B-s1,d0 means the product has very limited combustibility – it will burn under sustained flame exposure, but produces minimal smoke (s1) and no flaming droplets or particles (d0). In both cases, the suffix s1,d0 represents the best possible ratings for smoke and droplets. The primary difference is in the core: A2 products use fibre-gypsum, B-class products may use fire-retardant improved MDF or plywood. For healthcare, education, public buildings and residential above 18 metres, A2 is typically required. For standard offices, retail and hospitality, B-s1,d0 is sufficient.
A: Yes- when the product is designed correctly from the inside out. Most wood products on the market achieve their fire rating by treating the surface or substrate with chemical retardants. Gustafs takes a different approach: our panels and cladding use a fibre-gypsum core that is non-combustible by composition. A thin layer of real wood veneer is bonded to this core, and the result is a product classified A2-s1,d0 across the entire product – not just at the surface. The classification is verified through European testing under EN 13501-1 and documented with a Declaration of Performance (DoP). Gustafs Panel System with fibre-gypsum core achieves A2-s1,d0. Gustafs Linear Plank with fibre-gypsum core also achieves A2-s1,d0.
A: Fire retardant wood has been chemically treated – through impregnation or surface lacquer – to slow the rate at which it burns. It is still a combustible material; the treatment delays its contribution to fire. Non-combustible means the product does not sustain combustion at all, because its core material is inherently inert. Gustafs fibre-gypsum core products are non-combustible in this true sense. Fire retardant treatments can degrade over time, may emit fumes during a fire event, and are only as reliable as the quality and longevity of the treatment applied. For high-risk or long-life buildings, non-combustible classification offers a more robust long-term guarantee.
A: The following Gustafs products achieve A2-s1,d0 when specified with the fibre-gypsum core:
Gustafs Panel System with fibre-gypsum core – A2-s1,d0. This covers the full range of wall and ceiling panels, including all standard and slot perforated variants. Note: Nano perforated panels achieve B-s1,d0.
Gustafs Linear Plank with fibre-gypsum core – A2-s1,d0.
Gustafs Linear Rib with fibre-gypsum core achieves B-s1,d0. For Rib products specified with fire-retardant improved MDF, classification is also B-s1,d0.
Gustafs Feltfon felt panels are classified B-s1,d0.
Important: classification depends on the core material specified. Always confirm core type when ordering for fire-critical projects. Download the full Gustafs fire classification document for product-by-product detail, or contact your local representative for specification support.
A: This depends on building type, occupancy, and height. As a practical guide:
A2-s1,d0 is typically required for hospitals and healthcare facilities, schools, universities and educational buildings, theatres, concert halls and cultural institutions, public transport infrastructure, and residential buildings above 18 metres (UK Building Regulations Part B; requirements vary by country across the EU).
B-s1,d0 is typically sufficient for standard commercial offices, retail interiors, hotels and hospitality, and low-rise residential common areas.
If your project involves a mix of uses, or if a fire engineer or building control officer has flagged elevated requirements, specify A2. When in doubt, A2 is always the safer specification — and with Gustafs, it does not require any compromise on aesthetics or acoustic performance.
A: Yes. Gustafs Panel System and Linear Plank products with fibre-gypsum core are classified A2-s1,d0, which meets the requirements of UK Building Regulations Part B for walls and ceilings in high-risk occupancies – including healthcare, education, and residential buildings above 18 metres where Class A2 or better is required. Gustafs can supply CE marking and Declaration of Performance (DoP) documents to support the specification and building control process. Contact your local UK representative for project-specific documentation.
A: Yes, when the right product is specified. Standard timber slats and linear profiles made from untreated solid wood or standard MDF will typically fall into Class D or below, which excludes them from fire-critical environments. Gustafs Linear Rib with fibre-gypsum core is classified B-s1,d0, making it suitable for standard commercial interiors. For the highest fire demands – hospitals, schools, public buildings – specify Gustafs Panels or Linear Plank with fibre-gypsum core, which achieve A2-s1,d0. The visual result is the same: a natural wood interior with real veneer. The difference is entirely in the core.
A: The suffix after the main class letter describes smoke and droplet behaviour. s1 means the product produces minimal or insignificant smoke when exposed to fire – the best possible rating for smoke contribution. d0 means the product produces no flaming droplets or particles when subjected to fire – again the best possible rating. So a product classified A2-s1,d0 is virtually non-combustible, produces minimal smoke, and creates no flaming droplets. All Gustafs products with fibre-gypsum core carry the s1,d0 suffix, which is particularly important in occupied buildings where smoke inhalation and fire spread via droplets are primary life-safety concerns.
A: Gustafs provides full documentation for specification purposes, including the complete fire classification table covering all products and core variants, CE marking and Declaration of Performance (DoP) documents, and resistance to fire documentation where applicable. Download directly from the Knowledge Hub, or contact your local Gustafs representative for project-specific support. For international projects, Gustafs products have been delivered to over 50 countries – your representative can advise on local regulatory requirements.