Fire safety requirements in UK construction have never been more demanding. Whether you are designing a new-build development, upgrading an existing façade, or specifying a premium extension, fire rated timber cladding has become a core consideration across residential, commercial, and public sector projects. This guide explains what fire rated cladding is, how it is classified under UK building regulations, which timber species can be treated, and what to specify for your project.
Fire rated timber cladding combines certified fire performance with the natural appearance of real timber — suitable for a wide range of UK residential and commercial projects.
Fire rated timber cladding is timber treated with a certified fire-retardant system to achieve a measurable fire performance classification — typically Euroclass B-s1,d0 under BS EN 13501-1. No timber is technically fireproof, but correctly treated and specified timber cladding meets the highest fire performance standards required for the vast majority of UK residential and commercial projects.
What Is Fire Rated Timber Cladding?
Fire rated cladding is timber that has undergone a specialist fire-retardant treatment to increase its resistance to ignition and flame spread. Our timber products are treated using a fully certified fire-redundant system that meets stringent UK and European standards including BS EN 13501-1.
The treatment penetrates deep into the wood fibre rather than simply coating the surface, ensuring consistent protection across the entire board — including after cutting or machining on site. The result is a stable, compliant, and visually appealing façade suitable for projects where enhanced fire safety performance is required without sacrificing the natural appearance of timber.
The terms fireproof cladding and fire proof cladding are widely used but technically imprecise — no timber cladding is literally fireproof. When reviewing specifications, always look for a specific Euroclass performance classification such as Euroclass B-s1,d0 rather than general marketing terms. Our certified treatments deliver the highest realistic level of fire protection available for natural wood cladding materials.
UK Fire Performance Classifications Explained
Fire performance for external cladding in the UK is classified under BS EN 13501-1, the European standard for reaction-to-fire testing. Understanding these classifications is essential for architects, specifiers, and building control officers reviewing façade submissions.
| Euroclass Rating | Description | Smoke | Droplets | Typical Use |
|---|---|---|---|---|
| A1 | No contribution to fire | — | — | Masonry, steel, glass |
| A2 | Very limited contribution | s1 | d0 | High-rise non-combustible requirement |
| B (B-s1,d0) | Very limited contribution | Very low | None | Treated timber — most UK projects |
| C | Limited contribution | s1–s2 | d0–d1 | Lower-risk buildings |
| D | Acceptable contribution | s1–s3 | d0–d2 | Untreated timber — limited applications |
Our fire-retardant treated timber achieves Euroclass B-s1,d0 — meaning very limited contribution to fire, very low smoke production, and no flaming droplets. This satisfies fire performance requirements for the vast majority of UK residential and commercial projects.
Correct installation detailing — including cavity barriers — is as important as the fire classification of the cladding boards themselves.
UK Building Regulations: When Is Fire Rated Cladding Required?
External cladding fire requirements in England are governed by Approved Document B of the Building Regulations. The specific requirements depend on building height, occupancy type, and proximity to site boundaries. Following Grenfell Tower and the subsequent Hackitt Review, requirements were significantly tightened. The key thresholds are:
Always consult with your building control officer or fire engineer early in the design process. We can provide full certification documentation and technical data sheets to support your building regulations submission — contact our team here.
Fire rated timber cladding is increasingly specified on private residential extensions, even where not strictly required by building regulations.
Our Fire-Retardant Treatment Process
Our boards undergo a deep-penetration fire-retardant process carried out under controlled, certified conditions. Unlike surface-applied intumescent coatings, the treatment modifies the internal structure of the timber, ensuring long-term performance maintained even after cutting or re-machining on site.
The process involves pressure-impregnating the timber with a mineral-based fire-retardant solution that becomes permanently bound within the wood cell structure. Once dried and re-conditioned, the boards are dimensionally stable and ready for installation or factory coating. Full certification documentation, test reports, and CE-marked product declarations are available for all fire-treated products. View our fire redundant treatment service page for full specifications.
Timber Species Available with Fire Rating
Fire retardant treatment can be applied to multiple timber species, allowing architects and specifiers to maintain full aesthetic freedom while meeting enhanced safety requirements. All of the following species are available with Euroclass B-s1,d0 fire rating:
ThermoWood shadow gap and shiplap profiles are all available with full Euroclass B-s1,d0 fire retardant treatment.
Where Fire Rated Timber Cladding Is Used in the UK
Fire rated cladding is specified across a wide range of project types throughout the UK. Common applications include multi-storey residential developments where building regulations require enhanced fire performance, commercial offices and retail buildings, schools and public sector buildings where fire certification is a contractual requirement, and residential extensions in close proximity to site boundaries.
It is also increasingly specified on private residential projects where architects want additional peace of mind — even where not strictly required by building regulations. The cost uplift for fire treatment is relatively modest, typically 15–30% over untreated material, and the certification it provides can simplify planning and building control sign-off considerably. For a full breakdown of costs see our timber cladding cost guide.
Fire Rated Cladding with Factory Coatings
Fire rated timber cladding can be combined with our factory-applied coating service to produce a fully finished, certified product that arrives on site ready to install. Factory coating over fire-treated boards ensures a consistent, controlled finish and eliminates the need for site-applied treatments that can compromise fire performance if applied incorrectly.
This combination — fire treatment plus factory coating — is increasingly specified on high-specification residential and commercial projects where both compliance and appearance consistency are required. Available in a full range of RAL and BS colours. For more on profiles and installation see our ThermoWood cladding guide and ultimate guide to timber cladding.
Fire Rated vs Untreated Timber Cladding: Full Comparison
| Feature | Untreated Timber | Fire Rated Timber |
|---|---|---|
| Euroclass rating | Typically D or E | B-s1,d0 |
| Approved Document B compliance | Limited — lower-risk buildings only | Broad — most project types |
| Appearance | Natural timber finish | Identical — treatment is internal |
| Certification documentation | None | Full test reports, CE declaration |
| Cost premium | Base price | Typically 15–30% uplift |
| Suitable for schools / commercial | Rarely | Yes — with full documentation |
| Factory coating compatible | Yes | Yes — fully compatible |
Fire rated timber cladding weathers naturally over time in the same way as untreated timber — the treatment is internal and does not affect appearance or weathering behaviour.
Fire rated timber cladding is timber that has been treated with a certified fire-retardant system to improve its resistance to ignition and flame spread. The treatment penetrates the wood fibre rather than simply coating the surface, giving the timber a measurable fire performance classification such as Euroclass B-s1,d0 under BS EN 13501-1.
Euroclass B is a fire performance classification under the European standard BS EN 13501-1. It indicates a very limited contribution to fire and is one of the highest ratings achievable for treated timber cladding. The full classification Euroclass B-s1,d0 means very limited contribution to fire, very limited smoke production, and no flaming droplets or particles.
Fire performance requirements for external cladding in the UK are set out in Approved Document B of the Building Regulations. Requirements depend on building height, use, and proximity to boundaries. Buildings over 18 metres must use non-combustible materials. Lower-rise buildings may use fire-rated timber cladding where it meets the required Euroclass performance classification.
Fire retardant treatment can be applied to Siberian larch, ThermoWood, thermo pine, Nordic spruce, Douglas fir, and charred timber (Shou Sugi Ban). This allows architects and specifiers to maintain aesthetic freedom while meeting enhanced fire safety requirements for their project.
No timber cladding is technically fireproof — the term fireproof cladding is a common but imprecise description. Fire rated cladding has a certified, measurable level of fire resistance verified through testing to BS EN 13501-1. Always look for a specific Euroclass performance classification rather than general marketing terms like fireproof or fire proof cladding.
Request a Fire Rated Cladding Quote
We supply fully certified fire rated timber cladding across the UK with nationwide delivery in 7–14 days. Our technical team can advise on species selection, Euroclass certification, and installation requirements for your project.