Cladding and Fire Safety: Making Sense of Ratings, Resistance and Combustibility
Fire rated cladding, fire resistant cladding, fire retardant cladding and non-combustible cladding are often discussed as though they describe the same thing. They do not. Each term raises a different question about a product, its evidence or the construction in which it will be used.
Understanding those differences is the starting point for a more informed choice. A recognised classification is useful evidence, but it is not a universal seal of approval. A treatment may improve performance, but its effect needs to be documented. A non-combustible facing may meet a material requirement, while the complete external wall still needs careful design.
This guide explains the language, examines what buyers should ask and sets out NeoTimber’s published composite cladding ratings. It also argues for a higher standard of communication: one that makes fire-performance claims easier to understand, compare and verify.
The key distinction: NeoTimber® publishes C-s1,d0 for Classic composite cladding and D-s1,d0 for Deluxe and Slatted. These are combustible products with reaction-to-fire classifications. They should not be described as non-combustible cladding or as having a timed fire-resistance rating on that evidence alone.
Reviewed: 6 October 2026. Regulatory examples focus on England, with official links for the other UK jurisdictions. This is an educational guide; project suitability requires review of the applicable requirements and current product documentation.
Explore the guide
Fire Rated, Fire Resistant, Fire Retardant and Non-Combustible Cladding Compared
A useful comparison starts with the claim being made. Ask what the words mean for the exact product, which document supports them and whether that document answers the question your project needs resolved.
| Term | What to clarify | Evidence to request |
|---|---|---|
| Fire rated cladding | Which kind of performance has been classified? | The full classification, standard and scope. |
| Fire resistant cladding | Is a timed resistance claim being made for an element or assembly? | The relevant assembly details and fire-resistance classification. |
| Fire retardant cladding | What treatment or formulation is being described, and what improvement is demonstrated? | Classification evidence for the specified product and information about its intended exposure and care. |
| Non-combustible cladding | What classification supports the description, and which components does it cover? | Product evidence and confirmation that the proposed construction meets the project requirements. |
These questions are also useful when a brochure uses more than one term. Do not assume that several reassuring descriptions add up to several independently demonstrated benefits. Translate each description into an evidence request.
What Is Fire Rated Cladding?
In a product description, “fire rated” should lead to a specific declaration. For external cladding boards, that may be a reaction-to-fire classification under BS EN 13501-1. The standard classifies products using reaction-to-fire test data; it is not itself a guarantee of suitability for every application.
The BS EN 13501 series distinguishes reaction-to-fire classification from fire-resistance classification. When reviewing an offer, ask which part of the series and which performance are relevant to the claim.
Understanding the Main Reaction-to-Fire Classes
The main classes are A1, A2, B, C, D, E and F. The following is a simplified orientation, not a substitute for the classification criteria or project requirements.
| Class | How to interpret it |
|---|---|
| A1 | The highest main classification, associated with non-combustibility. |
| A2 | A high classification allowing only a very limited contribution to fire; check the complete designation. |
| B | A combustible product meeting the B-class performance criteria. |
| C | A combustible product meeting the C-class performance criteria. |
| D | A combustible product meeting the D-class performance criteria. |
| E | A product meeting the E-class criteria, which provide a more limited level of demonstrated performance. |
| F | Performance below the criteria for Class E. Missing evidence should not simply be assumed to establish Class F. |
Always request the classification document. A bare class letter on a quotation leaves out information that may be important to the review.
Smoke and Flaming Droplets Are Separate Parts of the Notation
Where included, “s” describes smoke production and “d” describes flaming droplets or particles under the relevant tests. For example, s1 is the lowest smoke-production category within s1–s3; d0 indicates no flaming droplets or particles during the specified observation period.
Neither suffix removes the significance of the main class. A favourable smoke or droplet category does not turn a C- or D-class board into an A1 product. Nor does s1 mean smoke-free or establish smoke toxicity. The government's smoke and toxicity research provides context for the distinction.
For further explanation of classification using multiple tests, see the Approved Document B FAQs.
Fire Resistant Cladding: Why the Assembly Matters
“Fire resistant cladding” can be an ambiguous purchasing phrase. In technical use, fire resistance concerns a building element or assembly maintaining specified functions during fire exposure. Depending on the element, those functions may include load bearing capacity, integrity and insulation, expressed through a classification and a duration.
A reaction-to-fire declaration for a board answers a different question. It cannot be translated into 30, 60 or 90 minutes of wall resistance. Ask the person making a timed claim to identify the complete element and the evidence supporting that duration.
Ask What Was Assessed
When a supplier describes a fire-resistant system, request the construction details associated with the claim. Ask which layers, joints, fixings and supporting components are included. Then give those details to the person reviewing your proposed wall.
This helps prevent a common purchasing mistake: accepting an accurate claim about one construction while planning to build another. The intention is to identify differences early and have them assessed, rather than to assume that similar appearance means equivalent performance.
Keep the Requirement and the Evidence in the Same Conversation
Write the project's required performance next to the supplier's declared performance. If one is a timed assembly requirement and the other is a board reaction-to-fire class, the mismatch becomes visible immediately.
At that point, ask for the missing evidence or revise the proposed system. Avoid collecting documents without checking that they answer the actual question. A large technical folder can still leave an important requirement unresolved.
Fire Retardant Cladding: What Does the Claim Establish?
Fire retardant cladding generally refers to a material whose burning behaviour has been modified through a treatment or formulation. The term does not, on its own, identify the achieved classification, establish non-combustibility or provide a timed fire-resistance rating.
For buying purposes, treat it as the beginning of a discussion. Ask what product has been assessed, how its performance is documented and what conditions apply to its intended use.
Ask About Exterior Exposure and Maintenance
For a product intended outdoors, ask whether the evidence and supplier guidance address the relevant exposure. Request information about care, permitted finishes and any treatment-related maintenance. Do not infer an indefinite performance claim from a treatment's name.
Government-published research on timber cladding found benefits from fire-retardant treatment in the new timber configurations tested, but did not establish the performance of aged or weathered treated timber. Those findings do not classify NeoTimber® composite products. They illustrate why evidence about new material should not automatically be presented as proof of long-term performance in every setting. See the timber-cladding research summary.
Do Not Assume an Applied Coating Creates a New Classification
If a coating or treatment is proposed after purchase, request evidence for the exact combination and intended application. Ask the board manufacturer whether it permits the proposed treatment, and refer the answer to the project reviewer.
This is especially important when a coating is being suggested to close a gap in the specification. The question is whether the required performance has been demonstrated for the proposed use. A statement that a treatment “improves fire performance” is not enough to answer it.
Non-Combustible Cladding: A Clear Claim Still Needs Clear Evidence
Non-combustible cladding addresses a material's contribution to combustion. A1 is the clearest main classification associated with non-combustibility. A2 describes very limited contribution and is often discussed as limited combustibility. Where a requirement accepts A2-s1,d0 or A1, keep that exact wording rather than treating the two classes as identical.
England's restrictions for certain relevant external walls accept those classifications within their defined scope and exemptions. The government's explanation of the combustible-material restrictions sets out the policy context.
Check the Finished Product, Not Only the Base Material
Ask for evidence that identifies the product being supplied. Material labels such as “metal”, “mineral” or “composite” are not a sufficient purchasing specification on their own. Record the proposed finish and construction, then confirm what the documentation covers.
Where the requirement applies to several components, ask for a schedule showing how each is addressed. This prevents the classification of the outer face from becoming an assumption about the whole wall.
Does NeoTimber® Composite Cladding Meet a Non-Combustible Requirement?
The Classic, Deluxe and Slatted composite ranges discussed here have published C- and D-class ratings. They do not meet an A1 or A2-s1,d0 requirement. If that is what the project needs, select another appropriately evidenced system.
This distinction should be easy to find during product selection. Readers searching for non-combustible cladding deserve a direct answer, even when that answer leads them away from a particular composite range.
NeoTimber® Fire Rated Cladding: Published Product Information
NeoTimber’s supplied article and published composite cladding fire-rating guide identify the following classifications. Request the current classification reports for the exact boards being considered; those underlying reports have not been independently examined for this article.
| Range | Reaction-to-fire classification | Material status |
|---|---|---|
| Classic | C-s1,d0 | Combustible |
| Deluxe | D-s1,d0 | Combustible |
| Slatted | D-s1,d0 | Combustible |
Use the table to begin the technical discussion, then compare the documents with the project requirements. It does not establish universal suitability for low-rise buildings or a timed resistance period.
How Project Requirements Affect Cladding Selection
Establish the requirements before comparing finishes. A product that suits one project may not suit another, even when both are described informally as residential or low-rise.
Height Is One Consideration, Not the Whole Assessment
In England, Approved Document B's external-surface guidance varies with use, height and distance to the relevant boundary. For example, Table 10.1 recommends B-s3,d2 or better for residential external surfaces at 11 metres or less where the wall is less than one metre from the relevant boundary, subject to the table's qualifications. C- and D-class boards do not meet that recommendation.
The document also includes separate provisions for materials, cavities and relevant buildings. Review them together, using the applicable measurement definitions. See Approved Document B Volume 1, Section 10. A claim that a board is acceptable on every building below 11 metres overlooks the context needed for selection.
Use the Applicable Jurisdiction and Edition
The GOV.UK Approved Document B collection applies to England and contains amendments with different commencement and transition arrangements. Confirm which provisions apply to the proposed work. Future changes in a collated publication should not automatically be treated as current requirements.
- Wales: use Welsh Approved Document B and applicable amendments.
- Scotland: use the relevant current Building Standards Technical Handbook.
- Northern Ireland: use Technical Booklet E and applicable amendments.
Ask the designer to record the regulatory starting point. It makes later conversations more efficient and avoids detailed advice being applied to the wrong location or type of work.
Keep Planning and Building-Control Questions Separate
Ask whether planning permission, building-control procedures or other project approvals are required. Do not use an answer about one process as an answer about another.
For product selection, also ask who will assess technical suitability and how the decision will be recorded. A supplier's general description of potential applications should not become the only basis for the project's specification.
Thought Leadership: Fire-Safety Language Should Help People Decide
Our view is that the cladding industry should measure the quality of its communication by what a reader can do with it. Can they identify the relevant classification? Can they find the supporting information? Can they tell whether the claim concerns a board, a treatment or a complete wall?
If the answer is unclear, the communication needs work. Adding more reassuring adjectives does not resolve a missing standard, an unspecified product or a claim whose scope nobody has explained.
State the Limits Where the Benefits Are Presented
A technically important limit should appear close to the claim it qualifies. If a board is combustible, make that clear when discussing its rating. If a declaration concerns reaction to fire, name that performance rather than allowing readers to infer a resistance duration.
This is a practical recommendation for better product pages. It gives customers a more accurate brief before they make contact, helping suppliers spend less time correcting misunderstandings and more time answering relevant questions.
Make Technical Documents Part of the Buying Journey
Provide a clear route to request the evidence needed for specification. Explain what documents are available and what details the supplier needs to identify the right ones.
A customer should be able to move from a product name to a document reference without guessing which brochure applies. Good organisation is part of good advice: the easier the evidence is to connect to the product, the easier it is to review.
Respect the Difference Between Confidence and Certainty
Confidence should come from knowing what has been checked and what remains open. A supplier can be confident about a published classification while still asking for a project review before recommending its use.
We recommend making unresolved questions visible. A written request for clarification gives the team something to act on. An unsupported assurance may remove the question from view without resolving it.
Help Customers Recognise When Another Product Is Needed
Good advice includes a clear route away from an unsuitable option. If the project requires a classification a proposed board cannot achieve, explain the mismatch early and allow the design team to compare alternatives.
This approach supports trust over the life of a project. It also places the supplier's role on a firmer footing: accurate information about its products, connected to a realistic understanding of the customer's needs.
A Practical Framework for Comparing Cladding Claims
Use the following steps to turn a broad search for fire rated cladding into a useful specification discussion.
Step 1: Write the Project Brief
Record the location, proposed use, scope of work and relevant elevations. Include drawings or photographs where they help explain the construction. Ask the project team to establish the required performance before asking suppliers which finish to choose.
Step 2: Translate Each Claim Into a Question
For “fire rated”, ask for the classification and standard. For “fire resistant”, ask what assembly and duration are being claimed. For “fire retardant”, ask what performance is demonstrated for the specified treated product. For “non-combustible”, ask which classification and components support the description.
Step 3: Identify the Exact Product
Record the range, profile, dimensions and finish in the quotation. Ask whether the supplied evidence covers them. Avoid accepting documentation for a broadly similar product without an explanation of its relevance.
Step 4: Compare the Evidence With the Proposed Use
Have the reviewer identify any difference between the documented conditions and the design. Record the substrate, support arrangement, cavity and other details needed for that comparison. Decide who will resolve any gaps and what information they need.
Step 5: Keep Changes Visible
If a substitute is proposed, review its own evidence before accepting it. If an installation detail changes, obtain a considered response before the work is concealed. A reviewed specification should remain connected to the product and construction actually delivered.
Step 6: Complete the Handover
Retain the final specification, product documents, reviewed changes and installation records. Add the maintenance information. Organise the records so that a future owner or adviser can understand the selection without reconstructing a series of conversations.
What Better Decisions Look Like in Practice
These examples illustrate the review process rather than approving a material for a particular application.
A Homeowner Comparing Two Attractive Finishes
Both boards look suitable, but their declared classes differ. Instead of choosing the higher class by default, the homeowner asks the designer what the wall requires. The comparison can then include appearance, cost and care among options that meet the brief.
An Installer Offered a Different Board
The replacement is described as equivalent and is available sooner. The installer records the substitution and asks for evidence for that exact product. The team reviews it before delivery, preserving the link between the approved choice and the work on site.
A Buyer Asked to Rely on a Treatment Claim
A product description says “fire retardant” without naming a class. The buyer requests the supporting classification and intended-use conditions. If the answer does not address the project requirements, the selection remains open rather than being settled by the wording on the label.
A Project Requiring Non-Combustible Cladding
The design team has established an A1 or A2-s1,d0 requirement. A proposed C- or D-class board is therefore removed from consideration. The team continues developing the aesthetic with appropriately evidenced alternatives, resolving suitability before becoming committed to a finish.
Frequently Asked Questions About Cladding and Fire Performance
Is Fire Rated Cladding Always Non-Combustible?
No. The complete classification matters. A combustible product can have a declared reaction-to-fire class.
Are Fire Resistant Cladding and Fire Retardant Cladding the Same?
No. Clarify whether the claim concerns timed assembly resistance or modified burning behaviour, then request the corresponding evidence.
Does BS EN 13501-1 Establish a Fire-Resistance Duration?
No. It classifies reaction to fire. A duration claim needs relevant fire-resistance evidence.
Does NeoTimber® Supply Non-Combustible Composite Cladding in These Ranges?
The Classic, Deluxe and Slatted ranges discussed here have C- or D-class declarations. They do not meet an A1 or A2-s1,d0 requirement.
Does s1 Mean That a Product Produces No Smoke?
No. It is a smoke-production category under test conditions, not a smoke-free or toxicity guarantee.
Can a Coating Turn My Cladding Into a Compliant Product?
Do not assume so. Request evidence for the exact combination and have it reviewed against the project requirement.
Is a Low-Rise Description Enough to Establish Suitability?
No. Ask for the applicable requirements and a review of the specific product and proposed construction.
Can Samples Replace Fire-Performance Documents?
No. Samples help assess appearance and texture. Use classification and technical documents for performance questions.
What Should I Do if a Supplier Cannot Explain Its Claim?
Request written clarification and refer it to the project reviewer. Leave the product selection unresolved until the information needed for a decision is available.
Choose Clear Claims, Relevant Evidence and an Appropriate Cladding System
The four terms in this guide are useful when they lead to precise questions. Identify the performance needed, ask what has been demonstrated and have the evidence related to the proposed building.
For NeoTimber® composite cladding, contact the team to request current product information. For more detail on the composite ranges, read the fire rated composite cladding guide. Once suitability is established, compare the available ranges and request samples for colour and texture.
A good specification makes its reasoning visible. That is the standard buyers should expect, and the standard the industry should make easier to achieve.
