Fire performance of wall panelling

At a glance

Re-typed by us from the online versions, 2019 edition with amendments to 2026. England only. s3,d2 means no limit on smoke or flaming droplets.

What Approved Document B asks of a lining

Requirement B2 of the Building Regulations asks that internal linings adequately resist the spread of flame and, if ignited, have a reasonable rate of heat release or fire growth. Approved Document B turns that into classes for the surface of walls and ceilings (Volume 2 Section 6, Volume 1 Section 4). The edition is the 2019 one incorporating the 2020, 2022, 2025 and 2026 amendments, as on GOV.UK in November 2026 (page updated 16 September 2026). It applies in England. The 2025 amendments removed the national classes for reaction to fire, so the Class 0 and BS 476 wording that still circulates online is no longer what the Document asks for.

The table above gives the classes. In both volumes the smoke and droplet letters are s3 and d2, which means no limit is set on smoke or flaming droplets (Appendix B, paragraph B7): only the class letter is asked for. A circulation space is a space mainly used as a means of access between a room and an exit, protected stairways included, and a room is an enclosed space not used solely as circulation (Appendix A). Paragraph 6.2 counts the inside surface of glazing (except in doors) and any ceiling sloping more than 70 degrees as wall. Note 1 to the table also accepts a wallcovering to BS EN 15102 reaching at least C-s3,d2 and bonded to an A2-s3,d2 substrate.

What is a lining and what is not: paragraph 6.3 (Volume 1: 4.3) lists what a wall does not include. Wall panelling is not on that list, so on our reading panelling that lines a room is a lining and the class applies to its exposed surface. Fitted furniture is on the list; whether a fixed panel, such as a headboard, is fitted furniture or a lining is for building control to say, and our fire documentation matrix covers the headboard question. The narrow members in the list are outside the classes, but the wall behind them is not, and cornices, dado rails and applied mouldings are not named (see moulding materials compared).

Reading a Euroclass

A Euroclass is the European way of grading how a product contributes to a fire, set by BS EN 13501-1. Approved Document B (Appendix B, paragraph B6) says products other than floorings are classed A1, A2, B, C, D, E or F, A1 being the highest performance and F the lowest, that F is given when a product fails to reach E, and that untested products cannot be classified. A2, B, C, D and E are accompanied by smoke letters s1 to s3 and/or droplet letters d0 to d2 (B7). The limits behind each letter are in Table 1 of the Annex to Commission Delegated Regulation (EU) 2016/364, as published on legislation.gov.uk, and are summarised below.

The smoke letters come from the SBI test: s1 is a smoke growth rate of 30 m²/s² or less and total smoke production in 600 s of 50 m² or less; s2 is 180 m²/s² or less and 200 m² or less; s3 is neither. d0 is no flaming droplets or particles within 600 s; d1 is none lasting longer than 10 s; d2 is neither. The Regulation gives these limits; BS EN 13501-1:2018 itself is paywalled and was not read.

Three points catch people out. First, a class is a result for a product in its end-use application, not a property of a material name (BSI describes the standard as considering products in relation to their end use; the Commission Decisions say the same in Article 3). Second, a class that is better is acceptable where a worse one is asked for: paragraph 6.4 speaks of walls “no worse than” D-s3,d2. Third, reaction to fire is not fire resistance. Fire resistance is how long an element keeps its load-bearing capacity, integrity and insulation (R, E and I, Appendix B paragraph B18), and it is a different test for a different job.

Four ways to show a class

Approved Document B says a performance classification is shown in one of three ways (Appendix B, paragraph B1): a specification shown by specific test to reach it, a design to relevant design standards, or an assessment of relevant test evidence in place of a test. Products on a generic list count as having been shown by test (the note to B1). For panelling that gives four practical routes.

The drawing shows why the evidence is for the whole build-up. Paragraph B2 says small differences in detail, such as fixing method, joints, dimensions and air gaps, might significantly affect performance, and B8 says a classification is valid only within the product’s direct field of application, which includes the substrate it was fixed to when tested. The substrate in your wall has to be one the test represents (B8 and B9).

The generic lists are the cheapest evidence, so it is worth knowing what they say. This is our re-typed summary of the tables as published on legislation.gov.uk (the EU Decisions as retained in UK law); the full footnotes are in the Decisions, and they name types of board, not products. Footnote (e) of the wood-based panel list says veneered, phenol- and melamine-faced panels are included. Nothing we read says whether a paint or lacquer film changes a listed class.

Two further points in the solid timber list matter for fluted and profiled faces. Footnote (g) limits the profiled area of the exposed face to a fraction of the plane area, and Figure a shows the minimum thickness measured at the thinnest point of the profile. On our reading a face fluted from edge to edge is outside the list, and the depth of a flute is capped by the total thickness less the minimum: 3 mm at 9 and 6, 4 mm at 12 and 8, and 6 mm at 18 and 12. See our fluted, reeded and slatted profiles sheet.

Three checks you can run yourself

1. How much lower-class lining a room may have. Paragraph 6.4 (Volume 1: 4.4) lets parts of the walls be class D-s3,d2, provided the total area is less than half the floor area of the room, up to a cap of 20 m² in residential accommodation or 60 m² in non-residential accommodation. The floor area we use is the room’s own; the Document does not say whether wall area is gross or net of openings.

In the first room, a panelled feature wall 9 m long and 3 m high is 27 m², which is over the 22.5 m² allowance, so part of it would need class C. A wall 7 m long and 3 m high is 21 m² and fits. Note that a 20 m² non-residential room is a small room (30 m² or less) and may be class D throughout; the allowance matters for larger rooms.

2. Does the timber clear the density floor? The generic list for solid timber panelling starts at a mean density of 390 kg/m³. The Wood Handbook gives specific gravity for US-grown species (Table 5-3a), and density at 12 per cent moisture is specific gravity x 1.12 x 1,000 (Table 4-6a).

Western redcedar is under the floor, and eastern white pine is within 1 per cent of it. The Decision conditions density as in EN 13238 (its flooring table gives 50 per cent humidity at 23 °C), which is drier than 12 per cent moisture, so a species this close to the line may be under it. European and imported timbers differ: ask the supplier for the mean density of the timber used, and do not assume a species clears it.

3. Is the sheet thick enough? The lists start at 9 mm (and 6 mm at the thinnest point of a profile for solid timber), and plywood and solid wood panels at 9 and 12 mm. A 5 mm sheet is thinner than all of them, so a thin fluted sheet cannot rely on a generic list as a stand-alone panel: it needs the evidence for the build-up it is fixed to.

What these checks give. A plain board or timber panelling that fits a generic list reaches class D, either D-s2,d0 or D-s2,d2. That meets D-s3,d2, so it can serve in a small room and within the paragraph 6.4 allowance. It does not meet the C-s3,d2 asked of other rooms or the B-s3,d2 asked of other circulation spaces. For those, the build-up needs a classification at the class asked for. This is our reading of two documents, for a fire engineer to confirm, not a claim for any product.

What to ask for, and what not to accept

• The class, the room and the standard. The class asked for, to BS EN 13501-1, for named rooms or areas, with the edition of the standard on the report.
• The document. A Declaration of Performance for a marked product, a classification report (its number, date and issuer: a notified body, or a laboratory accredited by UKAS for the test, as paragraph B5 describes), or a statement showing every condition of a generic list is met.
• The same build-up. Board type, thickness, density, veneer, adhesive and finish named in the report must be what is supplied.
• The field of application. The substrate behind, the fixing, the air gap and the joints the test used. A report for a different substrate does not carry over (B8).
• The date. Test standards are revised: BS EN ISO 11925-2 and BS EN 13238 both had new editions in 2026. Ask which edition the report used and whether the issuer still accepts it.
• Traceability. For fire-retardant boards and treated timber, a batch or lot reference and the treatment certificate.
• Changes. Any change of board, veneer, adhesive, finish or fixing needs the supplier to confirm in writing that the classification still holds.
• Handover. Regulation 38 and Section 19 of Approved Document B require fire safety information to be given to the responsible person at completion. Section 19 does not list linings, so the project team should agree that the classification evidence goes in the pack. See handover and O&M pack.

Not accepted: a material name or a standard number without a class; a certificate for the board alone when the finished build-up differs; a class for a different thickness; the old Class 0 or BS 476 wording; an undated statement from the supplier alone.

We coordinate this evidence with the partner workshop that will produce the panelling, before the specification is fixed, and the fire engineer or building control decides what class applies.

Wall panelling to [room names or areas] to achieve reaction to fire class [C-s3,d2 / B-s3,d2 / D-s3,d2] to BS EN 13501-1, as classified for the build-up as installed: [board type, thickness [ ] mm, density [ ] kg/m3, veneer, adhesive, finish [ ]] fixed to [substrate] with [battens / air gap [ ] mm] and [closed / open] joints. The supplier provides the classification report or Declaration of Performance, for approval before production, issued by a [notified body / UKAS-accredited laboratory]. The class applies to the build-up supplied, not to the board alone.

No change of board, thickness, veneer, adhesive, finish or fixing from the approved build-up without the supplier confirming in writing, with evidence, that the classification still applies. At handover provide, for the fire safety information, the classification report or Declaration of Performance for each build-up, the drawing showing where each applies, and batch references for [fire-retardant boards / treated timber].

Standards and sources

• Approved Document B Vols 1 and 2 (England), 2019 ed., amendments to 2026: Vol 2 s.6, Vol 1 s.4, Apps A and B.
• Commission Delegated Regulation (EU) 2016/364, Annex Table 1: classes of reaction to fire; legislation.gov.uk.
• Decisions 2003/43/EC (amended by 2007/348/EC), 2006/213/EC and 96/603/EC: generic lists; legislation.gov.uk.
• BS EN 13501-1:2018 and the test standards named: current on BSI Knowledge, 5-6 Nov 2026; none read.

Questions we are asked

What fire class must timber wall panelling reach in England?

Approved Document B asks the surface lining of a wall to reach D-s3,d2 in a small room, C-s3,d2 in other rooms and B-s3,d2 in other circulation spaces (Volume 2 Table 6.1; Volume 1 Table 4.1 is the same except that circulation spaces within a dwelling are C-s3,d2). Parts of a room’s walls may be D-s3,d2 within the paragraph 6.4 allowance. The class belongs to the build-up as installed. Confirm the room category and the evidence with building control.

Is untreated timber panelling good enough?

On the generic lists, solid timber or board that meets their conditions reaches class D, D-s2,d0 or D-s2,d2. That meets the D asked of a small room and of the lower-performance parts in paragraph 6.4, but not the C asked of other rooms or the B asked of circulation spaces. A fire engineer confirms the reading, and the species, thickness and mounting have to fit the list.

What does B-s1,d0 mean?

Class B for reaction to fire, s1 for the lowest smoke production and d0 for no flaming droplets or particles, as measured in the single burning item test. Table 6.1 asks only for the class letter, because it sets s3 and d2, which put no limit on smoke or droplets.

What is the difference between reaction to fire and fire resistance?

Reaction to fire is how much a product contributes to a fire, graded A1 to F in BS EN 13501-1. Fire resistance is how long an element keeps its load-bearing capacity, integrity and insulation (R, E, I), as for a fire door or a compartment wall. Panelling is a reaction to fire question; a door is a fire resistance one.

Does a veneer, lacquer or glue change the class?

It can. Approved Document B says small differences in detail can significantly affect performance (paragraph B2), and a classification holds only for the product as tested. The generic panel list says veneered, phenol- and melamine-faced panels are included, but we found nothing on coatings. Ask for the class for the finished build-up.

Do skirtings and architraves need a class?

Approved Document B leaves skirtings, architraves, cover moulds, picture rails and similar narrow members out of what counts as a wall (Volume 2 paragraph 6.3; Volume 1 paragraph 4.3). The wall behind them is still a lining. Cornices, dado rails and applied mouldings are not named, so ask building control.

What about Wales, Scotland and Northern Ireland?

This sheet covers England only. The other nations have their own guidance, which we did not read. Check the regulations and guidance for the nation the building is in.