Using timber in UK facades, cladding and interiors often means meeting reaction-to-fire requirements. This guide explains what to verify before specifying fire-retardant-treated wood: how EuroClass classification works, how it relates to UK guidance, and what evidence to request. It is general guidance - always confirm project requirements against current UK regulations and a qualified fire engineer.
In England, the fire performance of construction materials is addressed in the Building Regulations and Approved Document B (Fire safety). The reaction-to-fire performance required depends on the building type, height, and where the material is used (for example external walls, escape routes or internal linings). Similar principles apply across the UK, with separate guidance in Scotland, Wales and Northern Ireland. Always confirm the specific requirement for your project against current guidance.
EuroClass ratings come from EN 13501-1. B-s1,d0 means:
| Code | Meaning |
|---|---|
| B | Limited contribution to fire (high performance for a combustible material) |
| s1 | Very little smoke production |
| d0 | No flaming droplets or particles |
"Class 0" was a UK national classification defined in older guidance. It is not the same test or the same criteria as the European EuroClass system, and the two should not be treated as automatically equivalent. Modern UK guidance references EuroClass ratings. Do not assume a EuroClass B-s1,d0 product automatically satisfies a historic Class 0 requirement, or vice versa - confirm the exact requirement for your project.
These are different things. Reaction to fire (EuroClass A1 to F) describes how a material contributes to a fire - ignitability, flame spread, smoke and droplets. Fire resistance (e.g. 30 or 60 minutes) describes how long an element holds back fire and maintains its function. A B-s1,d0 reaction-to-fire classification does not by itself provide a period of fire resistance.
"Timber cladding to achieve reaction-to-fire classification EuroClass B-s1,d0 to EN 13501-1, evidenced by a current classification report covering the specified wood species, thickness, application rate and end-use condition. Fire-retardant treatment to be [transparent impregnation / other], with manufacturer's classification report and technical data provided prior to installation."
Adapt this wording to the specific project and confirm with the design team and fire engineer. It is a starting point, not a compliance statement.
SPFR100 is a transparent, water-based fire-retardant impregnation that keeps timber visible. Its published B-s1,d0 classification under EN 13501-1 applies to the certified spruce configuration; other wood species or configurations require project-specific verification. It can be applied on site or in the factory.