Flame-retardant treatments for timber products

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In many situations, timber and wood-based materials may be used in their natural, untreated state. However, flame-retardant (FR) treatments extend their use to situations that demand enhanced 'reaction to fire' properties.


This Wood Information Sheet (WIS) covers treatments that may be applied to wood and wood-based products both factory and site applied to upgrade their fire performance to Euroclass B or C or National class 1 or 2 (or Class '0', found only in Approved Document B to the Building Regulations (before the 2019 edition), where it is defined by a combination of performance in tests according to BS 476 Parts 6 and 7).



  • Types of FR treatment
  • Compatability of FR timber products and treatments with additional coatings
  • Performance requirements
  • Fire test evidence
  • CE marking

This Wood Information Sheet was revised in August 2019. The key changes include:

  • Class 0, which is found only in Approved Document B to the Building Regulations (before the 2019 edition)
  • European classes of reaction to fire performance are now the norm because of the need to comply with European product standards
  • Updates to the three types of FR treatments
  • Updates to treatments applied on site
  • Tables 1 and 2
  • UK Building Regulations
  • Durability of reaction to fire
  • The addition of two new standards for common wood-based products.


For queries about this technical document, please get in touch with its authors via BM TRADA’s Technical Helpline on +44 (0)1494 569601 or email timberadvice@bmtrada.com.


A paper/digital copy of this Wood Information Sheet is available in the BM TRADA Bookshop, which also hosts additional specialist timber publications.

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