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.

Suggested Reading

How does CLT perform in a fire?navigation-arrow

Oliver Neve explains what happens to CLT during a fire, extracted from TRADA’s forthcoming book on the performance of cross-laminated timber (CLT).


Article from Timber 2017 Industry Yearbook

01/03/2017 |  Magazine Article  

Fire performance of timber frame dwellingsnavigation-arrow

This Wood Information Sheet, produced in association with the UK Timber Frame Association, explains the basic principles used in meeting fire performance requirements and provides guidance to ensure that all parties involved understand their role in the design and construction of a timber frame building.

The sheet considers...

12/09/2016 |  Wood Information Sheet  

Fire test early to avoid last minute hold-upnavigation-arrow

Shop fitters may be asked to demonstrate that products installed on site meet reaction to fire requirements but many are leaving it too late, says Phil Howard.

Article from the TRADA Timber Industry Yearbook 2014

01/01/2014 |  Magazine Article