Should timber cladding be fire retardant treated?

Depending on its situation, UK Building regulations may stipulate that timber cladding is protected with a suitable fire retardant product. This can be when a boundary falls within one metre of the edge of the building or where cladding is used on multi-story, high rise buildings. It is advisable to check with the Building control office.

TDCA recommends using fire retardant products that are applied in a controlled, factory process such as NON-COM Exterior from Lonza Wood Protection. If a fire retardant treated timber is to be utilised, it’s imperative to ensure:-

  • the treatment is approved, leach resistant and suitable for external use
  • the treatment is compliant and is supported by a relevant, full classification report that identifies Euroclass rating specific to timber species and thickness being used

The fire retardant is compatible with any subsequent products that are to be used e.g. coatings. Reputable suppliers offer to factory apply compatible coatings which means you are dealing with a single supplier if issues arise.