Reaction to fire
The New Zealand Building Code also contains provisions designed to ensure that products used on interior walls and ceilings, floors and on external walls do not promote rapid surface spread of fire when exposed to growing fires.
These provisions are intended to allow more time for the safe evacuation of occupants or for fire-fighting interventions.
Wood is a combustible material and large areas of exposed timber surfaces may pose a fire spread hazard.
Design features to mitigate the risk may include use of:
- fire sprinklers to control or suppress the fire;
- fire separations to subdivide spaces;
- fire retardant treatments and coatings to improve the fire properties of wood, and/or
- area limits on the total exposed surfaces of wood products, especially for ceilings.
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Reaction to fire
Flooring
In New Zealand, regulatory requirements restricting the fire properties of flooring materials and coverings within buildings, are usually only required in hospitals, prisons, rest homes or similar occupancies, and in fire protected exit-ways in buildings.
There are no requirements governing fire properties of flooring materials and coverings for any building with an approved fire sprinkler system.
Where requirements do exist, the minimum performance needed to meet the NZBC compliance document for fire safety is for the flooring to be either non-combustible, or have a ‘low radius of effects of ignition’ when tested to the BS 4790 standard test for flammability of floor coverings (and assessed using criteria in BS 5287).
Wood-based products are typically able to achieve this level of performance.