(made mandatory April 2013)
In April 2012 the NZ Building Code Regulations for Reaction-to-Fire were changed. These changes became mandatory in April 2013.
Recognition of these changes has come late to the NZ timber industry, and some provocative statements have been made.
The changes were based on a large amount of work done at BRANZ on reaction-to-fire of internal linings of buildings. See BRANZ Study Reports 160,301,302 and 314.
These regulations have changed the ways in which timber can be used as linings in some types of buildings in New Zealand.
Most uncoated, paint coated or clear coated timber meets Material Group 3 under the regulations. (See Appendix).
Household units (detached homes)
- There is no limitation (i.e. no proof of Material Group No. is required) on the use of timber as wall or ceiling linings in
Single or multi-level
Household units (inside apartment buildings)
- There are no limitations on timber joinery.
- There are no limitations on heavy structural timber building elements made from solid timber, glue laminated timber and LVL.
- There is no limitation on general decorative trim, and non-conforming areas (i.e. where the material is not of the specified Material Group No. for that type of building,) of not more than 5.0 m2 are permitted.
If the walls are sprinkler protected wall linings can be of Material Group 3 in parts of buildings used for crowd/assembly purposes including classrooms, meeting rooms, public halls, gymnasiums, shops, cinemas and similar types.
(If the timber and/or coating does not comply with the Appendix then it will have to be tested to the appropriate Standard to confirm that it is Material Group 3.)
In sprinkler protected buildings, Material Group 3 materials cannot be used as interior wall and ceiling materials in:
- Sleeping areas where care and detention is provided
- Ceiling materials in sleeping spaces (except household units)
- Occupied spaces in buildings that are essential to post disaster recovery or associated with hazardous facilities (e.g. hospitals, police stations)
- Ducts for HVAC systems (internal surfaces)
- Ceiling linings in crowd spaces (e.g. restaurants, cafes, schools) and sleeping uses (except household units), but can be used as a wall lining.
- Timber has not been completely shut out of the interior linings of buildings in NZ.
- The unrestricted use of wood as wall and ceiling linings is allowed in residential use.
- In public spaces non –fire retardant treated or coated timber can be used as wall linings if the walls are sprinkler protected.
- In public spaces non –fire retardant treated or coated timber cannot be used as ceiling linings.
- In occupied spaces in buildings that are essential to post disaster recovery or associated with hazardous facilities (e.g. hospitals, police stations) non –fire retardant treated or coated timber cannot be used.
- There is a need for the identification and/or development of treatments and coatings which can enable clear finished timber to meet the requirements of Material Group 2.
Solid wood or wood product can be taken as achieving Group Number 3 rating (with or without coating) without the requirement for testing, provided it is:
Jeff Parker - Technical Manager
- at least 9mm thick
- at least 400kg/m3
- coated with water-based or solvent-based paint coatings, varnish or stain of at most 0.4mm thick
- coated with waterborne or solvent borne paint coatings, varnish or stain of at most 100g/m2
Wood Processors and Manufacturers Association