New Fire Retardant Regulations for External Cladding
On 1 January 2017 a restriction on the use of combustible external cladding was published as part of Amendment 4 of Acceptable Solutions C/AS2–7.
This is now applicable for all building consent application submitted after 31st of May 2017.
Previously, buildings up to 25m high or those with sprinkler protection required absolutely no testing of external cladding material.
The amendment removes this dispensation so all cladding for buildings over 7m high requires a fire test. The test is small-scale cone calorimeter test to ISO 5660 that provides a total and peak heat release rate of the material. The logic is - the higher the heat release rate the more combustible the material.
A cladding system is defined as the outside or exterior weather-resistant surface of a building and this includes cladding, underlays, cavity components, windows, doors and all penetrations, flashings, seals, joints and junctions.
Critically the testing requirement applies to all components within the cladding system.
There are two types of categories for cladding material:
Cladding Type A - Peak heat release rate (kW/m2): 100 / Total heat release rate (MJ/m2): 25
Cladding Type B - Peak heat release rate (kW/m2): 150 / Total heat release rate (MJ/m2): 50
From 1 January 2017 the Acceptable Solution requirements for external cladding are as follows:
Building height 0-7m - Distance to boundary <1m: Type A / Distance to boundary >1m: Type B for Risk Group SI, No Requirement for other Risk Groups
Building height >7m - Distance to boundary <1m: Type A / Type A for Risk Group SI, Type B for other Risk Groups
Risk Group SI is sleeping use where care or detention is provided, such as care home or hospital.
Non-combustible materials meet the requirements for both Type A and B without testing, for example, concrete, brick/block, ceramic tile, aluminum, glass, steel, cellulose fibre-cement products with applied finishes/coatings less than 1mm thick.
However, timber products would usually not meet the above requirements without an application of a fire retardant treatment. Same would clearly apply to products that are equally or more combustible as timber, for example EPS or uPVC type products.
Contact Abodo with your project details to see if we can help meet fire compliance requirements for timber cladding, weatherboards and fascia.