Soffit Insulation Manufacturers and Building Practitioners are alerted to the end of the concession period for acceptable demonstration of Group Numbers for building linings as required by the National Construction Code of Australia (NCC). This affects soffit insulation that is exposed to the space below, as it is then also effectively a building lining.
The soon to expire NCC 2016 Deemed-to-Satisfy provisions has called for Group Numbers to be determined under AS 5637.1 (NCC Vol.1 – Spec.C1.10 Cl.4(b)), which in turn determines that when a product or material is to be tested in the AS ISO 9705 test room for the purposes of determining a Group Number it must be tested with the product or material installed in the ceiling and three walls of the test room. This is referred to as the “standard specimen configuration”. (AS 5637.1:2015 Cl.5.2.1). In effect, this means that even if a soffit insulation is tested in it’s intended application, which is generally in the ceiling only, a Group Number cannot be determined in accordance with AS 5637.1.
However, the NCC 2016 also states in a note within it’s reference to AS 5637.1 that “Test reports indicating the group number of wall and ceiling linings determined under versions of the BCA applicable prior to 1 May 2016 remain valid until 1 May 2019”, which has allowed a concession period of three years for testing that has been conducted prior to the introduction of AS 5637.1 (NCC 2016 Vol.1 – Spec. A1.3).
Therefore, when the NCC 2019 becomes effective on 1st May the above concession will cease, and Group Numbers thereafter must only have been determined in accordance with AS 5637.1. Manufacturers are reminded that as of the 1st of May 2019 it will be inappropriate and nonconforming to supply product into a soffit insulation application without the appropriate Group Number and without that Group number having been determined by a NATA accredited laboratory (or similarly accredited laboratory under NATA’s Mutual Recognition Arrangement (MRA) Network) in accordance with AS5637.1.
Furthermore practitioners are alerted to the fact that they should be requesting manufacturers to demonstrate compliance via a legitimate AS 5637.1 test report from an accredited laboratory that confirms a Group Number of either 1, 2 or 3 dependent on the specification required, and a SMOGRARC index of less than 100 m2.s-2 x1000 in terms of smoke development for areas without NCC compliant fire sprinklers.
From 1st of May 2019 Group Numbers for internal linings that rely on ceiling only test reports are non-conforming and should not be relied upon to demonstrate compliance to the NCC.