I recently read with interest the following article claiming that in most cases combustible cladding identified in cladding audits around Australia are likely to have been installed on buildings in compliance with the National Construction Code (NCC). https://lnkd.in/gNyy87N
The article describes 2 key arguments to defend allegations that the use of combustible cladding on buildings was not complaint with the National Construction Code, namely:
- That although combustible, aluminium composite panels (ACP) is a ‘bonded laminated material’ permitted by Clause C1.12.
- That ACP could be used as an ‘attachment’ to a wall which has the required fire resistance levels under clause 2.4 of Specification C.1 if certain criteria are met.
The authors state that in the majority of cases they have seen, builders and building surveyors [who installed or approved the use of combustible ACP] have complied with the NCC.
This article looks more closely at these two arguments and the relevant provisions of the NCC.
In relation to the ‘bonded laminate’ argument, the article states:
The ‘bonded laminate concession’ in Clause C1.12(f). This permitted the use of materials which have non-combustible laminate layers bonded to a combustible core – i.e. two layers of aluminium, bonded to a polyethylene core, as is typically the case in ACP – wherever non-combustible materials were required, subject to the material satisfying four key criteria.
Until the NCC was amended earlier this year, clause C1.12 of Volume One of the NCC provided (as relevant):
C1.12 Non-combustible materials
The following materials, though combustible or containing combustible fibres, may be used wherever a non-combustible material is required:
(f) Bonded laminated materials where—
(i) each laminate is non-combustible; and
(ii) each adhesive layer does not exceed 1 mm in thickness; and
(iii) the total thickness of the adhesive layers does not exceed 2 mm; and
(iv) the Spread-of-Flame Index and the Smoke-Developed Index of the laminated material as a whole does not exceed 0 and 3 respectively.
In order for ACP to be a ‘bonded laminated material’ under this clause ‘each laminate’ must be non-combustible. Arguably this means that not only the aluminium but each layer of the panel (including the core) must pass the AS1530 Combustibility Test for Materials. It’s unlikely that each layer of many of the ACP panels installed over the past 20 years would pass this test. CSIRO’s Fire Safety Guideline for External Walls dated April 2016 discusses this issue further at pages 4-7. https://www.csiro.au/en/Do-business/Services/Materials-infrastructure/Fire-safety/Facade-guideline
Its also useful to note that the NCC requires evidence to support the use of materials in the form of specified test reports or certificates. Therefore, if a particular brand and type of ACP panel was proposed for use on the basis that each laminate was non-combustible, then reports confirming that each laminate of this brand and type of panel was non-combustible or another applicable certificate should have been submitted to the approval authority as evidence of compliance. Where a certificate was issued for the product, all conditions on the certificate, including any installation requirements would have to have been strictly met in the installation for the product to be installed in compliance with the NCC.
In relation to the ‘attachments’ argument the article states:
The ‘finish’ or ‘attachment’ exception in Specification C.1.1, Clause 2.4(a). This permitted combustible materials to be used as finishes or linings to walls and roofs, or as attachments to buildings, subject to a number of criteria being met.
Before the 2018 amendment to Volume One of the NCC, Specification C1.1, Clause 2.4(a) stated:
2.4 Attachments not to impair fire-resistance
(a) A combustible material may be used as a finish or lining to a wall or roof, or in a sign, sunscreen or blind, awning, or other attachment to a building element which has the required FRL if—
(i) the material is exempted under C1.10 or complies with the fire hazard properties prescribed in Specification C1.10; and
(ii) it is not located near or directly above a required exit so as to make the exit unusable in a fire; and
(iii) it does not otherwise constitute an undue risk of fire spread via the facade of the building.
(b) The attachment of a facing or finish, or the installation of ducting or any other service, to a part of a building required to have an FRL must not impair the required FRL of that part.
For ACP to be able to be used as an ‘attachment’ under this clause it would have to be determined that it would not otherwise constitute an undue risk of fire spread via the facade of the building. It’s certainly possible that ACP could be attached to an otherwise fire resistant wall in a way that would not constitute an undue risk of spread of fire. This might occur where the ACP is in the form of a sign or feature which which covers a relatively small external area only. However, if an ACP product with 100% polyethylene core was ‘attached’ to a large area of an external wall its hard to see how this would not constitute an undue risk of fire spread via the facade of the building and/or that it would not impair the required fire resistance level of the wall to which it was attached. The CSIRO report referred to above considers this issue at page 9. Clause 2.4 of Specification C1.1 also requires that the combustible material not be located over a required exit so as to make the exit unusable in a fire. This means that where ACP has been used as feature over an entry to a building, it is not likely to comply with clause 2.4.
Ultimately determining whether Clause 2.4 of Specification C1.1 applied will turn on the circumstances in each case and the opinions of fire safety experts. I note that ACP products with 100% polyethylene core have been described a ‘solid petrol’. I’d suggest that swathing a building in solid petrol would lead any lay person to conclude that in the event of a fire there would be an increased risk of spread of fire via the facade.
Further, the ability to use combustible attachments only applied where the ACP are attached to a wall that meets the required fire resistance level. Therefore, if the ACP is an integral part of the wall system itself (as was allegedly the case in the Lacrosse building), clause 2.4 of Specification C1.10 cannot apply.
In interpreting the NCC, the deemed to satisfy provisions should be read in the context of the relevant performance requirements and the objectives of the relevant legislation which include protecting the safety and health of people who use buildings. One might also assume that if practitioners proposing or assessing the use of ACP on buildings had turned their mind to important safety risks, such as the risk of spread of fire from using these products, this would have been carefully documented at the time.
Importantly, it is also possible that ACP was approved for use on a building as part of an performance solution. However, I understand that in many cases where ACP has been identified on buildings by cladding audits, if there was a performance solution relating to fire safety matters, it was unlikely to have addressed the proposed use of ACP other than in accordance with the deemed to satisfy provisions.
Finally, it is noted that since the clarifications to Volume One of the NCC in March this year, it seems any possible argument that the previous deemed to satisfy provisions allowed combustible ACP’s to cover large parts of external walls of buildings as an attachment or otherwise has been unequivocally put to rest.
In conclusion, yes, pre NCC 2016 Volume One Amendment 1, ACP products could be used on external walls of buildings under deemed to satisfy provisions in the NCC in limited circumstances and yes, every building will need to be assessed on its merits. However, it seems an over exaggeration to suggest that most of the thousands of buildings identified as having combustible ACP in the various cladding audits around the country have been built in compliance with the NCC. I also don’t accept the suggestion that simply because there are 1369 buildings in Victoria identified as having combustible cladding, there must have been clear pathways under the NCC to permit its use. Unfortunately, alleged non-compliant use of ACP is not just a storm in a tea cup, it’s a symptom of significant problems in Australia’s building and construction sector.