The latest amendments to the National Construction Code 2022 (NCC 2022) have presented several changes that could affect the compliance and performance requirements for building cladding and facade systems, as well as other construction materials and methods.
Overall, many of NCC 2022’s advocated changes (as part of the routine three-year amendment cycle) aim to make the code more accessible, understandable and practical. However, putting the code’s principles into practice is where architects, developers and specifiers encounter challenges that could require expert insight and help.
Fairview’s technical manager Ashley How explains how some NCC 2022 revisions will impact the facade cladding side of construction.
What does this mean for facades?
General impressions from these changes are that the ABCB has taken a ‘how can we make construction easier?’ type approach, by significantly adding more Deemed-to-Satisfy clauses approving products and installation methods. Some of these are better and readily workable, while others may increase risks around common defects such as weatherproofing.
The bonded laminates clause has been retained again in the NCC and is not slated for future amendments. For Fairview, this reinforces full compliance of our relevant products including the popular Vitracore G2 panels.
There’s a key new provision that prevents fixing of certain bonded laminated cladding panels by adhesive only, but this is unlikely to have much impact as the installation recommendations of several main product suppliers already align with this new clause.
The addition of Deemed-to-Satisfy weatherproofing requirements is a first in NCC 2022, but as waterproofing is one of the most common defects in high-rise construction, some concerns are flagged by the new requirements, and it’s worthy of explanation below:
The advocated change of clause F3D3 implies that where sarking is used in accordance with AS4200, it ticks the box for weatherproofing. Yet we have concerns that under tall building/high wind loads (where sarking can readily tear), this could be problematic.
Moreover, the approval of external metal wall cladding in line with AS1562.1 is, in our opinion, unlikely to enhance waterproofing performance. Waterproofing is the number one defect affecting high-rise constructions, so to assign weatherproofing of wall cladding to a standard designed for roofing performance under wind-loads – with no significant water or weatherproofing requirements – is perplexing. For absolute surety, compliance should be built around system-based weatherproofing testing, not on wind-load strengths or attributes. While not obvious in the code, the requirements of the standard means it is only really applicable for large format roof sheeting products, and not for the majority of metal cladding products used in high-rise facades.
Approving more materials agreed as non-combustible (in terms of their fire resistance) simplifies the choice of construction products and materials and slightly reduces build and product certification costs. This applies to recladding and replacement of combustible cladding. So, bravo on that front, NCC.
Sustainability and Thermal:
The changes in Section J (thermal and sustainability) are not included in this latest code preview and have been slated for release later this year. We understand there are no significant changes planned for this version of the code. Yet, at a time when we’re consulting for construction professionals and the wider market interested in sustainability and sourcing, there is a real desire to see more clarity and guidance around these topics.
For NCC 2022 more generally, our review confirms NCC 2022 adopts a new ‘consistent volume structure’ with a clause referencing system to create better consistency across all volumes. There are some clause name updates too; so, for instance, the performance requirement to prevent the spread of fire is now C1P2 rather than CP2. And although the NCC now looks different too, the reorganisation of content aims to improve the user experience, and make the Code more web-accessible.