FIRE-SAFE FACADES AND THE NCC 2019: A Guide to Specifying Code-Compliant Aluminium Cladding

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INTRODUCTION

In Australia, the aftershocks of the catastrophic Lacrosse and Grenfell tower fires continue to be felt throughout the building industry. According to industry reports, more than 3400 residential unit blocks across Australia have potentially flammable exterior cladding.1 Recent economic analysis estimates the total cost of fixing this national crisis to be over $6.2 billion.2

As evidenced by Lacrosse, Grenfell and other recent fires, the use of non-compliant, combustible cladding poses a serious public safety risk with wide-ranging consequences – from potential loss of human life and extensive building damage to severe economic and legal ramifications. Consequently, the fire performance of cladding systems has been the major focus of recent regulatory activity within the architectural, signage and shopfitting sectors.

With the adoption of the National Construction Code 2019 (NCC 2019), it is imperative for designers, specifiers and other industry stakeholders to ensure their materials are compliant. The demand for recladding is increasing to remedy existing buildings with non-compliant cladding. While this opens up opportunities for the industry, it also means greater care is required to avoid safety and compliance risks. Stricter requirements on aluminium composite panels (ACPs) with combustible cores has forced designers and specifiers to look at other cladding solutions that provide a more efficient path to compliance.

In this whitepaper, we take a close look at recent developments in Australia’s cladding crisis and outline the fire performance requirements for cladding under the recently updated NCC. We also discuss the key considerations when specifying cladding solutions in this context and present solid aluminium sheet panels as a safe, viable alternative.

THE COMBUSTIBLE CLADDING CRISIS

Recent DevelopmentsSince the Lacrosse and Grenfell tower fires, state and territory governments in Australia have been conducting building audits to identify buildings with non-compliant combustible cladding. Recent combined estimates for New South Wales and Victoria alone indicate approximately 1000 buildings that are considered high to extreme risk.3

Given the number of buildings affected in Australia, the cost of remediating building defects relating to non-compliant cladding is massive – an issue exacerbated by the fact that the roll-out of government funding for remedial works has been fragmented and contentious. Governments across the country are struggling to coordinate remedial works to ensure that existing buildings do not pose an unacceptable risk to public safety.

In August 2019, news reports indicated that the New South Wales government was unable to insure a statewide remediation package.4 Victoria is the only state to announce funding to assist remediation works,5 but its $600 million “rescue” package covers only the most dangerous cases.6 Queensland specifically announced it would not follow the Victorian government’s example.7 In many cases, property owners will be footing the remediation bill.

Updates to Building Codes and RegulationsOn 1 May 2019, the states and territories adopted an updated version of the NCC, superseding the 2016 version.8 As part of its effort to achieve elevated fire safety outcomes across the building industry, the NCC 2019 contains several changes to Section C – Fire Resistance.

Notably, the concession for bonded laminates was retained in the 2019 update. Bonded laminated material (including ACPs) with specified characteristics and controlled fire hazard properties are permissible where a non-combustible material would otherwise be required. However, clarification has been included in the NCC to avoid an incorrect interpretation that the concession applies to ACPs with combustible cores.

EXTERNAL CLADDING: FIRE PERFORMANCE REQUIREMENTS

COMPLIANCE PATHWAYS

The Australian Building Codes Board recently updated the Advisory Note “Fire Performance of External Walls and Cladding” to reflect changes made in the NCC 2019.9 Under Performance Requirement CP2 in NCC 2019 Vol. 1, a building must have elements that will avoid the spread of fire in a building and between buildings, in a manner appropriate for that building.10

This requirement applies to residential buildings, hotels, aged care facilities and hospitals above two storeys, as well as retail

and office buildings above three storeys. For buildings of Type A and Type B construction, a non-combustible external wall will inhibit the spread of fire via the outside of the building, helping the building comply with CP2.11

Under the NCC 2019, if a building element is integral to the construction of an external wall, then that element is part of the external wall. Accordingly, external cladding is considered part of the external wall in many cases and must meet the relevant performance requirements with respect to non-combustibility.12

Deemed-to-Satisfy SolutionsUnder the Deemed-to-Satisfy (DtS) provisions in the NCC, external walls of buildings of Type A and Type B construction must be constructed wholly of “non-combustible” materials. For the purposes of this requirement, “non-combustible” refers to materials that are not deemed combustible by testing under AS 1530.1-1994 Combustibility test for materials (see further Schedule 3 – definitions of ‘combustible’ and ‘non-combustible’, and C1.9).

The DtS provisions allow building materials to be used in specified ways to achieve compliance without further verification. There are potential exemptions set out by the requirements of C1.9(d), C1.9(e), C1.10 and C1.14.

Performance SolutionsIn contrast to DtS solutions, a performance-based solution requires the external wall system to be assessed by a qualified person for fire performance to determine compliance. This assessment can be made under a verification method, by expert judgment, by comparison with DtS solutions, and/or with other documentary evidence.

Bonded Laminated Materials: C1.9(e)(vii)The concession in C1.9(e)(vii) permits bonded laminated materials to be used as cladding provided every condition in the clause is met.13 For an ACP product to fall under this concession, each lamina including any core must be non-combustible as determined by testing under AS 1530.1. If the ACP product has a combustible core according to testing under AS 1530.1, then it is not permitted under C1.9(e)(vii).14

CLADDING SPECIFICATION: KEY CONSIDERATIONS

COLOUR COATED SOLID ALUMINIUM SHEETS: A COMPLIANT CLADDING & SIGNAGE SOLUTION

Considering the industry focus on external cladding and the recent changes in the NCC 2019, designers and specifiers must take extra care when specifying cladding for high rise buildings. ACP products with a polyethylene core and aluminium skins fixed to the core by an adhesive may be fire-rated but will not meet the requirement for non-combustibility. In such cases, an alternative and compliant cladding solution should be identified.

There are non-combustible ACP products available on the market with an aluminium beaded core. These solutions may be tested under AS 1530.1 and deemed non-combustible, but this does not ensure complete fire safety. The adhesive typically used in these products to fix the skin and core together could melt when exposed to high temperatures, causing the skin to peel off and creating a major hazard during a fire event. Due to this safety risk, these type of ACP products are only suitable for limited cladding applications, signage and internal applications. There are also height restrictions on where this product can be used.

Designers and specifiers should also note that fire performance is one of several qualities that must be considered when selecting cladding for modern high rises. Other material qualities that must be considered depending on the installation context include corrosion resistance, weather resistance, strength, sustainability values, maintenance requirements and aesthetics.

New Colour Coated Solid Aluminium Sheets, from SAS Supplier Group, which unlike ACPs are comprised of solid aluminium with no additional layers or core, provide designers and specifiers with an efficient means of complying with the fire performance requirements in the NCC 2019. Solid aluminium sheet panels do not include adhesives to fix multiple layers together, so there is no risk of such adhesives melting during a fire event. This quality enables these panels to be used safely at greater heights and in a wider variety of cladding and signage applications.

Designers and specifiers also benefit from aluminium’s inherent material properties, particularly its non-combustibility and high resistance to fire. Solid aluminium has a high melting point of 660°C.15 It also has high thermal conductivity, meaning it is less prone to “hot spots” where localised property loss can occur.16 Importantly, aluminium also meets the regulatory definition of “non-combustibility” in accordance with AS1530.1.

Beyond fire resistance, aluminium delivers in other performance categories.17 This high quality 5052 marine grade aluminium has a favourable weight comparison with ACP panels, while being high strength, making it suitable for a wide range of internal and external applications. These qualities also make aluminium easy to transport and install. Aluminium is ductile, so it can be easily processed to meet specific requirements without losing performance. Furthermore, the material itself is highly durable and highly resistant to corrosion, so aluminium products generally have exceptionally long service lives.

Aluminium is also a wise choice given the increasing market focus on sustainability. Aluminium is 100% recyclable and does not lose its quality or performance during the recycling process.18 The process of recycling aluminium uses 5% of the energy

used to create new aluminium, while emitting significantly lower greenhouse gas emissions.19 Aluminium can be recycled and reused indefinitely, minimising waste creation and improving the environmental credentials of Australian buildings.

Colour Coated Solid Aluminium Sheets come with a high gloss finish, available with FEVE coating (10+ years colour fastness) or PVDF coating (15+ years colour fastness) on the colour side, and a matte white undercoat on the reverse side. FEVE coated panels are available in 1.6mm thickness and PVDF coated panels are available in 2mm thickness. All panels come with clear protective masking film and can be folded and routered with no cracking or crazing on the folded edges. They are suitable for signage, internal shop fitting and low-level cladding applications. With the prominence of the issue of fire safety in the signage, architectural and building industries, Solid Aluminium Sheets are an exciting solution to commercial and residential projects both indoor and outdoor going forward.

Colour Coated Solid Aluminium Sheets are available in over 65 colours including: vibrant primary and secondary colours for a wide variety of stylised signage – mirror, metallic and pearl finishes for modern shop fitting and interior design effects and timber finishes for other vintage and unique effects. This vast colour range also includes earthly colours such as charcoals, steel grey, latte and olive green to create a variety of moods and settings to interior spaces, particularly shop spaces, that contrast beautifully with any point of sale display material.

Colour Coated Solid Aluminium Sheets, available in 1.6mm and 2mm thicknesses, come in sheet sizes: 2400 x 1200mm, 3600 x 1200 and 3000 x 1500mm.

SAS SUPPLIER GROUP

Based in four major cities around Australia (Melbourne, Brisbane, Sydney and Perth), SAS Supplier Group are the leading supplier to the signage industry and provide an extensive range of products for the signage, building and residential markets. SAS’s ever-expanding range of quality products include the largest range of printing and display equipment, cladding solutions, decorative films, LED lights, rigid board, internal decorative films and more.

With proven experience and a research and development team committed to finding the most innovative solutions, SAS consistently provides products that aim to surpass client expectations.

REFERENCES

1 Gorrey, Megan and Jacob Saulwick. “Australia’s building crisis fix will cost $6.2 billion: report.” Sydney Morning Herald. https://www.smh.com.au/national/nsw/australia-s-building-crisis-fix-will-cost-6-2-billion-report-20190730-p52c9x.html (accessed 26 Januay 2019).

2 Ibid.

3 Narvaez, Ana. “Building Owner ‘Attacks’ Cladding Audit Hours Before Deadline.” The Urban Developer. https://theurbandeveloper.com/articles/building-owner-attacks-cladding-audit-hours-before-deadline (accessed 26 Januay 2019).

4 Loomes, Phoebe. “Stalemate leaving fire-prone ticking time bombs around Australia.” news.com.au. https://www.news.com.au/national/stalemate-leaving-fireprone-ticking-time-bombs-around-australia/news-story/7b26701bd6a690238a98e590c7d9a76a (accessed 26 Januay 2019).

5 Ibid.

6 Varga, Remy. “Apartment owners to foot the bill as cladding fund runs dry.” The Australian. https://www.theaustralian.com.au/nation/politics/apartment-owners-to-foot-the-bill-as-cladding-fund-runs-dry/news-story/33461e36387b71399d5c2e93f9dd80d8 (accessed 26 Januay 2019).

7 Lynch, Lydia. “State won’t pay to fix Queensland cladding crisis.” Brisbane Times. https://www.brisbanetimes.com.au/national/queensland/state-won-t-pay-to-fix-queensland-cladding-crisis-20190717-p527y8.html (accessed 26 Januay 2019).

8 Australian Building Codes Board. “What to expect in NCC 2019.” ABCB. https://www.abcb.gov.au/Connect/Articles/2019/01/14/What-to-Expect-in-NCC-2019 (accessed 26 Januay 2019).

9 Australian Building Codes Board. “Fire performance of external walls and cladding: Advisory note 2019.2.1.” ABCB. https://www.abcb.gov.au/-/media/Files/Resources/Education-Training/Advisory_Note_2019_2_1_Fire_Performance_of_External_Walls_and_Cladding.pdf (accessed 26 Januay 2019).

10 Ibid.

11 Ibid.

12 Ibid.

13 Ibid.

14 Ibid.

15 Worldatlas.com. “What Is The Melting Point Of Aluminum?” World Atlas. https://www.worldatlas.com/articles/what-is-the-melting-point-of-aluminum.html (accessed 26 Januay 2019).

16 Aluminium Federation. “Aluminium and Fire.” Aluminium Federation. http://www.alfed.org.uk/files/Fact%20sheets/11-aluminium-and-fire.pdf (accessed 26 Januay 2019).

17 Designing Buildings Ltd. “Aluminium.” Designing Buildings Wiki. https://www.designingbuildings.co.uk/wiki/Aluminium (accessed 26 Januay 2019).

18 The Aluminium Association. “Aluminum Sustainability.” The Aluminium Association. https://www.aluminum.org/aluminum-sustainability (accessed 26 Januay 2019).

19 Australian Aluminium Council Ltd. “Recycling.” Australian Aluminium Council. https://aluminium.org.au/aluminium/recycling (accessed 26 Januay 2019).

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