Background At its meeting on 19 February 2016, the Building Ministers’ Forum (BMF) agreed to the development and implementation of a range of measures to help address risks associated with external cladding products on high rise buildings. This included a National Advisory Note on the subject that was issued in August 2016. The purpose of the National Advisory Note is to provide guidance on interpreting the National Construction Code (NCC) relating to the fire performance of external walls. It aims to assist practitioners in future decisions on product selection, installation and certification. After the Grenfell Tower fire in London that occurred in June 2017, the BMF directed the ABCB to ‘expedite progress in the implementation of measures through the NCC that will prevent the non-compliant use of cladding from occurring in the future.’ Given this direction, the range of measures that involved changes to the NCC were progressed through an out-of-cycle NCC amendment (NCC 2016 Volume One Amendment 1) that has effect from 12 March 2018. This Advisory Note has been updated to reflect changes made to the NCC fire safety provisions by this amendment. Introduction Performance Requirement CP2 of NCC Volume One requires, among other things, that 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. This requirement can be met, in part, under a Deemed-to-Satisfy Solution for buildings of Type A and Type B construction by non-combustible external walls (C1.9). A non-combustible external wall inhibits fire spread via the external wall of the building, thereby contributing to a building’s compliance with Performance Requirement CP2. This Advisory Note provides information to help clarify the application of Deemed-to- Satisfy Provisions and Verification Method relating to the fire performance of external walls (including cladding products) of buildings of Type A and Type B construction. This clarification is predicated on the intent of Performance Requirement CP2 (in part); that external walls (including cladding products) must not contribute to the spread of fire in a building and between buildings. Specifically, the following items are addressed:
Advisory Note: Fire Performance of External Walls and Cladding
Under the Deemed-to-Satisfy Provisions of NCC Volume One, external walls of buildings of Type A and Type B construction must be constructed wholly of materials that are not deemed combustible as determined by testing in accordance with AS 1530.1 (A1.1 – definitions of ‘combustible’ and ‘non-combustible’ and C1.9). In the case of an external wall that is required to have no fire rating, the external wall must still be non-combustible. Therefore building components determined to be part of an external wall in buildings of Type A and Type B construction must be non-combustible under a Deemed-to- Satisfy Solution, unless the requirements of C1.9(d), C1.9(e), C1.10 and C1.14 apply. The purpose of these Deemed-to-Satisfy requirements is to inhibit the spread of fire via the external wall of a building as required by Performance Requirement CP2. 1.2. What is an external wall? The term ‘external wall’ is defined in NCC Volume One as ‘an outer wall of a building which is not a common wall’. A ‘common wall’ is defined in NCC Volume One as ‘a wall that is common to adjoining buildings’. A building element is considered to be part of an external wall if it is integral (i.e. is not ancillary) to the construction of the wall. For example, the following elements are considered to be part of an external wall:
Advisory Note: Fire Performance of External Walls and Cladding 1.3. What is an ancillary element?1.3.1. Defined term A definition for ‘ancillary element’ has been introduced in NCC Volume One. It is defined as ‘an element that is secondary to and not an integral part of another element to which it is attached’. It is necessary to exercise judgement when assessing whether an element is ancillary or integral to another element. For example, a sunshade that is auxiliary in nature can be considered to be ancillary to an external wall. However, a protrusion of a wall near a window that also acts as a sunshade may be considered integral to the wall. 1.3.2. Permitted ancillary elements C1.14(a) permits any ancillary element that is non-combustible, as determined by testing in accordance with AS 1530.1, to be fixed, installed or attached to the internal parts or external face of an external wall required to be non-combustible. The ancillary elements listed in C1.14(b) to (m), even though combustible, can also be fixed, installed or attached to an external wall required to be non-combustible, provided they comply with any specified limitations or conditions. Some of these limitations or conditions are explained in sections 1.3.3 and 1.3.4 below. It should be noted that–
Advisory Note: Fire Performance of External Walls and Cladding fixed, installed or attached to an external wall required to be non-combustible where the sign–
Advisory Note: Fire Performance of External Walls and Cladding fire-resisting covering in a manner that impairs its performance, thereby reducing the fire-resistance level (FRL) of the building element. Specification C1.1 Clause 2.4 only applies to the method of attachment, not the component being attached. 2. Bonded laminated materials subject to C1.9(e)(vi) C1.9(e) contains a list of materials that, although combustible in entirety or part, may be used wherever a non-combustible material is required. Specifically C1.9(e)(vi) permits the use of bonded laminated materials where:
Australian Standard AS 2118.1 specifies requirements for the design, installation and commissioning of automatic fire sprinkler systems in buildings. The 2017 edition, including Amendment 1, of AS 2118.1 includes changes to the requirements for sprinkler protection of covered balconies. Covered balconies must now be sprinkler protected if they are more than 6 m2 in floor area or are greater than 2 m in depth when measured from the external wall. Under the previous edition, both conditions needed to be exceeded before sprinklers were required. This is in recognition that, particularly in residential buildings, balconies can often be used for Advisory Note: Fire Performance of External Walls and Cladding storage, which can be the source of or contribute to the spread of fire via the external wall of a building. NCC Volume One references the 2017 edition, including Amendment 1, of AS 2118.1. The 1999 edition of AS 2118.1 has been retained for a transitional period ending on 11 March 2019, however Clause 5.6.13 of the 1999 edition must be replaced with Clause 5.9.10 of the 2017 edition. Therefore, the increased level of stringency for the sprinkler protection of covered balconies has been adopted, even when using the 1999 edition of AS 2118.1. 4. Verification Method for testing of external wall assemblies for fire spread (CV3) 4.1. Verification Method CV3 Verification Method CV3 enables verification of the fire performance of external wall systems against the relevant Performance Requirements of the NCC. CV3(b)(i) requires that an external wall system be tested in accordance with Australian Standard AS 5113. AS 5113 is described in section 4.2 below. In addition to testing to AS 5113, CV3 requires the external wall system to be verified against CV1 or CV2, as well as meeting certain other fire safety measures, including ones specific to buildings of Type A and Type B construction. These measures are imposed in recognition that an external wall system tested to AS 5113 may contain combustible elements that still present a risk that needs to be mitigated in order to inhibit the spread of fire via the external wall of a building as required by Performance Requirement CP2. Some of these conditions are discussed further in 4.3-4.5 of this Advisory Note. It should be noted that CV3 is one method of verifying compliance with the relevant Performance Requirements. It need not be used if a Deemed-to-Satisfy Solution is proposed or if using another method of verifying compliance with the relevant Performance Requirements, as specified in A0.5 of NCC Volume One. 4.2. Australian Standard for external wall assemblies (AS 5113) The Australian Standard AS 5113 sets out the procedures for the fire propagation testing and classification of external walls of buildings according to their ability to limit the spread of fire via the external wall and to adjacent buildings. AS 5113 is based on international standards and adopts testing criteria prescribed in ISO 13785.2 and BS 8414 Parts 1 and 2. AS 5113 provides the option for an external wall to be tested to either ISO 13785.2 or BS 8414 Parts 1 and 2. Advisory Note: Fire Performance of External Walls and Cladding The specimen or form of construction being subject to the test needs to be representative of the proposed on-site installation, including any cavities and cavity barriers, treatment of penetrations and fixing methods. 4.3. Classification EW and cavity barriers For an external wall system to be used under CV3, CV3(b)(ii) requires an EW classification as determined in accordance with AS 5113. Under CV3(b)(iii), if the external wall system contains a cavity, it must have cavity barriers at the perimeter of each floor and these cavity barriers must have been included in the external wall system tested to AS 5113. The intent of specifically requiring cavity barriers at the perimeter of each floor is to minimise the risk of fire spread between floor levels through concealed spaces within the external wall. 4.4. Buildings of Type A construction In a building of Type A construction, in order to comply with CV3:
Advisory Note: Fire Performance of External Walls and Cladding 4.5. Buildings of Type B construction There are two options when using CV3 for a Class 2, 3 or 9 building of Type B construction. The building must either be protected throughout by a sprinkler system complying with Specification E1.5 or have any openings in the external wall separated by a slab or other horizontal construction. The slab or horizontal construction must comply with the requirements of C2.6(a)(iv), as for buildings of Type A construction. A Class 5, 6, 7 or 8 building or Class 4 part of a building, that is required to be of Type B construction, need not be provided with additional measures. 5. CodeMark Australia or CodeMark Certificates of Conformity A current Certificate of Conformity issued under the ABCB’s voluntary CodeMark Australia or CodeMark Scheme is evidence that a building material, method of construction or design fulfils specific requirements of the NCC. The NCC refers to both the current CodeMark Australia Scheme, which was progressively implemented from 1 August 2017, and the previous CodeMark Scheme. The continued reference to the previous Scheme recognises that Certificates of Conformity issued under it may still be valid forms of evidence of compliance with the NCC. Currently there are a number of external wall products on the market, including some aluminium composite panels that have a CodeMark Certificate of Conformity. Before relying on a CodeMark Australia or CodeMark Certificate of Conformity, users of products and systems should be mindful of the information on the certificate including:
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