2022 NCC Seminars: Volume Two - Roof and wall cladding

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[Music]

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My name is Phil Finnimore from the Australian  Building Codes Board, today I'm going to talk to  

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you about a particular part in the roof and  wall cladding section of Volume Two NCC 2022.

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H1D7 roof and wall cladding, what I'd like to  point out in this is the solutions relating to  

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gutters and downpipes. If you have a look on the  right there through those relevant  

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Australian Standards 1562.1, 2050 and 3500.3 you'll  find solutions for gutters and down pipes. Also, on  

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the left is a Deemed-to-Satisfy set of solutions  that are contained within the Housing Provisions  

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for NCC 2022, if that's the DtS solution that you  choose. So specifically we're talking about 

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clause H1D7 of Volume Two which will take you through  H1D7(4) subclause (b) to Part 7.4 of the Housing Provisions

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for solutions for gutters and downpipes. But before we move into that and talk  

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about the detail I'd like to point out that the  Housing Provisions, which is different to NCC 2019, 

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we've excluded the provision of box gutters  in those Deemed-to-Satisfy solutions.

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There are solutions for box gutters but they exist  in 3500.3, the only thing that 2019 talks  

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about in terms of box gutters is the requirement  for a fall and then it sends you across to 3500.3.

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So a decision was made for 2022 in  the Housing Provisions to exclude box gutters  

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entirely so that the complete solution is  in that reference document 3500.3.

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There were only a few changes to this  particular set of technical DtS provisions  

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in the Housing Provisions for 2022  and I'll point those out to you now.

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The first one is a change in  terminology from 2019 to 2022, which is  

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described there we've gone from the average  recurrence interval to annual exceedance probability

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it's a defined term and this term  has been changed to a line with 3500.3.

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Along with the data for rainfall intensity, so if  we're looking at these particular tables and this  

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one is for the Australian Capital Territory, you'll  note that there are differences in those rainfall  

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intensities this is based on weather bureau data  and it's also aligned with the review of 3500.3

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to maintain consistency between the code and  the relevant Australian Standard. For 2022 on the  

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Housing Provisions we've expanded a little bit  for valley gutters in the part relating to the  

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installation of gutters specifically clause  7.4.4, we provided in there a little bit more  

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detail through subclause (4) about dimensions and  the pitch relevant tables things like free board  

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set out in subclass (c) there and side angles. And  what we've done to support this is provided tables  

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with different rainfall intensities which will  give you different dimensions across those  

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three columns for effective depth and width, and  supporting that also is explanatory information  

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which sets out in profile in an illustrative way  what those table dimensions actually relate to.