New plumbing standards

AS/NZS3500 has some major changes to be aware of Master Plumbers’ technical Advisor, Aaron Bridger, explains.

The 2021 standards have been released, encompassing the AS/NZS 3500 suite. Here are the major changes:

The Water Standards – AS/NZS 3500.1:2021

Conformance to individual product standards has been removed. All products used in plumbing and drainage systems in Australia need to comply with the PCA and, in New Zealand, the NZBC, see appendix B for further information.

Definitions have been relocated to AS/NZS 3500.0. This was done for consistency across the series.

A number of the backflow prevention provisions, which were considered matters of public policy, have been elevated to PCA Part B5 Cross Connection Control. To remove duplication between PCA 2019 and AS/NZS 3500.1, the provisions relating to cross-connection hazards and the corresponding hazard rating have been removed. Consequently, Appendix F was deleted, and all remaining backflow provisions have been consolidated in Section 4.

Jointing requirements for plastics pipes have been clarified and expanded to allow different methods. (Clause 5.6.9).

Changes to the requirements for the marking of pipes in commercial buildings. (Clause5.19).

Changes to the requirements for the installation of water services located in metal framed walls to bring the provisions in line with those of the National Association of Steel- framed Housing. (Clause 5.5.2.1 C).

Clause 5.4 relating to bushfire zones has been removed in anticipation of requirements relating to bushfire prone areas being elevated to the PCA.

Section 12, relating to special connections for specific fixtures, has been removed. With backflow requirements being moved to the PCA; listing these few examples would be inappropriate. The WaterMark specifications for the product would identify what backflow devices were required.

Sanitary Plumbing & Drainage – AS/NZS 3500.2:2021

Conformance to individual product standards has been removed. All products used in plumbing and drainage systems in Australia need to comply with the PCA and, in New Zealand, the NZBC, see Appendix A for further information. Removal of specific product standard conformance requirements avoids inconsistencies and contradictions between this document and the PCA and NZBC.

Definitions have been relocated to AS/NZS 3S00.0 for consistency across the series.

The range of materials that can be used for wet wells has been expanded to encompass prefabricated wells.

Changes to the requirements for the marking of pipes in commercial buildings. (Clause 10.10).

Changes to the connection requirements for drains at grade. (Clause 4.9.1). These requirements are limited to 100mm branch drains, now required to be inclined at 15 degrees.

The requirement for a commercial dishwashing machine drainage just to connect to a disconnector gully with a 10 m discharge pipe has been removed. (Clause 13.25.3).

An appendix has been added providing guidance on the requirements of AS 2870 for flexible connections to be installed in plastics pipe drainage systems. It covers flexible connections, lagging and water ingress under the slab to accommodate a range of differential soil movement for Soil Classes M, M-D, Hl, H1-D, HZ, H2-D, E and E-D.

Changes to the number of pressure attenuators required to allow more flexible installation options. (Clause 6.11).

Stormwater Drainage AS/NZS 3500.3:2021

Definitions have been relocated to AS/NZS 3500.0 for consistency across the series.

Design rainfall intensities are now expressed in terms of the Annual Exceedance Probability (AEP) values to reflect the practice of the Australian Bureau of Meteorology (BOM). There has been no change in the requirements or the calculations, and the original ARI values are shown for comparison.

The 5 min duration rainfall intensities for representative places in Australia given in Table D.1 have been updated to show the latest values from the BOM.

The range of materials that can be used for wet wells has been expanded to encompass prefabricated wells.

Changes have been made to the requirements for the marking of pipes in commercial buildings. (Clause 1.7).

Heated Water Services AS/NZS 3500.4:2021

Conformance to individual product standards has been removed. All products used in plumbing and drainage systems in Australia need to comply with the PCA and, in New Zealand, the NZBC, see Appendix B for further information. Removal of specific product standard conformance requirements avoids inconsistencies and contradictions between this document and the PCA and NZBC.

Definitions have been relocated to AS/NZS 3500.0 for consistency across the series.

Jointing requirements for plastics pipes have been clarified and expanded to allow different methods. (Clause 4.4.8).

Changes to the requirements for the marking of pipes in commercial buildings. (Clause 4.13.2).

Changes to the requirements for the installation of water services located in metal-framed walls to bring the provisions in line with those of the National Association of Steel-Framed Housing (NASH). (Clause 4.6.11 C).

The separation between above-ground heated water services pipe work and electrical services has been reduced to bring it in line with AS/NZS 3000 and AS/NZS 3500.1. (Clause 4.3.2.2).

To improve the amenity of users and reduce wastage of water and energy, changes have been made to requirements for circulated heated water systems including water meters and entry points for heated water, thermal insulation for non-circulatory heated water piping, and maximum capacities of any dead leg from the branch offtake to its termination. Appendix Q has been added to provide a guide to determining capacity of dead legs and estimating wait times.

Heated water temperature control provisions, which are considered matters of public policy, were elevated from AS/NZS 3500.4 to the PCA Part B2 Heated Water Systems. To avoid conflict between the PCA and this document, clauses relating to sanitary fixtures delivery temperature and solutions for control of delivery temperatures have been deleted.

Until September 2022, Victorian plumbers can choose to use the existing 3500 series or the new Standards

This is a summary of the major amendments to the Standard. Information about more detailed changes will be provided to Master Plumbers members in coming months. Don’t forget - members of Master Plumbers Victoria receive access to the new AS/NZS 3500 suite. For more information, email [email protected] or phone 03 9329 9622.