There is now an apparent conflict between the Plumbing Standards which do not permit any aluminium products in sanitary applications and the updated Watermark Technical Specifications which does permit aluminium products in limited circumstances.
Watermark Technical Specifications (WMTS)
The WMTS issued by the Australian Building Codes Board sets out the materials that can be used in the manufacture of waste pipe connection outlets, channels and gratings – both separate and integrated for sanitary plumbing applications.
Permitted materials are:
• Sheet stainless steel – not less than 304 grade and 1.2mm thick (per ASTM A240/240M).
• Copper and copper alloy (per AS 1589).
• PVC plastic (per AS/NZS 1260).
• ABS (per ISO/TR 10358).
• Polypropylene (per ISO/TR 10358).
This list has been updated effective February 2021 to include aluminium products provided they are of a corrosion resistant grade and comply with the requirements of:
a) AS 1874 or BS 1490 for ingots and castings; or
b) AS/NZS 1734 for flat sheet, coiled sheet and plate; or
c) AS 1866 for extruded rod, bar, solid and hollow shape.
NOTE 1: Aluminium cannot be used where intended to be in direct contact with concrete/cement.
NOTE 2: Where aluminium is used as a grating surround, waste body or tile insert grating, instructions must be issued to detail the methods of installation to prevent direct contact with concrete/cement.
The Plumbing Standards
The Plumbers Licensing and Plumbing Standards Regulations 2000 (Plumbing Regulations) prescribe the plumbing standards that apply in Western Australia. In general, the plumbing standards that apply are in the Plumbing Code of Australia which is Volume 3 of the National Construction Code.A review of AS/NZS 3500 was published on 28 May 2021 as AS/NZS 3500:2021 Parts 1 to 4 which, if adopted, will commence from 1 September 2022.
AS/NZS 3500, and the proposed new AS3500.2-2021, do not permit aluminium products to be used in ANY sanitary applications despite the update to WMTS.
The rationale behind aluminium not being permitted is that:
• Aluminium is stable in the ph range of between 4 and 8.5.
• Bricks, concrete, stone, tile etc generate waters of between 10 and 13 ph.
• As a result, aluminium must ALWAYS be separated or insulated from these stagnate alkaline waters.
Hence there is now an apparent conflict between the plumbing standard AS3500 not permitting any aluminium products in sanitary applications and the updated Watermark Technical Specifications permitting aluminium products in limited circumstances.
The products offered by Civil and General Distributors for sanitary plumbing applications fully satisfy the plumbing standard AS/NZS 3500, the updated Watermark Technical Specifications WMTS 5200 040 2021 and thereby the Plumbing Code of Australia.