Understanding how product standards shape compliance and guide installation is becoming essential knowledge for plumbers navigating the National Construction Code. Terry Nguyen writes.

The plumbing industry is supported by various standards and specifications to ensure products are fit for purpose and ultimately meet the requirements of the Plumbing Code of Australia (PCA) and Part 3 of the National Construction Code (NCC).

The product standards used for the certification of plumbing products and materials are used as a means of demonstrating conformity with a set schedule of requirements. This, when used in conjunction with the appropriate AS/NZS 3500 installation standards, provides a simple solution where plumbing and drainage work complies with state or territory legislation, following a deemed-to-satisfy pathway outlined in the PCA.

Product standards are well-thought-out documents formulated by technical committees made up of industry experts and stakeholders. The standards and technical specifications used to certify plumbing products need to include enough detail to confirm that all important risks are adequately addressed from marking requirements through to detailed, rigorous test methods. Not all Standards follow an identical structure, but in general have at least the following:

• Material requirements
• Product information and marking
• Design requirements
• Performance requirements

The materials sections target the risks of failures caused by inferior base materials used in the construction of a finished product. It ensures that products are of adequate strength and will meet their required service life. For example, metallic components with adequate corrosion resistance, as well as resistance to moisture ingress in sanitary ceramic fixtures or plastics, are of sufficient strength for their intended function.

Product information and marking addresses the risks of incorrect installation based on limitations to the product, intended to prevent compliant products from being installed outside of their functional range. This includes maximum pressure or temperature ratings, flow performance, material compatibility and any other limitations of use based on how it was certified. This information also includes markings to identify a product WaterMark licence number, manufacturer and other batch release information to assist with any product recalls, if or when required.

Design requirements aim to eliminate risks by maintaining set dimensions, geometry, assembly or construction techniques that are known to work. They’re an important part of standards because they play a role in removing long-term performance testing to replicate real-world environmental problems in a controlled laboratory setting.

For example, specifying the minimum size/geometry of the waterway to avoid blockages from the build-up of matter from prolonged use. Or the minimum thickness required through metal parts to allow for some small amounts of corrosion that will occur over time.

Finally, the performance requirements specify what the products need to be tested against to confirm that the finished product can meet its specified duty. Functional performance requirements include testing at the National Association of Testing Authorities (NATA) (or equivalent) accredited laboratory to published test methods.

This can be as simple as a static pressure test, or as complicated as a cyclic endurance test on a single lever mixer cartridge, which is subjected to the best part of one million different directional movements to the shaft of a mixing cartridge while subject to hot and cold water temperature cycling.

Knowing the basics of the typical structure of product standards and specifications helps practitioners better understand the products they use and install day to day. It provides the blueprint for how product assessments are performed and outlines the ways that products are scrutinised.

Where this background becomes invaluable is when looking to have a plumbing installation approved under a performance solution, where perhaps a product isn’t regulated under the WaterMark scheme, and required to be certified.

A performance solution can be explained as a plumbing installation that doesn’t fit the deemed-to-satisfy pathway for compliance. In such cases, a performance solution can be sought to confirm that the installation still meets the requirements of the PCA. The performance solution will need to address all risks that are usually addressed by the WaterMark Certification Scheme, meaning that simply matching performance requirements may not be enough.

Other parts of the product standards and specifications addressing risks need to be considered. This includes relevant sections other than just performance requirements.

Some of the pitfalls in preparing performance solutions are looking to simply match the functional performance requirements of what a product would need to meet if it were seeking WaterMark certification through the traditional method.

This, however, only addresses the risk from the perspective of functional and performance requirements. Likely, risks usually addressed by other parts of a product standard or specification may go unmitigated. For example, standard design requirements may prohibit specific types of products for reasons that may not be initially obvious.

This issue can be of further concern for components of a plumbing and drainage system that have no published product standards or specifications. Box gutters and rainheads don’t have product standards, and it is easy to incorrectly assume that matching hydraulic flow performance through an alternate-shaped overflow outlet is suitable. Without a product standard to refer to, the required design elements appear to be easily misunderstood in the industry.

Product standards and specifications are a good start in identifying the types of risks that can be addressed by going through a few well-laid-out documents used for WaterMark certification.

Whilst memorising the detailed content of every standard is impossible, simply understanding the standard layout used provides great insight into what critical aspects of plumbing products need to be assessed.

Australian Standards are products that require purchase. However, WaterMark Technical Specifications (WMTS) are documents published by the Australian Building Codes Board (ABCB), which are available as free downloads from the ABCB website. Reading even some of these will not be the worst use of time if you are looking to find alternate ways to upskill your overall knowledge as a licensed plumber.