The Australian Building Codes Board have released an update to the WMTS-040:2016 waste pipe connection outlet and gratings, separate or integral specification. 

The objective of this Technical Specification is to enable product certification in accordance with the requirements of the Plumbing Code of Australia (PCA). The revision specifies suitable materials for waste pipe connection outlets and gratings. The WMTAC found WMTS-040 had no materials specified, leaving it open to interpretation.

Inclusion of a Materials section now avoids confusion which has allowed unsuitable  materials including aluminium to be used as waste pipe connection outlets and gratings, either separate or integral.

Aluminium, while generally durable and reliable, is unsuited to specific applications due to corrosion susceptibility in stagnant, oxygen deprived environments. While tolerant  to pH values between 4 and 8.5, Products such as mortar, cement, concrete, tile glue, grout and bricks can generate highly alkaline solutions up to pH 13. When this solution contacts the aluminium, particularly corners or surface scratches, corrosion can occur.

The WMTAC concludes that the use of aluminium should be restricted in its use under  WMTS-040, particularly where exposed to wet environments, such as bathroom floors. Stortmech welcomes this update to the Watermark specification, and all Stormtech grates and drainage products are 100% compliant with WMTS-040:2018.