19 August 2020
There are no current waterproofing requirements in Australian Standard 3740 2010 when installing a bidet.
However, the performance provision Part 2.4 Health and Amenity for a wet area of the National Construction Code (NCC) requires the following:
To protect the structure of the building and to maintain the amenity of the occupants, water must be prevented from penetrating:
- (a) Behind fittings and linings; or
- (b) Into concealed spaces, of sanitary facilities, bathrooms, laundries and the like.
If a handheld hose is to be attached to the bidet or any other faucet in that wet area, then you will need to ensure the performance provision 2.4.1 Wet Areas is meet.
To meet the requirement, you will need to prevent water from exiting the wet area, entering concealed spaces or cavities, damaging non-water-resistant building elements, and adversely affecting the health and amenity of the occupant.
Therefore, treat the area the same as a type 2 unenclosed shower. Waterproof walls to 1.8m from finished floor level and out to 1500mm from the hose connection at the bidet. Waterproof the entire floor with falls to a waste.
Generally, the handheld hose is being installed after the final inspection certificate has been issued. This can lead to serious safety issues. The Queensland Building Construction Commission (QBCC) previously released an article outlining these issues in 2020, however has now been removed from their website (as of September 2022).
The bidet system needs to be Watermarked (hoses, fittings, and spray etc). If it were an approved product, they represent a high hazard. The installation is required by a licensed plumber and a reduced pressure zone (RPZ- backflow preventer) must be installed.
It is illegal to both sell and install a non-Watermarked product. Under Non-conforming Building Products (NCBP) legislation, you are required to advise the QBCC of these products as soon as practicable or within two days.
Additionally, a vegetable spray that is watermarked is not intended to be used as a spray for a bidet and would violate the NCBP legislation. Keep in mind, putting Watermarked products together to create a product does not mean that product retains Watermark if it is outside of what the products were Watermarked for.