When installing a bath in a wet area, the waste connections must comply with the requirements of the National Construction Code (NCC) Series, whether or not there is a floor waste gully.
It's common in the building industry to remove central floor waste gullies from bathrooms and other wet areas. When installing plumbing and drainage in wet areas in class 1 residential buildings, plumbers need to be aware of a number of requirements.
The Building Code of Australia (NCC Volumes 1 and 2) states that bathroom floors in South Australia don't need to be graded to a floor waste gully as long as:
- all vessels (eg plumbing fixtures) include inbuilt overflow protection
- there is a permanent open trapped connection to the waste system (such as a toilet pan)
or - the floor drains to a floor waste within the shower area without ponding.
The Plumbing Code of Australia (NCC Volume 3) requires:
- any pipework and fittings materials and products used, where required under Section G of the NCC, must have WaterMarkTM certification
- compliance with provisions of the AS/NZS 3500 Sanitary plumbing and drainage standard.
Although a floor waste gully may not be required under the Building Code of Australia for draining floors in class 1 residential buildings if all vessels have inbuilt overflow protection, a floor waste gully may still be installed so plumbing installations meet the requirements of the Plumbing Code of Australia.
If there is no inbuilt overflow protection fitted on plumbing fixtures in wet areas and a floor waste gully is installed to meet Building Code of Australia requirements, the fall of the floor surface to the floor waste gully must comply with the NCC Volumes 1 and 2, including SA Variations and Additions.
Examples of bath waste connections
Figure 1: Bath waste discharging to outside disconnector gully
Figure 2: Bath waste discharging to floor waste gully in shower compartment
Figure 3: Bath waste discharging to a sanitary drain
Figure 4: Bath waste discharging to a floor waste gully located in bathroom floor
Figure 5: Bath waste discharging to a floor waste gully connected to a shower channel
Figure 6: Bath waste discharging indirectly to the top of a floor waste gully under a bath – not permitted
